Crops

Asparagus

Introduction

Asparagus (Asparagus officinalis) is a perennial crop in the lily family. It originated near the Mediterranean and has been used as an agricultural crop since the time of the ancient Greeks. Asparagus beds usually produce well for 10-15 years, so choose a site with that in mind. Avoid areas where this tall crop could shade other crops. Select soils that are deep and well drained, such as sandy loams or well-drained loams. However, the water table should not be more than four feet below the surface. The site should not have been planted with asparagus for a long period, preferably never for this crop. This is to minimize asparagus crown rot (Fusarium moniliforme) which can survive for a long time in the soil even without a host. Land cropped to corn within three years should also be avoided since some strains of F. moniliforme can also infect corn. Avoid areas subject to late spring frosts as emerging spears are easily injured. Site preparation should begin at least one year prior to planting in order to properly adjust soil pH, fertility, and eliminate serious perennial weed problems.

Types and Varieties

All-male hybrids that are tolerant to crown or root rot caused by Fusarium species should be grown. The varieties listed here are also tolerant to rust. Mary Washington and some other old varieties are still available, but are half male and half female plants making them highly susceptible to crown rot and are less productive than all-male hybrids.  Male plants do not expend energy producing seed and are thus more vigorous than female plants. Also, the lack of seed precludes the growth of nuisance seedlings which are not productive and act as weeds. 

Asparagus Varieties
Millennium
Purple Passion (purple)

Soil Fertility

The year before planting, adjust the pH and build fertility in the soil based on soil testing results (see Table below). Asparagus does not tolerate acid soils. Apply lime to maintain soil pH at 6.8-7.0. This may require yearly applications of lime. For new beds, deeply incorporate lime to insure proper pH at crown depth.

Asparagus is planted fairly deeply and the roots are known to penetrate deeper than six feet.  Since there is little downward movement of phosphorus in the soil, it is important to get phosphorus into the root zone before planting.  Till deeply and mix fertilizer material well into the deep root zone.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied  (see Table 1 and Table 7). The second year after planting, the asparagus should receive fertilizer in the early spring and late summer.  In subsequent years the bed should be fertilized after each harvest season.  Base fertilizer rates on soil test results. 

Asparagus has moderate requirements for boron. For soils low in boron, apply 1-2 lbs per acre of actual boron every three years to asparagus plantings.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR ASPARAGUS

ASPARAGUS

NITROGEN (N)* LBS PER ACRE

PHOSPHORUS (P) LBS P2O5 PER ACRE

POTASSIUM (K) LBS K2O PER ACRE

SOIL TEST RESULTS

 

VERY LOW

LOW

OPTIMUM

ABOVE OPTIMUM

VERY LOW

LOW

OPTIMUM

ABOVE OPTIMUM

New Asparagus Beds:

                 

Broadcast and Incorporate

50

150

90

30

0

200

150

75

0

In Bottom of Furrow at Planting

0

30

30

30

30

0

0

0

0

TOTAL RECOMMENDED

50

180

120

60

30

200

150

75

0

Established Hybrid Asparagus Beds:

                 

Broadcast after Cutting Season

75

150

90

30-60

0

300

150

75

0

TOTAL RECOMMENDED

75

150

90

30-60

0

300

150

75

0

Established Non-Hybrid Asparagus Beds:

                 

Broadcast after Cutting Season

50

150

90

30-60

0

200

100

50

0

TOTAL RECOMMENDED

50

150

90

30-60

0

200

100

50

0

Planting

Crowns: Plant healthy one-year-old crowns in raised beds at the bottom of 8-in. deep furrows. Be sure the bud is facing up and roots are spread out. Space crowns 12 in. apart in rows 54-60 in. apart. Closer spacing produces higher yields in early years, but thinner spears in older beds. This will require 8,712-9,680 crowns per acre or 100 crowns per 100 row-feet. This spacing is for hybrids and is somewhat greater than was recommended for less vigorous non-hybrids. Cover with two inches of soil, and during the rest of the season the furrow should be filled in bit by bit being careful not to cover the asparagus foliage.

Transplants: Fields can also be planted with 8-12-week-old asparagus seedlings after the danger of frost has passed. Plant spacing is the same as for crowns. Care must be taken in order to prevent the small young ferns from being smothered by soil especially after heavy spring showers. To accommodate the growth pattern of asparagus roots use trays with straight, non-foam, non-tapering cells measuring 2x2x3 inches. Use a sterilized medium consisting of half sand and half peat or use a commercial seed starting mix. Seed germination will take at least three weeks and the soil must be kept uniformly moist during this time. Young seedlings should be fed with quarter- or half-strength soluble fertilizer solution once each week or as needed. The nitrogen in this fertilizer should be in the nitrate form because young seedlings are sensitive to ammonium sources of nitrogen. The seedlings should be grown in the greenhouse for 6-8 weeks followed by two weeks of hardening off, prior to planting after the danger of frost has passed.

Field Culture

It is essential to maintain healthy fern growth during the first two growing seasons. Weed control is easily accomplished by slowly filling in the trenches over the course of the first season. These cultivations can be timed with flushes of weeds. Be sure ferns are not covered. During the second year the beds must be kept weed free, especially during late summer and fall. Weed competition late in the season will restrict crown growth. Close attention must be given to insects and diseases that attack young ferns. As ferns become vigorous and full, diseases can cause the ferns to die prematurely, especially in late summer and early fall during periods of humid weather. Fungicides should be applied to control this foliage decline.

Mow brush in early spring before spear emergence followed by shallow discing, no deeper than 2-3 in. in order to prevent crown injury. Some growers remove ferns in the late fall or burn the ferns during the winter. This can destroy rust and purple spot inoculum and reduce harboring sites for insects such as asparagus beetles. Beds can also be disced immediately after harvest to control weeds prior to herbicide application.

Harvest and Storage

Spears may be harvested two times at the beginning of the second season. The harvest season is increased one to two weeks in subsequent years and should be six to eight weeks in mature beds depending on plant health during the previous summer and fall. If spears are predominantly small in diameter, harvest should be stopped. Overcutting causes rapid decline in bed vigor. Spears can be snapped or cut at or below the soil surface. Avoid injury to newly emerging spears.

Once spears have been bunched and trimmed, they should be placed upright in shallow trays of water and kept cool. Ideally they should be refrigerated at 32-36ºF  and 95-99% relative humidity in order to maintain sugar content and tenderness. Storage life under ideal conditions is 14-21 days.

Mother Stalk Harvest Method (trial only): In Japan and China, harvest throughout the summer is common. In this method, spring harvest is carried out for two weeks, after which three or four strong spears are left to grow into full ferns. From this point, newly emerging spears can be harvested throughout the season into early fall. Spear production is influenced by soil temperature and nutrient availability. Fertigation is usually practiced with this method. Plants have been shown to have similar longevity as those harvested in the spring only.

 

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Crown Rot (Fusarium species)

Vigorously growing plants are less susceptible to crown rot. Buy top quality crowns. Use new land or land where asparagus has not been grown for 10 years. Use tolerant varieties.

Rust (Puccinia asparagi)

Rust disease attacks fern foliage and can spread rapidly affecting production in subsequent years. Fern residues should be removed and destroyed prior to spear emergence in the spring. Control volunteer asparagus plants that might be infected. Resistant cultivars are not available. Apply fungicides after spear harvest is complete.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

chlorothalonil (Bravo Weather Stik): 2.0 to 4.0 pt/A; PHI 190d, REI 12h, Group M05. Do not apply within 190 days of the harvest of spears in the following season.

copper (Badge SC): 1.0-2.5 pt./A; PHI 0d, REI 48h, Group M1. For suppression. Tank mix with other products registered for rust control. Addition of sticker/spreader recommended.

mancozeb (Dithane F45): 2.0 qt/A; PHI 180d, REI 24h, Group M3. Begin applications after spears have been harvested.

mancozeb + azoxystrobin (Dexter Max): 2.0-2.2 lb./A; PHI 180d, REI 24h, Group M3+11. Begin applications after spears have been harvested. Alternate with fungicides outside of Group 11.

myclobutanil (Rally): 5.0 oz/A; PHI 180d, REI 24h, Group 3. Begin applications after spears have been harvested. Observe a 30-day plant-back interval between the last application and planting new crops at the treatment site.

sulfur (Microthiol DisperssOG): 10.0 to 30.0 lb/A; PHI 0d, REI 24h, Group M2. Apply to ferns after cutting.

tebuconazole (Monsoon): 4.0-6.0 fl. oz./ A; PHI 180d, REI 12h, Group 3. Begin applications after spears have been harvested. Do not make more than 3 foliar applications per year.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Asparagus Aphids (Brachycorynella asparagi)

Asparagus aphids are small (1.6-2 mm), oval, green to gray aphids that may be covered in a waxy secretion. They overwinter as eggs on asparagus residue in the field. Eggs hatch in spring and nymphs and adults feed on spears, then on ferns. During the summer, wingless females produce live young (nymphs) which develop into reproductive females in 8-10 days. Populations can build up rapidly especially in hot, dry weather. Aphids feed on new growth and cause shortening of internodes, rosetting, or ‘witches broom’ appearance of the foliage. High aphid populations reduce root growth and plant vigor and may kill seedlings. Younger plantings are most vulnerable, especially 2 or 3-year-old plantings that are not being harvested.  Cold winters and aphid infestation have a synergistic effect on plant health, greater than either factor alone. Asparagus can also vector viruses, including asparagus virus I and II (AV-I and AV-II) and tobacco streak virus (TSV). During harvest, monitor any plantings that are not being harvested. After harvest, scout ferns for signs of feeding injury and aphid colonies, especially in the basal regions of the plant. Cultural controls include harvesting spears in spring, because only volunteer plants and young plantings that are not harvested will allow aphids to survive and multiply. Remove dead ferns during the fall or winter, and control between-row volunteers through spring tillage or herbicides. Natural biocontrol is provided by insect predators such as lady beetles, lacewings, predatory midges, and flower fly larvae, by the parasitic Braconid wasp, Diaeretiella rapea, and by a fungal pathogen that is more active in humid climates. Treat ferns when populations are low, if 5% of ferns show injury. Conserve beneficials by using a selective product. Scout again in 5-7 days to determine if further treatment is needed.

acetamiprid (Assail 30SG): 2.5 to 5.3 oz/A; PHI 1d, REI 12h, Bee: M, Group 4A.

dimethoate (Dimethoate 4EC): 1 pt/A; PHI 180d, REI 48h, Bee: H, Group 1B. Apply after last harvest. Systemic.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. Apply with companion aphicide.

malathion (Malathion 57EC): 1.5 to 2 pt/A; PHI 1d, REI 12h, Bee: H, Group 1B.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L.

pymetrozine (Fulfill): 2.75 oz/A; PHI 170d, REI 12h, Bee: L, Group 9B. Apply to ferns after harvest, and before populations build to damaging levels. Allow a minimum of 30 days between applications.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; PHI 0d, REI 12h, Bee: M, Group 3A.

Asparagus Miner (Opbiomyia simplex)

This fly was introduced to North America from Europe and is present wherever asparagus is grown. It feeds only on asparagus, and is found primarily on older stalks bearing ferns. The adult fly is shiny black, 3-4 mm long, with clear wings. Larvae are whitish, legless, tapered at both ends, with black mouth hooks at one end. Pupation takes place in the larval mine on the stalk. Overwintering puparia are usually in mines near or below ground level. There are 2 generations per year. Adults emerge in May and lay eggs underneath the epidermis of stems, usually near the base of the plant. Larvae feed in June, pupate inside their larval mines, and a second generation of adults emerges and lays eggs in late-July or early-August. Second generation larvae feed through August and pupate in the fall, overwintering until the following spring. Larvae feed just beneath the surface of the stem, burrowing upwards or downwards and forming mines. While direct feeding damage can girdle stems if there are several mines per stalk, the effect of miners on yield is usually minimal and the injury is largely cosmetic. The most important injury from asparagus miner is due to its association with Fusarium spp. and its ability to vector this pathogen into the plant through feeding wounds. Cultural practices to reduce damage from asparagus miner include removing overwintering stalks and destroying wild asparagus in the vicinity of commercial plantings. Select varieties that are resistant to Fusarium to reduce disease (see Varieties, page 115).

acetamiprid (Assail 30SG): 25.3 oz/A; PHI 1d, REI 12h, Bee: M, Group 4A. Suppression only.

Cutworms

Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed after dark. Crooks (misshaped spears) are often caused by cutworms injuring tips at or just below the soil surface or feeding on the sides of young spears. For best results, make application between midnight and dawn while cutworms are feeding above ground. Synthetic pyrethroids (group 3A) may work best during cool weather in May. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

carbaryl (Sevin XLR PLUS): 1 qt/A prior to fern growth; 2 qt/A on ferns; PHI 1d, REI 12h, Bee: H, Group 1A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A.

permethrin (Pounce* 25WP): 3.2 to 6.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 60d, REI 4h, Bee: M, Group 5. Scatter bait on soil around plants. For postharvest protection of ferns only.

Asparagus Beetles and Japanese Beetle

The common asparagus beetle (Crioceris duodecimpunctata) and spotted asparagus beetles (Crioceris asparagi) are less than 3/8" long, overwinter as adults in protected areas along fields, feed and lay eggs in the crop, pupate in the soil, and have 2 or sometimes 3 generations per year. The common asparagus beetle (CAB) has a bluish-black body with cream-colored, square or rectangular spots, while the spotted asparagus beetle (SAB) is tan to orange with 12 round, black spots. Eggs of CAB are dark brown, laid standing on end in rows along the spears, with 3-10 in each cluster.  During harvest, adult feeding by CAB on spears or the presence of CAB eggs can render the crop unmarketable. CAB larvae have 4 instars and are wrinkled, plump, hump-backed, and dull gray or brown with black head and legs. CAB larvae may cause severe defoliation of ferns and decline of the planting.  SAB larvae are yellow or orange and feed only on berries. During harvest, scout for adults and eggs on sunny afternoons. Treat spears if >10% of the plants are infested with beetles or 1-2% have eggs or damage. Scout ferns for all life stages of both pests and treat if 50-75% are infested. If possible, spot spray along edges of planting where overwintering adults colonize the field and/or band insecticide over the row to help conserve natural enemies. Use selective insecticides on ferns. During harvest, snap or cut spears close to the soil surface daily and eliminate volunteer plants or treat them with an insecticide to use them as a trap crop. Disk old ferns lightly in the fall and clean areas around planting of debris to reduce overwintering populations. Eliminating female plants, and thus berries, can reduce or eliminate SAB populations. Japanese beetles may feed in ferns in mid-summer.

acetamiprid (Assail 30SG): 2.5 to 5.3 oz/A; PHI 1d, REI 12h, Bee: M, Group 4A.

carbaryl (Sevin XLR PLUS): 1 qt/A prior to fern growth; 2 qt/A on ferns; PHI 1d, REI 12h, Bee: H, Group 1A.

dimethoate (Dimethoate 4EC): 1 pt/A; PHI 180d, REI 48h, Bee: H, Group 1B. Asparagus beetle only. Apply after last harvest.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A (foliar or soil drench); PHI 0d, REI 4h, Bee: M, Group M.

kaolin (Surround WPOG): 12.5 to 25 lb/A or 25 to 50 lbs/100 gal water; PHI 0d, REI 4h, Bee: L. Suppression and repellence only. Product residue may need to be washed off if applied to spears during harvest. Generally compatible as a tank mix with other insecticides.

malathion (Malathion 57EC): 1.5 to 2 pt/A; PHI 1d, REI 12h, Bee: H, Group 1B.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. Asparagus beetle only.

permethrin (Pounce* 25WP): 3.2 to 6.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. For Japanese beetle control, use high rate.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. For beetle larvae only. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A.; PHI 0d, REI 12h, Bee: M, Group 3A.

spinetoram (Radiant SC): 4 to 8 oz/A; PHI 60h, REI 4h, Bee: M, Group 5. Post-harvest protection of ferns from asparagus beetle only.

spinosad (Entrust SCOG): 4 to 6 oz/A; PHI 60d, REI 4h, Bee: M, Group 5. Post-harvest protection of ferns from asparagus beetle only.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient as an example of rates, preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Grass Weed Control - new plantings and established beds

clethodim (Select Max): PHI 1d, REI 24h, Group 1.  Apply 9 to 16 oz/A per application, minimum 14 days between applications.  Do not exceed 64 oz/A per year.  Will control grass weeds only. Apply to actively growing grasses (see product label for susceptible stage). Add 1 qt nonionic surfactant per 100 gal of spray (0.25% v:v).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI 1d, REI 12h, Group1.  For grass weed control only. 16 to 24 oz/A per application, minimum 14 days between applications, and not to exceed 48 oz/A per year.  Will control grass weeds only. Apply to actively growing grasses (see product label for susceptible stage). Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).

sethoxydim (Poast): PHI 1d, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 2.5 pt/A per application, minimum 14 days between applications.  Do not exceed 5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions. Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

New Plantings

glyphosate (Roundup Power Max): REI 12h, Group 9. Preplant or stale seedbed application. Rate depends on target weeds, see label for rate selection. See Stale Seedbed Technique, page 107.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2.5 to 4 pts/A.  Preplant or stale seedbed application. See Stale Seedbed Technique, page 107. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3% to 10% solution (3 to 10 gallons per 100 gallons).  See Stale Seedbed Technique, page 107.

pendimethalin (Prowl H2O)PHI 14d, REI 24h, Group 3. Can be applied to newly planted crowns but NOT to newly seeded crop.  When applying to newly planted crown asparagus, assure crowns are fully covered with 2 to 4 inches of soil.  Do not apply over the top of emerged spears or injury will occur.  Use as a single application of up to 8.2 pt/A.  On sandy soils do not use more than 2.4 pt/A.  Apply uniformly to the soil surface at least 14 days prior to the first harvest.  Cultivate or use Gramoxone to control emerged weeds. 

linuron (Lorox DF): PHI 1d, REI 24h, Group 5. Can be used for pre- and postemergence control of many annual broadleaf weeds.  See label for instructions on preemergence use after planting. For postemergence weed control, use 1 to 2 applications of 1 to 2 lbs/A when ferns are more than 6 inches tall.  Spray emerged weeds when they are less than 4 inches tall. Use the lower rate on coarse-textured (sandy) soils low in organic matter, and the higher rate on fine-textured (silt and clay) soils. A second application can be made 1 to 3 months after the initial application, not to exceed a total of 4 lbs/A per year.

Established Beds – Before spear emergence or after harvest season

clomazone (Command 3ME): PHI 14d, REI 12h, Group 13.  Make a single application of 42.7 fl oz/A in at least 10 gallons of water per acre prior to spear and weed emergence or after a clean harvest (must cover all asparagus plant parts with soil to prevent injury).  Will control annual grasses and many broadleaf weeds.

diuron (Karmex DF, Diuron 4L): REI 12h, Group 5. Karmex not registered in NH and VT. Diuron 4L registred in all New England States. Use lower rates on light sandy soils (and other soils low in clay and organic matter) and higher rates on soils high in clay or organic matter. Use in the spring preemergence to both crop and weeds.  If necessary, a second application can be made after cutting season.  If planning two applications, do not exceed 3 lbs/A per application.  The soil must be kept moist to activate diuron. If weeds start to germinate, cultivate lightly (not deeper than 1") and irrigate during cutting season. Do not use on newly seeded asparagus or on young plants or crowns during the first season. Do not use diuron on a bed the year it is to be abandoned and planted to another kind of vegetable.

flumioxazin (Chateau SW)REI 12h, Group 14.  Apply 3 to 6 oz/A per application, not to exceed 6 oz/A per season. For post-harvest applications, apply at least 2 weeks before fern emergence.  For preemergence use, apply at least 14 days before spears emerge.  Must be sprinkler or rainfall incorporated (0.5 to 0.75” of water) for preemergence weed control.  Will control many broadleaf weeds and some grass species.  If soil has been disturbed prior to application or if asparagus is not dormant, some crop injury may be observed.  Can be applied to dormant asparagus tank-mixed with Gramoxone for burndown of emerged weeds.  Use as an alternative to metribuzin, diuron, or terbacil.  Do not use every year. Limited data on efficacy and crop safety for use in the New England region.

linuron (Lorox DF): PHI 1d, REI 24h, Group 5. Can be used as a single 2 to 4 lb/A application for preemergence weed control.  Apply prior to spear emergence or after harvest for residual and postemergence control of many annual broadleaf weeds.  Use the lower rate on coarse-textured (sandy) soils low in organic matter, and the higher rate on fine-textured (silt and clay) soils.  See information about postemergence use in the following "Established Beds - Postemergence" section.

mesotrione (Callisto)REI 12h,  Group 27.  Apply 3 to 7.7 oz/A.  See lable to select appropriate rate for weeds and timings. Can be applied in the spring prior to spear emergence, or after harvest, or both, to control many winter and summer annual broadleaf weeds.  Maximum of two application permitted, minimum 14 days between applications, not exceed a total of 7.7 oz/A per year. When using Callisto after harvest, till the field or tank-mix with Gramoxone to eliminate emerged spears or crop injury may be observed as white or white streaks in the stems and fern when treated spears grow.  Callisto provides excellent control of horseweed (also called marestail or stickweed), including glyphosate-tolerant strains, and common lambsquarter. Callisto does not control most grasses.  Tank-mix Callisto with a residual annual grass herbicide to control annual grasses.  Add 1% crop oil concentrate (1 gal/100 gal of spray solution) or 0.25%  nonionic surfactant (1 qt/100 gal of spray solution) if target weeds are emerged at the time of application. 

metribuzin (Metribuzin 75): PHI 14d, REI 12h, Group 5.  Can be applied as a single application in the spring prior to spear emergence (1.3 to 2.6 lb/A), or as two applications in the spring and after harvest.  The total amount of metribuzin applied cannot exceed 2.6 lbs/A.  If using two applications, apply 0.6 – 1.3 lbs/A in the spring and 1.3 – 2.0 labs/A after harvest but before fern emergence.  If field is to be disked, apply after disking but before crop emergence. Do not use on newly seeded asparagus or on young plants or crowns during first season. Do not apply to established beds after emergence. Fair on grasses.

napropamide (Devrinol 2-XT): REI 12h, Group 0. Use up to 2 gal/A. Incorporate thoroughly with irrigation prior to spear emergence if adequate rainfall does not occur within 24 hours of application. Apply only to stands that have been established for atleast one growing season.

norflurazon (Solicam DF): PHI 14d, REI 12h, Group 12. Apply 2.5 to 5 lb/A, select rate based on soil type.  See label for details.  If adequate rainfall does not occur within 4 weeks of application, irrigation should be used to incorporate and activate. Apply after the cutting season. Controls most grasses and several broadleaf weeds. Also will suppress yellow nutsedge. Cannot be used unless planting is at least 12 months old, and should not be used if a crop rotation is planned within 24 months.

paraquat (Gramoxone SL 2.0*): restricted use. PHI 6d, REI 12h, Group 22. Use 2.5 to 4 pts/A, up to three applications per year. Apply prior to emergence of crop at least 2 years old, or after last clean cut harvest. Asparagus plants that have emerged at time of application will be killed. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pendimethalin (Prowl H2O)PHI 14d, REI 24h, Group 3. Apply before spear emergence or after harvest.  Do not apply over the top of emerged spears or injury will occur.  Use as a single application of up to 8.2 pt/A.  On sandy soils do not use more than 2.4 pt/A.  Apply uniformly to the soil surface at least 14 days prior to the first harvest.  Cultivate or use Gramoxone Inteon to control emerged weeds. 

terbacil (Sinbar WDG): PHI 5d, REI 12h, Group 5. Apply prior to spear emergence, after a clean cutting, or after the last harvest.  Do not apply more than 1.5 lb/A per application, and if more than one application is made, total rate cannot exceed 2.5 lb/A per year. Use a lower rate on coarse-textured soils.  Do not apply if roots are exposed or if the planting is weak; see label.

trifluralin (Treflan HFP): REI 12h, Group 3. Established plantings only. Can be used in the spring prior to spear emergence, after harvest before ferns emerge, or both. Rate based on soil texture and number of planned applications, see label for details. 

Established Beds - Postemergence to weeds

clopyralid (Clean Slate): PHI 48h, REI 12h, Group 4. Other clopyralid formulations may not labeled. Apply 0.5 to 0.67 pt/A. Two applications can be made as long as the total amount applied per year does not exceed 0.67 pts/A. Applications may be made before or during the asparagus cutting season, or after harvest is complete but prior to fern growth. Use the higher rate for more effective control of perennial weeds. Can control or suppress sensitive annual and perennial broadleaf weeds, including Canada thistle, goldenrod, mugwort, and wild aster species. For annual weeds, apply before flower stalks of weeds emerge. For perennial weeds, apply when majority of weeds’ basal leaves have emerged. Some crooking or twisting of treated spears may occur. Do not apply if some crooking of emerged spears is not acceptable. Clear-cutting spears just before applying may reduce occurrence of crooking. Post-harvest layby applications should be made as soon as possible after cutting. Malformed ferns may result from application when spears are longer than 3 inches or with open seed heads. Spur carryover may affect subsequent crops; observe all plantback restrictions list on label. Can be tank mixed with other herbicides. See the label for tank mixing guidance.

dicamba (Clarity): PHI 24h, REI 24h, Group 4. Apply 8 to 16 fl oz/A to emerged and actively growing weeds immediately after cutting field but at least 24 hrs before next cutting. Multiple applications can be made, but do not exceed 16 fl oz/A per year total. If spray contacts emerged spears, crooking (twisting) of some spears may result. If crooking occurs, discard affected spears.

glyphosate (Roundup Power Max): REI 12h, Group 9. Apply to emerged weeds well before spear emergence in the spring as contact with spears will result in serious crop injury.  Can also be applied after cutting season, after removal of all growing spears and fern (clean cut). Contact with growing spears or fern will result in crop injury. For later application use directed or shielded sprays to prevent plant contact. Rate depends on target weeds, see label for rate selection.

halosulfuron (Sandea): PHI 1d, REI 12h, Group 2. For transplanted crowns and established beds only. For transplanted crowns, apply no sooner than 6 weeks after fern emergence. For established beds, apply before or during harvest season. May also be applied as a directed spray to the base of the ferns. Contact with ferns will cause yellowing. Will provide preemergence and postemergence control of many weeds. Use 0.5 to 1.5 oz/A per application. Do not apply more than 2 times per season and do not exceed 2 oz/A per year. See label for list of weeds and other precautions.  Weed control may be reduced without the use of a surfactant.

linuron (Lorox DF): PHI 1d, REI 24h, Group 5. Use 1 to 3 applications of 1 – 2 lbs/A for postemergence weed control.  Spray emerged weeds when they are less than 4 inches tall. Use the lower rate on coarse-textured (sandy) soils low in organic matter, and the higher rate on fine-textured (silt and clay) soils. DO NOT exceed 4 pounds of product per acre per year total (including any preemergence applications).  See information about preemergence use in the previous "Established Beds – Before spear emergence or after harvest season" section.

pelargonic acid (Scythe)PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. These include tank mixes with glyphosate (Roundup), sulfosate (Touchdown), and residual herbicides. See label for complete details.

s-metolachlor (Dual Magnum): REI 12h, Group 15.  MASSACHUSETTS, MAINE, and NEW HAMPSHIRE ONLY. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge. All label instructions will be supplied after the application for use is completed.

2,4-D sodium salt (Amine 4): PHI 3d, REI 48h, Group 4.  Use 3 - 4 pt/A.  Two applications are permitted, a minimum of one month apart.  Spot spray when weeds appear. Keep spray off spears and ferns. 2,4-D is hazardous to most horticultural crops. Drift or sprays may seriously injure or reduce yields of these crops. May help to control unwanted seedling asparagus.

 

Note About Other Labeled Herbicides: Other products are labeled for use in asparagus but limited local data are available for these and/or they are not recommended in our region due to potential crop injury concerns. These include quinclorac (QuinStar), carfentrazone (Aim), sulfentrazone (Zeus and others), and diquat (Reglone).

Basil

Introduction

Basil (Ocimum spp.) is a member of the mint family. There are several species and numerous interspecific hybrids. The most common culinary type is sweet basil, O. basilicum, which also has purple and lemon-scented cultivars. Specialty types include Thai (O. tenuiflorum), lemon (O. americanum x O. citridorum) and small-leaved bush types of various species and crosses. Basil seed is not always true to type. Try to obtain high-quality seed that is uniform with a high germination percentage.

Types and Varieties

Basil Varieties
Sweet/Pesto Purple
Amazel - BDM Red Rubin - BDM
Aroma 2 - F Dark Opal
Elidia - F (intermediate) Amethyst Improved
Everleaf - BDM, F (intermediate) Purple Ruffles
Eleonora  - BDM  
Genovese Bush
Italian Large Leaf Spicy Bush
Newton - F Spicy Globe
Nufar - F  
Prospera - BDM Scented
Rutgers Devotion - BDM Sweet Dani (lemon) - BDM
Rutgers Obsession - BDM, F Lime Basil - BDM
Rutgers Passion - BDM Holy Basil (medicinal)
Rutgers Thunderstruck - BDM Cinnamon Basil
   
Thai  
Sweet Thai  
F: Some resistance to Fusarium wilt, BDM: Some resistance to basil downy mildew.

NOTE:  Basil downy mildew (Peronospora belbarhii) was first reported in the United States 2007. Eleonora and Everleaf (aka Pesto Party) were the first downy mildew resistant sweet basil cultivars available in the US. Varieties with stronger resistance have since been released: Prospera, Amazel, and the Rutgers varieties Obsession, Devotion, Passion, and Thunderstruck. In trials conducted in NY in 2018, Amazel and Prospera showed the strongest disease resistance, followed by Thunderstruck, Passion, Devotion, and Obsession. None of these varieties are fully resistant to the disease but all will develop disease more slowly than fully susceptible varieties. Thai, lemon, and spice basil varieties are generally less susceptible than sweet basil varieties.

Soil Fertility

Basil grows well in a warm, well-drained soil in a wide pH range, although the typical vegetable crop range of pH 6.0-6.8 is ideal. Although adequate fertility is required (see Table below), excess nitrogen applications can cause post-harvest discoloration and reduce flavor. Basil benefits from a sidedress application of nitrogen after the first or second cutting.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR BASIL

BASIL

NITROGEN (N)* LBS PER ACRE

   PHOSPHORUS (P) LBS P2O5   PER ACRE

   POTASSIUM (K) LBS K2O      PER ACRE

SOIL TEST RESULTS

 

VERY LOW

LOW

OPTIMUM

ABOVE OPTIMUM

VERY LOW

LOW

OPTIMUM

ABOVE OPTIMUM

Broadcast and Incorporate

100

120

60

30

0

100

50

25-50

0

Sidedress after 1st or 2nd cutting

15-30

0

0

0

0

0

0

0

0

TOTAL RECOMMENDED

115-130

120

60

30

0

100

50

25-50

0

*SEE PLANT NUTRIENTS FOR INFORMATION ON NUTRIENT MANAGEMENT AND APPLICATION.

Planting

In New England, basil is most commonly transplanted, but because it is highly sensitive to cold (low 40s), it should not be set out until after danger of frost. Seeds will germinate within 4-8 days at temperatures of 68-74ºF. Transplant at approximately 6 weeks old. Topping when plants are 5-6 in. tall encourages branching. Basil is often spaced at 6-12 in. between plants in double rows. Tighter spacing will promote longer shoots for bunching.

If field soils are warm enough, basil can be direct-seeded in a well-prepared seedbed at a spacing of 8-10 seeds per foot and later thinned. Basil can be direct sown using an onion seeder. Pelleted seeds are also available to facilitate outdoor seeding.

Field Culture

Because of the lack of herbicides for weed control and the need for warm temperatures, basil is well suited to growing in raised beds covered with black plastic mulch. Drip irrigation allows consistent application of water while also reducing foliar diseases. Cultural management of insects, diseases and weeds is necessary because few pesticides are registered for use on basil.  Summer weight row covers can help to exclude insect pests and create a more humid, tropical environment that is reminiscent of basil's native South Asian habitat. Some growers say that basil is more fragrant when grown in a wind-protected environment. However, high humidity is conducive to downy mildew, the most important pest of basil in recent years.

Harvest and Storage

Basil can be lightly harvested by pruning as early as 6 weeks after planting, with regular harvests starting a few weeks after that. Harvests should take place in the morning after the dew has left the plants. Depending on the intended use and market, individual leaves or entire stems may be harvested. Basil grown for culinary use should be harvested before flowering. Flavor will be adversely affected if allowed to flower. If grown for essential oil production, it should be harvested at full bloom. Plants will set seed if flower spikes are not removed as they appear. Sequential plantings can help ensure continuous production of quality shoots and leaves. However, harvesting basil by mid-summer can often prevent crop destruction from downy mildew.

Damage can be caused by rough handling, desiccation and chilling (<40°F). Cooling can be accomplished by rinsing in 55°F water, but foliage should be dried completely prior to packing. Maintenance of clean growing conditions, free from mud splash, enables some growers to avoid contact with water. Basil should then be stored at temperatures above 54°F.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

PESTICIDE USE IN GREENHOUSES AND HIGH TUNNELS:

Pesticides can be used on high tunnel and greenhouse crops if: 1) the crop and pest/disease is on the label, AND the products specifically says it can be used in the greenhouse; OR 2) the crop and pest/disease is on the label, AND the product is ‘silent’ about use in the greenhouse in the greenhouse. Products that specifically prohibit greenhouse use cannot be used in greenhouses or high tunnels regardless of the crops or pests/diseases listed on the label.

Purchase disease-free seed. Use resistant varieties where feasible. Promptly remove any stock plants that are diseased or low in vigor. Use separate greenhouses for herb production and keep stock plants separate from production areas. There are few fungicides or bactericides registered for herbs.

Bacterial Leaf Spot (Pseudomonas cichorii )

Disinfect all benches, equipment, and pots. Purchase culture-indexed plants and disease-free seed. Avoid overhead irrigation. Discard infected plants. Clean production areas thoroughly after harvest as bacteria can survive in dead leaves.

Botrytis blight and stem canker (Botrytis cinerea)

Management of environmental conditions such as temperature, relative humidity and duration of leaf wetness is vital to Botrytis control. Control weeds and remove plant debris between crops and during production. Provide good air circulation and reduce humidity within the plant canopy by proper plant spacing, plant height, and fertility. Water in the morning, never late in the day.

Bacillus amyloliquefaciens F727 (StargusOG): 2.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50.0 gallons of water/A.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Do not make more than 2 consecutive applications.

potassium bicarbonate (PB 133, AKA MilStopOG): 2.5 to 5.0 lb/100.0 gal; PHI 0d, REI 1h, Group NC. See label for small volume application rates.

Ulocladium oudemansii U3 strain (BotryStopOG): 2.0 to 4.0 lbs/A; REI 4h, Group NC. Begin application when conditions are conducive to disease development.

Damping-off, Crown and Root Rot (Pythium spp., Rhizoctonia spp., Fusarium spp. & Phytophthora spp.)

Use pasteurized soil or soil-less mixes for transplant production. Disinfect all flats, pots, and tools. Use bottom heat to promote rapid seed germination. Avoid over-watering, over-fertilizing, and overcrowding. Promptly rogue out infected plants. Manage fungus gnats and shoreflies. 

Bacillus amyloliquefaciens F727 (StargusOG): 2.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50.0 gallons of water/A.

mefenoxam (Ridomil Gold SL): 0.5 to 1.0 pt/A; PHI 21d, REI 48h, Group 4. Pythium and Phytophthora ONLY.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi. Does not control Pythium or Phytophthora.

potassium phosphite (K-Phite): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group NC. Apply in a minimum of 20.0 gal water/A.

Downy Mildew (Peronospora belbarhii)

Downy Mildew of basil can be serious in both field and greenhouse production. Start with certified, disease-free seed. Scout crops regularly and promptly remove and destroy infected plants. Reduce leaf wetness duration by plant spacing, improving air circulation, and watering when plants will dry quickly. In the greenhouse, use a combination of heating and venting to reduce humidity and condensation, especially when warm days are followed by cool nights. Varieties with some resistance to downy mildew are available (see varieties).

azoxystrobin (Heritage): 0.18 oz/A; PHI 0d, REI 4h, Group 11. See label for instructions.

Bacillus amyloliquefaciens F727 (StargusOG): 2 to 4 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50.0 gallons of water/A.

copper (Cueva): 16.8 gal/A; PHI 0d, REI 4h, Group M01. Begin applications when environmental conditions favor disease development. 

cyazofamid (Ranman): 2.75 to 3.0 fl oz/A; PHI 0d, REI 12h, Group 21. Registered for greenhouse use.

fenamidone (Reason SC): 6.0 fl. oz/A; PHI 2d, REI 12h Group 11. Greenhouse and field. Do not alternate with other Group 11 fungicides.

fluopicolide (Presidio): 4.0 fl oz/A; PHI 1d, REI 12h, Group 43. Field use only. Must be tank mixed with a fungicide with a different mode of action. 

hydrogen peroxide and peroxyacetic acid (Oxidate 2.0OG): 1:2 to 1:4 dilution; PHI 0d, REI 0h. Do not tank mix with copper. 

mandipropamid (Micora): 8.0 fl oz/A; PHI 1d, REI 4h, Group 40. NOTE: greenhouses use limited to structures with permanent flooring ONLY. Not labeled for field use.

mandipropamid (Revus): 8.0 fl oz/A; PHI 1d, REI 4h, Group 40. Labeled for field use.

mefenoxam (Subdue): 2.0 pt/A; PHI 21d, REI 48h, Group 4. Tank mix with fungicides from other groups. 

oxathiapiprolin (Segovis): 1.1 to 2.4 fl.oz/A; PHI 0d, REI 4h, Group 49. Begin foliar application prior to disease development. Use the higher rate when disease is present. 

potassium bicarbonate (PB 133 AKA MilStopOG): 2.5 lb/100 gal; PHI 0d, REI 1h, Group NC. Thorough coverage is essential. Registered for greenhouse and field use. See label for small volume application rates.

phosphorous acid (Fosphite): 1.0 to 3.0 qt/100.0 gal; PHI 0d, REI 4h, Group P07. Do not apply to plants that are heat or moisture stressed.

Streptomyces lydicus (ActinovateOG): 6.0 to 12.0 oz/A; PHI 0d, REI 1h, Group NC.

Fusarium Wilt (Fusarium oxysporum f.sp. basilici)

Fusarium wilt is very difficult to manage as it can persist in the soil or hydroponic system for many years. Practice strict sanitation. Begin with disease-free seed or treat seed with hot water or dilute bleach. The basil varieties Aroma 2, Nufar, Newton and Rutgers Obsession have some resistance to Fusarium wilt. Fusarium is a soil inhabitant that can become established in the field. Promptly remove and destroy all infected plants, infested soil, and plant debris. Rotate crops, excluding members of the mint family, which can be symptomless carriers of Fusarium.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details

Aphids

For more information on biology, see aphids in the pepper section.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L, Group un. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.

Beauveria bassiana (Mycotrol ESO): 8 to 32 oz/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after application to see control.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil, 1.2 oz/A foliar; PHI 14d soil, 7d foliar, REI 12h, Bee: H, Group 4A.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. Repeat application every 2 to 3 days until pest is under control. For enhanced and residual control apply with companion labeled aphicide.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A (foliar or soil drench); PHI 0d, REI 4h, Bee: M, Group UN.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Japanese and Oriental Beetles

Beetles move into basil after emerging from soil in turf, pastures or fallow areas, starting in late June and peaking in July.  Adult beetles skeletonize leaves as they feed. Row covers can prevent feeding, but watch for build-up of aphids due to exclusion of natural enemies. The basil variety Nufar is very attractive to Japanese beetles and can be used for a trap crop.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee:L, Group un. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake. 

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A (soil applications only); PHI 0d, REI 4h, Bee: M, Group un.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Weed Control

Suggestions for weed management in basil include use of the Stale Seedbed Technique and use of plasticulture. Both glyphosate (Roundup) and pelargonic acid (Scythe) are registered for stale seedbed use. Flaming can also be used. Stale seed beds can be used between plastic mulch (be careful with flaming as it melts the plastic). Basil usually grows quickly and shades the planting hole in plasticulture, out-competing weed growth. Apply the plastic at least 2 to 3 weeks prior to planting and kill the weeds between the mulch prior to setting the basil plants on the plastic. On bare ground culture, keep cultivations shallow to protect crop roots. Do not move soil into the crop row as basil plants may be more susceptible to diseases when soil is mounded against the stems of the crop.

Herbicides Used Preemergence to Weeds

napropamide (Devrinol 2-XT): REI 12h, Group 0.  Apply 2 to 4 qt/A as a preplant/preemergence application to weed-free soil surface.  Apply with ground spray equipment only, in 20 to100 gallons of water per acre. Apply to a weed free surface. Shallow incorporate no deeper than seeding depth or sprinkler irrigate within 24 to 72 hours using sufficient water to wet the soil to a depth of 2 to 4 inches. Use the lower rate on light soil (coarse textured - sandy) and the higher rate on heavy soil (fine textured - clay).

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max): PHI 14d, REI 24h, Group 1.  Has not been tested on all varieties.  Crop tolerance should be verified on a small area of the crop at the desired rate. If no crop response is evident seven days after treatment, Select Max Herbicide may be used on the entire field at the rate tested. Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14 days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3% to 2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Bean: Snap, Lima and Dry

Introduction

Snap and dry beans (Phaseolus vulgaris and P. coccineus) are relatively easy to grow in New England while lima beans (P. lunatus) are more difficult. Other specialty bean crops include Edamame soybeans (Glycine max) and fava or broad beans (Vicia faba). Beans should be planted in well-drained soil, and should not be repeatedly planted in the same field (use at least a 3-year rotation) to avoid soil-borne diseases.

Plant only when soil temperatures have reached 60°F (late May-early June). Optimum seed germination occurs at soil temperatures above 70°F. Irrigation may be necessary at time of bloom in order to ensure maximum pod set under dry soil conditions. Temperatures above 90°F or below 50°F cause poor pod set.

Types and Varieties

Snap beans can have green, purple or yellow (wax) pods, and grow in bush (P. vulgaris) or vine/pole forms (P. coccineus). Pods are oval, round, or flat (Italian types), depending on cultivar. Filet beans are ones that have slender stringless pods that stay small and thin. Good commercial yields for fresh market are 200 bushels or more per acre.

Lima beans (P. lunatus) are of minor importance in most areas in New England. Seed germination requires warm soil. A relatively long time to maturity reduces the length of the harvest season and restricts production in northern New England. A good yield of shelled lima beans is 3,000 lb/A.

Dry beans. In recent years, a significant acreage of pea beans and a small, but important, acreage of light red kidney varieties have been grown in northern New England. Vermont and Maine have a thriving tradition of growing heirloom varieties. For additional information about dry beans, see the Northeast Dry Bean Production Guide (University of Vermont Extension, March 2017) at https://cdn.sare.org/wp-content/uploads/20171204115634/NEDryBeanProductionGuide2017.pdf

Snap, Lima, and Dry Bean Varieties
Snap Beans - green Lima Beans
Affirmed - A, BCMV, BBR, HB:1,2 Fordhook 242
BA0958 - BCMV Eastland - DM
Bronco - BCMV King of the Garden - pole
Concesa - BCMV, HB  
Fortex - pole Dry Beans
Jade II - BCMV, BR Jacob's Cattle
Lewis - BCMV, CT, HB, BR, BBR Maine Yellow Eye
Provider - BCMV, PM Pinto
Savanna - BCMV, A, CT Redkote Kidney - HB
Seychelles - pole Seafarer Pea Bean - A, HB, BCMV
Tema - BCMV White Marrow
  Marfax
Snap Beans - Italian flat-podded  
Capitano (yellow) Snap beans - yellow/wax
Greencrop - BCMV Carson - BCMV, A
Roman II - BCMV Rocdor - BCMV, A
Romano Gold (yellow) Eureka - BCMV, BBR
  Monte Gusto - pole
Snap Bean - slender filet  
Maxibel Snap beans - purple
Tavera - A, BCMV Amethyst
Velour (purple) Royal Burgundy
  Carminat - pole

Resistant to: A: Anthracnose; BBR: Bacterial Brown Rot: BR: Bean Rust; BCMV: Bean Common Mosaic Virus; CT: Curly Top Virus; DM: Downy Mildew; HB: Halo Blight; PM: Powdery Mildew. Other codes: Pole = pole beans (all others are bush).

Soil Fertility 

Apply lime according to soil test to maintain soil pH at 6.5-6.8.

Apply no more than 80-100 lb/A combined weight of nitrogen and potash through the planter. Because beans are sensitive to salt or ammonia injury, keep fertilizer 2-3 in. away from the seed.

A sidedressing of 30 lb nitrogen/A at prebloom may extend harvest period of snap beans and increase yields, especially on sandy soils. Machine harvested snap or dry beans are unlikely to need sidedressing. Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

Beans can suffer from zinc (Zn) deficiency or boron (B) toxicity.  If soil tests report less than 1.0ppm Zn, then add 10 lbs per acre zinc sulfate to the starter fertilizer. If soils contain more than 0.5ppm B, then avoid growing beans in this field.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR Bean: Snap, Dry, and Lima
Bean: Snap, LIMA and DRY NITROGEN (N)* LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast or Planter* 50 100 75 0-50 0 100 75 0-50 0
TOTAL RECOMMENDED 50 100 75 0-50 0 100 75 0-50 0
*DO NOT EXCEED A TOTAL OF 80LB. N/A PLUS K20 AS A PREPLANT INCORPORATE, IF NECESSARY.

Planting

Seeds may be inoculated with the appropriate isolates of Rhizobium to increase nitrogen fixation and yields. When purchasing inoculum, purchase fresh inoculum each year, and follow suppliers' guidelines to make sure that you are purchasing the correct strains to inoculate each crop species.

Bush Snap Beans: Plants should be spaced 1.5-2 in. within rows and 18-36 in. between rows. Use the higher plant population under a more favorable environment. Sow 75-100 lb of seed/A (approximately 0.5 lb/100 feet of row) depending on seed type and percent germination. Plant seed 1-1.5 in. deep, depending on soil type and/or soil moisture content. Repeat seeding every 2-3 weeks for a continuous supply.

Pole Beans: Pole beans can be supported by a bean trellis of a large mesh nylon material or chicken wire fencing. Removing the plants from the fence is a chore, while nylon mesh is disposable. The traditional manner is to use a 4 pole tepee method. When using the trellis or fence method, plant seeds 1-2 in. deep, 6 in. apart, in rows 4 feet apart. For the tepee method, plant 6-7 seeds around each pole. One lb of seed will plant 240 feet of row or around 150 poles.

Lima Beans: Plants should be spaced 4-6 in. within rows and 18-36 in. between rows. Use 40-60 lb seed/A (4-6 oz/100 feet of row). Plant 1 in. deep in moist heavy soils and 2 in. deep in dry, sandy soils.

Dry Beans: Plants should be spaced 2-3 in. within rows and 28-36 in. between rows. Rate of seeding depends on seed size, percent germination, time of planting, and row spacing (check seed supplier recommendations for each cultivar). Plant 1 in. deep in moist heavy soils and 2 in. deep in dry, sandy soils.

Harvest

Snap beans: Snap beans for fresh market should be harvested when they reach the desired size. Beans should be harvested when the pod is bright green and fleshy, and the seeds are small and green.  Pods should snap easily when bent. Large-scale growers should investigate mechanical harvesters. Hand-harvest multiple times or machine-harvest once when the highest percentage of marketable beans are mature.  Optimum storage conditions are 41-45°F at 95-100% relative humidity, but storage time is limited. Temperatures of 38°F and lower may cause chilling injury. After >10% weight loss, beans will not be marketable. Avoid storing or shipping beans with ethylene-generating fruits and vegetables. 

Lima beans: Harvest should take place when 2/3-3/4 of the pods have filled and are yellowing, but before any pods have dried. Other harvest practices are similar to that for dry beans. 

Dry beans: Most require 90-100 days to mature. Dry beans should not be harvested until the majority of pods have turned yellow and thoroughly matured, but before the pods dry to the point of shatter. The mature beans should be so hard that you cannot easily bite into the seed. Harvesting in the morning while there is still dew can minimize loss to shatter. Mechanized harvesting can be done with a puller-cutter, which will uproot or cut the entire plant and lay it on the ground in windrows as the machine moves along the field. Windrows can be combined when beans have dried to 18% moisture.  Once shelled, beans should be conditioned using a low temperature and dried to a moisture level of 15-16%, then stored in rodent and insect proof bins at temperature ranging from 35-55ºF.

Defoliants/Harvest Aids for Dry Beans

carfentrazone (Aim EC): PHI 0d, REI 12h, Group 14.  Apply 1 to 6.1 fl oz per acre to use as a harvest aid to dry beans at maturity when 80 to 90% of seed pods are yellow or buck skin in color and only 30% of green leaves remain on the plant. Thorough coverage is essential for harvest aid and multiple applications may be needed. For optimum performance use 15 to 30 gallons per acre finished sprayed with a methylated seed oil (MSO) type adjuvant to ensure thorough coverage and retention for harvest aid.

flumioxazin (Valor SX): PHI 5d.  Apply when crop is mature and at least 80% of the pods are yellowing and mostly ripe with no more than 40% (bush type beans) or 30% (vine type beans) of the leaves still green in color. To ensure thorough coverage use 15-30 gallons spray solution per acre. Do not apply more than 3 oz/A during a single application and do not apply more than 3 oz/A during a single growing season.  Adjuvant required. Crop oil concentrate or methylated seed oil at 2% v/v should be used. A spray grade nitrogen source (either ammonium sulfate at 2-2.5 lb/A or a 28-32% nitrogen solution at 1-2 qt/A) may also be added to the spray mixture to enhance desiccation. Can be tank mixed with glyphosate or paraquat to increase control of emerged weeds and aid in harvest.

paraquat (Gramoxone SL 2.0)PHI 7d, REI 48h, Group 22.  Apply 1.2 to 2 pt/A in 20 gal water with ground equipment or in a minimum of 5 gal water with aerial equipment. Add spreader (nonionic) at 1 qt per 100 gal spray mix. For vining-type beans or bush-type with lush growth, use a single application of the higher rate. May also be applied as a split application. Do not make more than two applications or exceed a total of 2 pts/A. The split application method may improve vine coverage. Apply when the crop is mature and at least 80% of the pods are yellowing and mostly ripe with no more than 40% (bush type) or 30% (vine type) of the leaves still green in color. Do not apply when weather conditions favor spray drift. A drift control agent may be included to reduce spray drift. Do not use on Fava beans. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training. The training must be completed a minimum of every three years.

saflufenacil (Sharpen): PHI 2d. Make a single application of 1-2 fl oz/A in a minimum spray volume of 10 gallons/A over the top of dry edible beans that have reached physiological maturity (at least  80% yellow/brown pods, and no more than 30% of leaves still green for vine-type beans/lentils or no more than 40% of leaves still green for bush-type beans). Thorough spray coverage and a methylated seed oil plus ammonium-based adjuvant system (refer to the Additives Section of label for details) are required for optimum desiccation activity. Allow up to 10 days for optimum desiccation effect.

 

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Anthracnose (Colletotrichum lindemuthianum)

Anthracnose is common in beans and is primarily a seed-borne disease surviving on dry, undecomposed residues for up to 5 years. Symptoms begin as red spots on leaves and pods that develop into black lesions. Leaf veins can turn red-brown. Start with certified, disease-free seed and use resistant cultivars. Fungicides may be applied as seed treatments or foliar sprays.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 2.4 pt/A; PHI 14d, REI 12h, Groups 11 & M5. DRY bean only. See label for tank mix precautions.  

azoxystrobin plus propiconazole (Quilt Xcel): 10.5 to 14.0 fl oz/A; PHI 7d succulent; PHI 14d dry, REI 12h, Groups 11 & 3.

chlorothalonil (Bravo Weather Stik): 1.375 to 3.0 pt/A (succulent), 1.375 to 2.0 pt/A (dry); PHI 7d (succulent) to 14d (dry), REI 12h, Group M05.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 12 h, Groups 7 & 11.

penthiopyrad (Fontelis): 14.0 to 30.0 fl oz/A; PHI 0d, REI 12h, Group 7. Maximum 2 applications per year.

potassium bicarbonate (PB 133, AKA MilStopOG): 2.5 lb/100 gal; PHI 0d, REI 1h.

propiconazole (Tilt): 4.0 fl oz/A; PHI 7d, REI 12h, Group 3.

Pseudomonas chloraphis (HowlerOM): 2.5 to 7.5 lbs/A; PHI 0d, REI 4h, Group BM 02. Use preventatively.

pyraclostrobin (Headline): 6.0 to 9.0 fl oz/A; PHI 7d (succulent) to 21d (dry), REI 12h, Group 11. Apply at the beginning of flowering. Do not make more than 2 applications/ before rotating to a non-Group 11 fungicide.

Reynoutria sachalinensis extract (RagaliaOR): 1.0 to 4.0 qt/A ground application; PHI od, REI 4h, Group P5. Application to ensure thorough coverage. See label for specific application instructions.

thiophanate-methyl (Topsin 4.5 FL): 30 to 40 fl oz/A; PHI 14d (snap) to 28d (dry), REI 24h (succulent), 72h (dry), Group 1. Rate is dependent on crop phenology, see label for details.

Downy Mildew-Lima Beans (Phytophthora phaseoli)

Downy mildew resistant lima bean varieties are available. Rotate to non-susceptible crops. Apply seed treatments to protect germinating seedlings against soil-borne inoculum. Plow under infected debris in fall. Rotate with crops other than beans for two years.

chlorothalonil (Bravo Weather Stik): 1.375 to 3.0 pt/A (succulent), 1.375 to 2 pt/A (dry); PHI 7d (snap) to 14d (succulent), REI 12h, Group M5.

copper hydroxide (Kocide 3000): 0.5-1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman): Succulent beans ONLY. 2.75 fl oz/A; PHI 0d, REI 12h, Group 21. Tank mix with organosilicone or non-ionic surfactant.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 12h, Groups 7 & 11. Maximum 2 applications per year.

mefenoxam (Ridomil Gold XL): Succulent beans ONLY. 0.125 to 0.2 pt/A. PHI 3d, REI 48h, Group 4. Must be tank mixed with high rate of another fungicide registered for downy mildew.

phosphorous acid  (Fosphite): 1.0 to 3.0 qt/100 gal; PHI 0d, REI 4h, Group 33. Do not apply to heat or moisture stressed crops or plants recently treated with copper.

potassium bicarbonate (PB 133, AKA MilStopOG): 2.5 lb/100 gal; PHI 0d, REI 1h.

Pseudomanas chloraphis (HowlerOM): 2.5 TO 7.5 lbs/A. PHI 0d, REI 4h, Group BM 02. Use preventatively.

pyraclostrobin (Headline): 6.0 to 9.0 fl oz/A; PHI 7d (succulent) to 21d (dry), REI 12h, Group 11. Do not make more than 2 applications before rotating to a non-Group 11 fungicide.

Rhizoctonia solani

Rhizoctonia stem canker caused by strains of the soil-borne fungus Rhizoctonia solani is common throughout the world on peas and beans. The pathogen survives between crop seasons as sclerotia (survival structures), mycelium in the soil, or on or in infected plant debris.  It is spread in infested soil or plant debris by wind, rain, irrigation water, and machinery. When a soil becomes infested, it remains so indefinitely. Seedlings and young plants are highly susceptible to infection and disease severity is increased by low soil temperatures and compaction. Seed decay and damping off can be controlled by using high-quality seed, with high germination and vigor,  and by practices that encourage rapid germination and emergence.  Seed treatments are not effective against infections later in the season. The disease may be reduced by sowing seed as shallowly as possible in warm, moist soil. Land preparation that minimizes soil compaction and structural damage will lessen disease severity. Rotate crops with a cereal or pasture crop (avoid beets, beans, brassicas and potatoes which increase inoculum). Cover crops and other practices that increase organic matter and improve soil structure are recommended. Some brassica crops (mustard, rape) used as green manure have been reported to be disease suppressive. Avoid incorporating green manure immediately before planting or damaging roots by shallow cultivation. Fungicides can manage Rhizoctonia root rot on young seedlings if applied as a seed treatment or soil drench.

Bacillus amyloliquefaciens F727 (StargusOG): 2 to 4 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50 gallons of water/A.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi.

PCNB (Blocker 10G): Bush and pole beans ONLY. 1.0 lbs/1,000 ft. (bush), 1.0-2.0 lbs/1,000ft. (pole); REI 12h, Group 14. Apply in a 12-15 inch band over seed in-furrow at planting time and cover immediately. Do not feed treated vines to livestock.

Reynoutria sachalinensis extract (RagaliaOG): 1.0 to 4.0 qt/A ground application; PHI 0D, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application instructions.

Trichoderma asperellum, T. gamsii (BiotamOG): See label for in-furrow, drench, and broadcast rates; PHI 0d, REI 4h, Group BM02.

thiram (Thiram 42-S): 2.0 fl oz. (snap and dry), 3.0 fl. (Lima)/100 lb seed; REI 24h, Group M03.

Rust (Uromyces appendiculatus)

Symptoms are most visible on the undersides of leaves. Symptoms begin as tiny white raised spots called pustules that break open to produce distinct red spots with dust-like spores (uridiniospores) which easily brush off. Spots may be surrounded by yellow halos in some varieties. Severely infested leaves fall off plants. Overwintering spores (teliospores) are black in color. Plant resistant varieties. Plow under crop debris immediately after harvest. Bury or otherwise destroy crop residues to reduce overwintering inoculum. Rotate away from beans for 2 years or up to 5 years in reduced tillage. Avoid overfertilization with high levels of nitrogen, but ensure adequate potassium. Disinfect poles in production of pole beans. Avoid long periods of leaf wetness when irrigating during times when temperatures are warm. 

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. 

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 2.4 pt/A; PHI 14d, REI 12h, Groups 11 & M5. DRY bean only. See label for tank mix precautions. Not labeled for soybean. 

azoxystrobin plus propiconazole (Quilt Xcel): 10.5 to 14 fl oz/A; PHI 7d (succulent), 14 (dry), REI 12h, Groups 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group BM02. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

chlorothalonil (Bravo Weather Stik): 1.375 to 3.0 pt/A (succulent), 1.375 to 2 pt/A (dry); PHI 14d, REI 12h, Group M05.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 12 h, Groups 7 & 11. Maximum 2 applications per year.

myclobutanil (Rally): 4.0 to 5.0 oz/A; PHI 0d, REI 24h, Group 3. Observe a 30-day plant back interval.

penthiopyrad (Fontelis): 14.0 to 30.0 fl oz/A; PHI 0d, REI 12h, Group 7. Maximum 2 applications per year.

propiconazole (Tilt): 4.0 fl oz/A; PHI 7d, REI 12h, Group 3. 

pyraclostrobin (Headline): 6.0 to 9.0 fl oz/A; PHI 7d (succulent) to 21d (dry), REI 12h, Group 11.  Do not make more than 2 applications per season before rotating with another Group 11 fungicide.

sulfur (Microthiol DisperssOG): 3.0 to 10.0 lb/A; PHI 0d, REI 24h, Group M2.

Seed Decay

Buy treated seed. Do not use treated seed for food or feed.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.125 to1.0 lb/A at planting; PHI 0d, REI 4 h, Group BM02. Suppression only.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi.

mefenoxam (Apron XL): 0.16 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping off. Early season Phytophthora protection (0.64 fl oz/lb seed).

Streptomyces griseoviridis strain K61 (MycoStopOG): see label for rate information; REI 4h.

thiram (Thiram 42-S): 3.0 lb (lima) 2.0 lb (snap & dry)/100 lb seed; REI 12h, Group M3.

White Mold (Sclerotinia sclerotiorum)

Space plants to allow good air circulation. Plant on well-drained soil. Sclerotinia produces sclerotia, which are hard, black structures from 1/16" to 1/2" in length, inside or on the surface of infected tissue. Sclerotia can survive for years in the soil and are responsible for initiating disease. Germination of sclerotia and initiation of disease are dependent on prevailing weather conditions. Optimum temperature for sclerotia to germinate is about 52°F but some sclerotia germinate over a wider range of temperatures. Germination is also dependent on continuous soil wetness for 10 days.

Many vegetable crops and weeds are susceptible to this fungus; corn and grasses are not. Lettuce, cabbage, tomato, carrot, brassicas and snap beans are among the most susceptible and should not be grown on land known to be contaminated with Sclerotinia. After an episode of disease, rotate away from susceptible crops for 7 years. A single infected head of cabbage may produce more than 1,000 sclerotia. Removal of diseased plant material as soon as possible is highly is recommended.

Bacillus amyloliquefaciens F727 (StargusOG): 2.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply in furrow at planting in a minimum of 5.0-15.0 gallons of water/A.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 7d (succulent), 21d (dry), REI 12h, Group 7. Do not make more than 2 applications per season.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Make the first application at 10-20% bloom. In some locations a single application at this timing will provide adequate disease control.

Coniothyrium minitans (Contans WGOG): Apply 1.0 to 4.0 lb/A in 20 to 50 gal water; REI 4h, Group BM02. Spray on the soil surface and incorporate into the top 2" of soil. Fall application is best or 3 to 4 months before planting to allow for the biocontrol agent to infect the sclerotia of Sclerotinia. 

fluazinam (Omega 500F): 0.5 to 0.85 pt/A; PHI 14d succulent, PHI 30d dry and lima beans, REI 12h, Group 29. Make the first application at 10-30% bloom.

iprodione (Rovral 4F): 1.5 to 2.0 pt/A; PHI 14d, REI 24h, Group 2. See label for restrictions. Limit 2 application per season.

penthiopyrad (Fontelis): 16.0 to 30.0 fl oz/A (succulent), 16.0 to 20.0 fl oz/A (dry); PHI 0d (succulent), 21d (dry), REI 12h, Group 7.

thiophanate-methyl (Topsin 4.5 FL): 20 to 30 oz/A; PHI 14d snap or lima and 28d dry, REI 24h (succulent) and 72h (dry), Group 1.

Trichoderma asperellum, T. gamsii (BiotamOG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group BM02.

Ulocladium oudemansii (BotryStopOG): 2.0 to 4.0 lbs/A; REI 4h, Group BM02. Begin application when conditions are conducive to disease development.

Bacterial Diseases (Pseudomonas spp. and Xanthomonas spp.)

Bacterial leaf diseases include: bacterial bean blight (Xanthomonas campestris pv. phaseoli), bacterial brown spot (Pseudomonas syringae pv. syringae), and halo blight (Pseudomonas syringae pv. phaseolicola). Plant disease-free seed from a reliable supplier. Eliminate wild cherries and lilacs near bean fields. Do not cultivate or harvest when plants are wet. Use a 2-year rotation. Plow under infected debris in fall.

copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M1. Do not apply with a spray solution having a pH less than 6.5 or tank mix with Aliette.

Reynoutria sachalinensis extract (RegaliaOG): 1.0 to 4.0 qt/A ground application; PHI Od, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application instructions.

Bean Common Mosaic Virus (BCMV)

In addition to mosaic and lesions of the foliage, BCMV can also cause blackened roots. Several different strains of the virus are recognized; the symptoms and host ranges vary according to the strain. The virus can be seed-borne and is transmitted by at least 12 species of aphids in a nonpersistent manner. Resistant varieties are available and constitute the most reliable means of control. Seed treatment, insecticides, and roguing of diseased plants are of little value.

Bean Yellow Mosaic Virus (BYMV)

Many strains of this virus are known. Symptoms of BYMV are easily confused with BCMV. However, BYMV is not seed-borne and unlike BCMV, BYMV is spread in a persistent manner by more than 20 species of aphids. Entire plantings may become infected, resulting in substantial losses in yield. Disease outbreaks are often correlated with the presence of virus-source plants such as sweet clover, white clover, crimson clover, and Gladiolus sp. Since the virus overwinters in legumes such as clover and vetch, beans should be planted at least 800 ft away. Insecticides applied early will reduce spread. Control weeds. Plant mosaic resistant varieties (see varieties list, page 124).

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

All tolerances for chlorpyrifos in food crops were revoked in 2022, therefore products containing chlorpyrifos (e.g. Lorsban) cannot be applied to any food crop and growers CAN NOT use up existing stock.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aphids

Several species of aphids may probe, feed and cause direct damage or transmit disease in dry or snap beans: soybean, bean, pea, yellow clover, and green peach aphid. Soybean aphid (Aphis glycines) reproduces in soybeans but not green or dry beans; however, this species can colonize, inflict feeding injury and transmit virus to green and dry beans.  Soybean aphid is found on beans in New York and in the Midwest, with higher pressure in hot dry summers. It has been less important in New England but could increase, especially in soybean production areas. Virus diseases can be spread by aphids; however, using insecticides to control aphids is not effective for reducing these viruses. Generally, aphids in beans are controlled by natural enemies. Scout for aphids on undersides of leaves or terminal shoots. Treat only if aphids are well distributed throughout the field (50% or more of terminals with 5 or more aphids), natural enemies are lacking, and population is increasing. Use selective products for other pests to conserve natural enemies of aphids and to protect bees. Systemic insecticide may be used as seed treatment or at planting. Avoid planting beans near alfalfa or soybean.   See Peppers for more information about green peach aphid.

acetamiprid (Assail 30 SG): 2.5 to 5.3 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A. Edible-podded and succulent shelled peas and beans only.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 14d dried, 1d fresh lima, REI 24h, Bee: H, Group 1B. Use on succulent green beans (snap) not permitted, except those grown for seed. Not labeled for control of Black Bean aphid.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.9 oz/A; PHI 1d succulent shelled or edible-podded, 21 d dried, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group un.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Succulent beans only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

dimethoate (Dimethoate 4EC): 8 to 16 oz/A; PHI 0d, REI 48h, Bee: H, Group 1B.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 3A. For Pea aphid.

flonicamid (Beleaf): 2.8 oz/A; PHI 7d, REI 12 h, Bee: L, Group 29.

flupyradifurone (Sivanto): 7 to 10.5 oz/A; PHI 7d, REI 4h, Bee:L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d fresh; 21d dry, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 1.2 oz/A foliar, 7 to 10.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A foliar; PHI 0d, REI 4h, Bee: M, Group UN.

lambda-cyhalothrin (Warrior*II): 1.28 to 1.92 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1 d fresh at up to 1.5 pt/A, 3d for over 1.5 pt/A; 14 d dry, REI 48h, Bee: H, Group 1A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

sulfoxaflor (Transform WG): 0.75 to 1 oz/A; PHI 7d, REI 24h, Bee: H, Group 4C. Do not apply until after petal fall.

thiamethoxam (Cruiser 5FS): 1.28 oz/100 lb of seed; REI 12h, Bee: H, Group 4. Systemic seed treatment. For early-season protection from aphids. Use standard slurry seed treatment equipment which provides uniform coverage of seed.

Cutworms

Cutworm larvae may be dull gray, brown, or black and may be striped or spotted, depending on the species. Another distinguishing quality is their act of rolling into a tight C-shape if disturbed. The two major species are the variegated cutworm (Peridroma saucia), which feeds on lower leaves and petioles, and the black cutworm (Agrotis ipsilon), which largely feeds at the soil surface and below on roots and lower stems. The black cutworm will occasionally feed on leaves. Both are nocturnal feeders and take refuge under soil clumps, stones, vegetation, and other places during the day. Cutworms find weedy or minimum-tillage fields especially attractive sites to lay their eggs. Seedlings are most affected; look for cut stems or foliage feeding. Scout across the field, as injury may be limited to a few small areas. Control is warranted if overall plant stand or survival is threatened.  Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed on stems after dark. For best results, make application between midnight and dawn while cutworms are feeding aboveground. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 14d dry 1 d fresh lima, REI 24h, Bee: H, Group 1B. Use on succulent green beans (snap) not permitted, except those grown for seed.

alpha-cypermethrin (Fastac* EC): 1.3 to 3.8 oz/A; PHI 1d succulent shelled or edible-podded, 21d dried, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Succulent beans only.

carbaryl (Sevin XLR Plus): 1 to 1.5 qt/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 1A. Most effective on species which feed on upper portions of the plant.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 5 to 8 oz/A; PHI 7d edible-podded and succulent shelled, 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 3A. On snap beans, use only as a seedling spray. No restriction on dry beans.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.60 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 3d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 1.4 to 4.3 oz/A; PHI 1d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

European Corn Borer (Ostrinia nubilalis), Corn Earworm (Helicoverpa zea), and Cabbage Looper (Trichoplusiani)

These caterpillars are occasional pests of bean in New England. See Sweet Corn for more details on European corn borer (ECB) and corn earworm (CEW), and Cabbage and Other Brassica Crops for more information on cabbage looper (CL). In beans, ECB eggs are laid under leaves and larvae feed in stems, then bore into pods. The bloom period is most attractive for egg-laying. If a preferred host such as corn is not available, eggs will be laid in beans. This may occur where early beans are planted after a corn crop the previous year, or where late beans are near a maturing corn crop when the second ECB generation emerges.  The most susceptible period in snap bean is from bud stage (about 26 days before harvest) to pod formation (12 days before harvest), and in dry bean is for the 4 weeks preceding the onset of pods drying. Infestation depends on synchrony of ECB flight and bean stage. The most effective timing for a single insecticide application is bloom or pod formation. CEW or CL may lay eggs in beans when migratory flights are very high. CEW or CL caterpillars feed on leaves, buds, flowers, and pods, often damaging the beans. CEW and CL feeding holes may be larger than ECB entry holes. The impact of these caterpillars on overall plant growth and yield is minimal, but the tolerance for caterpillar infestation is extremely low in processing beans where larval contamination must be avoided. The most practical and effective control for ECB is to avoid planting early beans where corn was grown the previous year or late beans near corn where ECB may emerge. Monitor moth activity in corn using pheromone traps or refer to pest alert networks to detect peak or high flights. Scout if flights are high during the susceptible period of bean growth, looking for wilted or chewed trifoliate leaves, larvae, or pod injury. There is no set threshold for treatment.

acephate (Orthene 97): 0.5 to 1 lb/A for CL; 3/4 to 1 lb/A for ECB and CEW; PHI 14d dry, 1d fresh lima, REI 24h, Bee: H, Group 1B. Not permitted for use on succulent green beans (snap), except those grown for seed.

alpha-cypermethrin (Fastac* EC): 2.7 to 3.8 oz/A ECB and earworm, 3.2 to 3.9 looper; PHI 1d succulent shelled or edible-podded, 21d dried, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group un.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel). Looper only.

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari). Looper only.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Succulent beans only.

carbaryl (Sevin XLR Plus): 0.5 to 1.5 qt/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 1A. High rate for ECB. Not for CL.

chlorantraniliprole (Coragen): 5-7.5 oz/A soil at planting, 3.5-7.5 oz/A foliar; PHI 1d, REI 4h, Bee: L, Group 28. For ECB and CEW only.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 7d edible-podded and succulent shelled, 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN. Earworm and looper only.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d fresh, REI 12h, Bee: H, Group 3A. Not for ECB on dry beans.  

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d snap; 21d dry, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d fresh at up to 1.5 pt/A, 3d for over 1.5 pt/A, 14d dry, REI 48h, Bee: H, Group 1A.

methoxyfenozide (Intrepid 2F): 4 to 16 oz/A for ECB and CL, 10 to 16 oz/A for CEW; PHI 7d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinosad (Entrust SCOG): 3 to 6 oz/A ECB, 4 to 6 oz/A CEW & looper; PHI 3d, REI 4h, Bee: M, Group 5.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

Garden Springtails (Bourletiella hortensis)

Tiny (1/16") blue-grey insects that seem to hop like fleas. Important in the decomposition of dead plant matter. Occasionally, high populations feed on leaves of seedlings producing tiny pits in the leaf surfaces. Feeding resembles that of flea beetles. Plants may die of excessive water loss. Populations tend to be extreme in fields high in organic matter, with reduced-till systems, and with soils that crack when drying. Use clean cultivation and spot-treat areas where damage occurs. Most broad-spectrum insecticides registered for cutworms or leafhoppers will also control springtails.

ethoprop (Mocap* 15G): 13 to 20 lb/A for 36" row spacing or 0.9 to 1.4 lb/1,000 linear ft in a band 12 to 15" wide at planting; REI 48h, Bee: H, Group 1B. Incorporate in top 2" to 4" of soil. Do not use as seed furrow treatment. Treated beans may mature 1 to 2 weeks later. For snap and lima beans only. 

Japanese Beetles (Popillia japonica)

Beetles migrate from turf or pastures starting in July and skeletonize leaves.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A (soil applications only); PHI 0d, REI 4h, Bee: M, Group UN.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Mexican Bean Beetle (Epilachna varivestis)

Mexican bean beetle (MBB) most often builds up to damaging levels where snap beans are grown in the same or adjacent fields over successive years. Lima beans and dry beans are also susceptible, and MBB may feed in dry and edible-pod soybeans but are less likely to thrive on this host. Adults are copper-colored, oval, ladybeetles with black spots, 1/4-1/3 in. long. Eggs are orange to yellow in color, laid on the underside of leaves in clusters of 40-50.  Larvae are yellow with rows of branched, black-tipped spines. The pupa is attached to the leaf, lacks spines, and is yellow to yellow-orange. Adults spend the winter in hedgerows and move into fields in June. Adults and larvae skeletonize leaves and may cause pod damage if numbers are high.  There are 1-3 generations per year in New England, with newly emerging adults moving to the next succession planting of snap beans. A life cycle may be completed in 30-40 days during the summer. Populations are usually less abundant on early plantings and may not build to damaging levels until August. Prompt destruction of crop residue after harvest helps lower overwintering populations.  Avoid continuous production of beans in the same or adjacent fields year after year. Annual releases of the larval parasitoid Pediobius foveolatus, timed to coincide with egg hatch, can help control beetle larvae. The wasp will not survive our winters, so must be re-released each year, but reproduces and moves into later plantings. Parasitized larvae serve as pupal cases for the wasp, remaining on the leaf and turning brown. Scout for MBB by searching plants for adults, eggs and larvae, and assessing damage. Treat when defoliation exceeds 20% pre-bloom or 10% during pod development. The presence of adults, eggs and larvae indicates potential for further damage. Be sure to get coverage of the lower leaf surfaces. 

acetamiprid (Assail 30 SG): 2.5 to 5.3 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 14d dry, 1d fresh lima, REI 24h, Bee: H, Group 1B. Use on succulent green beans (snap) not permitted, except those grown for seed.

alpha-cypermethrin (Fastac* EC): 2.7 to 3.8 oz/A; PHI 1d succulent shelled or edible-podded, 21d dried, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group un.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 1A.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 5 to 8 oz/A; PHI 7d edible-podded and succulent shelled, 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

dimethoate (Dimethoate 4EC): 8 to 16 oz/A; PHI 0d, REI 48h, Bee: H, Group 1B.

esfenvalerate (Asana* XL): 2.9 to 5.8 oz/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression and repellence only.  Use on seedlings and young plants, prior to pod set to avoid unsightly residue. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.60 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 12 to 48 oz/A; PHI 1d fresh at up to 1.5 pt/A, 3d for over 1.5 pt/A, 14d dry, REI 48h, Bee: H, Group 1A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. For beetle larvae only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Cruiser 5FS): 1.28 oz/100 lb of seed; REI 12h, Bee: H, Group 4. Systemic seed treatment. Use standard slurry seed treatment equipment which provides uniform coverage of seed. For early-season protection from Mexican bean beetles.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d fresh, 21d dry, REI 12h, Bee: H, Group 3A

Potato Leafhopper (Empoasca fabae)

Adults are light yellow-green, 1/8" long, and wedge-shaped (wider at the head), while nymphs are bright green, flatter and wider than adults, and move sideways in a crab-like fashion. Adults lay eggs in stems and nymphs hatch and feed, passing through five instars before becoming adults. Presence of nymphs indicates an established population. Both adults and nymphs cause injury by injecting a toxin as they feed through piercing-sucking mouthparts. Potato leafhoppers (PLH) overwinter in Louisiana and vicinity and move north on storm fronts into the central states and then into New England on winds from the west. Arrival time varies with year and location, ranging from late May to late June. Low levels of leafhopper feeding can severely damage plants, especially at the seedling stage. Signs of injury begin with leaf veins turning pale, followed by yellowing or browning of areas of the leaf or leaf tips, which is known as ‘hopperburn’. Leaves become brown, curl up, and die. Plants and roots may be stunted and yields reduced or lost. This process may take less than a week. PLH may also vector many viruses. Scout using sweep net or observing adults flying up when plants are shaken. Nymphs can be counted on undersides of leaves. Seedling beans should be treated if they have 2 adults per foot of row. From 3rd trifoliate leaf to bud stage, treat when PLH exceed 1 nymph/leaflet or 5 adults per foot of row, and repeat application in 7-10 days, if necessary. Be sure to treat lower leaf surfaces. In fields where a systemic seed treatment was used (e.g. Cruiser), foliar treatment should not be needed before bloom.

acetamiprid (Assail 30 SG): 2.5 to 5.3 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A. Edible-podded and succulent shelled peas and beans only.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 14d dry, 1d fresh lima, REI 24h, Bee: H, Group 1B. Not permitted for use on succulent green beans (snap), except those grown for seed.

alpha-cypermethrin (Fastac* EC): 2.7 to 3.8 oz/A; PHI 1d succulent shelled or edible-podded, 21d dried, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 1.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Succulent beans only.

carbaryl (Sevin XLR Plus): 1 qt/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 1A.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 7d edible-podded and succulent shelled, 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

dimethoate (Dimethoate 4EC): 8 to 16 oz/A; PHI 0d, REI 48h, Bee: H, Group 1B.

esfenvalerate (Asana* XL): 2.9 to 9.6 oz/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

flupyradifurone (Sivanto): 7 to 10.5 oz/A; PHI 7d, REI 4h, Bee:L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 1.2 oz/A foliar, 7 to 10.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gall; PH 0d, REI 4h, Bee: L. Suppression and repellence only. Use on seedlings and young plants prior to pod set to avoid unsightly residue. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 12 to 48 oz/A; PHI 1d fresh at up to 1.5 pt/A, 3d for over 1.5 pt/A, 14d dry, REI 48h, Bee: H, Group 1A.

paraffinic oil (Organic JMS Stylet-OilOG): 0.75 to 1.5 gal/100 gal water; PHI 0d, REI 4h, Bee: L.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Cruiser 5FS): 1.28 oz/100 lb of seed; REI 12h, Bee: H, Group 4. Systemic seed treatment. Use standard slurry seed treatment equipment which provides uniform coverage of seed. For early-season protection from leafhoppers.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

Seedcorn Maggot (Delia platura)

Seedcorn maggot larvae feed on the seeds and young seedlings of large-seeded crops such as corn, beans, and peas, as well as early seedlings of spinach, onions, brassicas, tomato, cucurbits, and other crops. They are the first maggot flies to become active in spring, about one to two weeks earlier than onion or cabbage maggot. The adults look like small, gray houseflies with a slightly hump-backed shape. The seedcorn maggot larva is yellow-white, up to 1/4" long, legless, and has a wedge-shaped head. Pupae are oblong, brown, and about 4to 5mm long. The seedcorn maggot fly overwinters in the pupal stage, in the soil where they fed in the fall. In early spring, the adults emerge and lay eggs on the soil surface.  Growing degree days, using a base temperature of 39°F (4°C), can be used to predict peak emergence of the first generation (360ºF GDD or 200ºC GDD).  Flies are attracted to volatiles released from freshly tilled soil, as well as to buried cover crop residues, rotting manure, compost, organic surface residues (as is found in reduced till), and organic amendments such as fish, soybean or cottonseed meal.  Previously injured or diseased plants may also attract egg-laying. The eggs hatch within 2-4 days at soil temperatures of 60°F, and 7-9 days at 41 to 45°F. Larvae burrow downward in search of food and penetrate seeds as the seed coat splits open.  Though there are 2-4 generations per year, it is the first generation that causes the most damage. The first symptoms are usually poor emergence of seeds or wilting of transplants that have lost their roots to feeding. Look for maggots and feeding tunnels inside seeds or stems to help distinguish damage from that of wireworm feeding or damping off. Crops that are planted in wet soil, or soil that is too cool to support quick germination and seedling growth, are especially susceptible to damage. Wait until soil conditions favor crop emergence and growth to help seeds and seedlings avoid or quickly recover from injury. Plant shallowly to promote rapid emergence. Where possible, incorporate cover crops, manure or compost several weeks before seeding.  Put earliest plantings in lighter, well-drained, sandy soils that warm up fast. Among bean varieties, those with a dark seed coat sustain less injury than white varieties. Use row covers to exclude flies, except where flies may have fed in fall cover or vegetable crops and could emerge under the covers. Preventive chemical treatments include commercially applied systemic seed treatments and in-furrow applications of insecticides. Rescue treatments are not effective. If there is enough damage to warrant replanting, wait at least 5 days if maggots are a quarter inch long; if they are smaller than that, wait at least 10 days to make sure they have pupated and will not damage the new seeds.

phorate (Thimet* 20-G): 4.5 to 7 oz/1000 ft of row; REI 48h, Bee: H, Group 1B. Apply granules in band over row and lightly incorporate. DO NOT place granules in direct contact with seed. Make sure granules are covered with soil. Do not feed treated crop residue to livestock.

thiamethoxam (Cruiser 5FS): 1.28 oz/100 lb of seed; REI 12h, Bee: H, Group 4. Systemic seed treatment.  Use standard slurry seed treatment equipment which provides uniform coverage of seed. For early-season protection from seedcorn maggot.

Slugs

Damage appears as shredded foliage or fruit holes. Look for silvery slime trails on leaves or turn over soil clods or debris to find slugs during daylight hours. Grow plants away from moist, shaded habitats, use clean cultivation, control weeds, hand pick/crush slugs or scatter baits on the ground near infested plants. See the Cabbage section for more information on slugs.

iron phosphate (Sluggo: Slug and Snail BaitOG): 20 to 44 lb/A; PHI 0d, REI 0h, Bee: L, Group 9B. Apply around perimeter, scatter around base of plants, or band down rows. Apply to moist soil in the evening.

metaldehyde (Deadline Bullets): 20 to 40 lb/A; REI 12h, Bee: L. Soil surface treatment broadcast pre-planting, or band treatment between rows after formation of edible parts. Apply to moist soil in the evening. Do not apply directly to or contaminate edible portions of plants.

Tarnished Plant Bug (Lygus lineolaris)

See Lettuce for information about tarnished plant bug.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 14d dry, 1d fresh lima, REI 24h, Bee: H, Group 1B. Not permitted for use on succulent green beans (snap), except those grown for seed.

alpha-cypermethrin (Fastac* EC): 2.7 to 3.8 oz/A; PHI 1d succulent shelled or edible-podded, 21d dried, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Succulent beans only.

carbaryl (Sevin XLR Plus): 1 to 1.5 qt/A; PHI 3d fresh, 21d dry, REI 12h, Bee: H, Group 1A.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 7d edible-podded and succulent shelled, 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A foliar; PHI 0d, REI 4h, Bee: M, Group UN.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d fresh, 21d dry, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d fresh at up to 1.5 pt/A, 3d for over 1.5 pt/A, 14d dry, REI 48h, Bee: H, Group 1A.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

sulfoxaflor (Transform WG): 1.5 to 2.25 oz/A; PHI 7d, REI 24h, Bee: H, Group 4C. Do not apply between three days prior to bloom and until after petal fall.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

Two-spotted Spider Mite (Tetranychus urticae)

Also known as Red Spider Mite. Outbreaks are favored by hot, dry weather and may be triggered by the use of broad-spectrum insecticides that kill the numerous natural enemies of mites. Spider mites affect dry, Lima and snap beans. Infestations begin on the lower portions of the plant and move upward. Watch for white speckling and bronzing on the upper surface of leaves (veins may remain green) and grayish webbing on the undersurface around leaf veins. Use a 10X hand lens to see mites. Avoid early-season, broad-spectrum insecticide applications for other pests; use selective products whenever possible. Registered products for mites on beans may not provide complete control of the pest. With most miticides, use 2 applications approximately 5-7 days apart, to help control immature mites that were in the egg stage and protected during the first application. Coverage of the lower surface of the leaves is important. If further applications are needed, switch to an alternate resistance group to help prevent or delay resistance.  For more information on TSSM management, see the Eggplant section.

abamectin (Agri-Mek SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic activator type wetting, spreading, and/or penetrating spray adjuvant. Do not use binder or sticker type adjuvant.

acequinocyl (Kanemite 15SC): 31 fl oz/A; PHI 7d, REI 12h, Bee: L, Group 20B. Succulent shelled bean only.

bifenazate (Acramite 50WS): 1 to 1.5 lbs/A; PHI 3d, REI 12h, Bee: M, Group UN.

dimethoate (Dimethoate 4EC): 8 to 16 oz/A; PHI 0d, REI 48h, Bee: H, Group 1B.

fenpyroximate (Portal XLO): 2 pt/A; PHI 7d, REI 12h, Bee: L, Group 21A.

neem oil (TrilogyOG): 0.5 to 2% solution in 25 to 100 gal water/A; PHI 0d, REI 4h, Bee: M, Group 18. Avoid mid-day applications and ensure good coverage.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

sodium tetraborohydrate decahydrate (Prev-AM Ultra): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

sulfur (Microthiol DisperssOG): 3 to 10 lb/A; REI 24h, Bee:L, No IRAC classification. Check for sulfur sensitivity prior to treating the whole field; some varieties may be injured by sulfur.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d fresh, 21d dry, REI 12h, Bee: H, Group 3A.

Weed Control

Weeds may develop quickly because beans are slow to establish a canopy. Use a tine-weeder or a rotary hoe if there is not too much field residue for pre-emergent mechanical weed control. Do not cultivate when the beans are starting to emerge as seedlings are very fragile and can easily snap. Cultivate 3 to 4 times when beans are 2 to 3 inches tall until canopy closure. Bean taproots are easily torn from the ground during imprecise mechanical cultivation. To minimize damage to plants, do not cultivate when leaves are wet or just after they have flowered.

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107) for information on the use of these herbicides.

glyphosate (Roundup Power Max): REI 12h, Group 9. Rate based on target weed species. See label for info.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Snap and lima only. Use 2 – 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Preplant Incorporated/Preemergence to Weeds

dimethenamid (Outlook): PHI 70d, REI 12h, Group 15.  Dry beans only (including small whites, navy, black turtle soup, pink, pinto, great northern, red Mexican, red kidney, cranberry, and lentils). May be applied preplant surface, preplant incorporated, preemergence, or early postemergence (1st to 3rd trifoliate). As a single application, apply 12 to 18 oz/A on coarse-textured soil and 14 to 21 oz/A on finer textured soils. A split application may be used (10 to 14 oz/A per application, not to exceed 21 oz/A total).  Allow 14 days between applications. Will not control emerged weeds. Check with seed supplier for potential varietal susceptibility to injury.

EPTC (Eptam 7E): REI 12h, Group 15. Do not use on lima beans. Apply 2.25 to 4.5 pt/A prior to planting, incorporate immediately to a depth of 2" to 4". Soil surface must be dry. For nutsedge, incorporate 4" to 6" deep. Do not exceed 3.5 pt/A on green beans grown on coarse-textured soil.

ethalfluralin (Sonalan HFP): REI 24h, Group 3. Not registered in CT or RI. Apply and incorporate before planting 1.5 to 4.5 pt/A (rate based on soil texture and target weeds, see label) prior to planting to a depth of 2" to 3".

pendimethalin (Prowl H2O): REI 24h, Group 3. Apply 2 to 3 pt/A preplant and incorporate into the soil 2" to 3".  Rate based on soil texture; see label for details.  Do not apply after seeding.

s-metolachlor (Dual Magnum): REI 12h, Group 15.  Apply either preplant incorporated or to the soil surface just after seeding. See label for specific rates on different soil types and organic matter content (1 to 2 pt/A). May be tank mixed with either EPTC or trifluralin. Follow precautions on all labels when tank mixing. NOTE: Crop injury has been noted on both snap beans and lima beans from the use of metolachlor. Use of tank mixes, where the rate of metolachlor could be lowered, will decrease the likelihood of crop injury.

trifluralin (Treflan HFP): REI 12h, Group 3. Rate based on soil texture and crop, see label for details.  Incorporate 1 to 2 pt/A before planting (1 to 1.5 pt/A for snap and lima bean). Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation.

Preemergence to Weeds - At Planting

clomazone (Command 3ME): PHI 45d, REI 12h, Group 13.  Snap beans only. Apply 6.4 to 10.7 fl oz/A to the soil surface after seeding but before crop emergence. Use lower rate on coarse soils. Will control annual grasses and many broadleaf weeds including common lambsquarters, velvetleaf, and jimsonweed. Combining with Dual Magnum will also control yellow nutsedge and pigweed. Some temporary crop injury (partial whitening of leaf or stem tissue) may be visible after crop emergence. Complete recovery will occur from minor early injury without affecting yield or earliness. See label for replanting restrictions.

halosulfuron (Sandea): PHI 30d, REI 12h, Group 2. Rates vary based on crop and application timing (0.5 to 1 oz/A for succulent beans (snap and lima) and 0.5 to 2/3 oz/A for dry beans). Use the lower rate on lighter textured soils. Can cause temporary stunting. Heavy rains following application will increase the potential for crop injury. Use of organophosphates can increase crop injury from halosulfuron.  See the label for other precautions and a list of weeds controlled.

Preemergence: Can be applied as a preemergence after seeding and before crop emergence.

Postemergence: Use postemergence after dry beans reach 1-3 trifoliate leaf stage or snap/lima reach 2-4 trifolate leaf stage, but before the crop flowers.  Treatments applied when beans are younger increase the risk of crop injury. Application after the third trifoliate leaf increases the risk of split set. Add a nonionic surfactant at a rate of 0.25% v:v (1 qt/100 gal) spray solution. Will control yellow nutsedge and many broadleaf weeds. Will not control lambsquarters postemergence.

Postemergence to Weeds

bentazon (Basagran): PHI 30d, REI 48h, Group 6.  Used postemergence on actively growing weeds.  Rate varies based on weed species targeted (1 to 2 pt/A). See label for info.  Apply after the first trifoliate leaf (three leaflets) has fully expanded to avoid crop damage. An effective treatment in an emergency situation to control certain broadleaf weeds and fairly effective against yellow nutsedge when 4" to 6" tall.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

Postemergence Grass herbicides

clethodim (Select Max): PHI 30d dry beans, PHI 21d for snap beans, REI 24h, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  For dry beans, multiple applications permitted of 9 to 32 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  For snap beans, only a single application of 9 to 16 oz/A is permitted.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI 60d, REI 12h, Group 1.  Dry beans only.  For grass weed control only. Apply up to 24 oz/A.  See label to select rate based on grasses targeted for control. Allow for minimum 14-days between applications, and not to exceed 48 oz/A per year.  Apply to actively growing grasses (see product label for susceptible stage). Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).

quizalofop (Assure II): PHI 30d dry beans, PHI 15d snap beans, REI 12h, Group 1. Apply to actively growing grasses. Rate based on target weed species, see label for grass growth stage and rate selection.  Multiple applications permitted.  Allow at least 7 days between applications.  Do not exceed 24 oz/A per season for dry beans and do not exceed 14 oz/A per season for snap beans.  Apply with either crop oil concentrate or non-ionic surfactant. Do not apply when crop or weeds are under drought stress.

sethoxydim (Poast): PHI 30d dry beans, PHI 15d snap beans, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 2.5 pt/A per application, minimum 14-days between applications.  Do not exceed 4 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions. Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Beet and Swiss Chard

Introduction

Beets (Beta vulgaris var. crassa) and Swiss chard (Beta vulgaris var. cicla) are members of the Chenopodiaceae family, along with lambquarters. Both are cool-season crops that can tolerate frosts and light freezes. Chard is raised for its large leaves and stems, and beets are raised both for greens and roots. The best quality is obtained when beets are grown under conditions of good sunlight and cool temperatures (50-65°F). The higher temperatures of summer can cause "zoning" in beets, e.g. alternating light and dark rings and lower sugar content. Beets grow best in deep, friable, well-drained, sandy loams to silt loams. High organic content in the soil is desirable and will help maintain an adequate moisture supply. Organic matter should be well decomposed to avoid scab problems with beets.

Types and Varieties

Beet and Chard Varieties
Bunching Spring Beets Summer and Fall Beets
Kestrel Kestrel
Boro Boro
Red Ace Red Ace
Red Cloud Red Cloud
Detroit Supreme - OP Moneta (monogerm)
Early Wonder - OP Pacemaker III
   
Beet Greens Specialty Beets
Bull's Blood - OP Cylindra - cylindrical
Early Wonder Tall Top - OP Taunus - cylindrical
Fresh Pak Boldor - yellow
  Touchstone Gold - yellow
Chard Varieties Chioggia Guardsmark - OP, striped interior
Bright Lights - multicolored mix Avalanche - OP, white
Fordhook Giant - OP  
Large White Ribbed - OP  
Silverado  
Ruby Red  
OP: open-pollinated

Soil Fertility

Apply lime according to soil test to maintain soil pH at 6.5-6.8. In alkaline soils, the chance of boron and manganese deficiency is increased. High levels of nitrogen in relation to phosphorus and potassium will result in heavy leaf production with poor root development. Beets have a high potassium requirement. Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

Beets are subject to boron deficiency; young leaves fail to develop normally, turn black and die. This is accompanied by internal breakdown, canker, or dry rot of the root. To prevent deficiency, apply 2 lb B per acre (10 lb Solubor, 20 lb borax) with the broadcast fertilizer application. Make sure that the next crop in the rotation schedule is not sensitive to boron residue.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR BEET AND SWISS CHARD
BEET AND SWISS CHARD NITROGEN (N)* LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 75-100 150 100 50 0 300 150 75-100 0
Sidedress after 1st or 2nd cutting 30 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 105-130 150 100 50 0 300 150 75-100 0

Planting

Seed is planted 0.25-0.5 in. deep in rows 18-24 in. apart aiming at a density of 15-30 plants per foot. For most beet varieties (except monogerm varieties) each seed ball contains up to 6 seeds, so thinning is required. Both beets and chard may be transplanted for an earlier spring crop. 

Harvest and Storage

Swiss chard: Chard does not bolt or go to seed as readily as spinach and, therefore, is a good summer substitute. Many successive harvests can be made from one planting. Chard is frost resistant and can be harvested well after the first killing frost. Once harvested, chard can be kept for 1-2 weeks at 32°F and 95%-98% relative humidity.

Beet: Bunched beets can be kept for 10-14 days at 32°F and 98% relative humidity. Topped beets can be stored for 3-6 months or more at 33-36ºF and 98% relative humidity. 

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Leaf Spots and Blights (Alternaria, Ascochyta, Cercospora, Powdery Mildew)

Select resistant cultivars where available. Use cultural practices that minimize periods of leaf wetness such as plant spacing, planting in the direction of prevailing winds, and avoiding overhead irrigation. Promptly incorporate plant debris after harvest to speed decomposition.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Applications of Quadris to leafy vegetables may cause phytotoxicity; proceed with caution with regards to tank mixes and adjuvants. Rates vary depending on crop and disease: see label for details. Do not alternate with other Group 11 fungicides. 

copper hydroxide (Kocide 3000): 0.75 to 2.0 lb/A. Beet ONLY; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil plus fludioxonil (Switch): 11.0 to 14.0 fl oz/A, PHI 7d (beet), 0d (chard) REI 12h, Groups 9 and 12

fluopyram plus pyrimethanil (Luna Tranquility): 8.0 to 11.2 fl oz/A, PHI 7d, REI 12h, Groups 9 and 12. 

fluxapyroxad plus pyraclostrobin (Merivon Xemium): 9.0 to 15.5 fl oz/A (beet), 4.0 to 11.0 fl oz/A (chard); PHI 7d (beet), 24h (chard), REI 12h. Groups 7 and 11. Use highest labeled rate for Cercospora. 

penthiopyrad (Fontelis): 4.0 to 5.5 fl oz/A (beet), 14.0 to 24.0 fl oz/A (chard); PHI 7d (beet), 3d (chard), REI 12h, Group 7.

propiconazole (Tilt): 4.0 fl oz/A; PHI 14d, REI 12h, Group 3. Not labeled for powdery mildew on chard. 

pydiflumetofen plus fludioxonil (Miravis Prime): 6.8 fl oz/A (beet), 9.2 to 13.4 fl oz/A (chard); PHI 7d, REI 12h, Groups 7 and 12. 

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A (beet), 12.0 to 16.0 (chard); PHI 0d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

Reynoutria sachalinensis extract (RegaliaOG): 1.0 to 4.0 qt/A ground application; PHI 0d, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application instructions. 

Swinglea glutinosa extract (EcoSwingOG): 1.5 to 2 pts/A; PHI 0d, REI 4h, Group BM 01. Labeled for Alternaria leaf spot and powdery mildew.

trifloxystrobin (Flint): 2.0 to 3.0 oz/A; PHI 7d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

Downy Mildew (Peronospora farinosa f. sp. betae )

Plant resistant cultivars where available. Use cultural practices that minimize periods of leaf wetness such as plant spacing, planting in the direction of prevailing winds, and avoiding overhead irrigation. Promptly incorporate plant debris after harvest to speed decomposition. 

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12 h, Groups 45 and 40. Not labeled for beets.

azoxystrobin (Quadris): 12.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Do not alternate with other Group 11 fungicides. Not labeled for beets. 

Bacillus amyloliquefaciens F727 (StargusOG): 2.0 to 4.0 qt/A; PHI 0d, REI 4h, Group 44. Apply preventatively in a minimum of 50.0 gallons of water/A.

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Must be tank mixed with a fungicide with a different mode of action. Not labeled for downy mildew on beets.

oxathiapiprolin (Orondis Gold 200): 4.8 to 9.6 fl.oz/A; PHI 0d, REI 4h, Group 49. Begin foliar application prior to disease development. Not labeled for beets.

phosphorous acid (Fosphite): 1.0 to 3.0 qt/minimum 20.0 gal; PHI 0d, REI 4h, Group 33. Do not apply to plants that are heat or moisture stressed. Do not apply directly to copper treated plants within 20-day interval to avoid plant injury.

pyraclostrobin (Cabrio): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11. Do not alternate with Quadris or Flint. Not labeled for beets.

Seed Decay

Plant on well-drained soil. Buy treated seeds. Do not use treated seed for food, feed or oil purposes.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi. Does not control Pythium and Phytophthora.

mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping-off protection.

thiram (Thiram 42 S): 8.0 lb/100 lb seed; REI 24h, Group M 03.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aphids (Myzus persicae or Aphis fabae)

Aphids may include green peach aphid (Myzus persicae) or bean aphid (Aphis fabae). See Peppers for more information about green peach aphid. Bean aphid favors plants in the Chenopodiaceae family (beets, chard, spinach, sugar beet) and feeds on a wide range of weeds (e.g. curly dock, lambsquarters, shephardspurse) as well as many other vegetables, but only rarely builds to damaging levels. Bean aphid adults and nymphs are dark olive-green to dull-black in color, with dark legs. They feed in young tissue of actively growing plants; high numbers can cause leaf curling and stunting. In general, using selective products for other pests will conserve natural enemies of aphids and prevent outbreaks. 

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A. Swiss chard only.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A beets, 2.2 to 3.8 oz/A chard; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group un.

bifenthrin (Brigade* 2EC): 5.1 to 6.4 oz/A on beets, 2.1 to 6.4 oz/A on Swiss chard; PHI 1d beets, 7d Swiss chard, REI 12h, Bee: H, Group 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Green peach aphid only. Swiss chard only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. For control of green peach and suppression of potato aphid only. Swiss chard only.

dimethoate (Dimethoate 4EC): 8 oz/A; PHI 14d, REI 48h, Bee: H, Group 1B. Swiss chard only.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip. For Swiss chard only.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 3d beets, PHI 0d chard, REI 12, Bee: L, Group 9C.

flupyradifurone (Sivanto): 7 to 10.5 oz/A for foliar application, 21 to 28 oz/A for soil application (Swiss chard only); PHI 1d foliar, 21d soil, REI 4h, Bee:L, Group 4D.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.

malathion (Malathion 57 EC): 1.5 to 2 pt/A beets, 1 to 1.6 pt/A Swiss chard; PHI 7d beets, 14d Swiss chard, REI 12h, Bee: H, Group 1B.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Swiss chard only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

pymetrozine (Fulfill): 2.75 oz/A; PHI 7d, REI 12h, Bee: L, Group 9A. Swiss chard only.

spirotetramat (Movento): 4 to 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility. Swiss chard only.

sulfoxaflor (Closer SC): 1.5 to 2 oz/A. Foliar applications only; PHI 3d, REI 12h, Bee: H, Group 4C.

sulfoxaflor (Transform WG): 1.5 to 2.25 oz/A. Beets only; PHI 7d, REI 24h, Bees: H, Group 4C.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 12 oz/A on beets, 5 to 11 oz/A on Swiss chard; PHI 30d Swiss chard, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment.

tolfenpyrad (Torac): 17 to 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A. Except lettuce aphids. Swiss chard only.

Blister Beetles (Epicauta funebris and E. vittata)

The margined blister beetle, Epicauta funebris and the striped blister beetle, Epicauta vittata, are the most common blister beetles in the Northeast. These beetles have also been called the "old fashioned potato beetle". They attack chard, beet and spinach along with other vegetable crops including bean, eggplant, pepper, potato, sweet potato, tomato, and sometimes brassicas. They are very attracted to pigweed and other Amaranthus spp., and also feed in alfalfa and clover. Adults are soft-bodied, slender, long-legged beetles, about 5/8 in. long.  The section of the body between the head and the wings is distinctly narrower, giving the impression that the insect has a neck. The egg, larval and pupal stages occur in the soil, and grasshopper eggs are a favored food for larvae. There is one generation per year in the Northeast, and beetles overwinter as larvae in the soil. Margined blister beetles are dark gray or black with light-gray lines along the margins of the wings. They feed primarily on flowers and blossoms of plants, but may also feed on the leaves. Striped blister beetles are yellow to rusty orange with 2 black spots on the head and 2 black stripes dorsally on the thorax and the wings. They are mainly foliage feeders and often appear in large swarms, sometimes quite suddenly, and concentrate in one particular area of a field where they can cause significant feeding damage. Blister beetles contain an oily, caustic substance called cantharidin that protects them from natural enemies. In humans, it causes temporary blisters on the skin; in livestock, especially horses, consuming cantharidin causes severe injury and contamination of hay with blister beetles is a serious concern. Where local swarms occur in a crop, a single spot spray with a broad-spectrum insecticide registered for flea beetles on these crops effectively controls blister beetles.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group un.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Cabbage Maggot

Floating row covers can be used. No insecticides currently registered. For more information see cabbage maggot in the cabbage section. 

Flea Beetles

Several species of flea beetles feed on beets and chard. Most have a wide host range and tend to be moving among various crops and weeds. Most are black. The species that feed especially on brassicas do not tend to feed on beets or Swiss chard.  Damage (small 'shot holes') is most common on seedlings but can occur on older leaves as well.

alpha-cypermethrin (Fastac* EC): 1.8 to 3.8 oz/A beets, 2.2 to 3.8 oz/A chard; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group un.

beta-cyfluthrin (Baythroid* XL): 2.4 to 3.2 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Swiss chard only.

bifenthrin (Brigade* 2EC): 5.1 to 6.4 oz/A on beets, 2.1 to 6.4 oz/A on Swiss chard; PHI 1d beets, 7d Swiss chard, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 7d beets, 14d Swiss chard, REI 12h, Bee: H, Group 1A.

dinotefuran (Venom): 1 to 3 oz/A foliar. Swiss chard only; PHI 7d, REI 12h, Bee: H, Group 4A.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only. Beets only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 12 oz/A on beets, 5 to 11 oz/A on Swiss chard; REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone at planting/transplanting.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. For Swiss chard only.

Leafminers (Pegomya hyoscyami and P. betae)

Spinach leafminer (Pegomya hyoscyami) and beet leafminer (P. betae) attack crops in the family Chenopodiaceae (chard, beet, and spinach). Spinach leafminer may also cause damage in Solanaceous crops. In beets, leafminer is only a pest if the leaves are marketed or pressure is high enough to reduce root growth. The fly overwinters as a pupa in the soil and the small (5-7 mm) gray hairy adult flies emerge from late-April to mid- May. The two species are similar, but beet leafminer adults are slightly larger and darker, and beet leafminers prefer laying eggs on beet leaves. Female flies lay oblong white eggs (<1mm) in neat clusters on the underside of the leaves. Eggs hatch in 3-6 days. The larva burrows between the upper and lower epidermis of the leaf and feeds, creating a slender, winding ‘mine’ or tunnel. This expands into large blotches of translucent, dead tissue across the leaf, with a white maggot inside. Damaged leaves are unmarketable. When fully grown, maggots usually drop into the soil to pupate. The entire life cycle takes 30-40 days and there are 3-4 generations per season, with peak activity periods in mid to late-May, late-June and mid-August. Leafminer is most important as an early spring pest, but when populations are high, overlapping generations can cause continuous season-long damage to succession-planted spinach, beets and chard. After August, pupae enter overwintering phase and won’t emerge until next spring. A commercially available biological control is the tiny wasp parasitoid, Diglyphus isaea, which is most often used against Liriomyza leafminers (see Celery section) but has also been known to control leafminers in chard. They work best in warm weather. 

For prevention, rotate beet, chard and spinach to new fields in the spring and during the growing season. Avoid spring plantings near tunnels where winter greens were grown. Control weed hosts including lambsquarter, nightshade, chickweed and plantain. Row covers protect the crop by excluding flies, but scout for eggs on transplants before covering. Scout spring transplants in the greenhouse and in the field for eggs, which are easy to spot on the underside of leaves. Treat when eggs are first observed. If tunnels and eggs are present, treat to prevent further damage. Scout again to determine if a second treatment is needed in 7-10 days. Use an adjuvant and ensure coverage of lower leaf surface. Some systemic insecticides are registered that may be applied to transplants or to the soil. Among organic products, spinosad has demonstrated efficacy when applied before egg hatch. Note that some products are labeled only for Swiss chard.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading and/or penetrating spray adjuvant; do not use binder or sticker type adjuvant. Swiss chard only.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group un.

chlorantraniliprole (Coragen): 5.0 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through drip chemigation and as a foliar spray. Swiss chard only.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Swiss chard only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. Swiss chard only.

cyromazine (Trigard): 2.66 dry oz/A; PHI 7d, REI 12h, Bee: M, Group 17. Swiss chard only.

dimethoate (Dimethoate 4EC): 8 oz/A; PHI 14d, REI 48h, Bee: H, Group 1B. Swiss chard only.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip. Swiss chard only.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Leafminer suppression on Swiss chard only.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A foliar; PHI 0d, REI 4h, Bee: M, Group UN.

paraffinic oil (Organic JMS Stylet-OilOG): 0.75 to 1.5 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Beets only.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Swiss chard only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d Swiss chard, 3d beet greens, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 4.5 to 10 oz/A beets, 6 to 10 oz/A Swiss chard; PHI 3d beets, 1d Swiss chard, REI 4h, Bee: M, Group 5. Control may be improved with the addition of an adjuvant. Do not apply to Swiss chard seedlings intended for transplant.

thiamethoxam (Platinum): 5 to 12 oz/A on beets, 5 to 11 oz/A on Swiss chard; PHI 30d Swiss chard, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. Suppression only and only on Swiss chard.

Slugs

Damage appears as shredded foliage. Look for silvery slime trails on leaves or turn over soil clods or debris to find slugs during daylight hours. Grow plants away from moist, shaded habitats, use clean cultivation, control weeds, hand pick slugs or scatter baits on the ground near infested plants. See the Cabbage section for more information on slugs.

iron phosphate (Sluggo: Slug and Snail BaitOG): 20 to 44 lb/A; PHI 0d, REI 0h, Bee: L, Group 9B. Apply around perimeter, scatter around base of plants, or band down rows. Apply to moist soil in the evening.

metaldehyde (Deadline Bullets): 20 to 40 lb/A; REI 12h, Bee: L. Soil surface treatment broadcast pre-planting, or band treatment between rows after formation of edible parts. Apply to moist soil in the evening. Do not apply directly to or contaminate edible portions of plants.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107) for information on the use of these herbicides.

glyphosate (Roundup Power Max): REI 12h, Group 9.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

cycloate (Ro-Neet): REI 48h, Group 15. Beets only. Not for use in Vermont, Connecticut or Rhode Island.  Preplant incorporated.  Apply 1/2 to 2/3 gal/A 10 to 50 gallons of water per acre. Must be immediately incorporated into the soil to a depth of 2 -3” to prevent loss of the herbicide.  Use on mineral soils ONLY. Use lower rate on sandy soils. Use higher dosage rate on heavier soils. Works by interfering with seed germination and seedling development.  Will not control existing weeds. 

s-metolachlor (Dual Magnum): REI 12h, Group 15. MASSACHUSETTS, MAINE, and NEW HAMPSHIRE ONLY. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge. All label instructions will be supplied after the application for use is completed.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max): PHI 30d, REI 24h, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

clopyralid (Stinger): PHI 30d, REI 12h, Group 4.  Beets only.  For postemergence control of weeds in the composite and legume families. Apply when beets are in the 2- to 8-leaf stage and weeds are young and actively growing. Common annuals include galinsoga, ragweed, pineappleweed, clover, and vetch. Perennial weeds controlled include Canada thistle, goldenrod species, aster species, and mugwort (wild chrysanthemum). Stinger is very effective on small seedling annual and emerging perennial weeds less than 2" to 4" tall, but is less effective and takes longer to work when weeds are larger. Use 0.25 pt/A (4 oz/A) to control annual weeds less than 2" tall. Use up to 0.5 pt/A (8 oz/A) to control larger annual weeds, and to suppress perennial weeds. Spray additives are not needed or required by the label and are not recommended. Stinger is a postemergence herbicide with some soil residual activity. Observe replant restrictions on the label or injury may occur from herbicide carryover.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 60d for beets, PHI 30d for chard, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  For beets, maximum 2.5 pt/A per application, minimum 14-days between applications.  Do not exceed 5 pt/A per year. For chard, maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 3 pt/A per year. Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Cabbage, Broccoli, Cauliflower, and Other Brassica Crops

Introduction

The term "cole crops" refers to waxy-leaved brassicas of European origin, of the species Brassica oleraceaeCabbage, broccoli and cauliflower and other brassica crops are hardy crops that are well adapted to New England. Plants maturing under cool weather conditions are of especially high quality. This diverse family has similar cultural requirements, diseases and pests.

Types and Varieties

Cabbage is the most widely grown and easily cultivated of the brassica crops. Some varieties mature in as few as 60 days or as many as 120 days from transplanting. The early and mid-season varieties are generally better suited for fresh market sales where small heads of 3-4 lb are desired. 

Cauliflower is more difficult to grow than other brassica crops. Common problems include failure to head properly and poor curd quality. For successful production of cauliflower, a fertile, moist soil relatively high in organic matter and nitrogen is needed. Buttoning is the premature formation of the head, when the leaves are not large enough to produce a head of marketable size. Conditions that reduce the vigor of the plant and retard vegetative growth, such as cold temperatures at transplanting and any of a number of other stresses appear to encourage buttoning. Cauliflower varieties range in maturity from 55 to 95 days.

Broccoli is not as exacting in its requirements as cauliflower, however, it must be harvested promptly to avoid flowering. The earliest spring plantings often experience buttoning. In summer months, temperatures over 85° F during the critical period when the head begins to form can result in poor head quality. In southern New England, broccoli is best grown as a fall crop. Broccoli varieties range in maturity from 55 to 75 days.

Brussels sprouts are generally a long season crop grown for harvest in the fall.  Brussels sprouts should be harvested when they are round, firm, tight and of good color. Brussels sprout varieties range in maturit from 90 to 110 days or longer.

Kale is cold-hardy and grows best as a fall crop when grown for full-size leaves, but can be succession-planted all season. Kale is also commonly grown as a component of salad mix (see Salad Mix Section). The flavor of the leaves is improved after a light frost.

Kohlrabi looks like a turnip growing on the top of the ground with sprouting leaves over the surface. It must be harvested when 1 1/2" to 3" in diameter or it will become tough and stringy.

Chinese cabbage (Brassica napa), Mustard (Brassica juncea) and Bok choi (Brassica rapa var. chinensis), are grown as salad or braising greens or as a heading crop. They have non-waxy leaves and most are Asian in origin. See Salad Mix section for more details on production of salad mix. Crops in this group are more susceptible to damage from flea beetles, but tend to be less attractive to caterpillars than waxy brassica crops. When grown as heading crops, these should be direct seeded from early May to mid-July depending on intended harvest date and location in New England. Chinese cabbage is especially sensitive to bolting in response to stress or cold. Nitrogen management for Chinese cabbage should differ slightly from other brassica crops (see Soil Fertility below).

Many other brassica greens, such as mizuna, mibuna, tatsoi, komatsuna, arugula, and mustard are usually direct seeded. Some varieties are prone to premature flowering, which is enhanced by cold temperatures in the spring. Transplanting, which is less common than direct seeding, can also increase premature flowering in the spring due to increased plant stress. Plant densities vary tremendously and should be geared toward the intended harvest age and size.

Brassica Crop Varieties
Broccoli - Spring-planted for summer harvest Cabbage - Early
Green Magic - DM Caraflex (pointed) 
Gypsy - DM Farao - TB
Emerald Crown Primero (red)
Imperial - DM Primo Vantage - Y
Diplomat - DM Tendersweet
Eastern Magic Tiara
   
Broccoli - Summer-planted for fall harvest Cabbage - Midseason
Emerald Crown - DM Early Thunder - Y, BR, TB
Diplomat - DM Integro (red)
Eastern Magic Omero (red) - TB
Lieutenant Red Jewel (red)
   
Cauliflower Cabbage - Late Season / Storage
Amazing Buscaro (red)
Earlisnow Passat - Y, TB, BR
Flame Star (orange) Report - Y, TB, BR, CR
Graffiti (purple) Ruby Perfection (red)
Mardi Storage #4 - Y, TB
Skywalker Typhoon - Y
Snow Crown  
Twister Cabbage - Savoy
Veronica (romanesco) - Y Alcosa - DM
Vitaverde (green) Clarissa - TB
  Deadon (tinged red) - Y
Kale Famosa - TB, DM
Darkibor  
Lacinato (toscana type) Cabbage - Chinese
Red Russian Bilko - Y, CR
Redbor (red) Blues - DM
Starbor Minuet (mini) - DM
Winterbor Miss Hong (red)
  Wawa Tsai (mini) - CR
Kohlrabi  
Azur star (purple) Pak Choi
Kolibri (purple) Joi Choi
Konan Mei Qing Choi
Korist  
Kossack (giant) Brussels Sprout
  Dagan
  Divino
  Gustus
Resistant or tolerant to: BR: black rot, CR: clubroot, DM: downy mildew, TB: tipburn, Y: yellows

Soil Fertility

Apply lime according to soil test to maintain soil pH at 6.5-6.8. Maintain a high level of calcium to minimize tip burn.

The best method to apply a small amount of boron is as an additive to the fertilizer. For example, if the level of boron in the soil is low, apply 3 lb of B (15 lb Solubor, or 30 lb Borax) per acre before planting broccoli and cauliflower, and 2 lb/A for cabbage. See Tables 6 and 6a.

For Chinese cabbage, pepper spot can develop on the stalks of the plants as a result of excess nitrate uptake. Apply only 50 lb of actual nitrogen at planting and sidedress additional nitrogen at diminishing rates as the plant nears harvest maturity, for a total of 150 lb/A. Foliar or drip applications scheduled at 6 to 8 lb per week may be the most practical.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

If using transplants, use of a liquid starter fertilizer at planting time is beneficial, especially with cool soil conditions. Use a high phosphorus starter fertilizer mixed at a rate of 3 lb per 50 gallons of water. Apply 8 fluid ounces (1 cup) per transplant.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR CABBAGE, BROCCOLI, CAULIFLOWER, AND OTHER BRASSICA CROPS
CABBAGE, BROCCOLI, CAULIFLOWER AND OTHER BRASSICA CROPS NITROGEN (N)* LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 100 150 100 50 0 175 125 50 0
Sidedress 4 weeks after transplant 60* 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 160 150 100 50 0 175 125 50 0
*CAULIFLOWER APPLY 30 LBS/A

Planting and Field Culture

Early plantings of cabbage and other brassica crops are generally made by setting out transplants grown in greenhouses or cold frames. Transplants should be 5-7 weeks old at field setting; and, for cauliflower and broccoli, transplants should be produced in greenhouses with a minimum nighttime temperature of 50° F. Excessive cold, transplant stress, inadequate fertility or other sources of stress in early stages can cause brassica crops to button, or to go to seed without heading. Transplants with thick stems are likely to head prematurely or button. Midseason and late plantings can be transplanted or direct seeded. If cabbage, broccoli or cauliflower are direct seeded, 2-3 weeks should be added to the number of days to maturity.

Generally, coarse-textured soils (sands, sandy loams, etc.) are favored for early plantings because they can be worked earlier in the spring and will warm up faster. These soils are also less likely to become waterlogged under rainy spring conditions. Finer textured soils which have a greater water holding capacity can frequently be used to advantage for producing later crops. 

Cabbage grown for fresh market should be planted to stand 12-15 in. apart within rows and 24-36 in. between rows. With most early or midseason varieties the closer spacing will give larger yields and smaller heads, which can be a more desirable size for fresh markets. Where direct seeding is used, seeding depth is 1/2-3/4 in. One-half to 1 lb of seed will be required per acre (0.125-0.25 oz per 100 feet of row) depending on variety, seed size, and spacing. Thin seedlings to desired stand when plants are 2-4 in. tall. Do not allow plants to become crowded.

Cauliflower should be planted to stand 15-18 in. apart within rows and 30-36 in. between rows. Broccoli should be spaced according to market needs. Large single heads can be achieved by a 15-18 in. spacing. To acheive three-head bunches, which require 5-6 in. heads with small stalks, plant double row beds with 36 in. between beds and 10-12 in. between rows within bed, and 6-9 in. between plants, depending on variety. Early varieties usually require closer spacing. Southern grown plants can be purchased for transplants, but insect and disease problems often accompany them. If purchasing bare root transplants from nurseries, plant soon upon receipt. Field-grown cabbage transplants, once pulled, should not be stored for longer than 9 days at 32°F or 5 days at 66°F prior to planting in the field. Cauliflower and broccoli can be direct seeded to stand, with precision type planters. Raised beds of 4 in. are recommended. For cauliflower this will require about 4 oz seed per acre (0.0625 oz per 100 feet of row); for broccoli about 0.5 to 1 lb/acre (0.125 to 0.25 oz per 100 feet of row).

Brussels sprouts are most commonly grown from transplants as a long season crop for fall harvest. Cool weather and light frosts prior to harvest increase quality. Rows are typically spaced 36 in. apart with 15 in. spacing within the row. Plants can be topped in early September, when 80% of the sprouts have reached marketable size, to improve sprout size uniformity if harvesting entire stalks. Stripping the foliage from the lower 1/2-2/3 of the plant will allow more light to reach the developing sprouts, as well as increase air circulation, both of which increase sprout quality.

Kale can be successfully grown from direct seeding or from transplants. For direct seeding, sow seed at 3-4 lb per acre in rows spaced 16-36 in. apart. Thin to 4-5 in.  apart in the row. Transplants are set in rows 16-36 in. apart and 6-12 in. apart in the row. Use wider between-row and in-row spacing for multiple hand harvests by stripping leaves. 

Kohlrabi may be grown for spring crops by transplants. Transplant into the field at the same time as broccoli or cabbage. Fall crops can be established by direct seeding between June 25 and July 15. Seed open-pollinated varieties at the rate of 2-3 lb per acre and thin to 6-8 in. between plants in the row. Precision-seed hybrid varieties. Set transplants July 20 to August 15. Space rows 18-24 in. apart.

Irrigation

The availability of water can be critical for successful production. Adequate soil water must be maintained during seedling or transplant establishment and the period of rapid vegetative growth that follows. This is extremely critical prior to head initiation for cabbage, since excessive water applied after cabbage heads have formed can result in split heads. When harvest periods of broccoli and cauliflower occur during times of high temperatures, light irrigation (0.33-0.5 in.) can be used to cool plants and help maintain quality. 

Harvest and Storage

Cabbage. Harvest as soon as the head has reached full size for the variety grown. Many varieties will stand in the field for considerable periods of time after heading without serious deterioration, but harvest should not be delayed unnecessarily as plants become more susceptible to disease and to splitting.

Cauliflower heads must be blanched in order to produce attractive white curd. Blanching refers to covering the developing cauliflower head in order to shade it from sunlight. Newer varieties are self-blanching or self-wrapping. Unless a variety is reported as being self-blanching, when the head is 2-3 in. diameter, gather the large outer leaves loosely over the head and tie with twine or rubber bands. Tie every 2-3 days with different colored bands to help coordinate harvest dates. Hot, humid, rainy weather after tying can result in a rotting curd. In hot weather, the head should be ready to harvest in 3-5 days; in cool weather, blanching takes 8-12 days. Harvest when head is compact, clear white and about 6" in diameter. Avoid bruising during harvest and packing.

Broccoli is harvested when heads are dense and 3-6 in. diameter, and before individual flower buds are distinguishable or yellow flowers can be seen. Cut 8-10" of stem with the head. Broccoli should be cooled as rapidly as possible and stored under cool conditions after harvest to slow down flower development. Side heads develop rapidly following removal of the terminal head, unless the variety used is a nonsprouting type. Harvesting may continue for several weeks. Broccoli is especially sensitive to postharvest heat and should be hydrocooled or packed on ice immediately after harvest.

Brussels sprouts should be harvested when sprouts are firm and are of the desired size for market. Sprouts can be harvested sequentially, working up the stalk as the season progresses, or entire stalks can be cut and marketed whole. 

Kale and Collards may be harvested by cutting off entire plants near ground level, then bunching whole plants. Alternatively, mature leaves may be stripped from plants and either bunched or packed individually. Multiple harvests are possible. 

Kohlrabi. The targeted harvest stage is when stems are full sized but before they begin to split. Bulbs are cut at the soil line, and foliage is trimmed as dictated by markets.

Many brassica crops are very sensitive to ethylene, and may yellow upon exposure to low levels of ethylene. These crops should be stored as close to 32ºF as possible without freezing, at greater than 95% relative humidity. Air circulation should be adequate to remove heat of respiration, but excessive air circulation will speed transpiration and wilting of leafy crops. Expected storage life varies widely. Consult USDA Handbook 66: The commercial storage of fruits, vegetables and florist and nursery stocks, for crop-specific information. 

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Alternaria Damping Off

Buy seed certified as disease-free or treat with hot water at 122°F for 25 minutes (see Hot Water Treatment of Seed, page 78). Brassica crop seed is susceptible to seed vigor loss from hot water treatment. Seed should be treated as close to planting as possible.

Alternaria Leaf Spot and Head Rot

Alternaria leaf spot and head rot are caused by at least three species of the fungus Alternaria, and may be seed-borne. Start with certified disease-free seed, or treat seed with hot water. Practice a 3-year crop rotation with all brassica crops. Take measures to decrease the amount of time that leaves are wet: increase row and plant spacing to improve air circulation and irrigate with overhead irrigation early in the mornings on sunny days or use drip irrigation instead of overhead irrigation. Control brassica weeds. Avoid working in fields when foliage is wet. Promptly incorporate plant debris after harvest, or mow if tillage is not possible in late fall crops. Differences in variety susceptibility exist but no resistant varieties are available. Avoid overhead irrigation to prevent broccoli head rot.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Do not repeat the application or rotate with other strobilurins. See label for list of allowed brassica crops.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group BM 02. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

boscalid (Endura): 6.0 to 9.0 oz/A; PHI 0d, REI 12h, Group 7. Maximum 2 applications per year.

botanical extract (EcoswingOG): 1.5 to 2.0 pt/A; PHI 0d, REI 4h, Group BM 01.

chlorothalonil (Bravo Weather Stik): 1.5 pt/A; PHI 7d, REI 12h, Group M 05.

copper hydroxide (Kocide 3000): 0.5 to 0.75 lb/A; PHI 0d, REI 48h, Group M 01.  Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 and 12.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Group 3 and 9. Apply in sufficient volume to achieve thorough coverage. 

fenamidone (Reason SC): 8.2 fl oz/A; PHI 2d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

flutriafol (Rhyme 2.08 SC): 5 to 7 fl oz/A; PHI 7d, REI 12h, Group 3.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 6.0 to 8.2 fl. oz/A; PHI 3d, REI 12 h, Groups 7 and 11.

mancozeb (Manzate Pro Stick): 1.6 to 2.1 lb/A; PHI 7d, REI 24h, Group M 03. Cabbage and broccoli only.

penthiopyrad (Fontelis): 14.0 to 30.0 fl oz/A; PHI 0d, REI 12h), Group 7.

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium bicarbonate (PB 133, AKA MilStopOG): 2.5 lb to 5.0 lb/100 gal; PHI 0d, REI 1h, Group NC. See label for small volume application rates.

pseudomonas chloraphis (HowlerOM): 2.5 to 7.5 lbs/A. PHI 0d, REI 4h, Group BM 02. Use preventatively. 

pydiflumetofen plus fludioxonil (Miravis Prime): 11.4 fl oz/A; PHI 7d, REI 12h, Groups 7 and 12.

pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11.

triflumizole (Procure): 6 to 8 fl oz/A; PHI 1d, REI 12h, Group 3.

Black Leg (Phoma lingam, Leptosphaeria maculans)

Black leg is a fungal disease of brassica crops. Use 3- to 4-year crop rotation. Start with certified, disease-free seed, or treat seed with hot water. Inspect seedlings for infection before planting out into the field. Take measures to decrease the amount of time that leaves are wet: increase row and plant spacing to improve air circulation and irrigate with overhead irrigation early in the mornings on sunny days or use drip irrigation instead of overhead irrigation. Control brassica weeds. Avoid working in fields when foliage is wet. Promptly incorporate plant debris after harvest, or mow if tillage is not possible in late fall crops.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 6.0 to 8.2 fl. oz/A; PHI 3d, REI 12 h, Groups 7 and 11.

iprodione (Rovral 4F): 2.0 pt/A; PHI 0d, REI 24h, Group 2. Broccoli ONLY.

potassium bicarbonate (MilStopOG): 2.5 to 5.0 lb/100 gal; PHI 0d, REI 4h, Group NC. See label for small volume application rates.

pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11.

thiram (Thiram 42-S):  8 lb/A. Seed treatment; REI 24h, Group M3.

Black Rot (Xanthomonas campestris pv. campestris)

Black rot is a bacterial disease of brassica crops. Practice a 3-year crop rotation with all brassica crops. Start with certified disease-free seed or treat seed with hot water. Take measures to decrease the amount of time that leaves are wet: increase row and plant spacing to improve air circulation and irrigate with overhead irrigation early in the mornings on sunny days or use drip irrigation instead of overhead irrigation. Control brassica weeds. Avoid working in fields when foliage is wet. Promptly incorporate plant debris after harvest, or mow if tillage is not possible in late fall crops.

acibenzolar-S-methyl (Actigard): 0.5 to 1.0 oz/A; PHI 7d, REI 12h, Group P 01. Suppression only.

copper hydroxide (Kocide 3000): 0.5 to 0.75 lb/A; PHI 0d, REI 48h, Group M 01.  Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

mancozeb plus copper hydroxide (ManKocide): 1.0 to 1.75 lb/A; PHI 7d, REI 48h, Groups M 03 & M 01. Not labeled for cauliflower.

pseudomonas chloraphis (HowlerOM): 2.5 to 7.5 lbs/A. PHI 0d, REI 4h, Group BM 02. Use preventatively. Not labeled for cauliflower.

Club Root (Plasmodiophora brassicae)

There is currently no way to eliminate club root from infested soil, but the pathogen can be slowed down by practicing a long crop rotation and increasing soil pH. Maintain soil at a pH of 7.0 to 7.2 by applying lime a maximum of 1000 lbs/A per application. Practice a routine 3-year rotation for all brassica crops; if club root is detected in a field, rotate out of brassicas in that field for 7 years. After a 7-year crop rotation, pH adjustment and fungicide applications may reduce the viable club root spores to below economic threshold levels of infection for many growing seasons to come. Cold, wet soils favor club root development and spore survival. Resistant varieties of some brassica crops are available. Prevent the movement of infested soil and irrigation water into uninfested fields.

cyazofamid (Ranman): 12.9 to 25.75 fl oz/100 gal (transplant drench); PHI 0d, REI 12h, Group 21. Tank mix with an organosilicone surfactant. Transplant soil drench or soil incorporation. See label for details.

fluazinam (Omega 500 F):  6.45 fl oz/100gal (transplant drench); PHI 7-50d, REI 12h, Group 29. Transplant soil drench or incorporation. PHI varies by crop. See label for details.

PCNB (Blocker 4F): Rate varies depending upon application method - see label; REI 12h, Group 14. For transplant applications, mix 3 pts into 100 gal water and use 0.5 to 0.75 pts solution per plant, based on severity of field infestation. Maintain agitation to hold product in suspension. For banded applications, apply as a 12-inch band, in 25 gal water per acre or 5.5 fl oz water per 100 ft of row based on 40-inch row spacing. For broadcast applications, apply in 30 gal water prior to planting. For all application methods, thoroughly incorporate into soil after application.

Downy Mildew (Hyaloperonospora parasitica)

Resistant varieties of some brassica crops are available. Take measures to decrease the amount of time that leaves are wet: increase row and plant spacing to improve air circulation and irrigate with overhead irrigation early in the mornings on sunny days or use drip irrigation instead of overhead irrigation.  

acibenzolar-S-methyl (Actigard): 0.5 to 1.0 oz/A; PHI 7d, REI 12 h, Group P 01.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44. Suppression only. For improved control, mix or rotate with an approved chemical fungicide.

chlorothalonil (Bravo Weather Stik): 1.5 pt/A; PHI 7d, REI 12h, Group M 05. See label for replant restrictions.

copper hydroxide (Kocide 3000): 0.5 to 0.75 lb/A; PHI 0d, REI 48h, Group M 01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman):  2.75 fl oz/A (foliar application); PHI 0d, REI 12h, Group 21. Tank mix with an organosilicone surfactant. 

dimethomrph (Forum): 6.0 fl oz/A; PHI 7d, REI 12h, Group 40. Apply in combination with a labeled rate of another non-group 40 fungicide.

fenamidone (Reason SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

fluazinam (Omega 500F): 15.35 fl oz/A (foliar application); PHI 7d, REI 12-48h, Group 29. Cabbage and Chinese cabbage ONLY. REI = 48h for handset irrigation, 12h for all other activites.

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Tank mix with a fungicide from a different group.

fosetyl aluminum (Aliette WDG): 3.0 to 5.0 lb/A; PHI 3d, REI 12h, Group 33. Do not mix with copper fungicides. Lower rates of Aliette (2 to 3 lb) can be used when tank mixed with another fungicide labeled for downy mildew control.

mancozeb plus copper hydroxide (ManKocide): 1.0 to 1.75 lb/A; PHI 7d, REI 48h, Groups M 03 & M 01. Broccoli and cabbage only.

mandipropamid (Revus): 8.0 fl oz/A; PHI 1d, REI 4h, Group 40. A spreading/penetrating type adjuvant must be added.

mefenoxam (Subdue MAXX): 25 to 50 pt/A; PHI 7d, REI 48h, Group 4. Do not apply foliar sprays without a labeled tank mix partner.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo): 1.5 pt/A; PHI 7d, REI 48h, Groups 4 and M 05. See label for plant-back restrictions and restrictions on certain crucifers.

oxathiapiprolin and mandipropamid (Orondis Ultra): 5.5 to 8.0 fl.oz/A; PHI 1d, REI 4h, Groups 49 and 40. Begin foliar application prior to disease development. Use higher rate when disease is present. A spreading/penetrating adjuvant must be added.

phosphorous acid  (Fosphite): 1.0 to 3.0 qt/100 gal; PHI 0d, REI 4h, Group 33. Do not apply to plants that heat or moisture stressed. Do not apply directly to copper treated plants within 20-day interval to avoid plant injury.

potassium bicarbonate (PB 133, AKA MilStopOG): 2.5 to 5.0 lb/100 gal; PHI 0d, REI 1h, Group NC. See label for small volume application rates.

pseudomonas chloraphis (HowlerOG): 2.5 to 7.5 lbs/A. PHI 0d, REI 4h, Group BM 02. Use preventatively.

pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11.

Reynoutria sachalinensis extract (RegaliaOG): 1.0 to 4.0 qt/A ground application; PHI 0d, REI 4 h, Group P5. Apply to ensure thorough coverage. See label for specific application instructions.

Fusarium Yellows

This fungal pathogen is soil-borne and may also be seed-borne. Plant resistant varieties. Prevent the movement of infested soil to clean fields. Provide adequate fertility; potassium deficiency increases disease severity.

Seed Decay and Damping-off

Buy treated seed. Do not use treated seed for food, feed or oil purposes.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.125 to 1.0 lb/A at planting; PHI 0d, REI 4h, Group 02. Suppression only.

mefenoxam (Apron XL): 0.32 to 0.64 fl oz/lb seed; REI 48h, Group 4. For Pythium damping-off protection.

Streptomyces griseoviridis strain K61 (MycoStopOG): See label for rate information; REI 4h.

thiram (Thiram 42-S): 8.0 fl oz/100 lb.; REI 24h, Group M 03.

Wire Stem, Crater rot, and Head rot (Rhizoctonia solani)

Diseases of brassica crops in this section caused by R. solani include wirestem and damping-off (seedlings) and bottom or head rot (cabbage). Rhizoctonia can be carried on the seeds of most brassica species and is ubiquitous in most soils, where it survives indefinitely. Start with certified, disease-free seed. Practice good sanitation in transplant production – sanitize transplant trays between uses and keep production tools and hoses off of the greenhouse floor when not in use. Successful sanitation in transplant production prevents further need for fungicide drenches. Use treated seed for direct seeding into field. Practices that encourage rapid germination and establishment limit disease development. Avoid planting transplants too deeply. Rotate crops. Do not plant susceptible crucifers in fields with undecomposed crop residues. No highly resistant varieties are available. Fungicide treatments in the field have limited effectiveness.

PCNB (Blocker 4F): Rate varies depending upon application method - see label; REI 12h, Group 14. Pathogen referred to as Corticium solani on label.

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Turnip Mosaic Virus

Turnip mosaic virus can infect most brassica crops but it is most commonly seen in Chinese cabbage and bok choy. It is spread by many species of aphids in a nonpersistent manner; therefore, insecticides are of little or no value in controlling its spread. This virus survives the winter in perennial weeds. It is spread by many species of aphids. Resistant cultivars include: Nabyeng, Kongng, Tip Top and Ta Feng. These cultivars may not be completely resistant and may have some intolerance to heat.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

All tolerances for chlorpyrifos in food crops were revoked in 2022, therefore products containing chlorpyrifos (e.g. Lorsban) cannot be applied to any food crop and growers CAN NOT use up existing stock.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

A spreader-sticker should be used with insecticides on these crops as it will help provide better coverage and more insecticide persistence.

Cabbage Aphid (Brevicoryne brassicae)

Only crops and weeds in the brassica family are suitable hosts for cabbage aphid (CA).  Cabbage, cauliflower, broccoli and Brussels sprouts are most severely affected, but other crops may become infested. Aphids tend to be more of a problem in fall plantings. Adults, both winged and wingless, and nymphs are grayish green with a dark head and short, dark cornicles, but appear more grayish white because the body is covered with a fine, white, powdery secretion. In fall, eggs are laid on the underside of leaves of the same crops or weeds that were fed on during the summer, and survive the winter on brassica host plants. This differs from the life cycle of many aphid pests of vegetables, where eggs are laid and overwinter on alternate hosts outside the field. Eggs typically hatch in April. Nymphs feed and develop into reproductive females who produce live young without mating. Winged adults disperse with wind and infest new crops. There are multiple summer generations and potential for huge population growth, especially where long-season crops are infested early. CA prefers to feed on young leaves, flower buds or seed stalks in the upper part of the plant and also feeds in developing Brussels sprout buds. Dense colonies may develop. Feeding injury includes wrinkled and downward-curling leaves, yellow leaves, reduced growth, contamination with aphid honeydew, and contamination of the marketable parts of the plant with aphids. CA can also transmit cauliflower mosaic and cabbage ring spot virus, among other viruses; transmission is non-persistent, with virus particles passed to new plants by probing. Natural enemies can suppress cabbage aphid populations, but may not be able to prevent high densities that may occur in cool fall weather. Cultural controls include soil incorporation of crop residues immediately after harvest or, for overwintering brassicas, before eggs hatch in spring. Control brassica weeds in or near fields. Check transplants to be sure they are clean. Use reflective mulch to repel aphids. Use selective products when controlling other pests to conserve beneficials. If CA is a consistent problem, systemic insecticides used at planting or sidedress may eliminate early infestations. Scout weekly to determine % infested plants, starting before harvested portions of the plant form. Treat if >10% of the plants are infested with aphids, especially after heads or sprouts begin to form. Or select 10 leaves at 10 sites for 100 leaves per field, and treat if >20% have aphids. Coverage of all leaf surfaces, buds and new growth is key. Waiting until there are heavy outbreaks or until just before harvest makes it hard to prevent loss of marketable yield.

Green peach aphid (Myzus persicae) can also infest brassicas.  For more information, see green peach aphid in the Pepper section

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 14d, REI 24h, Bee: H, Group 1B. For green peach aphid. For Brussels sprouts and cauliflower only.

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

afidopyropen (Versys): 1.5 fl oz/A; PHI 0d, REI 12 h, Bee: L, Group 9D.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

Beauveria bassiana (Mycotrol ESO): 8 to 32 oz/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN. Suppression only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark):  6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting.

dimethoate (Dimethoate 4EC): 8 to 16 oz/A for broccoli and cauliflower, 8 oz/A for kale and mustard, 16 oz/A Brussels sprouts; PHI 7d broccoli and cauliflower, 14d kale and mustard , 0d Brussels sprouts, REI 48h, Bee: H, Group 1B. Broccoli, cauliflower, kale, mustard, Brussels sprouts only.

dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. Broccoli, Brussels sprouts, cabbage, cauliflower and kohlrabi transplants only while in greenhouse. Not for field use.

dinotefuran (Venom): 1 to 4 oz/A for foliar applications or 5 to 7.5 oz/A for soil applications to head and stem Brassicas. 2 to 3 oz/A for foliar application only to leafy Brassicas; PHI 1d foliar, 2PHI 1d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip. For head and stem Brassicas only. 

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A Danitol 2.4EC + 3-4 oz/A Belay. Do not apply during bloom or if bees are actively foraging. For head and stem brassicas only; PHI 21d, REI 24, Bee: H, Group 3.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12h, Bee: L, Group 9C.

flupyradifurone (Sivanto): 7 to 12 oz/A; PHI 1d, REI 4h, Bee: L, Group 4D.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A soil; 1.3 oz/A foliar; PHI 21d soil, 7d foliar, REI 12h, Bee: H, Group 4A.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with companion labeled aphicide.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. For head and stem Brassicas only. Suppression only.

malathion (Malathion 57 EC): 1 to 2 pt/A for broccoli, Brussels sprouts, cauliflower, cabbage, kohlrabi; 1 to 1.6 pt/A for kale and mustard greens; 1.5 to 1.6 pt/A for collards; PHI 2d broccoli, Brussels sprouts, cauliflower; 7d cabbage, kale, collards, kohlrabi, mustard greens, REI 48h broccoli, Brussels sprouts, cabbage, cauliflower; 24h kohlrabi; 12h collards, kale, mustard greens, Bee: H, Group 1B.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pymetrozine (Fulfill): 2.75 oz/A; PHI 7d, REI 12h, Bee: L, Group 9A. Selective control of aphids including cabbage aphid. Translaminar.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spirotetramat (Movento): 4 to 5 oz/A; PHI 1d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 3d, REI 12h, Bee: H, Group 4C.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d leafy Brassica greens, 0d head and stem brassicas, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1d, REI 12 h, Bee: H, Group 21A.

Cabbage Looper (Trichoplusia ni), Diamondback Moth (Plutella xylostella) and Imported Cabbageworm (Pieris rapae)

Diamondback moth (DBM) and imported cabbageworm (ICW) are pests throughout the growing season, while cabbage looper (CL) generally does not become a pest until mid- to late-season.

Imported cabbageworm (ICW) is the offspring of the cabbage butterfly, a daytime flyer often visible in brassica fields. Wings are white, and the forewing has a dark border and 1-2 round black spots. Eggs, laid singly on leaves, are about 0.125 in. long, light green or yellow, and slightly elongated, standing upright. Imported cabbageworm caterpillars are gray-green with a thin yellow line down the back, slightly fuzzy, reach 1.25 in. long, and are sluggish when touched. Feeding and resting occur on the underside of leaves, and larvae feed more heavily in the center or head of cabbage or broccoli. Damage includes round or ragged feeding holes and deposits of wet, green or brownish frass. The overwintering stage is the chrysalis (pupa), which is green or brown, smooth, with 3 pointed ridges on its back. There are 3-4 generations per year with adults first appearing in May.

Cabbage looper (CL) does not overwinter in New England but arrives in migratory flights from farther south. Generally, numbers are not significant until late July or August. Adult moths are mottled gray-brown, 0.75 in. long, with a distinct, round, silver-white mark on the wing. Bucket-type pheromone traps can be used to monitor moth flight. Eggs are globe-shaped, light green or yellow, and laid underneath the foliage. Caterpillars are light green, with wavy, white or light yellow lines down the back and sides, reaching 1.5-2 in. when full grown. Cabbage loopers of any size move like inchworms by raising the middle of their body in a characteristic "loop" shape. Feeding damage from older larvae consists of ragged, large holes in foliage, on both frame leaves and heads.

Diamondback moth (DBM) adults are small (<0.5 in.), light brown with a yellow diamond-shaped marking, and rest with their wings folded together like a tent. Adult moths are active at dusk and during the night. Caterpillars reach a length of 3/4 in., are light green, and are segmented and pointed at both ends. When disturbed they wiggle vigorously and may drop off the plant on a string of silk. Feeding causes small, round holes and tends to be spread across the foliage rather than concentrated in the head.

Incorporate crop residues shortly after harvest to reduce movement to successive plantings and reduce overwintering populations. Populations are suppressed by a wide range of natural enemies and there are several selective materials that control caterpillars and have minimal non-target effects (e.g. Xentari, Dipel, Coragen, Intrepid). Parasitic wasps that attack caterpillars include Cotesia rubecula on ICW and Diadegma insulare on DBM; their small white cocoons may be found on leaves.

Scout fields by checking leaves (top and bottom) on 25 plants across the field. In the Northeast, there is generally no need to treat young plants unless weather conditions delay plant development and at least 35% of them are infested with any of these pests. Treat plants between the start of heading and harvest if 20% or more of the plants are infested. The most critical time to scout and apply chemical controls is just prior to head formation. Use a 10-15% threshold throughout the season for kale, collards, mustard, and other leafy greens.

Do not use less than 50 gal spray material/A; higher volumes provide better coverage. Better coverage of lower leaf surfaces can be achieved by using drop nozzles. Use a spreader-sticker. Use selective materials to spare beneficials that help control aphids and caterpillars. DBM has become resistant to many synthetic and microbial insecticides.  Even if you are getting excellent control of this pest with the materials presently being used, you should alternate between effective materials to retard development of resistance. Newer materials and the aizawai strain of Bacillus thuringiensis will usually provide better control of resistant DBM than older products. Use transplants grown in New England to avoid importing DBM that have already developed resistance to one or more classes of insecticides.

acephate (Orthene 97): 1 lb/A; PHI 14d, REI 24h, Bee: H, Group 1B. For Brussels sprouts and cauliflower only. DBM has developed resistance in some areas. 

acetamiprid (Assail 30SG): 4 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A. For suppression of DBM only.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A DBM and ICW, 3.2 to 3.8 oz/A looper; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group un.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups un & 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. Particularly effective against DBM. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A DBM & ICW, 0.5 to 1 lb/A looper; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. Particularly effective against DBM. For resistance management, may be rotated with Bt aizawai products (XenTari).

Beauveria bassiana (Mycotrol ESO): 16 to 32 oz/A; PHI 0d, REI 4h, Bee: L, Group UN. Use high rate for CL. May be used alone or tank mixed with Bacillus thuringiensis products. Takes 7 to 10 days after application to see control.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.4 oz/A for CL and ICW, 2.4 to 3.2 oz/A for DBM; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 3d broccoli, Brussels sprouts, cabbage, cauliflower and kohlrabi, 14d Chinese cabbage, collards, kale and mustard greens, REI 12h, Bee: H, Group 1A. DBM and ICW only.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 3d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through chemigation and as a foliar spray. Do not apply more than twice to any generation of DBM.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cryolite (Prokil Cryolite): 8 to 16 lb/A; PHI 7d, REI 12h, Bee: L, Group UN.

cyantraniliprole (Exirel): 10 to 17 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark):  6.75 to 13.5 oz/A for loopers, 5 to 10 oz/A for DBM and ICW; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4 h, Bee: H, Group 28.

emamectin benzoate (Proclaim*): 2.4 to 4.8 oz/A for DBM and ICW, 3.2 to 4.8 for CL; PHI 7d head and stem, 14d leafy brassicas, REI 12h, Bee: H, Group 6. Rotate to another product after 2 applications.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A for most species, 2.9 to 5.8 oz/A for ICW on broccoli, cabbage, cauliflower, and Chinese cabbage; PHI 3d broccoli, cabbage, cauliflower, Chinese cabbage, kohlrabi, 7d collards and mustard greens, REI 12h, Bee: H, Group 3A. Use high rate for mustard greens. Not for DBM. On kohlrabi, not for ICW.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A. For CL and ICW on head and stem brassicas only. May be combined with DiPel DF to control ICW and CL on head and stem brassicas only - see label for rates; PHI 7d, REI 24, Bee: H, Group 3

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A for looper and ICW, 1.02 to 1.54 oz/A DBM; PHI 1d, REI 24h, Bee: H, Group 3AHead and stem Brassicas only.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22. Use high rate for DBM. Add a wetting agent to improve spray coverage.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A for CL and ICW, 1.28 to 1.92 oz/A for DBM; PHI 1d, REI 24h, Bee: H, Group 3A. For head and stem Brassicas.

malathion (Malathion 57 EC): 1 to 2 pt/A for broccoli, Brussels sprouts, cauliflower, cabbage, kohlrabi, 1 to 1.6 pt/A for kale and mustard greens; 1.6 pt/A for collards; PHI 2d broccoli, Brussels sprouts, cauliflower, 7d cabbage, kale, collards, kohlrabi, mustard greens, REI 48h broccoli, Brussels sprouts, cabbage, cauliflower; 24h kohlrabi; 12h collards, kale, mustard greens, Bee: H, Group 1B. Not for DBM except on collards.

methomyl (Lannate* LV): 1.5 to 3 pt/A for CL and DBM, 0.75 to 3 pt/A for ICW on broccoli, cabbage, cauliflower, 1.5 to 3 pt/A for ICW on Brussels sprouts, collards, kale, mustard greens; PHI 1d cabbage, 3d broccoli, Brussels sprouts, cauliflower, 10d Chinese cabbage, collards, kale, mustard greens, REI 48h, Bee: H, Group 1A. Not for ICW or DBM on Chinese cabbage.

novaluron (Rimon 0.83EC): 6 to 12 oz/A; PHI 7d, REI 12h, Bee: L, Group 16B. Not labeled for collards, kale.

permethrin (Pounce* 25WP): 3.2 to 6.4 oz/A for Brussels sprouts, cauliflower, cavalo broccolo and kohlrabi, 3.2 to 12.8 oz/A for broccoli, Chinese broccoli, cabbage and Chinese cabbage; PHI 1d, REI 12h, Bee: H, Group 3A. Not for other Brassica crops.

methoxyfenozide (Intrepid 2F): 4 to 8 oz/A for ICW and CL; 12 to 16 oz/A for DBM; PHI 1d, REI 4h, Bee: L, Group 18. Suppression only for DBM.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Efficacy improves with the addition of an adjuvant.

spinosad (Entrust SCOG): 3 to 6 oz/A looper & ICW, 1.5 to 4 oz/A DBM; PHI 1d, REI 4h, Bee: M, Group 5. See label for resistance management restrictions for DBM.

tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Use low rate for early season applications to young, small plants. Use of an adjuvant is recommended. Not for DBM.

tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1 d, REI 12 h, Bee: H, Group 21A.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A for DBM, ICW, 3.4 to 4.3 for CL; PHI 1d, REI 12h, Bee: H, Group 3A.

Cabbage Maggot (Delia radicum)

Cabbage root maggot is a pest of all types of brassicas, but is particularly damaging in cabbage, broccoli, Chinese cabbage, radish, turnips, and rutabaga. The first flight in April and May damages early spring brassicas, and the third flight from mid-August into September primarily injures fall root crops. Flies overwinter as pupae near roots of fall brassica crops and weeds. Adult flies become active at about 288 growing degrees days (GDD, base temperature 40°F), which occurs 1-2 weeks after forsythia starts to bloom and when yellow rocket (winter cress, Barbarea vulgaris) blooms. Fifty percent emergence (peak flight) occurs at about 450 GDD (base 40°F). Adult flies are delicate, hump-backed, gray-brown flies with long legs, about 5-7 mm long. Small (1.1mm), white, bullet-shaped eggs are laid singly or in clumps in the top 1-3 inches of soil, near the stem. Wet areas with heavy or rich soil are attractive for egg-laying. Maggots are white with black mouth hooks, feed on roots, and grow to 8 mm. The oval, brown pupae are found close to the roots. There are 2 to 3 generations per year in New England. Root damage causes plants to wilt, turn yellow or purple, become stunted or delayed, or die. Early infestation and large pest populations increase plant losses. Eggs are killed by exposure to soil temperatures above 95°F for several days in a row, especially in dry soil. Often these conditions occur in late May or early June.

Incorporate and disk brassica crop residues after harvest to expose and kill pupae, especially in the fall. Rotate spring crops to fields that were not planted with brassicas the previous fall. Avoid spring applications of manure or compost, which increase attractiveness of the field for egg-laying.  Avoid wet fields or sections of the field. Protect spring crops with spunbonded row covers, and use covers only on rotated fields, or else the flies will emerge under the covers.  Place covers over the crop at the time of seeding or transplanting and seal the edges with soil. Time your seeding or transplanting to avoid exposing young plants to peak flight periods; delay spring crops until after peak flight and when soils warm up. 

Most labeled materials are labeled only for use pre-plant, at the time of planting or seeding—either in the seed furrow or as a transplant drench—or immediately after setting transplants.Use pre- or at-plant treatments only if damaging populations are expected, such as in fields with high organic matter or a history of infestations. Scout transplant trays before setting out plants in the field. Treat transplants if eggs are found, either in the tray, in transplant water, or as a post-plant drench, as labels allow. A pencil is a good tool to gently stir the soil at the base of the plant and look for eggs. Yellow sticky cards placed near brassicas capture adult flies, and along with GDD, are a good indicator of the onset of adult flight. Scout for eggs—in transplant trays and the field—as soon as flies are active. In the field, finding an average of 1egg per plant can indicate a damaging population. Again, control options are limited once plants are in the field, but scouting to understand infestation levels can help inform management decisions in future plantings. Resistance to organophosphate (group 1B) insecticides has been documented; rotate among chemical classes where possible to retard development of resistance. 

bifenthrin (Capture LFR): 3.4 to 6.8 oz/A; REI 12h, Bee: H, Group 3. Apply as a 5 to 7-inch T-band over the open seed furrow, or in-furrow with the seed.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 3d, REI 4h, Bee: L, Group 28. May only be applied as transplant water treatment to soil at planting. For suppression only.

cyantraniliprole (Verimark):  10 to 13.5  oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting.

diazinon (Diazinon* AG500): Pre-plant incorporation applications: 2 to 3 qt/A; transplant water drench applications: 4 to 8 oz/50 gal water; PHI 7d, REI 4 days, Bee: H, Group 1B. Broccoli, Brussels sprouts, cabbage, cauliflower only. Transplant water treatments may result in stand reduction due to plant stress at time of transplanting.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. For direct seeded crops, apply directly to base of plants and adjacent soil when crop has developed to the two true leaf stage, and make second application 2-3 weeks later. For transplanted crops, apply immediately after transplanting and make second application 2-3 weeks later. A third application may be needed under high cabbage root maggot pest pressure conditions, such as when there is a large amount of debris from a previous brassica crop or when adjacent brassica fields are being harvested. For optimum control, direct the spray in a narrow band at the base of the plants. Do not make more than three applications of Group 5 insecticides (spinetoram and spinosad) per crop cycle for cabbgage root maggot suppression. For brassica leafy vegetables only (e.g., broccoli, Brussels sprouts, cabbage, kale). Not for brassica roots (e.g., radish, turnip). 

spinosad (Entrust SCOG): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. For direct seeded crops, apply directly to base of plants and adjacent soil when crop has developed to the two true leaf stage, and make second application 2-3 weeks later. For transplanted crops, apply immediately after transplanting and make second application 2-3 weeks later. A third application may be needed under high cabbage root maggot pest pressure conditions, such as when there is a large amount of debris from a previous brassica crop or when adjacent brassica fields are being harvested. For optimum control, direct the spray in a narrow band at the base of the plants. Do not make more than three applications of Group 5 insecticides (spinetoram and spinosad) per crop cycle for cabbgage root maggot suppression. For brassica leafy vegetables only (e.g., broccoli, Brussels sprouts, cabbage, kale). Not for brassica roots (e.g., radish, turnip). 

tolfenpyrad (Torac): 21 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

Cabbage Whitefly (Aleyrodes proletella)

An emerging pest in the Northeast United States, cabbage whitefly originates from Europe and is a pest in many areas of the world. Adults are small (1.5 mm) with white wings, and can be distinguished from greenhouse and sweet potato whitefly by two gray blotches on each forewing. Eggs are laid in a half-moon or circular pattern on the undersides of leaves. Immature stages are flat and scale-like. Both adults and nymphs feed on plant sap. Large populations will reduce plant vigor and quality, and adults and nymphs deposit honeydew on leaf surfaces on which sooty mold grows. Cabbage whitefly feeds and reproduces on brassicas, as well as other crops and weeds such as alfalfa, fava bean and dandelion. Preferred hosts are kale and Brussels sprouts.  

beta-cyfluthrin (Baythroid* XL): 3.2 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. For suppression of adults only.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

chlothianidin (Belay): 3 to 4 fl oz/A; PHI 7d, REI 12 h, Bee: H, Group 4A. Suppression only.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, drip chemigation, or soil injection. Allow 1-3 days for material to be translocated into aerial portions of the plant. When populations are high, use a foliar control during this period.

dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil for heading brassicas, 2 to 3 oz/acre leafy; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip.

flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, 45d soil, REI 4h, Bee:L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A soil, 1.3 oz/A foliar, 0.44 oz/10,000 plants on seedling transplants in greenhouse; PHI 21d soil, PHI 0d foliar, REI 12h, Bee: H, Group 4A. Planthouse applications only provide short-term protection; an additional field application must be made within 2 weeks following transplanting to provide continuous protection.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with a companion labeled insecticide.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only. Head and stem brassicas only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9A. Suppression only. Apply when whiteflies first appear.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee:M, Group 3A.

pyriproxyfen (Knack): 8 to 10 fl oz/A; PHI 7d, REI 12 h, Bee: L, Group 7C. Insect growth regulator, only effective on immature stages.

thiamethoxam (Actara): 3.0 to 5.5 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used in an in-furrow, banded, drench, or drip irrigation application to the seedling root zone during or after transplanting operations.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 23. Most effective on immature stages.

Cross-striped Cabbageworm (Evergestis rimosalis)

Formerly restricted to areas south of New England, this insect is now a significant pest of brassicas in CT, RI and MA. It has 2 to 3 generations per year and is most abundant on late-season plantings. Unlike the other major caterpillar pests on brassicas, the cross-striped cabbageworm (CSC) lays its eggs in batches (3-25) rather than singly, so caterpillars emerge in clusters. Egg batches are yellow, flattened, overlapping like fish scales, and attached to the lower leaf surfaces. Larvae grow to 3/4 in. long in 2-3 weeks. The caterpillars are light bluish-grey on top and green underneath, with numerous black bands across their backs and a yellow stripe down each side. Pupation takes place in soil, near the surface. Caterpillars produce small holes in leaves until only veins remain, or target terminal buds and sprouts, or may burrow into heads. Plants with larvae present are often completely skeletonized, while adjacent plants may be left undamaged. Plow under debris after harvest and control wild mustard and Shepherd's purse to help reduce pest populations. Scout weekly for caterpillars and damage. Spray if 5% of the plants are infested with CSC. Use selective insecticides to preserve parasitic wasps.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 3d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through chemigation and as a foliar spray.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4 h, Bee: H, Group 28.

Chromobacterium subtsugae strain PRAA4-1 (Grandevo OG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

emamectin benzoate (Proclaim*): 2.4 to 4.8 oz/A; PHI 7d heading and stem, 14d leafy brassicas and turnip greens, REI 12h, Bee: H, Group 6. Rotate to another product after 2 applications.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24, Bee: H, Group 3. For head and stem brassicas only. May be combined at with Dipel DF for control of other caterpillars. See label for rates.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22. Add a wetting agent to improve spray coverage.

methoxyfenozide (Intrepid 2F): 8 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Use low rate for early season applications to young, small plants. Use of an adjuvant is recommended.

Cutworm

See cutworms in the Pepper and Outdoor Tomato sections for more information on the black and variegated cutworms.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

carbaryl (10% Sevin Granules): 20 lb/A; PHI 3d broccoli, Brussels sprouts, cabbage, cauliflower and kohlrabi, 14d Chinese cabbage, collards, kale, mustard greens, REI 12h, Bee: H, Group 1A. For broadcast treatment only. Use within 30 days of crop emergence or transplanting.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cryolite (Prokil Cryolite): 8 to 16 lb/A; PHI 7d, REI 12h, Bee:L, Group UN.

diazinon (Diazinon* AG500): 2 to 4 qt/A broadcast and incorporate before planting; REI 24h, Bee: H, Group 1B. For broccoli, Brussels sprouts, cabbage, collards, kale, mustard greens and cauliflower.

esfenvalerate (Asana*XL): 5.8 to 9.6 oz/A; PHI 3d, PHI 7d collards, REI 12h, Bee: H, Group 3A. For broccoli, cabbage, cauliflower, Chinese cabbage, collards only.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24, Bee: H, Group 3. For head and stem brassicas only.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Head and stem Brassicas only.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. For head and stem Brassicas only.

methomyl (Lannate* LV): 1.5 pt/A; PHI 1d cabbage, 3d Brussels sprouts and cauliflower, 10d collards, REI 48h, Bee: H, Group 1A. For variegated cutworm only.

methoxyfenozide (Intrepid 2F): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Suppression only.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Cabbage and Chinese cabbage only.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft; PHI 1d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Flea Beetles (Phyllotreta cruciferae and P. striolata)

In New England, two species are found on brassicas: the crucifer flea beetle (Phyllotreta cruciferae), which is uniformly black and shiny, about 2 mm in length; and the striped flea beetle (P. striolata), which is black with 2 yellow stripes on its back. These two species feed only on brassicas, and attack all types of brassica crops and weeds.  Populations have increased over the past twenty-five years, so that on many farms flea beetle is a key pest of brassicas. Adult beetles overwinter outside cropped fields, in the soil surface and decaying plant residue of shrubby or woody borders. They search out host crops from early May into June and feed on leaves and stems, leaving small round pits and holes. Beetles hop quickly off the plant when disturbed. Eggs are laid in soil near the plant. Tiny white larvae feed on root hairs and pupate underground. New adults emerge from mid-July through early August and feed throughout August. Spring crops are damaged by over-wintered adults, while fall crops are damaged by summer adults, but it may be difficult to distinguish the generations when pressure is severe. Feeding generally declines in September, as adults leave fields for overwintering. There may be a small second generation of adults, which emerges in late September. Heavy feeding can kill seedlings, and moderate damage can stunt growth, delay maturity, reduce yield, and make crops unmarketable. Crops with more waxy leaves (Brassica oleracea such as cabbage, broccoli, and kale) are less attractive and feeding is more restricted to leaf margins, especially as crop matures. Crops with glossy leaves (e.g. B. rapa such bok choy, Napa cabbage, or B. juncea such as mustard) are highly attractive; the whole leaf is damaged and the crop is susceptible until harvest.

Escape peak adult activity and avoid the buildup of high populations by rotating spring crops as far as possible from last season's fall brassica crops, and planting late-season crops far from early brassicas. Where feasible, avoiding all early brassicas (until July) can be used to break the reproductive cycle. Incorporate and till crops immediately after harvest to expose and kill larvae and pupae. Provide adequate water and nutrients for crop growth. Avoid soil compaction. Floating row covers provide excellent protection of the crop if well secured with soil or bags around all edges immediately after seeding or transplanting. Remove and replace the same day for cultivation, as needed. Use attractive brassica types (B. rapa or B. juncea) on borders or within the field as a trap crop to draw beetles from less attractive types. Spray the trap crop to suppress beetles in the whole field, and to protect the trap crop for harvest. Scout across the field by counting beetles from above, then under the leaves, and estimating % leaf damage. Because brassica crops differ greatly in susceptibility and attractiveness there is no fixed economic threshold that applies to all crops and crop stages. A working threshold of 1 beetle per plant or >10% average leaf damage on 50% of the plants has proved effective in leafy greens and early stages of heading brassicas. Repeated applications may be needed if pressure is high.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

beta-cyfluthrin (Baythroid* XL): 2.4 to 3.2 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 3d cabbage, cauliflower, broccoli, Brussel sprouts, kohlrabi, 14d kale, collards, Chinese cabbage, mustard, REI 12h, Bee: H, Group 1A.

cryolite (Prokil Cryolite): 8 to 16 lb/A; PHI 7d, REI 12h, Bee: L, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark):  6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting.

cyclaniliprole (Harvanta): 16.4 fl oz/A; PHI 1d, REI 4 h, Bee: H, Group 28.

dinotefuran (Venom): 1 to 4 oz/A for foliar application to head and stem brassicas, 2 to 3 oz/A for foliar application to leafy brassicas; PHI 1d, REI 12h, Bee: H, Group 4A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, 7d collards, REI 12h, Bee: H, Group 3A. For broccoli, cabbage, cauliflower, Chinese cabbage, collards only.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24, Bee: H, Group 3. For head and stem brassicas only. Do not apply during bloom or if bees are actively foraging.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Head and stem brassicas only.

imidacloprid (Admire Pro): 1.3 oz/A; PHI 7d foliar, REI 12h, Bee: H, Group 4A. Foliar applications only.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression and repellence only. May be applied to transplants prior to setting in field. Use on seedlings and young plants. White residue is difficult to wash off leaves and heads; use only on very young leaves or leaves that will not be harvested.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. For head and stem brassicas.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Cabbage and Chinese cabbage only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. For beetle larvae only. 

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Suppression only.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d leafy brassica greens, PHI 0d head and stem brassicas, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Onion Thrips (Thrips tabaci)

Onion thrips can be a significant problem on cabbage, where thrips feed on inner leaves of the head which are difficult to target by spraying. Damage may also occur on leafy brassicas such as broccoli, kale and collard, especially fall crops that are planted near a maturing onion crop.  Thrips cause rough, golden or brown scars to form on the underside of open leaves, or produce scars and discolored layers within cabbage heads. Inspection with a 10X lens shows wounds to the epidermis from the rasping mouthparts, and scars from wounds that healed over.  Thrips damage can be confused with oedema, a physiological disorder. See onion thrips in the Onion section for more information on identification, life cycle and management.  Damage is most severe in hot, dry weather.

Tolerant varieties are the most cost-effective means of controlling thrips in cabbage. Varietal resistance is generally not available in other brassicas. Consult your seed suppliers and search recent research trials regarding thrips tolerance on new varieties.

Avoid thrips by not planting cabbage or fall brassica crops near alliums (onion family), or field crops such as alfalfa, clover, wheat, or oat that can harbor large populations of thrips, which may migrate to brassicas when these crops are cut or harvested. Scout young plants for presence and feeding injury. Begin applications when damage is first noticed; in cabbage, apply foliar treatments before heads form. In fall brassicas, the need for thrips controls may coincide with sprays for flea beetle or caterpillars and some insecticides control both.  Repeat applications at 7- to 10-day intervals based on scouting. Use a shorter interval in hot, dry weather. Use spreader-sticker for better coverage. Apply in early evening, using high pressure and 100 gal water/A for best results. Systemic insecticides applied as a side dress up to 4-6 weeks after transplanting may provide adequate control in long-season cabbage. Rotate between insecticide groups to help prevent or delay resistance.

acetamiprid (Assail 30SG): 4 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.  Applications during the "cupping" stage of cabbage may be especially helpful in preventing injury.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group un.

Beauveria bassiana (Mycotrol ESO): 8 to 32 oz/A; PHI 0d, REI 4h, Bee: L, Group UN. Thoroughly cover foliage. Takes 7 to 10 days after application to see control.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Suppression only.

cyantraniliprole (Verimark):  6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. Suppression only.

dinotefuran (Safari 20SG): 0.16 to 0.32 dry oz/1,000 sq ft or 7 to 14 oz/A; REI 12h, Bee: H, Group 4A. Broccoli, Brussels sprouts, cabbage, cauliflower and kohlrabi transplants only while in greenhouse. Not for field use. Suppression only.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only. Head and stem Brassicas only.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A; PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil applications only.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with companion labeled inseccticide.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. For head and stem brassicas. Suppression only.

novaluron (Rimon 0.83EC): 12 oz/A; PHI 7d, REI 12h, Bee: L, Group 16B. For head and stem brassicas.

permethrin (Pounce* 25WP): 3.2 to 6.4 oz/A for brussels sprouts, cauliflower, cavalo broccoli, kohlrabi; 3.2 to 12.8 oz/A for broccoli, Chinese broccoli; PHI 1d, REI 12h, Bee: H, Group 3A. Not for other brassicas.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Efficacy improves with the addition of an adjuvant.

spinosad (Entrust SCOG): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Efficacy improves with the addition of an adjuvant.

sulfoxaflor (Closer SC): 5.75 oz/A; PHI 3d, REI 12h, Bee: H, Group 4C. Suppression only.

thiamethoxam (Actara): 3 to 5.5 oz/A; PHI 7d leafy brassica greens, 0d head and stem brassicas, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

zeta-cypermethrin (Mustang*): 3.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Slugs

There are several species of slugs that damage vegetable crops in New England, including grey garden, banded, marsh and spotted garden slugs.  They may be dark gray, black, yellow or brown, covered with spots, and range from ¾ to nearly 4" long. Eggs may be laid several times per year, and slugs reach maturity in 3-6 months. They can become abundant in low- and no-till situations, in land that was recently fallow, along hedgerows, or wherever plant debris, mulches, stones or boards provide cover and daytime hiding places. Slugs usually feed at night but may also feed during the day during prolonged periods of cloudy wet weather. They are attracted to succulent leaves in moist environments, such as cabbage, pak choi, and Chinese cabbage. They will also feed on fruiting crops such as tomato, pepper and eggplant. Damage appears as shredded foliage or shallow fruit holes. They have a rasp-like tongue that wears a hole through the leaf instead of making a clean cut like a caterpillar or beetle. On some thick-leaved brassicas such as cabbage, the hole will appear larger on one leaf surface and taper to a smaller hole in the opposite surface.  Scout by looking for silvery slime trails on leaves or turn over soil clods or debris to find slugs during daylight hours, or scout plants after dusk. Slug populations can also be monitored with unbaited traps consisting of 6 in. deep holes covered with foil-covered shingles, which provide a cool hiding place during the day. To control slugs use habitat and cultural management supplemented by handpicking or trapping (on a small scale), repellents and toxic baits.  Grow plants away from moist, shaded habitats, use clean cultivation, control weeds, and eliminate hiding places.  Use trickle irrigation instead of overhead to reduce humidity and moist surfaces. On a small scale, handpick slugs after dusk using gloves and drop slugs in soapy water; repeat for several days. Baits should be applied to the ground near infested plants. It may be necessary to reapply after a rain, or make multiple applications when populations are high.

iron phosphate (Sluggo: Snail and Slug BaitOG): 20 to 44 lb/A; PHI 0d, REI 0h, Bee: L, Group 9B. Apply around perimeter, scatter around base of plants, or band down rows. Apply to moist soil in the evening.

metaldehyde (Deadline Bullets): 20 to 40 lb/A; REI 12h, Bee: L. Soil surface treatment broadcast pre-planting, or band treatment between rows after formation of edible parts. Apply to moist soil in the evening. Do not apply directly to or contaminate edible portions of plants.

Swede Midge (Contarinia nasturtii)

A serious pest of crucifers in Europe. Recently introduced into North America, currently established in northwestern Vermont, with range expanding southward and eastward. Adults are tiny (1/16 in.), weak-flying, brown flies, while larvae are translucent maggots when small and turn yellow as they grow to 1/8 inch. They spend the winter as pupae in the top 2 in. of soil. Maggots infest the tissue near the growing tip and produce malformed plants with brown corky tissue, galls, no-heads, multi-heads, and twisted leaf petioles. Damage is most severe on broccoli, Chinese broccoli, Brussels sprouts, cauliflower and brassica greens. There may be 3-4 generations each year. Scout young plants near field borders and tree lines prior to heading or at the pre-cupping stage. Avoid importing infested plants by using New England-grown transplants. Use a 3-year crop rotation. Plant spring brassicas at least 1/2 mile from fall brassica fields. Deep plowing destroys pupae. Spring plantings may avoid peak populations later in the season. If possible, plant away from tree lines that shelter weak-flying adults. Report and confirm infestations to a state IPM specialist or to the diagnostic lab.

acetamiprid (Assail 30SG): 4 oz/A; PHI 7d, REI 12h, Bee: H, Group 4.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN. Suppression only.

spirotetramat (Movento): 4 to 5 oz/A; PHI 1d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107) for information on the use of these herbicides.

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Broccoli, cabbage, and cauliflower only. Use 2 – 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): REI 12h, Group 0.  Apply 5 to 6 qt/A.  Can be preplant incorporated by shallow cultivation (1-2”) or applied preemergence and incorporated by irrigation within 36 hours of application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

DCPA (Dacthal W-75): REI 12h, Group 3.  Apply 6 to 14 lb/A at seeding or transplanting. Can be sprayed over transplants without injury. For collards, kale, broccoli raab and other leafy crops apply at seeding.  Will not control ragweed, galinsoga or smartweed. Use lower rates on sandy soils.

napropamide (Devrinol 2-XT): REI 12h, Group 0. Apply up to 2 qt/A to a weed-free surface. A higher rate is permitted for use on broccoli in Maine only.  See label for details.  May be applied to direct seeded and transplanted crop as preplant incorporated or as a surface spray after planting. Must be shallow incorporate or incorporated thoroughly with irrigation if adequate rainfall does not occur within 24 hours of application (sufficient water to wet soil to a depth of 2" to 4").

oxyfluorfen (Goal): REI 24h, Group 14.  Pre-transplant application only to broccoli, cabbage, and cauliflower.  Apply 1 to 2 pt/A after completion of soil preparation but prior to transplanting. Do not incorporate. May cause temporary crop injury, and can cause severe crop injury if not applied properly. Read product label carefully before applying. 

pendimethalin (Prowl H2O): PHI 60d for broccoli, PHI 70d for all others, REI 24h, Group 3.  Use as a postemergence-directed spray on the soil beneath plants and between vegetative rows of brassica head and stem vegetables. Apply a single application of up to 2.1 pt/A.  For transplants, apply when crop is at the 2 to 4-leaf stage 1 to 3 days after transplanting.  For direct-seeded crops, apply when crop is at the 2 to 4-leaf stage.  Apply DO NOT spray foliage or stems because crop injury will occur. If rainfall or irrigation does not occur, mechanically incorporate to activate the herbicide. Apply before weed germination. Emerged weeds will not be controlled.

s-metolachlor (Dual Magnum): REI 12h, Group 15.  MASSACHUSETTS AND NEW HAMPSHIRE: Broccoli, cabbage, and leafy brassica greens only.  MAINE: cabbage only. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge.

trifluralin (Treflan HFP): REI 12h, Group 3. Incorporate 1 to 1.5 pt/A before seeding crops, or 1 to 2 pt/A before transplanting (broccoli, brussels sprouts, cabbage, and cauliflower). For greens (collard, kale, mustard and turnip), can be used before seeding only. Select rate based on soil texture, see label for details.  Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation.Little or no control of ragweed, galinsoga, mustard or nutsedge.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 30d, PHI 14d for leafy brassica greens, REI 24h, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

clopyralid (Stinger): PHI 30d, REI 12h, Group 4. Apply 1/4 to ½ pt/A for postemergence control of common ragweed, galinsoga, prickly lettuce, sweet clover, and wild buckwheat and suppression of sowthistle. Stinger is very effective on small seedling annual and emerging perennial weeds less than 2" to 4" tall, but is less effective and takes longer to work when weeds are larger. Spray additives are not needed or required by the label and are not recommended. Stinger is a postemergence herbicide with some soil residual activity. See label for crop rotation restrictions, or injury may occur from herbicide carryover. Make 1 to 2 applications a year, but do not exceed 1/2 pt/A per year.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d, PHI 14d for leafy brassica greens, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 3 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

 

Note About Other Labeled Herbicides: Other products are labeled for use in asparagus but limited local data are available for these and/or they are not recommended in our region due to potential crop injury concerns. These include clomazone (Command 3ME) and sulfentrazone (Zeus and others).

 

Physiological Disorders

Buttoning and Lack of Heads (Broccoli and Cauliflower)

Buttoning refers to premature formation of broccoli or cauliflower heads; these premature heads never size up. Buttoning is most common when transplants are too old and past the juvenile growth stage when transplanted. Other stress factors such as low fertility, low moisture micronutrient deficiencies, or disease and insects can also be causes. Strong healthy plants lacking heads can occur due to periods of extremely warm weather (days over 86º F and nights over 77º F).

Bracts (Leaves) in Cauliflower or Broccoli Heads

High temperatures or low soil moisture can result in the formation of bracts, small leaves, between segments in the heads of cauliflower and broccoli. Choose heat-tolerant varieties to avoid bract formation in heads.

Head Rot and Brown Beading (Broccoli)

Both problems can be caused by several factors. Reduced calcium uptake due to low transpiration rates under extended wet or dry conditions during warm temperatures, combined with rapid growth can result in either condition, even when soil calcium levels are high. Head rot results from bacteria breaking down the tissues under wet conditions, and brown beading results from individual flower buds aborting under dry conditions. Mixing varieties based on rate of maturity offers growers the only practical defense against either head rot or brown beading; selecting a later-maturing variety to be harvested along with your typical variety during those parts of the growing season when problems have typically occurred can reduce the risk of whole-crop losses during challenging weather conditions.

Oedema of Cabbage

Oedema is a physiological response of the plant to excessive soil moisture during periods of cool nights and warm, humid days. Many small scabby lesions form on the underside of the cabbage leaves. Avoid irrigation during times when day-night temperature variations are great. Oedema may be confused with thrips damage.

Ricing or Fuzziness of Heads (Cauliflower)

The development of cauliflower curds that appear fuzzy is called ricing. Ricing can be caused by exposure of the developing curds to high temperatures or direct exposure to sun, rapid growth after head formation, high humidity, and high nitrogen fertility.

Tipburn

Tipburn is a result of localized calcium deficiency in leaf tips, which can occur due to irregular soil moisture content or low plant transpiration rates even when soil calcium levels are high. Providing consistent irrigation and taking measures to prevent root-compromising disease can help reduce incidence of tipburn.

Yellow or Brown Beads in Broccoli Heads

Yellowing of florets may be due to an over mature head, high storage temperatures after harvest, or exposure to ethylene. Brown beads in broccoli are areas where florets do not properly develop and die. Possible causes include nutritional imbalances, or feeding damage by insects such as harlequin bugs or tarnished plant bugs.

Carrot and Parsnip

Introduction

Carrot (Daucus carota) and parsnip (Pastinaca sativa) both belong to the Umbelliferae (Apiaceae) family, along with several other crops including celery, fennel, dill, cilantro, and parsley. Best production of these root crops is obtained from deep, well-drained sandy loam soils. Raised beds tend to increase the depth of tilled soil and can help provide good root shape. Some growers chisel plow before forming beds to loosen the soil and enhance root development. Do not destroy soil structure by overworking soils or working them while wet. Some growers rototill to obtain a deep, friable soil. Hilling soil over the shoulders of the roots at the last cultivation can help reduce greening.

Types and Varieties

Carrot and Parsnip Varieties
Roadside Market Carrot Specialty Carrot
Bolero - nantes/imperator, A, C Yellowstone - yellow
Mokum - nantes, A White Satin - white
Ya Ya - nantes, A Purple Haze - purple
Napoli - nantes Rainbow - assorted colors
  Atlas - small round parisian type
Wholesale Market Carrot  
Maverick - imperator, A Parsnip 
Sugar Snax 54 - imperator, A, C Harris Model
  Javelin
  Albion
Resistant or tolerant to: A: Alternaria, C: Cercospora

Soil Fertility

Apply lime according to soil test recommendation to maintain soil pH at 6.5-6.8. Calcium levels should be maintained at a high level to avoid cavity spot. Calcium should be 60%-85% base saturation.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7). Application of high amounts of nitrogen to parsnips can cause excessive top growth, increasing their susceptibility to diseases. Using urea as a source of nitrogen for sidedressing may increase the incidence of cavity spot. Fresh manure or urea as nitrogen source can result in branched roots. Manure may also create a food safety issue, so plan on at least 120 days between application of manure and harvest. If large amounts of potassium are needed or if soils are highly leachable, some of the potassium can be applied with the first nitrogen sidedressing application. Carrots and parsnips have relatively high requirements for potassium, but excessive applications can inhibit calcium uptake and thus increase the incidence of cavity spot. 

Suggested rates of nitrogen, phosphorus and potassium are based on high yield expectations of 20-25 tons per acre for carrots. If soil type or other factors limit potential to a lower yield, reduce fertilizer application accordingly.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR CARROT AND PARSNIPS
CARROT AND PARSNIPS NITROGEN (N)* LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 50 150 100 50 0 300 200 75-100 0
Sidedress 4-6 weeks after planting 30-50 0 0 0 0 0 0 0 0
Sidedress when Roots are 1/2" in Diameter* 30-50 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 110-150 150 100 50 0 300 200 75-100 0
* IF EXPECTED YIELDS WILL BE LESS THAN 20 TONS/A, THE SECOND SIDEDRESSING CAN BE OMITTED.

Planting

Carrots should be planted to a stand of 15 plants per foot of row, which requires 2-3 lb of seed/A (about 0.0625 oz per 100 feet of single row). Parsnips should be planted to a stand at 8-10 plants per foot of  row, which requires 4-5 lb of seed/A (about 0.5 oz per 100 feet of single row). Parsnip seeds have a short life and lose viability quickly during storage; parsnip seeds should be purchased new each year.

Sow 0.5-0.75 in. deep with row spacing 12-18 in. with 3 or 4 rows per bed. Seeds should be scattered uniformly in a 3-4 in. band when seeding with non-precision seeders. A more uniform stand may be obtained using pelleted seed and precision seeders to seed in bands of 3 rows, 1.5 in. apart.

These crops are slow to germinate; an adequate and constant moisture supply is necessary during this period. Parsnips require a long growing season (110-130 days) and should be seeded as early in the spring as practical. 

Harvest and Storage

Carrots and parsnips must be topped before storage. Mature roots can be kept in good condition for 4-5 months at temperatures near 32°F if not allowed to freeze. Avoid relative humidity higher than 95%, which cause condensation and dripping. Carrots that are not fully mature can be stored only 4-6 weeks. Parsnips should not be harvested until fully mature for good quality. Parsnips can be left in the ground over winter but should be harvested before growth starts in the spring (this is risky because poor spring weather may prevent timely harvesting). Do not store these crops in a building with apples, pears or other ethylene-producing fruits since bitterness can result.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Leaf Blight (Cercospora, Septoria, or Alternaria)

Use certified, disease-free seed or treat seed with hot water or fungicides. Rotate fields. Irrigate early in the day to allow foliage to dry quickly. Use wider plant spacing and/or raised beds to improve air circulation. Plant resistant or tolerant varieties where available. Apply fungicides based upon a disease forecasting system.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 pt/A; PHI 0d, REI 12h, Groups 11 & M 05. See label for tank mix precautions. Not labeled for parsnip.

azoxystrobin plus propiconazole (Quilt): 14.0 fl oz/A; PHI 14d, REI 12h, Groups 11 & 3. Not labeled for parsnip.

boscalid (Endura): 4.5 oz/A; PHI 0d, REI 12h, Group 7. For Alternaria only. Do not make more than two applications per season. 

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Groups 3 & 9. Not labeled for parsnip.

chlorothalonil (Bravo Weather Stik): 1.5 to 2.0 pt/A; PHI 0d (carrot), 10d (parsnip), REI 12h, Group M 05.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M 01. Do not apply in a spray solution having a pH of less than 6.5 or tank mix with Aliette. Not labeled for parsnip.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. For Alternaria only. 

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 12h, Group 29. For Alternaria on carrot only. 

fluxapyroxad plus pyraclostrobin (Merivon): 4.0 to 5.5 fl oz/A; PHI 7d, REI 12h, Groups 7 & 11. 

iprodione (Rovral 4F): 1.0 to 2.0 pt/A; PHI 0d, REI 24h, Group 2. For Alternaria on carrot only. 

penthiopyrad (Fontelis): 16.0 to 30.0 fl oz/A; PHI 0d, REI 12h, Group 7.

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Pseudomonas chloraphis (HowlerOM): 2.5 to 7.5 lbs/A; PHI 0d, REI 4h, Group BM 02. Use preventatively. 

propiconazole (Tilt): 4.0 fl oz/A; PHI 14d, REI 24h, Group 3.

pydiflumetofen plus fludioxonil (Miravis Prime): 6.8 fl oz/A; PHI 7d, REI 12h, Groups 7 & 12. 

pyraclostrobin plus boscalid (Pristine): 8.0 to 10.5 oz/A; PHI 0d, REI 12h, Groups 11 & 7. Do not alternate with other Group 11 fungicides.

Swinglea glutinosa extract (EcoSwingOM): 1.5 to 2.0 pt/A; PHI 0d, REI 4h, Group BM 01. Use preventatively.

trifloxystrobin (Flint): 2.0 to 3.0 oz/A; PHI 7d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

Crater Rot (Rhizoctonia carotae)

Crater rot caused by Rhizoctonia carotae is a post-harvest disease of carrot that results from prolonged cold storage (greater than 30 days). The pathogen is soilborne and initial infection occurs before harvest. Late harvested carrots may have higher amounts of infection. The fungus then develops in cold storage (4-6°C), especially when there is a film of moisture or very high humidity. Under high disease pressure, carrots can be dipped in fungicides or inorganic salts prior to storage. Washing carrots in water can also reduce inoculum clinging to root surfaces. Disinfestation of crates and other equipment minimizes disease development. Proper cold storage that avoids temperature fluctuations and condensation reduce disease and prevent dehydration. Removal of carrots from cold storage early can prevent losses.

Parsnip Blight (Pseudomonas marginalis)

Causes browning through the interior of the root. Practice at least a 2-year rotation.

Root and Crown Rot (Rhizoctonia solani)

The pathogen has a wide host range making crop rotation as a disease management tactic unsuccessful. Problems with this disease are more severe in organic soils and whenever undecomposed crop residue is present. Avoid crops such as alfalfa and legume cover crops which can increase disease risk. Wide spacing, weed control, and clean cultivation help reduce field infection by allowing soil to dry quickly. Avoid harvesting late in the season. Maintain storage conditions at 50°F.

azoxystrobin (Quadris): See label for in-furrow and drench rates; PHI 0d, REI 4h, Group 11.

Bacillus amyloliquefaciens F727 (StargusOG): 2.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM 02. Apply preventatively in a minimum of 50.0 gallons of water/A.

Trichoderma asperellum, T. gamsii (Bio-tamOG): See label for in-furrow, drench, and broadcast rates; REI 4h, Group BM 02.

Sore Head (Itersonilia perplexans)

Occurs on parsnip only. Plant on raised beds in well-drained soil. The variety Model is somewhat resistant. Rotate parsnip with non-susceptible hosts and control wild Apiaceae plant hosts. Start with certified, disease-free seed. Protect roots by covering crowns and exposed upper roots with soil. Deep plow plant residue to reduce soilborne inoculum. Rarely occurs on young plants. Monitor fields near maturity and harvest affected fields early. Fungicide sprays are not effective.

White Mold (Sclerotinia sclerotiorum)

Handle carrots carefully at harvest and washing.  Use chlorine and change wash water frequently to reduce spread of pathogens. Clean and disinfect storage containers and harvesting equipment between batches. Cool carrots quickly to remove field heat. Inspect and dispose of infested carrots. Maintain storage and shipping temperatures of 32°F and 95% relative humidity.

penthiopyrad (Fontelis): 16.0 to 30.0 fl oz/A; PHI 0d, REI 12h, Group 7.

thiabendazole (Mertect 340F): 41.0 fl oz/100 gal; REI 12h, Group 1. Dip carrots before storage. 

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 12h, Group 29.

Ulocladium oudemansii (BotryStopOG): 2.0 to 4.0 lbs/A; REI 4h, Group BM 02. Begin application when conditions are conductive to disease development. 

Aster Yellows

Remove inoculum sources by controlling weeds (alternate hosts). Avoid fields near pastures or river banks that harbor susceptible vegetation. Destroy residues from susceptible crops immediately after harvest. Control the six-spotted leafhopper that carries the mycoplasma (see Carrot and Parsnip, Insect Control).

Root-Knot Nematode (Meloidogyne sp.)

Low densities of root knot nematodes before planting means susceptible crops will suffer damage. Monitor soils for nematode populations. Rotate with non-hosts such as cereals. Practice soil solarization or field fumigation in the fall. See Soil Fumigation Outdoors, page 89.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aster Leafhopper (Macrosteles quadralineatis)

Aster leafhopper is currently a minor pest in New England, but a major pest in the Midwest.  Although it inflicts very little direct feeding injury to carrots or parsnips, it is important because it vectors aster yellows, a mycoplasma-like pathogen which causes distortion and discoloration of leaves as well as stunted, hairy and bitter roots in both carrot and parsnip. Lettuce, celery, celeriac, parsley, corn and potato are also susceptible. Aster leafhoppers also feed in cereal grains, especially oats, wheat and barley, clover and various weeds. The adults are small, less than 4 mm, light green with grey wings, and have 6 pairs of black spots on the top and front of the head. Among vegetables, lettuce is the primary crop that is suitable for leafhopper reproduction.  Eggs are laid in plant tissues, and the yellowish nymphs feed and develop into adults in 3-4 weeks. There are 3 generations per year in northern states. Aster leafhoppers migrate north annually from the southern US, and can arrive as early as May, sometimes already infected with the aster yellows pathogen.  In northern states, they can also overwinter in the egg stage, on weeds or winter grains.

Unlike many insect-vectored viruses, transmission of the aster yellows mycoplasma is ‘persistent’. This means that to become infected with aster yellows, adults or nymphs must feed for at least 2 hours on an infected host, which could be a crop in a southern state prior to migration, or a local crop or weed. Weeds that may be infected include thistle, fleabane, wild lettuce, sow thistle, chicory, wild carrot, galinsoga, dandelion, plantain, and cinquefoil.  There is an incubation period of 2-3 weeks inside the leafhopper; thereafter it is able to transmit the pathogen for the duration of its life.  Transmission from the leafhopper to a non-infected plant also requires at least 2 hours of feeding. It takes 10-15 days for infected plants to show symptoms.

If aster yellows disease becomes a problem on your farm, plant tolerant or resistant varieties, which are available for carrot and lettuce. Control weed hosts and avoid growing susceptible crops in fields close to winter grains. Reflective or light-colored straw mulch effectively reduces aster yellows infection, and row cover prevents infection by keeping out leafhoppers. Cool, wet weather limits leafhopper activity and disease transmission. Monitor nearby grain fields or carrot crops in July and August using sweep nets. Thresholds widely used in the Midwest are based on the aster yellows index, which is the product of the percent infection of the leafhopper population (determined by testing) and the number of leafhoppers per 100 sweeps. At 2% infection, the threshold in carrots is 25 leafhoppers per 100 sweeps in susceptible varieties, and 37/100 in tolerant varieties. In the absence of actual test results for % infection, assume 2%. It is important to control leafhoppers before infection takes place. Because several hours of feeding are required for the aster leafhopper to transmit aster yellows to a plant, disease suppression can be achieved by killing the vector before inoculation occurs.

alpha-cypermethrin (Fastac* EC): 1.8 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

beta-cyfluthrin (Baythroid*XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 7d, REI 12h, Bee: H, Group 1A.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Carrot only.

flupyradifurone (Sivanto): 7 to 10.5 oz/A; PHI 7d, REI 4h, Bee: L, Group 4D.

imidacloprid (Admire Pro): 0.3 to 0.7 oz/1,000 row ft or 4.4 to 10.5 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression and repellence only.

malathion (Malathion 57 EC): 2 pt/A; PHI 7d, REI 24h, Bee: H, Group 1B. Carrots only.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. Carrot only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

sulfoxaflor (Transform WG): 1.5 to 2.75 oz/A; PHI 7d, REI 24h, Bees: H, Group 4C.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 12 oz/A; REI 12h, Bee: H, Group 4A. Systemic insecticide used at seeding or within 24 h of seeding as an in-furrow or narrow surface band with sufficient water for incorporation, or in drip irrigation.

zeta-cypermethrin (Mustang*): 1.9 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Carrot Rust Fly (Psila rosae)

Carrot rust fly feeds on many umbelliferous crops and weeds. Though it is considered principally a pest of carrots, it can also damage parsnips, celery, celeriac, parsley and dill. Adults are slender flies, 4-5 mm long, with slightly iridescent wings, yellowish-brown head and legs, dark red eyes, and shiny black thorax and abdomen. Adult flies enter fields to oviposit and return to field edges on a daily basis. Clusters of 1-3 eggs are laid in the soil near the base of food plants. Larvae are milky-white to yellowish, without legs, tapered at the head with dark mouth hooks, and 6-9 mm when full grown. Root feeding of hatching larvae may kill young plants or cause forked, stunted or fibrous roots. Larvae burrow into the main root as they grow larger, then leave the root to form an oval brown pupa up to 10 cm deep in the soil. Sometimes larvae overwinter in fall carrot roots, but mainly pupa overwinter in the soil, and adults emerge in May and June. Cool, moist conditions favor adult emergence. Early season carrots are susceptible to attack by this first flight, especially the earliest successions, as flies tend to select larger carrots to lay eggs. The summer generation of adult flies emerges in August and is active through September, causing damage to late or long-season carrots. Fall damage may increase in later harvests. The larva mines the surface of the root, leaving trails and blotchy areas that develop a rusty color and render the root unmarketable.  Wounds provide entry to plant pathogens. The foliage may become red or yellow.  In carrot, the larval mines are mostly in the lower portion of the root, but in parsnip, they are in the upper portion.  In celery, the larva may tunnel upward into the crown and stalks. Damage is often worst near sheltered field edges, with damage decreasing toward the center of the field.

Avoid leaving crops in the field over the winter, where they support overwintering larvae or attract spring egg-laying. Because adults are weak flyers and are limited to one crop family, crop rotation to a separate field is effective. If possible, plant carrots in open fields where wind protects them from adult flights. The crop is most vulnerable around the edge of sheltered fields surrounded by woods. Row covers protect the crop from egg-laying. Intercropping with onion has been shown to reduce damage by carrot rust fly. Some varieties show partial resistance to rust fly. Stagger plantings to distribute risk, or if possible, time plantings to avoid the first and second flight periods. In the fall, harvest edges first, as these may have the most damage. Monitor flight with yellow sticky traps placed upright on a stake just above the canopy and several feet into the field; count flies twice weekly. Use multiple traps per field, especially along field edges that are sheltered from wind. Traps reflect population levels and indicate the beginning, peak and end of flight periods, and are used to time insecticides or determine when it is safe to remove row cover. In Quebec and Ontario, insecticides are recommended at thresholds of 0.1-0.2 flies per trap per day, although there are currently no available registered products in New England. Where active periods coincide, sprays for carrot weevil may help control carrot rust fly.

Carrot Weevil (Listronotus oregonensis)

Carrot weevil attacks crops and weeds in the Umbelliferacae family, and can cause severe damage to parsley, dill, carrot, celery and parsnip. Adult beetles are brown, less than 6 mm long, with the typical weevil ‘snout-like’ mouthparts. They overwinter in soil or plant debris near previous host crops. Although able to fly, they travel and invade fields mostly by walking. In spring, females lay eggs into holes that they gouge in petioles or tops of roots, but only oviposit in plants that are older than 4 leaf stage.  Egg-laying starts at 234 growing degree days (GDD), using a base temperature of 44.6°F. Young larvae tunnel in stalks or roots and may kill young plants. Larvae tunnel downward as they grow.  Tunnels are very pronounced and may be invaded by fungi. Unlike carrot rust fly, feeding damage by weevil larvae is limited to the upper third of the root. Pupation takes place in the soil and new adults emerge from the soil after 1-2 weeks. There is generally 1 generation per year in New England. Weevils tend to be worse in organic soils. To prevent damage, rotate carrot and parsnip crops to new fields, to escape overwintering adults.  Delay planting until after eggs have been deposited (90% of oviposition is expected to be completed by 820 GDD). Carrot-baited traps (Mason jar, Boivin or modified Boivin traps) deployed at field edges can be used to detect incoming adults.  Sampling roots is an effective way to estimate the population of larvae. Insecticide must be applied before egg-laying begins, so timing is important; GDD can be a useful tool. Sprays targeting the adult beetles should be applied once or twice, 10 to 14 days apart, from the 1- to 3-leaf stage.

alpha-cypermethrin (Fastac* EC): 1.8 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

beta-cyfluthrin (Baythroid*XL): 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

esfenvalerate (Asana*XL): 9.6 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Begin treatment when weevils become active, and provide thorough spray coverage of crowns. For carrot only.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A soil drench; PHI 0d, REI 4h, Bee: M, Group UN.

malathion (Malathion 57 EC): 1 to 2 pt/A; PHI 7d, REI 24h, Bee: H, Group 1B. For parsnips only.

oxamyl (Vydate* L): 2 to 4 pt/A; PHI 14d, REI 48h, Bee: H, Group 1A. Use as a soil directed spray in 20 gal water/A. Must be incorporated into soil by water or mechanical means to a depth of at least 2 ". Carrot only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Cutworms

In carrots, cutworms feed on petioles, cutting them near the ground. One cutworm can destroy several plants in a single night. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms. Use spot treatments in affected areas.

alpha-cypermethrin (Fastac* EC): 1.3 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 5.1 to 6.4 oz/A; PHI 21d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 7d, REI 12h, Bee: H, Group 1A. Most effective on species that feed on upper portions of the plant.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. For carrot only.

methomyl (Lannate* LV): 0.75 to 1.5 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For variegated cutworm on carrot only.

methoxyfenozide (Intrepid 2F): 8 to 16 oz/A; PHI 14d, REI 4h, Bee:L, Group 18. Suppression only.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 1d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 1.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.  

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107) for information on the use of these herbicides.

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Carrots only. Use 2 – 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

linuron (Lorox DF): PHI 14d, REI 24h, Group 5. Parsnips only. Make a single application of 1.5 to 3 lbs/A after planting but prior to crop emergence. Seed should be planted at least 1/2 inch deep.

pendimethalin (Prowl H2O): PHI 60d, REI 24h, Group 3. Carrots only. Apply 2pt/A to the soil surface within 2 days of seeding. Do not apply over the top of emerged carrots.

s-metolachlor (Dual Magnum): REI 12h, Group 15. MASSACHUSETTS, MAINE, and NEW HAMPSHIRE ONLY. Carrots only. This is a restricted label available only to those growers who apply through the website www.farmassist.com and agree to a waiver of liability.  Main target weeds for this registration are galinsoga and yellow nutsedge. All label instructions will be supplied after the application for use is completed. Once on the farm assist web site, click products at top left, then indemnified labels.  Create a username and password, select Dual Magnum, and the crop.

trifluaralin (Treflan HFP): REI 12h, Group 3. Carrots only. Apply 1 to 2 pts/A as a preplant soil incorporated treatment. Select rate based on soil texture, see label for details.  Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation.Little or no control of ragweed, galinsoga, mustard or nutsedge.

Herbicides Used Pre- and Postemergence to Weeds

prometryn (Caparol 4L):  PHI 30d, REI 12h, Group 5. Carrots only. Primarily controls annual broadleaf weeds. Annual grasses may only be suppressed. Can be applied preemergence and/or postemergence over the top to carrot. Up to three applications at the rate of 2 - 4 pt/A per application are permitted.  Do not exceed 8 pt/A per crop cycle. Do not exceed one preemergence application (up to 4 pt/A) plus two postemergence applications each at up to 2 pt/A or one postemergence application at up to 4 pt/A.  Use lower rate on coarse-textured sandy soils and the higher rate on fine-textured soils. 

For preemergence use, follow with overhead irrigation if rainfall does not occur to activate.

For postemergence use, apply after the crop is at the six-leaf stage. Include nonionic surfactant (0.5% v:v, 2 qt per 100 gallons of spray) or crop oil concentrate (1% v:v, 1 gallon per 100 gallons of spray). Do not apply when temperatures exceed 85°F.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 30d, REI 24h, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI 45d, REI 12h, Group 1.  Carrots only.  For grass weed control only. Apply to actively growing grasses (see product label for susceptible stage). Apply up to 24 oz/A. Up to 2 applications per year, allow for minimum 14-days between applications (max 48 oz/A per year).  Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).

linuron (Lorox DF): PHI 14d, REI 24h, Group 5.  Carrots only.  Carrot varieties can vary in their tolerance to Lorox.  Apply 1.5 to 3 lb/A after carrots are at least 3".  Multiple applications are permitted, not to exceed a total of 4 lb/A per season. Apply before annual grasses exceed 2" tall and before broadleaf weeds exceed 6" tall. Do not exceed 40 psi spray nozzle pressure as crop injury may result. Do not apply when the temperature exceeds 85° F as crop injury may result. Do not apply Lorox as a tank mix with surfactant, nitrogen solution or other pesticides.

metribuzin (Metribuzin 75): PHI 60d, REI 12h, Group 5.  Carrots only. Apply 0.3 lb/A when carrots have 5 to 6 true leaves and weeds are less than 1" tall and 1" in canopy diameter. A second application can be made 3 weeks after the first. Do not apply within 3 days of cool or wet weather or within 3 days of other sprays. Fair on grasses.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d, REI 12h, Group 1.  Carrots only. Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 2.5 pt/A per application, minimum 14-days between applications.  Do not exceed 5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Celery and Celeriac

Introduction

Celery (Apium graveolens) is a long-season crop that grows best under cool, consistent conditions (60-75° F). A deep, loamy and fertile soil with an ample and uniform supply of water is ideal for celery.  Muck soils are also used for celery production.  Even though most of the celery root system is within the top 6" of soil, many roots penetrate as deep as 2 feet; thus, heavy clay soils are unsuitable.  Hardpans should be avoided or disrupted before planting to allow for adequate drainage.

Celeriac (Apium graveolens var. rapaceum), also called celery root, is a smaller plant that looks like celery, but that is grown for its swollen tuberous base, which has a strong celery-like flavor. The petioles or stalks are not edible. Celeriac can be used much like any root vegetable: roasted, in stews and soups, or eaten fresh in salads. The plant is ready for harvest about 100-110 days from seed or 80-90 days from transplanting. Tubers may be blanched by covering with soil a few weeks prior to harvest, although plants with tubers sitting higher on the ground will have fewer roots to trim. Cultural requirements are similar to celery. 

Types and Varieties  

Celery and Celeriac Varieties
Celery Celeriac
Balada (F) Samba (F) Balena (F) Monarch
Command (F) Stalker (F) Brilliant President
Conquistador Tall Utah Cisko RZ Rex
Hudson (F) Tango Diamant (F) Rowena
Kelvin TZ 6200 (F) Mars  
Merengo (F, CW) Ventura (F)    
Redventure Victoria    
Sabroso (F)      
Resistant or tolerant to: F - Fusarium, CW - Common Wilt.

Soil Fertility

Celery and celeriac are heavy feeders and require adequate fertility to produce a quality crop. Apply lime according to soil test to maintain soil pH at 6.0-6.8. Use a liquid starter fertilizer at transplanting, especially with cool soil conditions. Use a high phosphorus starter fertilizer mixed at a rate of 3 lb/50 gals of water. Apply 8 fl oz (1 cup) per transplant. Sidedress 40 lb N/ac 3-4 weeks after transplanting. On light soils, a second sidedressing may be necessary. The second sidedressing application of nitrogen can be reduced or eliminated if legume biomass was incorporated ahead of planting, or if manure was applied  (see Table 1 and Table 7). 

Celery is very susceptible to magnesium and calcium deficiencies.  Interveinal yellowing of older leaves is a good indication of magnesium deficiency. Magnesium requirements can be partially met by using dolomitic (high magnesium) limestone. Any further need of magnesium can be met by spraying or fertigating the plants with Epsom salts (magnesium sulfate) at 8 lb/ac per week until green color is restored. Calcium deficiency can result in a physiological disorder known as blackheart (equivalent to tipburn in other crops), where the growing tips of the heart die and turn black. However, this is typically a result of inconsistent water supply and not inadequate soil calcium. Provide a steady water supply to maintain even plant growth and calcium uptake, and provide foliar applications of calcium nitrate or calcium chloride during prolonged dry periods. High soil potassium can result in decreased magnesium and calcium uptake; maintain high levels of these nutrients relative to potassium to facilitate their uptake.

Boron, manganese, and copper are also critical in the growth and development of celery. Plants grown on organic soils with low levels of boron and high levels of potassium often have brown, cross-checked cracks and russeting on the inside of the petiole (“brown checking”). Add boron to fertilizer at planting and foliar apply it during dry periods. Tissue analysis is the best method of determining the sufficiency of these elements.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR CELERY and Celeriac
CELERY and celeriac NITROGEN (N)* LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE    POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 100 180 120 30-60 0 240 180 45-90 0
Sidedress 3-4 weeks after setting 40 0 0 0 0 0 0 0 0
Sidedress 7-8 weeks after setting 40 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 180 180 120 30-60 0 240 180 45-90 0

Planting

Celery should be seeded 10-12 weeks before transplanting into the field. This is often done in flats, where seedlings are transplanted into cell trays once they have 2-3 true leaves. Keep greenhouse temperatures above 55º F to prevent bolting and ensure continuous development. Ideal temperatures for germinating celery are 70-75º F, and temperatures can be lowered to 65-70º F thereafter. Heating mats can be used to augment soil temperature if necessary. Do not lower temperature to harden off plants. Transplant to the field in June when outside temperatures have warmed. Although this crop will withstand light frosts, bolting (premature flowering) will occur if plants are exposed to temperatures below 40º F for 10-14 days. Pelletized seed is generally used because of the small size of raw seed. Mature seed and ample moisture are critical for germination. Use two- or three-year old seed that has all matured and maintain planting media near field capacity. Priming seed improves germination. One ounce of seed produces about 15,000 plants.  Use 2-4 oz to produce enough plants for one acre (20,000-58,000 plants).  Space rows 18-36" apart and 6-12" between plants in rows (100-200 plants per 100 feet of row).  Double or single rows on plastic-lined beds are common.  Flat culture is used on muck soils.  

Field Culture

Celery is a long-season crop that grows best under cool conditions (60° F-75° F) with an ample and uniform supply of water.  It may be necessary to irrigate when transplanting and once or twice each week thereafter. Drip irrigation is recommended to mitigate the spread of pathogens.

Harvest and Storage

To harvest, cut the whole celery plant at the soil level. Older outer petioles may need to be removed to provide a fresh tender crop. Freshly harvested celery may have a bitter flavor, which can be improved by storing at 32-34° F for a few days. Chilling injury can result if the storage temperature falls below 32° F. Celery left in the field beyond peak will continue to mature and deteriorate in quality, becoming pithy and developing an off-flavor. In storage, celery can impart its flavor to other crops.

Celeriac holds well in the field. It is harvested and trimmed of roots and stalks when tubers reach 4" in diameter. Celeriac may be stored for 3-6 months if kept at 32-34° F and 95% relative humidity. 

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Anthracnose Leaf Curl (Colletotrichum fioriniae and C. nymphaeae)

Celery anthracnose caused by Colletotrichum fioriniae and C. nymphaeae (formerly C. acutatum)Colletotrichum fioriniae also causes bitter rot in apples while C. nymphaeae  causes anthracnose of strawberries and garlic scapes. Symptoms on celery include curled leaves, occasional discoloration of leaf margins, twisted petioles, and lesions on petioles. Leaves remain green but often appear fan-like and curl downward.  Leaf curl is often the most prominent symptom observed and can resemble injury from growth regulator type (e.g. 2,4-D) herbicides. In advanced stages, the disease can resemble blackheart, the physiological disorder caused by low calcium assimilation. Celery leaf curl thrives under warm, wet conditions. Rapid growth occurs when temperatures are 77-86° F, with substantially more disease development at 86º F. Temperatures as cool as 60° F will support fungal growth and spread, but field progression will be slow. This disease may be seedborne. Start with clean seed, flats, and growth medium. Plant tolerant varieties. Avoid planting in fields with a history of strawberry or garlic anthracnose. Scout plants twice a week for symptoms; remove and destroy affected plants. Manage weeds—several common species harbor celery anthracnose without clearly expressing symptoms. Remove crop debris after harvest and/or plowing crop residue. A 3- to 4-year crop rotation with non-host plants should be followed. Avoid working the fields when the plants are wet, work in fields with a history of the disease last, and power wash equipment between fields. Research has shown that the strobilurin fungicides are most effective; however, be careful to rotate as resistance can develop quickly in this group.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Do not apply more than one application before alternating with a non-Group 11 fungicide.

flutriafol (Rhyme): 5.0 to 7.0 fl oz/A; PHI 7d, REI 12h, Group 3. Apply preventitively when conditions are favorable for disease development.

pyraclostrobin (Cabrio EG): 12-16 oz /A; PHI 0d, REI 12h , Group 11. Do not apply more than pne application before alternating with a non-Group 11 fungicide. Apply no more than 64 oz per year.

pyraclostrobin plus boscalid (Pristine): 10.0 to 15.0 oz/A; PHI 0d, REI 12h, Groups 11 & 7. Maximum of 2 applications per year.

pyraclostrobin plus fluxapyroxad (Merivon Xemium): 4.0 to 11.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 7. Maximum of 3 applications per year.

Leaf Blight [Cercospora apii (Early Blight) or Septoria apicola (Late Blight)]

The primary symptom of early blight is the occurrence of small yellow spots that are visible from both sides of the leaf. These spots may develop into larger lesions that become papery and tears. Gray, fuzzy fungus may be noticed in well-developed lesions. Favorable temperatures for early blight range from 60 to 86º F. This pathogen can be seedborne, can survive on celery residue, and spores can spread via wind and water splashing.

Small, yellow, circular spots on leaves are also symptoms of late blight in celery, which has similar symptoms to early blight in celery overall. One difference is that the small, round, and dark reproductive bodies of late blight, called pycnidia, can be seen in the center of lesions. This pathogen develops when temperatures are greater than 55º F, and particularly in wet conditions with temperatures over 70º F.

Use certified, disease-free seed or treat seed with hot water or fungicides. Practice careful sanitation in transplant greenhouses or rotate ground seedbeds. Irrigate early in the day to allow foliage to dry quickly. Use wider plant spacing and/or raised beds to improve air circulation. Plant resistant or tolerant varieties where available. Apply fungicides based upon a disease forecasting system.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Do not apply more than one application before alternating with a non-Group 11 fungicide.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 7d, REI 12h, Groups 11 & M05. See label for tank mix precautions.  

azoxystrobin plus propiconazole (Quilt Xcel): 14.0 fl oz/A; PHI 14d, REI 12h, Groups 11 & 3

bacillus amyloliquefaciens F727 (StargusOG): 2.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. See label for specific instructions.

chlorothalonil (Bravo Weather Stik): 2.0 to 3.0 pt/A; PHI 7d, REI 12h, Group M05.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH of less than 6.5 or tank mix with Aliette.

cyprodinil plus fludioxonil (Switch): 11.0 to 14.0 fl oz/A; PHI 0d, REI 12h, Groups 9 & 12.

fluxapyroxad plus pyraclostrobin (Merivon): 4.0 to 11.0 fl oz/A; PHI 1d, REI 12h, Groups 7 & 11.

penthiopyrad (Fontelis): 14.0 to 24.0 oz/A; PHI 3d, REI 12h, Group 7.

propiconazole (Tilt): 4.0 fl oz/A; PHI 14d, REI 24h, Group 3.

pyraclostrobin plus boscalid (Pristine): 10.0 to 15.0 oz/A; PHI 0d, REI 12h, Groups 7 & 11. Maximum 2 applications per year. 

pydiflumetofen plus fludioxonil (Miravis Prime): 9.2 to 13.4 fl oz/A; PHI 0d, REI 12h, Groups 7 & 12. 

trifloxystrobin (Flint): 2.0 to 3.0 oz/A; PHI 7d, REI 12h, Group 11. Do not make more than one application before alternating with a non-Group 11 fungicide.

Basal Stalk Rot (Rhizoctonia solani)

Sometimes called crater rot, or simply stalk rot. This pathogen causes symptoms on celery petioles where they are in contact with the soil, where reddish brown lesions form on either side of the petiole, and can become sunken. This pathogen is soilborne and infects many plants. It is favored by warm, humid/wet conditions, and can survive in soil as sclerotia for a long time.

A 2-year rotation is recommended to prevent buildup of disease-causing organisms.  Avoid crops such as alfalfa and legume cover crops which can increase disease risk.  Avoid cultivating late in the season. Maintain storage conditions at 50°F.

azoxystrobin (Quadris):  0.4 to 0.8 fl oz/1,000 row feet; PHI 0d, REI 4h, Group 11 (see label for clarification). Apply in a 7" band in-furrow or shortly after emergence.  After emergence, direct application to stem.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 7d, REI 12h, Groups 11 & M5. See label for tank mix precautions.  

Bacillus amyloliquefaciens F727 (StargusOG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50.0 gallons/A. 

chlorothalonil (Bravo Weather Stik): 2.0 to 3.0 pt/A; PHI 7d, REI 12h, Group M05.

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Pink Rot (Sclerotinia sclerotiorum)

Pink rot in celery is caused by the same pathogen than causes white mold in beans and peas. This pathogen can infect celery at any developmental stage, but is most commonly seen in near harvest. Initially brown lesions on the lower portion of petioles that turn watery and pink in color is the most characteristic symptom. Lesions can contain white mycelia and/or hardened black sclerotia. Severely infected plants may totally collapse. Do not plant seed contaminated with sclerotia or plant into severely infested fields. Irrigate in the morning or with subsurface drip systems to promote drier soil. Rotate with non-hosts. Soil sterilization with chemicals, heat, or steam can reduce sclerotia in the soil.

Bacillus amyloliquefaciens F727 (StargusOG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50.0 gallons of water/A.

boscalid (Endura): 8.0 to 9.0 oz/A; PHI 0d, REI 12h, Group 7.

chlorothalonil (Bravo Weather Stik): 3.0 pt/A; PHI 7d, REI 12h, Group M05. For disease suppression.

Coniothyrium minitans (Contans WGOG): 1.0 to 4.0 lb/A in 20.0-50.0 gal water; REI 4h, Group BM02. Spray on soil surface and incorporate into top 2" soil. Apply in fall or 3-4 months prior to planting.

cyprodonil plus fludioxonil (Switch): 11.0 to14.0 oz/A; PHI 0d, REI 12h, Groups 9 & 12. Make first application at thinning and once more two weeks later.

pyraclostrobin plus boscalid (Pristine): 25.0 oz/A; PHI 0d, REI 12h, Groups 7 & 11. Maximum 2 applications per year. 

Ulocladium oudemansii (BotryStopOG): 2.0 to 4.0 lbs/A; REI 4h, Group BM02. Begin application when conditions are conducive to disease development.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aphids

See Pepper section for more information about green peach aphid.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. Green Peach Aphid. Tops must be removed before use; do not use tops for food or feed. Celery only.

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A. Celery only.

afidopyropen (Versys): 1.5 fl oz/A; PHI 0d, REI 12 h, Bee: L, Group 9D.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A celery, 3.2 to 3.8 celeriac; PHI 1d, REI 12h, Bee: H, Group 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Green peach aphid only. Celery only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. For control of green peach and suppression of potato aphid only. Celery only.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4 h, Bee: H, Group 28.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Suppression of green peach and potato aphids. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress, or through drip. Celery only.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d celery, 3d celeriac, REI 12, Bee: L, Group 9C. 

flupyradifurone (Sivanto): 7 to 10.5 oz/A for foliar application, 21 to 28 oz/A for soil application (celery only); PHI 1d foliar, 21d soil, REI 4h, Bee: L, Group 4D.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A soil; 1.3 oz/A foliar celery; PHI 45d soil, 7d foliar, REI 12h, Bee: H, Group 4A. Foliar applications allowed for celery only.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications and/or use a companion insecticide.

malathion (Malathion 57EC): 1.5 pt/A; PHI 7d, REI 12h, Bee: H, Group 1B. Celery only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Celery only.

pymetrozine (Fulfill): 2.75 oz/A; PHI 7d, REI 12h, Bee: L, Group 9B. Celery only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM):  100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spirotetramat (Movento): 4 to 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility. Celery only.

sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 3d celery, 7d celeriac, REI 12h, Bee: H, Group 4C. Application to celeriac foliage and celery only.

sulfoxaflor (Transform WG): 0.75 to 1.5 oz/A; PHI 7d, REI 24h, Bees: H, Group 4C. Celeriac only.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platimum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. 

tolfenpyrad (Torac): 17 to 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A

Cabbage Looper and Imported Cabbageworm

See Cabbage and Other Brassica Crops for more information on cabbage looper and imported cabbageworm.

acephate (Orthene 97): 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. Tops must be removed before use; do not use tops for food or feed. Cabbage Looper on celery only.

alpha-cypermethrin (Fastac* EC): 1.8 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A looper, 0.25 to 1 lb/A ICW; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.4 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Celery only.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A. Imported cabbage worm only.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through chemigation and as a foliar spray. For drip application, must be applied uniformly in the root zone. For foliar application an adjuvant may be used. Cabbage looper only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 10 to 17 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Cabbage looper on celery only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. Celery only.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4 h, Bee: H, Group 28.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Cabbage looper on celery only.

indoxacarb (Avaunt): 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22. Cabbage looper on celery only.

methomyl (Lannate* LV): 3 pt/A; PHI 7d, REI 48h, Bee: H, Group 1A. For cabbage looper on celery only.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

permethrin (Pounce* 25WP): 3.2 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Cabbage looper on celery only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Celery only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils. Cabbage looper only.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d celery, 3d celeriac, REI 4h, Bee: M, Group 5. Do not apply to celery seedlings intended for transplant.

tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Use higher rate for late-season applications or for heavy infestations. Low toxicity to natural enemies. One pint of adjuvant per 100 gallons of spray mixture is recommended. Celery only.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A for ICW; 3.4 to 4.3 oz/A for CL; PHI 1d, REI 12h, Bee: H, Group 3A.

Leafminers (Liriomyza species)

There are several species of leafminers in the genus Liriomyza, including the serpentine leafminer (Liriomyza trifolii), the vegetable leafminer (L. sativae), pea leafminer (L. huidobrensis) and cabbage leafminer (L. brassicae).  Most of these species feed on a very broad range of vegetables, weeds, flowers and wild plants. Cabbage leafminer is most often found on brassicas, and rarely on other crop groups. In southern regions of the US, Liriomyza leafminers can be pests of basil, beans, cabbage and other brassicas, celery, lettuce, pepper, eggplant, tomato, and cucurbits. In New England, especially with greater use of selective insecticides that conserve natural enemies, these leafminers rarely reach pest status.

Adults in this group are small (2.0-2.5mm), hump-backed, clear-winged flies with black and yellow markings.  Females lay eggs within the leaf, and larvae feed between the upper and lower surfaces of the leaf, creating winding mines. When full grown, larvae emerge and form a brown pupa about the size of a rice grain on the leaf or in the soil. The life cycle takes 3 to 4 weeks depending on temperature. Mines render the leaf unmarketable, reduce photosynthetic capacity, and provide entry for pathogens. Leafminers generally are controlled by naturally occurring parasites unless disrupted by broad-spectrum insecticide applications. There is also a commercially available biological control, the tiny wasp parasitoid, Diglyphus isaea, used against Liriomyza leafminers in a wide range of crops; this works best in warm weather. 

In the southern and western US, pesticide resistance has become a problem.  Avoid obtaining transplants from outside the Northeast, which could carry resistant strains. Control broadleaf weeds in and around the crop. Incorporate infested crop residues after harvest to prevent emergence and movement to new plantings. Most importantly, use selective insecticides on other pests to conserve natural enemies. Scouting methods include catching adults on yellow sticky traps placed in mid or lower canopy, or trapping pupae in trays underneath the plants. Counting mines is a good index of past activity, but mines may be vacant and searching for larvae in mines is time consuming.  Treatment may be warranted if damage is delaying growth or marketable parts of the plant are being damaged, and adult fly populations are increasing. 

See the beets and chard section for leafminers that occur on the Amaranthaceae (spinach, beets, chard) crop group.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading and/or penetrating spray adjuvant; do not use binder or sticker type adjuvant. Celery only.

chlorantraniliprole (Coragen): 5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through chemigation and as a foliar spray. For foliar application an adjuvant may be used. Celery only.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Celery only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. Celery only.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4 h, Bee: H, Group 28.

cyromazine (Trigard): 2.66 oz/A; PHI 7d, REI 12h, Bee: M, Group 17. Celery only.

dimethoate (Dimethoate 4EC): 1 pt/A; PHI 7d, REI 48h, Bee: H, Group 1B. Celery only.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress, or through drip. Celery only.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Suppression only. Celery only.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications and/ or use a companion insecticide.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Celery only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Celery only.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Control may be improved with the addition of an adjuvant to the spray mixture.

spinosad (Entrust SCOG): 3 to 6 oz/A celeriac, 6 to 10 oz/A celery; PHI 1d celery, 3d celeriac, REI 4h, Bee: M, Group 5. Control may be improved with the addition of an adjuvant. Do not apply to celery seedlings intended for transplant.

Mites

See Eggplant for more information about mites.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading and/or penetrating spray adjuvant; do not use binder or sticker type adjuvant. Use high rate on celeriac.

Chromobacterium subtsugae (GrandevoOG): 2 to 3 lb/A; PHI 0d, 4h REI, Bee: M, Group UN.

malathion (Malathion 57EC): 1.5 pt/A; PHI 7d, REI 12h, Bee: H, Group 1B. Celery only.

Metarhizium anisopliae Strain F52 (Met 52 EC): 40 to 80 oz/100 gal soil, 8 to 64 oz/A foliar; PHI 0d, REI 0h, Bee: L, Group UN. Celery only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Celery only.

sulfur (Microthiol DisperssOG): 4 to 6 lb/A; REI 24h, Bee: L, No IRAC classification. Celery only.

Tarnished Plant Bug (Lygus lineolaris)

See Lettuce for information about tarnished plant bug. Bugs may feed on leaf petioles or produce lesions or small sunken cavities on stalks.  Injury to the inner growing tip can cause foliar discoloration and tissue destruction that is similar to the physiological condition known as ‘blackheart’.  If your crop is near weedy fallow fields or alfalfa, scout weekly from when celery is 4" tall until 3 weeks before harvest to detect TPB and injury, as the economic injury level is low. Treat at 2 to 4 bugs per 20 plants. Control weeds in and around the field.  Do not plant near legume crops that may be harvested during the season or TPB may migrate to celery. 

beta-cyfluthrin (Baythroid* XL):  2.4 to 3.2 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Celery only.

carbaryl (Sevin XLR plus):  1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications and/or use a companion insecticide.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d celery, 3d celeriac, REI 12, Bee: L, Group 9C

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Celery only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique for information on the use of this weed control method. Because celery is slow growing, plasticulture is often used to reduce the need for hand weeding and cultivation.

glyphosate (Roundup Power Max): REI 12h, Group 9.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Celery only. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): REI 12h, Group 0.  Apply 5 to 6 qt/A.  Celery only.  Can be preplant incorporated by shallow cultivation (1-2”) or applied preemergence and incorporated by irrigation within 36 hours or application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

trifluralin (Treflan HFP)REI 12h, Group 3. Celery only.  Rate based on soil texture, see label for details.  Apply 1 to 2 pt/A of Treflan HFP as a soil-incorporated treatment. Treflan HFP may be applied to direct seeded or transplant celery before planting, at planting, or immediately after planting. Little or no control of ragweed, mustard, and nutsedge.

Herbicides Used Pre- and Postemergence to Weeds

linuron (Lorox DF): PHI 45d celery, PHI 60d celeriac, REI 24h, Group 5. Apply as a single application of up to 3 lb/A after the celery or celeriac has been transplanted and establish, but before the crop is 8” tall.  For use in celery, only use on celery grown on muck soils. Do not apply when temperatures exceed 85 degrees F.  Do not apply as a tank mixture with surfactants, nitrogen or fertilizer solution, or other pesticides, as injury to the crop may result. Preemergence to weeds, can control annual weeds as they germinate. Postemergence to weeds, can control up to 2 inch tall annual grasses and up to 6 inch tall broadleaf weeds. See label for list of susceptible weeds.

prometryn (Caparol 4L): PHI 30d for celery, PHI 60d for celeriac, REI 12h, Group 5. Primarily controls annual broadleaf weeds. Annual grasses may only be suppressed. Do not use on sand or loamy sand. Do not apply if crop is under water stress. Do not apply within 2 weeks after an application of an herbicidal oil, such as “carrot” oil.

For celery: Can be used pre- or postemergence. To avoid crop injury, make either 1 preemergence or 1 postemergence application (not both) per crop. For preemergence use, apply 2.4 to 3.2 pt/A at planting or shortly after planting but before the crop emerges. For postemergence use, 1.6 to 2 pt/A after the crop has 2 to 5 true leaves. May be applied over the top of the crop. Apply before weeds are 2" tall.

For celeriac: Do not exceed 4 pt/A per crop cycle. Make a single broadcast application at 1.6 to 4 pt/A in a minimum of 20 gal of water per acre after the crop has 6 to 8 leaves. Application may be made over the crop. Use the lower rate on coarse-textured soils and soils low in organic matter.  Apply before weeds are 2" tall.

Herbicides Used Postemergence to Weeds 

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 30d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Celery only. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d, REI 12h, Group 1.  Celery only. Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 3 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Physiological Disorders

Blackheart

Blackheart is a physiological disorder akin to tipburn in other crops. It is associated with poor calcium assimilation as a result of inconsistent water uptake. Blackheart can be identified by the death of the growing points of the innermost petioles, or heart. Blackheart occurs in most celery growing regions, and significant losses have been reported in Florida, California, Texas, Utah and Wisconsin. If conditions favorable for the development of blackheart persist, the entire crown may be destroyed in a few days. In minor cases, the plants may recover or seem to recover, although symptoms can return. Symptom development is much more severe as plants approach maturity. The appearance of symptoms is closely linked to fluctuating water levels and available calcium. Environmental conditions that favor rapid growth, such as heavy rain or irrigation subsequent to drought, favor symptom development. High nitrogen, potassium, and sodium levels may also play a role. Certain celery cultivars are more susceptible to blackheart. Blackheart is prevented by ensuring steady plant growth, avoiding wide fluctuations in moisture and nutrients. Drench applications of soluble calcium can lessen or prevent the development of blackheart. Plant celery cultivars that are not prone to the syndrome. Drip irrigation, which provides more even moisture levels, can help reduce risk.

Corn, Ornamental and Popcorn

Introduction

Ornamental corn varieties are mostly flint type corns (Zea mays indurata) with hard variously colored kernels. While originally grown as food, today they are grown primarily for ornamental purposes. Popcorn (Zea mays everta) is a variant of flint corn that can be popped. Broom corn (Sorghum vulgare), which is commonly grown as an ornamental, is not actually corn, but rather a relative of the sorghum grown for syrup and seed.

All of these ornamental corns will grow in any sunny, well-drained, fertilized soil that will grow field or sweet corn. Adequate moisture, especially after the ears form, is necessary. Isolation from other types of corn is suggested. Bird damage can be a concern. Use nutrient and pest management recommendations for sweet corn.

Types and Varieties

Hybrids are available, but most ornamental corn varieties are open-pollinated. Seed can be saved if it is isolated from other types of corn including sweet corn and dent corns. Ornamental popcorn should be considered for miniature decorative ears and the dual purpose of popping.

Ornamental Corn and Popcorn Varieties
Full-sized ornamental  Miniature ornamental
Autumn Splendor Carousel
Bloody Butcher Indian Fingers
Earth Tones Dent Little Jewels
Fiesta F1  
Indian Art 104 Popcorn
Indian Art Cranberry Cherry Berry
Painted Mountain Red Strawberry Corn
Rainbow White Cloud
  Mini Blue
Broom corn Robust 997 (R997)
Colored Uprights  
Red Broom Corn  
Texas Black  

Soil Fertility

See sweet corn Soil Fertility.

Planting

Because of its hard seed coat, ornamental corn should be planted early to allow for full maturity on the stalks. Plant at a spacing of 9-10" within rows and 30-36" between rows at 1-1.5" deep. Keep ornamental corn away from sweet corn or popcorn that pollinates at the same time as ornamental corn.

Harvest

Harvest when the kernels are hard and bright and the husks are brown. Husk and hang to dry. Do not box or bag ears when they are first harvested, or they may mold. Mold may occur on the husk and the ear if proper handling and storage techniques are not used.

Corn, Sweet

Introduction

Sweet corn (Zea mays convar. saccharata var. rugosa) is a warm-season crop and one of the major vegetables grown in New England.  It is an extremely popular crop for roadside stand and farmers' market sales as well as for wholesale markets.

Sweet  corn grows on a wide range of soil types.  Early planting should be on light, well-drained soil in a warm, sheltered location.  Heavier soils are best for the main crop.  Plowing under corn stalks and cover crops to maintain high levels of organic matter in soils is recommended for best crop production.  Irrigation may only be necessary in dry weather, particularly on light soils, and especially as silking starts.

Types and Varieties

Sweet corn varieties are categorized by their genotype.  The most common types are normal/sugary (su), sugar enhanced (se), and supersweet/shrunken (sh2).  Other newer varieties include sweet breeds, synergistic, sweet genes, or improved supersweets which have a combination of genes.

su           "Normal" or "Sugary"

Standard hybrid sweet corn is a mutant type of corn that differs from field or dent corn by a mutation at the sugary (su) locus. This type accumulates about twice as much sugar than field corn.

se          Heterozygous Sugary Enhanced or "Modified Sugar" or "Everlasting Heritage (EH)"

se+        Homozygous Sugary Enhanced  

There are two distinct groups within the cultivars containing the "se" gene, which increases sugar levels above those found in "su" varieties.  The "homozygous se" or se+ cultivars have higher sugar levels in 100% of their kernels.  Cultivars that are "heterozygous se" have higher sugar levels in 25% of their kernels; the other 75% contain the normal "su" gene with lower sugar levels.  Thus, "se+" cultivars are usually sweeter than "se" cultivars.

  • Sugar conversion to starch is about the same rate as standard sweet corn.  Refrigeration is essential to maintain quality.
  • Isolation not required, but desirable. Note directions on seed tag label.
  • Kernels tender and creamy.
  • Tip cover weak on some varieties

sh2           "Super Sweet" or "Extra Sweet" 

  • Sugar content twice as high as standard sweet corn.
  • Slow sugar conversion to starch so quality will hold 7-10 days. Refrigeration suggested to extend quality.
  • Isolation is required from all other types of corn. Note directions on label.
  • Kernels can be somewhat tough or crunchy.
  • Does not germinate well in cold, wet soil.  Plant after soil temperatures exceed 65° F and be sure there is adequate soil moisture.  Adjust planting depth for soil conditions and soil type.  Seed of the "sh2" type is light-weight, wrinkled, and fragile and should be handled gently to prevent damage.

syn          "Synergistic"

These include synergistic or improved supersweets such as Sweet Breed and Sweet Genes.  These varieties have combinations of su, se, se+, or sh2 genes.  Synergistic varieties having the sh2 gene may be grown with other "Super Sweet" varieties, but must be isolated from "se" and "su" types to achieve best quality.

aug          "Augumented Shrunkens"

Augmented Shrunken sweet corns are a new type of shrunken corn types. They contain the "sh2" gene, but kernels of augmented shrunken are more tender, like "se" varieties.  Augmented shrunken varieties should be hand harvested because their tender kernels will likely be damaged by machine picking. These varieties need to be isolated from normal, "se" and synergistic hybrids. Additionally, they have the same seed vigor problems as supersweet varieties and should only be planted under optimal conditions.

MiraiTM    

MiraiTM sweet corn varieties carry two copies of all three sweet corn genes: su, se and sh2. They have all tender supersweet kernels and, like the augmented shrunken varieties, need to be hand-harvested. Mirai varieties also need optimal soil conditions for seedling establishment. Mirai types do not require isolation to avoid starchy kernels, but isolation from other sweet corn types will assure best quality.

Bt Hybrids

These are genetically-modified (GM) varieties that are protected from European corn borer, and to a lesser extent, fall armyworm and corn earworm caterpillars because they express the protein toxin of the bacteria Bacillus thuringiensis. They are currently available as super sweet (sh2) or as synergistic "TripleSweet" varieties, composed of 75% "se" and 25% "sh2" kernels. In the synergistic varieties, the Bt toxin is expressed in the "se" kernels, the stalks, leaves, tassels and fresh silk. Bt varieties are still susceptible to attack from flea beetles, cutworms, aphids, sap beetles, high levels of corn earworm and soil-dwelling insects. Bt seed costs more than the seed of other sweet corn varieties and currently comes with a list of resistance management strategies with which to comply. These varieties may reduce the time, energy and expense associated with insect control and may simplify sweet corn pest management. There are many other less obvious potential risks and benefits that may be associated with the use of this technology. GM sweet corn varieties, including all Bt varieties, are not allowed in organic production. Growers in Maine must be certified to grow Bt corn. Contact the Maine Board of Pesticides Control for more information. 

Sweet Corn Varieties
Variety Type Color Wilt Rust MDMV
Sweet Chorus (67) syn Bi L M M
Sweetness (68) syn Bi - - -
Latte (68) syn Bi M M -
Vitality (68) se Bi - - -
Espresso (70) syn Bi M M -
Mirai 308BC (70) mirai Bi - - -
Harris 1001 (72) se Bi M - -
Temptation (72) se+ Bi - - -
Reflection (72) syn Bi - M -
Cuppa Joe (73) syn Bi M M -
XTH 2170 (73) sh2 Bi M - -
Mirai 336BC (73) mirai Bi - M M
Sweet Rhythym (73) syn Bi M L -
Anthem XR (73) sh2 Bi L H -
Charisma (74) se Bi M M -
Fanstastic (74) sh2 Bi - - -
XTH 274A (74) sh2 Bi M - -
Sweet Ice (74) syn W M L L
Kristine (74) syn Bi M M -
Mystique (75) se+ Bi H M L
SC1102 (75) syn Bi - - -
Sparkler (75) syn Bi - - -
Mirai 301BC (76) sh2 Bi M M -
Awesome (76) sh2 Bi M - -
Luscious (77) se Bi - - -
Accord (78) se Bi - - -
Legion (78) sh2 Bi M M M
Pow Pow (78) syn Bi - - -
Essence (78) syn Bi M M -
Providence (79) syn Bi - M -
Montauk (79) syn Bi M - -
Delectable (80) se+ Bi M H L
Precious Gem (80) se+ Bi M M L
Primus (81) sh2 Bi M M -
BC 805 (82) * se Bi - H -
Jackpot (82) se+ Bi M M -
Silver King (82) se+ W M M -
Argent (83) se W H M L
Incredible (85) se+ Y H - -
Cameo (84) se Bi M M -
Silver Queen (94) su W H L L

The number in parentheses is the approximate number of days to maturity from seeding.

H, M, L indicates high, medium or low resistance or tolerance to the following diseases - Wilt: Stewart's wilt, Rust: Common rust, MDMV: Maize dwarf mosaic virus.

Other codes: mirai: mirai, su: normal sugary, se: sugar enhanced, se+: sugar enhanced homozygous, sh2: supersweet/shrunken, syn: has some combination of su, se and sh2 genes, Y: yellow kernels, W: white kernels, Bi: bicolor, *: Bt hybrid

Cultural Practices

Soil Fertility

Apply lime according to soil test to maintain soil pH between 6.5 and 6.8.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1, page 2 and Table 7, page 15). 

Apply no more than 80-100 pounds per acre combined weight of actual nitrogen and potassium applied 2" on the side and 2" below the seed as a band. Higher amounts of nitrogen and potash applied as a concentrated band may damage corn seed and young plants.

Plant Nutrient Recommendation According to Soil Test Results for Sweet Corn
  Nitrogen (N) Lbs per acre

   Phosphorus (P) Lbs P2O5 per acre

   Potassium (K) Lbs K2O per acre

Soil Test Results   Very Low Low  Optimum Above Optimum Very Low Low  Optimum Above Optimum
Broadcast and Incorporate 0 100 40 0 0 150 90 0 0
Band Placement at Planting 40 40 40 40 0-40* 30 30 0-30 0
Sidedress 60-90** 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 100-130 140 80 40 0-40* 180 120 0-30 0
*Phosphorus applications are recommended only for early-season corn sown in cold soils.
**Before sidedressing use a nitrate test to determine the need for additional N

Planting

Effective isolation is required in some cases with the present types of sweet corn on the market. Isolation is affected by distance, wind direction, time of pollen shed and silking, and blocking. From a practical standpoint, the same methods are needed as when separating white and yellow varieties. Field experience indicates isolation can be managed more easily than initially expected.

Plant early varieties 8"-10" apart within rows with 30"-36" between rows. Plant main season varieties 10"-12" apart within rows with 36" between rows. This requires 10-15 lb of seed/A (1-2 oz per 100 feet of row) or 17,500-26,000 seeds/A for early and 14,500-17,500 for main season varieties. Match seed size to seed plate. Read seed container or contact the company regarding appropriate plate sizes. 

First plantings are made in early April in southern New England and in May in northern New England.  Growers planting in cold soils run the risk of erratic germination and poor stands.  Avoid planting while soil temperature is lower than 55° F.  If soil temperature is below 60° F, it is advisable to plant treated seed.  If you are planting untreated seed, wait until the soil temperature is at least 65° F.  Most seed companies perform cold germination tests of their seed.  If in doubt about the suitability of a corn variety for early planting, ask your seed dealer about the low temperature germination and vigor of the seed. 

Clear plastic mulch raises soil temperature and can be used for the earliest plantings.  This can allow for earlier planting and provide corn 7-10 days earlier than non-mulched corn.   Apply fertilizer and herbicides, and plant seed before laying the plastic over seeded rows.  Two rows 18"-24" apart are usually planted under each strip of 5 ft-wide plastic.  To avoid plant injury, do not let temperatures beneath the plastic get too high (90° F or more).  When such conditions occur, or when the plants reach 4" in height, cut slits in the plastic to allow heat to escape and plants to grow through.  Remove the plastic completely by the time the corn is knee high to facilitate removal and permit cultivation.

Spunbonded row covers offer a potential three-way benefit for early sweet corn production.  Maturity is increased by 5-10 days, yields are generally increased by 15%-20%, and the first generation corn borer can be controlled if the covers are left on until after the peak of the first generation corn borer flight.  They can also be used to pre-warm the soil before planting.  They can be removed to allow planting and then replaced.  Weight cover edges with soil or sand bags to prevent damage by gusty winds, but leave adequate slack for plant growth to the tassel stage.

Transplanting Sweet Corn

Transplanting sweet corn offers some advantages to growers over direct seeding, including better stands, earlier harvest, and less dependence on pre-emergent herbicides.  However, transplanting is more labor intensive, costly and requires attention to detail in order to be successful.

Corn can be seeded by hand, or a simple, inexpensive drop seeder can be built to fit the size of tray to be used.  98-128 cell trays work best (a 128 cell tray requires 82 trays per acre).  The smaller plug trays require less media, but are more easily root-bound. Fill trays with a peat-based potting mix, and plant one or two seeds per cell.  Place trays on tables or benches to prevent plants from rooting in the ground.  Greenhouse temperatures should be set for 65-degree days and 60-degree night temperatures. Transplants should be ready in about 14-18 days, and should be hardened off before planting in the field, by placing the trays outdoors and limiting water for a few days.  Fertilizer should be banded prior to planting, or applied as a liquid at planting.  The plants should have good, cohesive roots that come out of the tray with relative ease. They may be planted by hand or machine.  Plants can be spaced 14-16 inches apart within rows, with about 3 feet between rows.  Floating row covers should be placed over the corn for the first two to three weeks after planting.  These can be pulled back to allow cultivation.  Transplanting and row covers should bring corn to maturity about two weeks earlier than direct seeding.  Not all varieties perform well in this system.  Test your favorite early-mid maturity varieties in small trials before committing large amounts of trays and greenhouse space to them. 

Harvesting and Storage

The sweetness and tenderness of sweet corn will deteriorate rapidly after harvest. Sweet corn should be cooled immediately after harvest and kept at 32º F to retain optimum freshness. The crop is best harvested early in the morning when there is less field heat. Harvesting at the proper stage (milk stage) is critical in maintaining quality. During the summer, sweet corn will be at the proper stage only 1-2 days. It will approach maturity 16-22 days after silking and should be picked daily. As the kernel passes the prime harvest time, sugars convert to starch and the pericarp becomes tough. Supersweet varieties retain their sweetness longer than su and se varieties; extra tender varieties maintain eating quality even longer.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Leaf Spots (Helminthosporium, Cochiliobolus, Cercospora)

Plant resistant varieties. Improve air circulation by plant spacing and site selection. Plow under crop debris promptly after harvest to speed decomposition. Fungicide rotation is critical for prevention of resistance development- do not make back-to-back applications of products with active ingredients from the same group.

azoxystrobin (Quadris F AKA Abound F): 6.0 to 15.5 fl oz/A; PHI 7d, REI 4h, Group 11. May be extremely phytotoxic to certain apple varieties. See label for restrictions. 

azoxystrobin & propiconazole (Quilt): 7.0 to 14.0 fl oz/A; PHI 14d (sweet), PHI 30d (popcorn), REI 12h, Groups 11 & 3. 

chlorothalonil (Bravo Weather Stik AKA Bravo 720): 0.75 to 2.0 pt/A; PHI 14d, REI 12h, Group M05. Do not apply to sweet corn to be processed. Not labeled for popcorn.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (sweet), PHI 21d (popcorn), REI 12h, Groups 7 & 11.

mancozeb (Dithane F45): 1.2 qt/A; PHI 7d, REI 24h, Group M03

propiconazole (Tilt): 2.0 to 4.0 fl oz/A; PHI 14d (sweet), PHI 30d (popcorn), REI 24h, Group 3.

pyraclostrobin (Headline): 6.0 to 12.0 fl oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus metaconazole (Headline AMP AKA BAS 556 SC): 8.0 to 14.4 fl oz/A; PHI 7-20d (see label), REI 12h, Groups 11 & 3.

trifloxystrobin plus propiconazole (Stratego): 10.0 fl oz/A; PHI 14d, REI 12h, Groups 11 & 3.

Northern Corn Leaf Blight (Exserohilum (Helminthosporium) turcicum)

Northern corn leaf blight is an emerging problem on farms up and down the Connecticut River Valley. Northern corn leaf blight can develop very rapidly resulting in a complete blighting of leaves. E. turcicum overwinters in and on leaf debris and conidia can be spread long distances by wind. Under the right conditions (prolonged leaf wetness, extended rainy and humid weather, moderate temperatures), conidia are produced abundantly and disease spread is rapid. Reduce primary inoculum by crop rotation and tilling under of crop residue. Evidence suggests more severe disease in reduced-till systems; 1-year rotations are suggested for conventional practices and 2-year rotations for reduced-till. Resistant hybrids of all maturity groups are available. Lesions may vary in morphology when certain genes for resistance to this disease are present. The presence of these genes results in long, yellow, linear streaks that resemble the symptoms of Stewart's Wilt. Growing susceptible varieties will cause the resistance of nearby resistant varieties to break down. Fungicide rotation is critical for prevention of resistance development- do not make back-to-back applications of products with active ingredients from the same group.

azoxystrobin (Quadris F AKA Abound F): 6.0 to 15.5 fl oz/A; PHI 7d, REI 4h, Group 11. May be extremely phytotoxic to certain apple varieties. See label for restrictions.

azoxystrobin plus propiconazole (Quilt):  7.0 to 14 .0fl oz/A; PHI 14d (sweet), PHI 30d popcorn), REI 12h, Groups 11 & 3.

chlorothalonil (Bravo Weather Stik AKA Bravo 720): 0.75 to 2 pt/A; PHI 14d, REI 12h, Group M05. Do not apply to sweet corn to be processed. Not labeled for popcorn.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (sweet), 21d (popcorn), REI 12h, Groups 7 & 11.

mancozeb (Dithane F45): 1.2 qt/A; PHI 7d, REI 24h, Group M03. 

propiconazole (Tilt): 2.0 to 4.0 fl oz/A; PHI 14d (sweet) PHI 30d (popcorn), REI 24h, Group 3.

pyraclostrobin (Headline): 6.0 to 12.0 fl oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus metaconazole (Headline AMP AKA BAS 556 SC): 8.0 to 14.4 fl oz/A; PHI 7-20d (see label), REI 12h, Groups 11 & 3.

trifloxystrobin plus propiconazole (Stratego): 10.0 fl oz/A; PHI 14d (sweet), 30d (popcorn), REI 12h, Groups 11 &3.

Rust (Puccinia species)

The common rust fungus that occurs on sweet corn does not overwinter in the Northeastern United States; each year it is blown up from the south. Rust can cause significant reduction in ear weight and yield on susceptible varieties. Corn is more susceptible to infection prior to tasseling so later maturing plantings may have higher losses. Fungicides will control this disease but should be applied before tasseling. Apply fungicides when 80% of the plants show 1 or more pustules per leaf. Resistant varieties are available. Fungicide rotation is critical for prevention of resistance development- do not make back-to-back applications of products with active ingredients from the same group.

azoxystrobin plus propiconazole (Quilt): 10.5 to 14 fl oz/A; PHI 14d (sweet), PHI 30d (popcorn), REI 12h, Groups 11 & 3.

benzovindiflupyr (Trivapro A): 4.0 to 10.5 fl oz/A (see label); PHI 7d, REI 12h, Group 7.

chlorothalonil (Bravo Weather Stik AKA Bravo 720): 0.75 to 2 pt/A; PHI 14d, REI 12h, Group M5. Do not apply to sweet corn to be processed. Not labeled for popcorn.

fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (sweet), 21d (popcorn), REI 12h, Groups 7 & 11.

mancozeb (Dithane F45 ): 1.2 qt/A; PHI 7d, REI 24h, Group M03.

propiconazole (Tilt): 4.0 fl oz/A; PHI 14d (sweet), PHI 30d (popcorn), REI 24h, Group 3. 

pyraclostrobin (Headline): 6.0 to 12.0 fl oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus metaconazole (Headline AMP): 8.0 to 14.4 fl oz/A; PHI 7-20d (see label), REI 12h, Groups 11 & 3.

trifloxystrobin plus propiconazole (Stratego): 10.0 fl oz/A; PHI 14d, REI 12h, Groups 11 &3.

Seed Decay

Buy treated seed. Do not use treated seed for food, feed or oil purposes.

Common Smut (Ustilago maydis)

Smut occurs sporadically from one season to another but usually less than 2% of the plants are affected. The disease is favored by dry conditions when temperatures are between 80° F and 90° F and nitrogen fertility is high. Injury due to cultivation, hail or wind-blown sand can increase the incidence of disease when environmental conditions are favorable. Fungicides will not provide effective control of common smut.

Stalk Rots (Gibberella, Stenocarpella, Macrophomina, Colletotrichum, Fusarium)

Fungal stalk rots continue to be serious diseases of corn. Their occurrence and severity vary from year to year. Stalk rots cause losses by causing premature plant death, difficulties with mechanical harvesting,  and ear rot due to contact of ears with the soil. Factors that influence stalk rot include the susceptibility of the hybrids, weather conditions, the presence of foliar diseases, plant densities, insect damage, moisture availability, soil fertility, and tillage practices. Soil fertility, tillage, and plant density can be adjusted to provide control. Stalk rot is more severe and more common where soil fertility is high. Nitrogen (N) levels can both increase and decease stalk rot; an excess of N in relation to potassium (K) increases stalk rot. A balanced and continuous supply of N reduces the occurrence of stalk rot. Adequate K reduces stalk rot severity by strengthening cell walls. In general, corn debris left on the surface of the soil harbors many foliar diseases that increase stalk rot by reducing photosynthesis. As the population of plants increases, the incidence and severity of stalk rot also increase, especially in susceptible hybrids. Control is most successfully achieved through the use of resistant hybrids. Cultural practices such as balanced fertility, proper plant spacing, and reduction of other plant stresses, such as insect damage, can also reduce stalk rot.

Stewart's Wilt (Pantoae (Erwinia) stewartii )

This bacterial disease is spread by the corn flea beetle and is particularly damaging when susceptible varieties are planted following mild winters. P. stewartii overwinters in the alimentary tract of adult corn flea beetles, not in the soil or in plant debris. Severity of Stewart's Wilt depends on three factors: the winter temperatures prior to planting, the amount of disease the previous season, and cultivar susceptibility. If cold winter temperatures occur, fewer flea beetles survive to transmit the disease. The amount of disease in the previous season determines the percentage of emerging beetles carrying the bacterium. Hybrids with greater levels of resistance can tolerate more infection with less yield loss. Resistance restricts the movement of the bacteria in the plant. Grow varieties that are resistant to the disease.  Use insecticides to control flea beetles, particularly on susceptible varieties in the seedling stage. This is not as effective as resistant varieties, but reduces losses where susceptible hybrids must be planted. Scout frequently for flea beetles as rapid growth of leaf tissue makes untreated surfaces available.

 Maize Dwarf Mosaic Virus (MDMV)

There are several strains of MDMV which are spread by more than 20 species of aphids. The virus can be seedborne in maize and probably in some annual grasses. The virus is nonpersistent but is retained by the aphid for up to 18 hours. This allows time for the vector to be transported from southern states where MDMV is more prevalent and many weed hosts occur. Johnson grass is an important perennial weed host for MDMV occurring in southern New England and it should be eradicated. Plant resistant or tolerant corn varieties. Golden Gleam, Sundance, Spring Gold, Seneca Star, Early Fortune, Sugar Loaf, Dandy and Capitan have some tolerance. Enforcer, Biguard, Silver Red and Seneca 258 are resistant. MDMV is more likely to be a problem for later plantings. Plant late plantings away from peach trees, overwintering host of the green peach aphid.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

All tolerances for chlorpyrifos in food crops were revoked in 2022, therefore products containing chlorpyrifos (e.g. Lorsban) cannot be applied to any food crop and growers CAN NOT use up existing stock.

Caution: Insecticides should not be applied when bees are active in the field.  Avoid products with high bee toxicity during pollen shed. If application of an insecticide is necessary while the crop is blooming, select products with low bee toxicity or with short residual period; apply in the evening after the bees have left the field. See Protecting Honeybees and Native Pollinators in the Insect Management section for more suggestions on how to avoid harmful effects on pollinators.

Sprayer Type and Configuration

In sweet corn, the best coverage is achieved with a boom-type sprayer with drop nozzles. The nozzles should be arranged so that one nozzle is over the row and a double-drop system is used between rows, with the lower nozzle is directed up toward the ear and upper nozzle directed down, to bracket the ear zone.  For whorl and pretassel stages, one nozzle over the row or with a single drop nozzle is adequate. Use hollow-cone nozzles at 75 to 100 psi to achieve good penetration, droplet size and coverage.  Mist blowers do not provide as effective coverage of the ear zone and may result in poorer coverage in the center of the block because each row of corn acts as a filter. However, on hilly land or for other reasons a mist blower may be the most feasible sprayer option. If a mist blower is used, plant fewer rows per block for later corn when insect pressure is typically higher. Direct some spray over the canopy, so it can settle into the corn from above, as well as through the corn rows.  Spray only in very calm conditions. For all sprayers, assess sprayer coverage by clipping water-sensitive cards on ears at the edge and center of the block and on both sides of the plant, then spraying water at the pressure and speed normally used.

Armyworm, Fall (Spodoptora frugiperda) and Common (Pseudaletia unipunctata)

The fall armyworm (FAW) does not overwinter in New England. Infestations result from moths carried northward on storm fronts from mid-July into September. Flights are heavier near the coast, but occur inland as well. FAW flights are sporadic and unpredictable, and do not necessarily correspond with corn earworm flights, so monitoring with pheromone traps in whorl stage corn is very useful. Male adult moths are ¾" long and have mottled brown forewings with a slanting white bar across the wing, and plain light tan hindwings. Female moths lay clusters of eggs on the leaves of a variety of host plants, preferring whorl stage corn to older corn. Eggs hatch in 2 to 10 days, depending upon temperature. Caterpillars are smooth (unlike CEW) and dark green or brown with lengthwise stripes and dark spots. Full-grown larvae reach 1.5 inch. The head capsule is dark with a distinctive light-colored marking in the form of an upside-down Y.

Feeding damage from caterpillars occurs first in whorl stage corn, deep within the whorl, on leaves and in the newly forming green tassel. In whorl stage corn, caterpillars produce ragged feeding damage to leaves and masses of sawdust-like excrement. As corn matures, larvae burrow into the side of corn ears, leaving behind frass and a large hole, and into the tip, making a mess of the kernels and rendering the ear unmarketable. When full grown, larvae drop to the ground and pupate in the soil. The most effective way to prevent ear damage is to apply controls during whorl and tassel stage. If flights remain high throughout ear development, silk sprays may be needed.

Monitor fall armyworm moth flight with a bucket trap (e.g., Universal Moth Trap or Multipher traps) with a lure clipped under the lid (Scentry 4-component lure is recommended) and a vapor strip placed inside the trap. Hang the trap on a stake at plant height in whorl stage corn. Identify and count FAW moths at least weekly. Flag the location well and move the trap to younger corn at tasseling. Replace the lure every 2 to 4 weeks, and the vapor strip every 6 to 8 weeks.

Scout whorl and emerging tassel stage corn by checking 100 plants in groups of 10 or 20 in a V or X pattern across the field. Avoid checking only field edges and select plants at random, not only where you can see damage. A plant is ‘infested’ if at least one caterpillar is found. If feeding damage is old and no larva is found, the caterpillar may have left the plant to pupate in the soil. If 15% or more of plants are infested with FAW, a control is needed.
In emerging tassels, combine counts for ECB and FAW. For example, if 10% of plants have FAW and 12% have ECB, the combined infestation is 22%, above the 15% threshold.

Common armyworm, also known as armyworm or true armyworm, migrates from southern areas anytime from March to September. Eggs are laid on grasses and grains in preference to corn and other crops. Larvae feed at night and are grayish green with a broad stripe on each side and a yellow-brown head. Damage is similar to fall armyworm and is often spotty and not sufficient to require treatment. Outbreaks are not common in New England but do occur occasionally, and can cause significant damage.

alpha-cypermethrin (Fastac* EC): 2.8 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Use alone to control light populations or first and second instar larvae. Add a contact insecticide to control more mature larvae and higher populations. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Use alone to control light populations or first and second instar larvae. Add a contact insecticide to control more mature larvae and higher populations. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. For first and second instar only.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M. Group UN.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 2d ears, REI 24h or 21 days for workers detasseling corn, Bee: H, Group 1A. For fall armyworm. Hand harvesting is prohibited. Highly toxic to bees; avoid use in corn that is shedding pollen. May encourage buildup of aphids by killing natural enemies.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/APHI 1d, REI 4h, Bee: L, Group 28. For foliar applications.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Apply to early instar larvae prior to boring into ear or stalk.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. For fall armyworm, target first and second instar only. Direct the application to the ear zone to obtain thorough coverage of the corn silk.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. FAW only.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A; PHI 3d, REI 12h for mechanically harvested and 14 days for hand harvested, Bee: H, Group 22. Whorl through tassel emergence (prior to silking) application only. For fall armyworm only.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Use high rate for large larvae.

methomyl (Lannate* SP): 0.25 to 0.5 lb/A; PHI 0d, REI 48h, Bee: H, Group 1A. Some sweet corn varieties may be damaged by methomyl. More severe damage may occur with the Lannate* LV formulation than with the Lannate* SP (Soluble Powder) formulation.

methoxyfenozide (Intrepid): 4 to 16 fl. oz./A; PHI 3d, REI 4h, Bee: L, Group 18.

methoxyfenozide + spinetoram (Intrepid Edge): 4 to 12 fl. oz./A; PHI 3d, REI 4h, Bee: M, Group 5 & 18.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinetoram (Radiant SC): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Apply as directed spray into leaf whorls or as broadcast spray.

spinosad (Entrust SCOG): 1.5 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Apply as directed spray into leaf whorls or as broadcast spray.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Brown Marmorated Stink Bug (Halyomorpha halys)

See stink bugs in the insect control section of Tomato, Outdoor for information on brown marmorated stink bug.       

acetamiprid (Assail): 2.3 oz./A; PHI 7d, REI 12 h, Bee: M, Group 4A. Suppression only.

bifenthrin (Brigade* 2EC): 6.4 oz/A; PHI 1d, REI 12 hr, Bee: H, Group 3A. Do not make aerial or ground applications to corn if heavy rainfall is imminent.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee: H, Groups 28 & 3A.

methomyl (Lannate* LV): 1.5 pt/A; PHI 0d, REI 48h, Bee: H, Group 1A.

Corn Earworm (Helicoverpa zea)

Corn earworm (CEW) moths migrate annually into the Northeast, traveling north on storm fronts, and may arrive anytime from late June through September. Heaviest numbers are found in coastal areas and up the major river valleys. The severity of infestations varies from year to year and may change suddenly during the season. CEW feeds in a wide range of crops and among vegetables its favorite crops are corn and tomato (hence it is also known as ‘tomato fruitworm’). 

Adult moths are light tan with a distinctive dark spot on each forewing, and a dark band near the margin of the hind wing, and a wingspan of 1.2" to 1.5". Live moths have bright green eyes. Moths are active at night. Fresh silk is highly attractive for egg-laying.  When migratory flights arrive, females are ready to lay eggs. Single, globe-shaped eggs are laid directly on fresh silk and hatch in 2.5 to 6 days depending on temperature. Newly-hatched caterpillars crawl down the silk channel and feed on the kernels at the tip, leaving unsightly frass. In the tip, they are protected from insecticide sprays. Corn earworm larvae may be brown, tan, green, or pink, with light and dark longitudinal stripes and reach 1.5 to 2" when full grown. CEW can be distinguished from FAW and ECB by the plain, golden brown head capsule and small bumps and spines that give the body a rough texture.

Monitoring moth flight with pheromone traps is key to successful season-long control, because it enables farms to respond quickly to changes in flight and to avoid unnecessary sprays. Reports of moth trap captures at selected locations are provided in most New England states. The most accurate and timely flight information will be obtained by monitoring your own fields. Heliothis net traps baited with Hercon Heliothis zea pheromone lures are commercially available and widely used in the region. Place traps in blocks with fresh silk and count moths twice weekly to monitor average nightly catch. Replace lures every 2 weeks and move traps to a block with fresh silk as soon as silk dries.

Sprays or other control measures must be timed to prevent larvae from entering the ear. Control depends upon maintaining insecticide coverage on the silks when eggs are being laid and hatching. Directed sprays to the ear zone provide the best control. Repeat applications to silk every 3 to 6 days depending on trap captures according to the chart below. If maximum daily temperature is below 85º F for 2 to 3 days, spray intervals may be extended by 1 day. Continue treatments until 5 to 7 days before final harvest or until silk is completely dry and brown. Use selective materials to conserve natural enemies of aphids and other pests.

Spray Intervals for Corn Earworm

Based on moth captures in Heliothis net traps

Moths/Night Moths/Week Spray Interval
0 - 0.2 0 - 1.4 no spray
0.2 -0.5 1.4 - 3.5 6 days
0.5 - 1 3.5 – 7 5 days
1 - 13 7 – 91 4 days
Over 13 Over 91 3 days

Bt hybrids that express the insect toxin found in Bacillus thuringiensis (Bt) in leaves, husks and kernels offer protection against CEW and may not require additional insecticide applications for control of this pest.

alpha-cypermethrin (Fastac* EC): 2.8 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Use alone to control light populations and add a contact insecticide to control moderate to heavy populations. Maintain frequent spray intervals.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M. Group un.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 2d ears, REI 24h or 21 days for workers detasseling corn, Bee: H, Group 1A. Hand harvesting is prohibited. Highly toxic to bees; avoid use in corn that is shedding pollen. May encourage buildup of aphids by killing natural enemies.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/APHI 1d, REI 4h, Bee: L, Group 28. For foliar applications.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Apply to early instar larvae prior to boring into ear or stalk.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* SP): 0.25 to 0.5 lb/A; PHI 0d, REI 48h, Bee: H, Group A. Some corn varieties may be damaged by methomyl. More severe damage may occur with the Lannate* LV formulation than with the Lannate* SP (Soluble Powder) formulation. May not provide effective control under high corn earworm pressure.

methoxyfenozide (Intrepid): 4 to 16 fl. oz./A; PHI 3d, REI 4h, Bee: L, Group 18.

methoxyfenozide + spinetoram (Intrepid Edge): 8 to 12 fl. oz./A; PHI 3d, REI 4h, Bee: M, Group 5 & 18.

nuclear polyhedrosis virus of Helicoverpa zea (GemstarOG): 4-10 fl. oz./A; PHI 0d, REI 4h, Bee:L, Group UN. Do not tank mix with Bt products. Frequent application at low rates is usually more effective than infrequent application at high rates.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

soybean oil (Golden Pest Spray OilOG): 0.5 ml applied by hand directly to silk within 6 to 7 days after 50% of the ears are silking; REI 4h, Bee: L, Group 25. Apply at least 5 days after silk initiation to avoid tip injury, and before 7 days after silk initiation to gain optimum control. Mix with Bacillus thuringiensis, spinosad or neem for improved control. One application per field. Commercial oil applicators (i.e., Zea-later) are available.

spinetoram (Radiant SC): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Apply as broadcast or directed spray into ear zone.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Apply as directed spray to ear zone or as broadcast spray; ensure thorough wetting of silks. Effective for low to moderate CEW pressure; may be less effective when CEW pressure is high (13 or more moths/night in pheromone trap) or when a 3-day spray schedule is warranted. A 1 to 2-day re-treatment schedule may be necessary at silking.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Corn Leaf Aphid (Rhopalosiphum maidis)

The corn leaf aphid (CLA) is blue-green or black, with black legs. These aphids overwinter as eggs or females on grass weeds and grains, including barley and wheat. When these cereals mature, winged aphids develop and migrate to corn and wild grasses.  Both winged and wingless female aphids occur together.  Females produce live young (nymphs) which mature in as little as 6 days, resulting in many generations per year. In corn, CLA first colonize whorl leaves and the immature tassel. Populations may become numerous enough to interfere with pollen shed and to stunt plants, and to infest layers of the husk with aphids. Maize dwarf mosaic virus may be spread by the corn leaf aphid, though the most important vector for this disease is the green peach aphid. In addition, aphids excrete a sugary liquid called ‘honeydew’ which coats leaves and husks and encourage growth of sooty mold fungus. The presence of aphids and honeydew on corn husks reduces their marketability. Varieties with purple or green tassels seem to be less susceptible to aphid build-up than those with yellow tassels. Ample rainfall or irrigation during the silk stage can reduce or eliminate aphid damage. Natural enemies reduce aphid numbers, but may not provide adequate control, especially in dry seasons. Whenever possible, conserve predators and parasites by using selective insecticides to control caterpillars. Sweet corn plantings that are seeded before 10 June are generally not bothered by corn leaf aphids. Monitor for aphids while scouting whorl or pre-tassel stage corn for ECB or FAW in July and August. Pre-tassel stage sprays may be needed when 50% of the plants are infested, or if 25% have heavy infestations. Sprays applied before 50% of the tassels emerge are more effective than later sprays.

alpha-cypermethrin (Fastac EC*): 2.8 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

acetamiprid (Assail): 0.9 to 1.2 oz./A; PHI 1d, REI 12 h, Bee: M, Group 4A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Suppression only.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

flupyradifurone (Sivanto): 7 to 14 fl oz/A; PHI 7d, REI 4h, Bee: M, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only.

methomyl (Lannate* SP): 0.25 to 0.5 lb/A; PHI 0d for ears, PHI 3d if used for forage, REI 48h, Bee: H, Group 1A. See ECB section for phytotoxicity warning.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L.

thiamethoxam (Cruiser 5FS): 1.28 to 5.1 oz/100 lb of seed; REI 12h, Bee: H, Group 4. Systemic seed treatment. Use standard slurry seed treatment equipment to ensure uniform coverage of kernels. For early season protection from corn leaf aphid.

Cutworms, including Black Cutworm (Agrotis ipsilon)

Black cutworm is the most common of the many cutworm species that damage corn in New England. Adults are night-flying tan and black moths, while the caterpillars are dark-grey to black and up to 2" in length. Moths from the South arrive between March and June. Eggs are laid mostly on grasses and winter annual weeds, usually near areas of the field prone to flooding. Certain fields tend to have a history of repeated cutworm damage. The larvae feed after dark while hiding under the soil surface during the day. There are 2 to 3 generations per year but usually only the first generation, which produces larvae in May and June, damages corn. Small larvae feed on leaves and occasionally larger larvae cut seedlings off near the soil line. Adults can be monitored with a yellow and white Unitrap from March through May. A catch of over 40 moths before June indicates that frequent spring and early summer scouting is prudent. Scout problem fields weekly, checking at least 100 plants for leaf feeding and cut stems, especially near field margins. Spot spray heavily hit areas or edges of the field if 5% of the plants have been cut down. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Foliar-applied rescue treatments are recommended over preventative soil-applied insecticides. Ground beetles, parasitic flies and wasps and other general predators help reduce populations. When corn follows sod/hay in rotation, fall-plowing may lower cutworm populations by reducing spring egg-laying sites. Weedy and reduced-till fields tend to suffer the most damage.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

beta-cyfluthrin + tebuprimphos (Aztec* 2.1G): 6.7 oz/1000 row ft; REI 48h, Bee: H, Groups 3A and 1B.

bifenthrin (Capture* LFR): 3.4 to 13.6 oz/A for at-plant applications; 4 to 5.3 oz/A for pre-plant incorporation applications; 3.4 oz/A for pre-emergence applications; REI 12h, Bee: H, Group 3A. Apply as T-band over open furrow or over the row on soil surface, in-furrow with the seed, or incorporated pre-planting to seed planting depth.

 

bifenthrin + Bacillus amyloliquefaciens strain D747 (Ethos XB): 8.5 to 17.0 fl oz/A, PHI 1d, REI 12h, Bee: H, Group 3A and BM 02 fungicide. Apply as a 5 to 7 inch band (T-band) over an open furrow, or in-furrow with the seed mixing. Can be mixed directly with liquid fertilizer. Biofungicide suppresses pathogens responsible for damping off. 

carbaryl (10% Sevin Granules): 10 lb/A; PHI 2d, REI 12h or 21 days for workers detasseling corn, Bee: H, Group 1A. Ground broadcast equipment applications only. Hand harvesting prohibited.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee:H, Groups 28 & 3A.

deltamethrin (Delta Gold*): 1 to 1.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Apply to early instar larvae prior to boring into ear or stalk.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

ethoprop (Mocap* 15%G): 20 lb/A; REI 48h, Bee: H, Group 1B. Apply 3 days before planting toat-planting time. Broadcast and incorporate immediately into top 2" of soil.

gamma-cyhalothrin (Declare*): 0.041 oz/1000 row ft for at-plant soil application, 1.02 to 1.54 oz/A foliar; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.33 fl oz/1,000 ft. as T-band or furrow application at planting, 1.28 to 1.92 oz/A foliar; PHI 1d, REI 24h, Bee: H, Group 3A. 

methomyl (Lannate* SP): 0.5 lb/A; PHI 0d, REI 48h, Bee: H, Group 1A. Some sweet corn varieties may be damaged by methomyl. More severe damage may occur with the Lannate* LV formulation than with the Lannate* SP (Soluble Powder) formulation.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 1d, REI 4 h, Bee: M, Group 5. Spread bait on soil around plants; reapply after heavy rain or at least every 2 to 4 weeks but not more than 3 times per 30 days.

tefluthrin (Force* CS): 0.46 to 0.57 oz/1000 row feet; REI 48h, Bee: H, Group 3A. For t-banded or in-furrow applications.

thiamethoxam (Cruiser 5FS): 1.28 to 5.1 oz/100 lb of seed; REI 12h, Bee: H, Group 4A. Systemic seed treatment. Use standard slurry seed treatment equipment to ensure uniform coverage of kernels. For early season protection from black cutworm.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

European Corn Borer (Ostrinia nubilalis)

European corn borer (ECB) is a resident pest that has 2 generations per year in southern and central New England and 1 generation in northern New England. Sweet corn is one of over 200 crop and weed host plants of this pest; other vegetable crops affected include bean, pepper and potato. Larvae overwinter in stalks of corn and other host plants and pupate in the spring. Adult moths emerge in late May or early June and mate in weedy or grassy areas. Growing degree days (GDD) with a base temperature of 50°F may be used to predict the beginning of moth flight (374 GDD), first eggs (450 GDD), and peak flight (631 GDD). The moths are about ¾" long, light brown in color with lighter bands on the wings. Three to 7 days after emergence, depending on temperature, females begin to lay flat, white egg masses on the underside of leaves in early corn. Eggs hatch in about 5 to 7 days (100 degree days). ECB larvae are light-colored, with a pattern of small dark spots on each segment. The head capsule is flattened and black or dark brown. Newly hatched larvae are 1/8" long and full-grown larvae are 3/4" to 1" long. Larvae feed in the whorl, leaving pinhole damage, and in the succulent emerging tassel creating brown frass in the florets. As the corn matures, these larvae move downward, bore into the stalk and tunnel into ears through the side or tip. Pupae form inside larval tunnels in the stalk. A second flight begins in mid-July to mid-August, depending on location and the seasonal growing degree day accumulation (beginning of second flight, 1400 GDD; first eggs 1450 GDD; egg hatch 1550 GDD). When moths are active during silking, eggs are laid on leaves near the ear and larvae move directly into the ear by tunneling through the husk or down the silk channel.

Since the ECB overwinters as a mature larva in corn stalks and stubble, plowing under corn refuse in the fall or early spring will help control this pest. Fields that have been in sweet corn or field corn for a long time tend to have higher pressure from ECB. Weedy fields also have higher pressure.  Natural enemies include the twelve-spotted ladybeetle which preys on eggs and small larvae. Releases of Trichogramma ostriniae, a tiny parasitic wasp which attacks ECB eggs, can reduce the need for insecticide applications. See Table 22, Biological Controls for Insect Pests for more information.

ECB flight can be monitored with 2 Scentry Heliothis net traps baited with either a New York E (II) or Iowa Z (I) lure, placed at least 50'  apart in weedy borders of corn fields with the bottom at weed height. Both types of lures are needed in New England because both E and Z strains are present. Check traps once or twice per week and replace lures every 2 weeks. Once flight is detected, corn with newly emerging tassels should be scouted weekly for the presence of ECB larvae by inspecting the tassels of 50 to 100 plants, in groups of 5 to 20 plants throughout the field. Treat if more than 15% of the plants have one or more larvae present. Timing sprays for tassel emergence reaches larvae in the whorl and the young tassel. A sprayer configuration with one nozzle directed into the tassel and a single drop nozzle to the upper parts of the plant gives the best control.  At high levels of infestation, 2 applications may be needed to provide control. Use of selective products to control ECB will conserve natural enemies of aphids and ECB.

Corn started under plastic or row cover often reaches silk stage during the first flight of ECB, such that the first eggs laid hatch during ear development. As a result, ears can be heavily infested by this pest even though scouting in early tassel did not show any feeding damage or larvae. If plants are in silk and moths are active, it is important to protect developing ears. This is also true for late season corn during the second ECB flight, especially when other caterpillar pests are absent.

Genetically modified Bt hybrids that express the insect toxin found in Bacillus thuringiensis (Bt) generally provide adequate defense against European corn borer and may not require additional insecticide applications, but scouting is still recommended to assess ECB and other pests.

alpha-cypermethrin (Fastac* EC): 2.8 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. See the general recommendations for B.t. kurstaki below. For resistance management, may be rotated with Bt kurstaki products.

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply when larvae are actively feeding. Ensure good coverage and use a spreader sticker. Use a shorter spray interval (4 to 5 days) and high rates under high borer pressure. For resistance management, may be rotated with Bt aizawai (XenTari).

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M. Group un.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Applications must be made prior to larva boring into the plant.

carbaryl (Sevin XLR Plus): 1.5 to 2 qt/A; PHI 2d ears, REI 24h or 21 days for workers detasseling corn, Bee: H, Group 1A. Hand harvesting is prohibited. Highly toxic to bees; avoid use in corn that is shedding pollen. May encourage buildup of aphids by killing natural enemies.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/APHI 1d, REI 4h, Bee: L, Group 28. For foliar applications.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Apply to early instar larvae prior to boring into ear or stalk.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A; PHI 3d, REI 12h for mechanically harvested and 14 days for hand harvested, Bee: H, Group 22. Whorl through tassel emergence (prior to silking) application only.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Use higher rates for large larvae.

methomyl (Lannate* SP): 0.25 to 0.5 lb/A; PHI 0d, REI 48h, Bee: H, Group 1A. Treat a small area of the field to determine cultivar sensitivity before spraying entire field. Phytotoxicity may occur on some varieties. More severe damage may occur with the Lannate* LV formulation than with the Lannate* SP (Soluble Powder) formulation.

methoxyfenozide (Intrepid 2F): 4 to 16 oz/A; PHI 3d, REI 4h, Bee: L, Group 18. Direct application at the whorl for early season infestations; broadcast over row for mid- to late-season infestations.

methoxyfenozide + spinetoram (Intrepid Edge): 4 to 12 fl. oz./A; PHI 3d, REI 4h, Bee: M, Group 5 & 18.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinetoram (Radiant SC): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Apply as directed spray into leaf whorls or as broadcast spray.

spinosad (Entrust SCOG): 1.5 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Apply as directed spray into leaf whorls or as broadcast spray. Time applications to coincide with peak egg hatch of each generation. Frequent treatments may be necessary when the crop is growing rapidly, during silking or under heavy pest pressure.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Flea Beetle, Corn (Chaetocnema pulicaria)

Corn flea beetles are black, tinged with bronze or bluish green, and overwinter in plant residue around the fields. They move to corn seedlings in early spring, where they feed and lay eggs in soil. Direct feeding damage is not significant, but economic damage can be caused by Stewart’s bacterial wilt, which is vectored by the beetles.  Cold winters reduce the risk of this disease, while mild winters improve beetle survival and hence transmission of wilt. A Winter Temperature Index uses the sum of the average monthly temperatures of December, January and February (in ºF) to forecast the Stewart’s wilt severity for the season: wilt is predicted to be absent if the Index is <90º F, intermediate if 90º F to 100º F, and destructive if >100º F.   The disease may appear on the earliest plantings and grow worse on succession plantings of susceptible varieties. Use resistant or tolerant varieties where possible, especially on early plantings (see Sweet Corn Varieties Section). Spunbonded row covers protect plants against this pest. Scout on sunny, calm days when beetles are active. Start applications when plants are in the spike stage if beetles are present and causing damage, especially on susceptible varieties. Apply additional treatments as needed.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

acetamiprid (Assail): 1.7 to 2.3 oz./A; PHI 7d, REI 12 h, Bee: M, Group 4A.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 2d ears, REI 24h or 21 days for workers detasseling corn, Bee: H, Group 1A. Hand harvesting is prohibited. Highly toxic to bees; avoid use in corn that is shedding pollen. May encourage buildup of aphids by killing natural enemies.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee:H, Groups 28 & 3A.

deltamethrin (Delta Gold*): 1 to 1.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* SP): 0.25 to 0.5 lb/A; PHI 0d, REI 48h, Bee: H, Group 1A. See ECB section for phytotoxicity warning.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

phorate (Thimet* 20-G): 4.5 to 6 oz/1,000 row feet; PHI 30d, REI 48h, Bee: H, Group 1B. Apply in a 7" band over the row at planting and lightly incorporate. DO NOT use in-furrow.

terbufos (Counter* 20G): 4.5 to 6 oz/1,000 row feet for any row spacing; REI 48h, Bee: M, Group 1B. Place granules in seed furrow behind planter shoe or in a 4-5" band over the row, and lightly incorporate.

thiamethoxam (Cruiser 5FS): 1.28 to 5.1 oz/100 lb of seed; REI 12h, Bee: H, Group 4A. Systemic seed treatment. Use standard slurry seed treatment equipment to ensure uniform coverage of kernels. For early season protection from corn flea beetles.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

Japanese Beetle (Popillia japonica)

These beetles feed on corn silk, but are usually controlled by sprays directed at controlling ECB and corn earworm.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

acetamiprid (Assail): 2.3 oz./A; PHI 7d, REI 12 h, Bee: M, Group 4A.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Adults only.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 2d ears, REI 24h or 21 days for workers detasseling corn, Bee: H, Group 1A. Hand harvesting is prohibited. Highly toxic to bees; avoid use in corn that is shedding pollen. May encourage buildup of aphids by killing natural enemies.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee: H, Groups 28 & 3A.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Adults only.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Adults only.

lamba-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Adults only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Adults only.

Sap Beetles, Fourspotted (Glischrochilus quadrisignatus) and Dusky (Carpophilus lugubris) Sap Beetle

Sap beetle problems are more likely to occur on farms producing a variety of fruit and vegetable crops. Adult beetles are 3/16" long and are black (Dusky sap beetle), or black with orange spots (Fourspotted sap beetle, also known as ‘picnic beetle’). They survive the winter as pupae or adult beetles under soil or plant debris in fields, or under leaf litter along hedgerows and field margins. Eggs may be deposited in rotting fruit or discarded vegetable debris (cull piles), in wounds created by corn borer or birds, and on silk or in kernels at the tip of the ear.  Eggs are milky white and resemble tiny grains of rice, about 1/16" long. The larva is a white or light yellow grub that resembles a tiny, thin caterpillar or maggot. Larvae hollow out developing kernels, and damage may be found in the tip and scattered through the upper half of the ear.  Full grown larvae drop to the ground to pupate in the soil. Marketability of ears declines when damage, larvae or adults are present on or in kernels. Adults feed on pollen, sap, silk and injured or rotting fruit.  Males have an aggregation pheromone that attracts other beetles, both male and female. Adults move to corn at full tassel to feed on pollen, and build up as corn matures and silk turns brown. There are 2 to 4 generations per year with peak infestations in July (larvae) and late July and August (adults).

Cultural controls are essential to managing sap beetles. Ears with exposed tips, especially super sweet and Bt varieties, are more susceptible to infestation.  Research has shown that both the length and tightness of the tip cover is important to reduce infestations. Some varieties with long, tight tip cover include:  Accord, Argent, Avalon, Awesome, Bon Jour, Cuppa-Joe, Easy Money, Fantasia, Ka-Ching, Precious Gem, Prime Plus, Profit, Providence and Renaissance. To prevent or reduce damage, select varieties that have good tip cover, use clean cultivation, and control birds and ear-infesting caterpillars.  Eliminate or bury deeply any cull piles or other areas with decaying vegetables or fruit, included infested ears. Do not leave infested blocks standing; mow aggressively to chop ears as soon as the block is finished. Deep plowing may be necessary after harvest if infestations are high, to bury ears at least 4" deep.

Scout blocks at full tassel and early silk to determine if beetles are present. Unfortunately, there are no specific thresholds based on scouting. Insecticides may be warranted in fields with a previous history of 10% ear damage.  Research in Maryland showed that ear infestation begins just after silk emerges and that 1 or 2 applications made 3 and 6 to 7 days after silking begins is more effective than later or more applications. Insecticides will reduce the number of damaged kernels and ears but will not completely control heavy infestations.  Sap beetle adults and larvae are not susceptible to the Bt toxin that is present in Bt corn. Efficacy trials have shown that carbaryl (Sevin), lambda-cyhalothrin (Warrior II), bifenthrin (Bifenture), and methomyl (Lannate) are more effective than most other insecticides.  However, carbaryl cannot be used during the early silk period while corn is shedding pollen and does not allow for hand harvesting after use.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

acetamiprid (Assail): 1.7 to 2.3 oz./A; PHI 1d, REI 12 h, Bee: M, Group 4A.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 2d, REI 12h, Group 1A. 1 to 2 qt/A; PHI 2d ears, REI 24h or 21 days for workers detasseling corn, Bee: H, Group 1A. Hand harvesting is prohibited. Highly toxic to bees; avoid use in corn that is shedding pollen. May encourage buildup of aphids by killing natural enemies. Sap beetles only.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee:H, Groups 28 & 3A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Adult sap beetle only. 

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Adult sap beetle only.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Adult sap beetle only.

malathion (Malathion 57 EC): 1.5 pt/A; PHI 5d, REI 12h or 72h for workers detasseling corn, Bee: H, Group 1B. Begin treatment when 10% of ears show silk. Apply when nymphs are young. Injury may occur in the whorl and silk stages using this type of Malathion product.

methomyl (Lannate* SP): 0.25 to 0.5 lb/A; PHI 0d for ears, PHI 3d if used for forage, REI 48h, Bee: H, Group 1A. See ECB section for phytotoxicity warning.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Adult sap beetle only.

Seedcorn Maggot (Delia platura)

See seedcorn maggot in the insect control section of Beans for more information about biology and management.

beta-cyfluthrin + tebuprimphos (Aztec* 2.1G): 6.7 oz/1000 row ft; REI 48h, Bee: H, Groups 3A and 1B.

bifenthrin (Capture* LFR): 3.4 to 6.8 oz/A for at-plant applications; 4 to 5.3 oz/A for pre-plant incorporation applications; PHI 2d, REI 12h, Bee: H, Group 3A. Apply as T-band over open furrow, in-furrow with the seed, or incorporated pre-planting to seed planting depth.

gamma-cyhalothrin (Declare*): 0.041 oz/1000 row ft for at-plant soil application; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.33 fl oz/1,000 ft as T-band or furrow application at planting; PHI 1d, REI 24h, Bee: H, Group 3A.  

phorate (Thimet* 20-G): 4.5 to 6 oz/1,000 row feet in a 7" band over the row at planting and lightly incorporate; PHI 30d, REI 48h, Bee: H, Group 1B. DO NOT use in-furrow.

tefluthrin (Force* CS): 0.46 to 0.57 oz/1000 row feet; REI 48h, Bee: H, Group 3A. For t-banded or in-furrow applications.

terbufos (Counter* 20G): 4.5 to 6 oz/1,000 row feet; REI 48h, Bee: M, Group 1B. Place granules in seed furrow behind planter shoe or in a 4-5" band over the row, and lightly incorporate.

thiamethoxam (Cruiser 5FS): 1.28 to 5.1 fl oz/100 lb of seed; REI 12h, Bee: H, Group 4A. Systemic seed treatment. Use standard slurry seed treatment equipment to ensure uniform coverage of kernels. For early-season protection from seedcorn maggot.

Stalk Borer (Papaipema nebris)

Stalk borer (also known as common stalk borer) is an occasional pest of corn and of other vegetable crops. It is the egg stage that overwinters, on grassy weeds where adult moths deposited them in the fall. Upon hatching in the spring, the caterpillars feed on grasses by boring into and along the stalk. When the caterpillars become too large to feed within the grass, they migrate to nearby thicker-stemmed wild and cultivated plants. In corn, infestations are heaviest in border rows and in fields with grassy weeds. Borers feed in the stalk or deep in the whorl, which may kill the growing tip. Larvae are brown to purplish brown with a broad white stripe on the back and each side. These stripes are interrupted by a distinctive, large brown spot around the whole body.  Pupation occurs in the soil in late summer, with adult emergence and activity from August to October. There is one generation per year. Reduced tillage fields, which may have higher levels of grassy and broad-leaf weeds, may result in increased levels of stalk borer. To reduce overwintering eggs, prevent or eliminate grassy weeds especially from August on. Destroy weeds and grasses at field margins to reduce invasions at field borders. Scout for injury soon after the corn emerges in the spring and treat infested corn as needed. Apply insecticides to outer rows at the first sign of damage by this pest. Treat small larvae before they bore into stalks.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Application must be made prior to larva boring into the plant.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 1d, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Apply to early instar larvae prior to boring into ear or stalk.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Wireworms and White Grub

See wireworms in the insect control section of Potato for more information. To avoid wireworm problems, corn should not be grown in rotation with sod or grass crops. Delay planting susceptible crops, such as corn or potatoes, on such land for at least two years after the sod has been broken. Summer fallow is recommended for at least one season.

Land that was in sod or pasture should be planted to legumes, such as alfalfa or clover, for a year or more before planting corn or other vegetables to reduce the number of white grubs in the soil.  Plow or harrow in mid-summer, after harvesting early corn, to reduce grub numbers.

beta-cyfluthrin + tebuprimphos (Aztec* 2.1G): 6.7 oz/1000 row ft; REI 48h, Bee: H, Groups 3A and 1B. 

bifenthrin (Capture* LFR):  3.4 to 13.6 oz/A for at-plant applications; 4 to 5.3 oz/A for pre-plant incorporation applications; PHI 2d, REI 12h, Bee: H, Group 3A. Apply as T-band over open furrow, in-furrow with the seed, or incorporated pre-planting to seed planting depth.

ethoprop (Mocap* 15%G): 8 oz/1,000 row feet; REI 48h, Bee: H, Group 1B. Apply as 6" to 7" band over closed seed furrow, then incorporate immediately into top 0.5" of soil. Suppression only for white grubs. Extremely toxic to birds; do not leave granules on soil surface.

gamma-cyhalothrin (Declare*): 0.021 oz/1000 row ft for at-plat soil applications; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.33 fl oz/1,000 ft. as T-band or furrow application at planting; PHI 1d, REI 24h, Bee: H, Group 3A.

phorate (Thimet* 20-G): 4.5 to 6 oz/1,000 row feet; PHI 30d, REI 48h, Bee: H, Group 1B. Apply in a 7" band over the row at planting and lightly incorporate. DO NOT use in-furrow.

tefluthrin (Force* CS): 0.46 to 0.57 oz/1000 row feet; REI 48h, Bee: H, Group 3A. For T-banded or in-furrow applications. Use high rate for heavy infestations. For best control, place in seed furrow.

terbufos (Counter* 20G): 4.5 to 6 oz/1,000 row feet; REI 48h, Bee: M, Group 1B. Place granules in seed furrow behind planter shoe or in a 4-5" band over the row, and lightly incorporate.

thiamethoxam (Cruiser 5FS): 1.28 to 5.1 fl oz/100 lb of seed; REI 12h, Bee: H, Group 4A. Systemic seed treatment. Use standard slurry seed treatment equipment to ensure uniform coverage of kernels. For early-season protection from wireworms and white grub (including Japanese beetle larvae, European chafer larvae, true white grub, annual white grub, May/June beetle larvae).

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Delayed Herbicide Applications

Growers using atrazine (Aatrex) and or mesotrione (Callisto) for broadleaf weed control and either metolachlor (Dual) or pyroxasulfone (Zidua) for grass control in corn should consider delayed applications in their earliest plantings. Reasons for delaying herbicide applications in the earliest sweet corn plantings include:

  1. Corn is most tolerant to both Dual and Zidua after emergence. Supersweet varieties and some "se" sweet corns are easily injured by these herbicides when the soil is below 60°F. Both Dual and Zidua as well as atrazine and Callisto can be applied at any time as long as the corn is less than 5" high. Bicep Lite II, a very commonly used prepack of atrazine and Dual, can also be used this way as can Lumax, a prepack of metolachlor, atrazine, and mesotrione.
  2. If the first few plantings of sweet corn are sprayed on the same day, the amount of cleaning and rinsing of the spray tank is reduced since it does not need to be cleaned between applications when the same herbicide is used.
  3. Delaying herbicide applications on the earliest plantings will also extend the activity of the herbicide later into the season. This is important in maintaining good weed control throughout the season to minimize weed seed production. Growers often rely on sweet corn rotations to reduce weed seed populations in the soil.

Growers should consider waiting until their first planting of sweet corn is 3" to 5" high to apply herbicide. At this time all fields of sweet corn planted to date can be treated. Each field sprayed will be at a different stage of growth. After that, each field should be sprayed soon after it is planted, since soils will be warmer and grasses are more likely to emerge soon after seeding the crop.

A possible problem with delayed applications involves the potential for poor control of grasses. Dual, Zidua, Bicep (atrazine + Dual), or Lumax (atrazine + Dual + Callisto) must be applied before grasses emerge. If grasses are not controlled in corn, yield reductions will likely occur. Also, as the soil warms up, grasses are likely to emerge soon after seeding.

Reduced Herbicide Rates for Corn Weed Management 

Be sure to follow the herbicide rates recommended in this guide. Only 1 lb active ingredient of atrazine is recommended for sweet corn in New England. This is well below the rate on the label and constitutes best management practices for groundwater protection. This rate could be reduced further, although the grower should be prepared to make a second application of atrazine if any weeds escape. Rates for Dual and Lasso should be selected based on soil type. Follow the label to determine the correct rate. Reducing the rate of Dual or Zidua is risky since it is very difficult to control grasses in sweet corn once they emerge.

Special Atrazine Precautions

The Environmental Protection Agency and Syngenta have revised the label uses of all atrazine products to reflect the potential for surface and groundwater contamination. Be sure to read and follow all directions and restrictions listed on the label. The preceding section on Reduced Herbicide Rates for Corn Weed Management reflects these concerns. All of the rates listed in this guide for atrazine are within the guidelines of the label. These include uses for single applications (applied before crop emergence or early postemergence) and sequential applications (applied both at planting and postemergence). Please read all labels carefully.

Stale Seedbed Applications

The following herbicides are nonselective and are used to control weeds which are present in a field prior to planting the sweet corn or before the sweet corn emerges (see Stale Seedbed Technique, page 107). If a grower is using "no-till" or "minimum tillage," these herbicides are also used to kill the cover crop that may be present in the field.

glyphosate (Roundup Power Max): REI 12h, Group 9. Apply to emerged annual or perennial weeds prior to crop emergence. Do not feed crop residue to livestock for 8 weeks following treatment. Consult the manufacturer's label for specific weeds and rates. May be tank mixed with atrazine, simazine or alachlor.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A.  Apply in 20 to 60 gallons spray mix to emerged weeds. Field should be prepared several days ahead of treatment to allow maximum weed emergence. Use a nonionic surfactant at a rate of 16 to 32 oz per 100 gal spray mix. May be tank mixed with atrazine or simazine preemergence. Can also be applied as a preemergence. Check label for directions. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training...(link is external). The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

acetochlor (Surpass): REI 12h, Group 15.  Not for use in New Hampshire. Works to inhibit weed seed germination, and will not work on emerged weeds.  Labeled for control of annual grasses and broadleaf weeds.  Can be used early preplant, preplant incorporated, preemergence, postplant-preemergence, and early crop postemergence.    Rates based on both soil texture and tillage system used (conventional, reduced, or no-till).  Read label for proper rate selection. Also see label for herbicides approved as tank-mixing partners. 

dimethenamid (Outlook): PHI 50d, REI 12h, Group 15.  May be applied preplant surface, preplant incorporated, preemergence, or postemergence to corn up to 12-inches tall. May be applied as a single application or two split applications.  See Table 2. of product label to select correct rate for your soil texture and organic matter content. A split application may be used (8 to 16 fl oz/A per application, not to exceed 24 fl oz/A per year).  Allow a minimum of 14 days between applications. First application can be applied preplant, preemergence, or postemergence, then apply the remainder (8 to 16 oz/A) of the seasonal maximum rate during the second application (postemergence).  Can be tank-mixed with many other herbicides, see label for details.  Check with seed supplier for potential varietal susceptibility to injury. Outlook is a selective residual herbicide for controlling many annual grasses, annual broadleaf weeds, and sedges as they germinate. Will not control emerged weeds.

pendimethalin (Prowl H2O): REI 24h, Group 3. Apply before weed germination. Emerged weeds will not be controlled.  Work against annual grasses and some broadleaf weeds.  Can be used after planting but before weeds germinate and crop emerges, or after corn emerges until it is 20 to 24-inches tall or at V8.  Rate based on soil texture, see label for details.  When used after planting, there is potential for crop injury if herbicide is moved into the seed zone.  Minimize the potential for crop injury by preparing a firm seedbed and planting corn seed at least 1.5" deep.  If heavy rains follow an application to dry soil, Prowl can move to the seed zone and cause crop injury. Specific weeds for which this herbicide should be considered include triazine-resistant lambsquarters, and velvetleaf. 

pyroxasulfone (Zidua): PHI 37d, REI 12h, Group 15.  A root-and-shoot growth inhibitor that controls susceptible germinating seedlings before or soon after they emerge from the soil. Application rates vary depending on soil texture, see label for details. May be applied preplant surface, pre-plant incorporated, preemergence, or early postemergence to corn for residual preemergence control of weeds. See label for application instructions for each timing.  Plant corn seed at least 1" deep.  Labeled for use against many annual grasses and broadleaf weeds. Controls most annual grasses including crabgrass, panicum, foxtails, and barnyardgrass.  Weak on common lambsquarters but will control redroot pigweed, carpetweed, nightshade, and common purslane.  Has activity on yellow nutsedge. 

s-metolachlor (Dual Magnum)PHI 30d, REI 12h, Group 15.  Can be used either preplant surface, preplant incorporated, preemergence, or lay-by.  See label for application instructions and rates based on timing and soil type. 

simazine (Princep): PHI 45d, REI 12h, Group 5. Apply up to 2 qt/A preplant incorporated or to the soil surface immediately after planting before corn emerges. Use alone only if annual grasses are not a problem.  Do not apply on highly erodible soils unless there is at least 30% plant residue cover. 

Herbicides Used Pre- and Postemergence to Weeds

2,4-D (Amine 4): PHI 45d, REI 28h, Group 4.   Can make one preplant or preemergence application per crop cycle. Apply up to 2.14 pt/A (1.0 lb ae/acre) to soil anytime after planting but before corn emerges. Can make one postemergence application per crop cycle. Apply a maximum of 1.07 pt /A (0.5 lb ae/acre) per application. Use drop nozzles to direct spray toward base if corn is over 8" tall. Do not apply from 7 to 10 days before tasseling to dough stage. Allow a minimum of 21 days between applications. Use a maximum of 3.2 pts/acre (1.5 lbs ae/acre) per year. Reduce rate of 2,4-D if temperature is hot and soil is wet. Use only the amine formulation of 2,4-D; Do not use any ester or low-volatile ester formulations. Use all precautions to avoid spray drift to desirable broadleaf crops.

atrazine (Aatrex 4L): REI 12h, Group 5.  Apply preplant incorporated or to the soil surface immediately after planting. Use alone only if annual grasses are not a problem.  Shallow cultivation may help to control annual broadleaf weeds. May be tank mixed with any of the preemergence grass herbicides listed above as well either glyphosate or paraquat for burndown of existing weeds.

For postemergence applications, add either 1 qt/A of crop oil concentrate or 1 gal/A of spray oil. Apply when weeds are 1 to 1 1/2" high and before corn is 12" high. This treatment can be used as the primary broadleaf herbicide treatment instead of an application at planting or it can be used as an emergency treatment if the soil-applied broadleaf herbicide treatment failed. If applied correctly, this application will control the emerged weeds and will continue to provide residual control for later-emerging broadleaf weeds. Check label for additional precautions regarding the use of crop oil and petroleum oils.

Only 1 lb active ingredient of atrazine is recommended for sweet corn in New England. This is well below the rate on the label and constitutes best management practices for groundwater protection. This rate could be reduced further, although the grower should be prepared to make a second application of atrazine if any weeds escape.

halosulfuron (Sandea): PHI 30d, REI 12h, Group 2.  Apply 2/3 to 1 oz/A over the top or with drop nozzles from the spike through layby stage of the corn.  If necessary, a sequential treatment of this product at 2/3 oz/A acre may be applied only with drop nozzles semi-directed or directed to avoid application into the corn plant whorl.  Do not apply more than 2 applications per year.  Do not use on “Jubilee” sweet corn.  Other varieties may also be sensitive to injury.  The use of non-ionic surfactant is recommended for use on emerged weeds (1 to 2 qt/100 gal spray). Works on germinating broadleaf weed seeds, and also on emerged broadleaf weeds.  Control varies with type and size of weed.  Species listed on the label include redroot pigweed, pokeweed, common ragweed, Pennsylvania smartweed, common sunflower, velvetleaf, wild mustard, yellow nutsedge, and wild radish. Do not cultivate for 7 days after application.

mesotrione (Callisto): PHI 45d, REI 12h,  Group 28.  May be applied by ground for preemergence or postemergence weed control.  See label for list of susceptible species. Callisto provides excellent control of many problem broadleaf species such a velvetleaf and triazine-resistant lambsquarters.  Callisto provides only partial control of yellow nutsedge and no control of ragweed when applied postemergence.

Make a single preemergence application of 6.0-7.7 oz/A after seeding to the soil surface. Can be tank mixed with many other herbicides, and it also included in some premixed products.  See label for details. Use 5 to 6 oz/A if tank mixing with atrazine. In a tank mix, the atrazine rate can be reduced to 0.5 to 1 pt/A.  A grass herbicide must also be used. On cool soils in the spring, Callisto may be a better option than using Prowl to control these two weed species. Callisto does not provide preemergence control of yellow nutsedge. With this weed, it is important to continue to use atrazine (alone or in combination with Callisto) as well as either Dual, Outlook, or Zidua preemergence. See the label for precautions and more information on tank mixes, rates, and weeds controlled.

For postemergence weed control, apply 3 oz/A to corn up to 30" tall when weeds are no more than 3" tall.  Include a nonionic surfactant.  Do not make more than 2 applications per season to corn and do not exceed a total of 7.7 oz/A of Callisto. Applications should be a minimum of 14 days apart.  Use other options if these weeds are present. See the label for precautions and more information on tank mixes, rates, and weeds controlled.  Severe corn injury resulting in yield loss may occur if any organophosphate or carbamate insecticide is applied foliar postemergence within 7 days before or 7 days after Callisto application.  May cause crop bleaching in some yellow popcorn and sweet corn hybrids. Crop bleaching is typically transitory and has no effect on final yield or quality.

Herbicides Used Postemergence to Weeds

The following herbicides are applied after weeds have emerged. They can be used as the only broadleaf weed control to supplement a soil-applied grass herbicide or they can be used as an emergency treatment if the soil-applied broadleaf herbicide fails to provide adequate control. Timing is very important when using these herbicides. Be careful to check both the ideal weed stage of growth as well as the ideal timing and application precautions for the crop.

bentazon (Basagran): PHI 30d, REI 48h, Group 6.  Apply early post-emergence overtop when weeds are small and corn has 1 to 5 leaves. Rate varies based on weed species targeted (1 to 2 pt/A). See label for info. Bentazon will not control redroot pigweed and will provide only partial control of common lambsquarters, giant ragweed and morning glory. Bentazon should be primarily used as an emergency treatment when a soil-applied broadleaf herbicide has failed. There is less chance of adjacent crop injury from spray drift than with 2,4-D.

carfentrazone (Aim EC): REI 12h, Group 14.  Apply 0.5 to 1 oz/A to actively growing weeds anytime from preplanting until corn is at the 14 leaf-collar stage.  Can be broadcast applied until corn reaches the 8 leaf-collar stage.  For application after corn is at the 8 leaf-collar stage, use drop nozzles to avoid spraying into the whorl and on the corn foliage. Tank mix with atrazine at reduced rates or another broadleaf herbicide to increase the spectrum of weeds controlled. Add non-ionic surfactant at a rate of 1 qt/100 gal spray solution. Expect to see speckling of the crop foliage after application. Initially, the injury appears to be substantial, but it is not systemic and the corn outgrows the injury rapidly. Cultivar sensitivity may vary with Aim. Use caution when treating new cultivars. Weather conditions may also affect the degree of injury observed. Injury may be more severe during periods of warm, cloudy weather with high humidity and plentiful soil moisture when corn growth is rapid and soft. Do not apply more than 2 oz/A per season.  Works best before weeds reach 4” tall or rosettes are 3” in diameter.

clopyralid (Stinger): PHI 30d, REI 12h, Group 4.   For postemergence control of weeds in the composite and legume families. Use Stinger for postemergence control of annual sowthistle, Canada thistle, common cocklebur, common sunflower, giant and common ragweed, Jerusalem artichoke, jimsonweed and other broadleaf weeds infesting field corn.  Apply timing and rates specified on the label. Spray additives are not needed or required by the label and are not recommended. Stinger is a postemergence herbicide with some soil residual activity. Observe replant restrictions on the label or injury may occur from herbicide carryover.

fluthiacet-methyl (Cadet): REI 12h, Group 14. Can be applied as a preplant burndown or after corn emerges as a postemergence weed control.  Can be used anytime until corn is 48” tall or until tasseling occurs. Apply to actively growing weeds before they reach the maximum height listed on the product label for each target weed species.  Does not control grasses, but can be tank mixed with many other herbicides.  See label for details.  Do not exceed 1.25 oz/A per season.  Do not apply to crop under stress or injury may occur. 

nicosulfuron (Accent Q):  REI 4h, Group 2. Apply 0.45 to 1.8 oz/A.  Not for use in New Hampshire. Postemergence grass herbicide.  Works on grasses only.  Best results are obtained when broadcast applied to young, actively growing grasses before corn is 12” tall.  If corn is 12" to 18" high, applications should be made with drop nozzles.   Applications must include either a non-ionic surfactant or crop oil concentrate.  An ammonium nitrate nitrogen fertilizer must also be used unless the label of a potential tank mix partner prevents it.  Do not apply if corn is greater than 18" or 5 leaf collars.  Not all sweet corn varieties are tolerant to Accent.  Check with the Dupont representative or Extension for further information.  Also see the label for optimum sizes of grasses.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

tembotrione (Laudis):  REI 12h, Group 27.  Apply 3 fl oz of Laudis per acre postemergence to control many annual broadleaf weeds, including common lambsquarter and triazine-resistant broadleaf weed biotypes, and many annual grasses.  Add oil methylated seed oil (MSO) or concentrate (COC) to be 1% of the spray solution (1 gal/100 gals of spray solution).  In addition, the label requires the addition of nitrogen liquid fertilizer (1.5 qt/A) or AMS (1.5 lb/A).  Tank mix with 0.25 to 1 lb ai/A of atrazine for improved control and to broaden the spectrum of weeds control.  Local university data supports the use of at least 0.5 lb ai/A of atrazine. 

Do not apply tank-mixes of Laudis and atrazine to corn greater than 12" tall.  Do not use postemergence if Callisto, Lumax or Lexar was used preemergence.  Do not tank-mix with Callisto.  Laudis will control/suppress most annual grass species, but may not control certain grass species or grasses larger than the maximum recommended size when treated.  Fall panicum is not controlled by Laudis.  Most broadleaf weeds should be treated before they are 6" tall and grass weeds should be treated before 2" in height.  Laudis has up to an 18 month replant restriction for many vegetables.

tolpyralate (ShieldEx 400 SC): PHI 35d, REI 12h, Group 27. Can control or suppress the growth of many young and actively growing broadleaf and grass weeds. See label for list of susceptible weeds. Apply up to 1.35 fl oz/A when corn is up to the 6 leaf collar (V6) stage or up to 20 inches tall, whichever is more restrictive. Up to two applications are permitted at least 14 days apart. Not to exceed 2.7 fl oz/A per year. Use an adjuvant for optimum activity (refer to adjuvant section of label for details). Rainfast within 1 hour after application.

topramezone (Armezon): PHI 45d, REI 12h, Group 27.  Absorbed by leaves, roots, and shoots and translocated to the growing points of sensitive weeds to control emerged weeds. Crops under stress may show transient bleaching. These symptoms are temporary and occur infrequently.  Apply up to 1 oz/A when weeds are actively growing, up until corn stage V8.  Controls many annual broadleaf weeds, including common lambsquarter and triazine-resistant broadleaf weed biotypes, and annual grasses.  Postemergence applications of Armezon require the addition of an adjuvant (crop oil concentrate) and nitrogen fertilizer for optimum weed control. Do not use postemergence if Callisto, Lumax or Lexar was used preemergence due to herbicide resistance concerns.  Will control/suppress annual grass species and broadleaf weeds, but may not control species when larger than the maximum recommended size for treatment.  Most broadleaf weeds should be treated before they are 6" tall and grass weeds should be treated before 2" in height.  Use the higher rate to suppress or control panicum species or in rescue applications where the target weeds have grown beyond the size indicated on the label.  Can be tank mixed with 0.25 to 1 lb ai/A of atrazine for improved control and to broaden the spectrum of weeds control.  Local university data supports the use of at least 0.5 lb ai/A of atrazine. 

Perennial Weed Control

Several perennial weed species, including quackgrass, bindweed and milkweed, may be present in a corn field. The grass and broadleaf herbicides described above will have limited activity on these weeds. Use of glyphosate as described below can provide excellent control of these perennial weed species.

glyphosate (Roundup Power Max): REI 12h, Group 9. Apply as a spot treatment BEFORE silking of corn. Do not treat more than 10% of the total field area to be harvested. Any crop plants receiving spray in the treated area will be killed.

Apply AFTER corn harvest to actively growing quackgrass 6" to 8" high. Wait at least 5 days and then plow. Do not plant subsequent crops other than those on the label for 30 days following application. Most effective on bindweed and milkweed at or after bloom.

Mixing Herbicides for Weed Control in Sweet Corn

Many corn herbicides can be tank mixed with one or more other herbicides to extend the spectrum of weed control.  Labels will have detailed instruction about compatible tank mixing partners and instructions on selecting rates, etc. when tank mixing.

Formulated Mixes (Prepackaged Tank Mixes)

In recent years, many products have come on the market as prepackaged combinations of herbicides which were often recommended in the past as tank-mix combinations of products purchased separately. They are designed for to expand the spectrum of control (i.e. grass herbicide mixed with broadleaf herbicide). 

There are 3 questions that a grower or pesticide applicator should ask when deciding whether to use a formulated mix or the individual herbicide.

  1. Which is less expensive on a per acre basis?
  2. Which formulation is easier to apply? Most pesticide applicators prefer to avoid wettable powders, for example.
  3. Is the ratio of the two herbicides in the formulated mix appropriate for the given field situation? For example, Bicep Lite contains 2/3 as much atrazine as Bicep and should allow growers a better opportunity to obtain good grass control without using more atrazine than is needed.

Following are some examples of formulated mixes registered for use on sweet corn. There are many others in addition to those listed.

Formulated Mix individual Herbicides Contained in Mix
Acuron atrazine (Aatrex, Group 5) + s-metolachlor (Dual, Group 15) +mesotrione (Callisto, Group 27) + Bicyclopyrone
Anthem fluthiacet-methyl (Cadet, Group 14) + pyroxasulfone (Zidua, Group 15)
Armezon Pro topramezone (Armezon, group 27) + dimethenamid (Outlook, Group 15)
Bicep Magnum
Bicep Lite Magnum (Aatrex)
metolachlor (Dual, Group 15) + atrazine (Aatrex, Group 5)
Laddock bentazon (Basagran, Group 6) + atrazine (Aatrex, Group 5)
Lexar and Lumax atrazine (Aatrex, Group 5) + metolachlor (Dual, Group 15) + mesotrione (Callisto, Group 27)

 

Cucumber, Muskmelon, and Watermelon

Introduction

Cucumbers and muskmelons (genus Cucumis) and watermelons (genus Citrullus) are related crops of tropical origin that have similar cultural requirements. All three are tender, warm season vegetables that will not tolerate chilling or soil temperatures below 55° F. Having a good rotation plan is particularly important for these crops, as they are susceptible to several soilborne pathogens such as Phytophthora blight, scab and angular leaf spot.

Types and Varieties

Cucumber types include pickling (short, with spines), slicing (long, with spines), and beit alpha types (long, with tender spineless skins). Muskmelons have orange, musky flesh, and are the most common type of melon grown in New England. Specialty melons with white or green flesh include casaba, crenshaw and honeydew types. Watermelons exhibit a range of flesh colors (red, yellow, orange) and both seeded and seedless varieties are available.

Cucumber, Muskmelon, and Watermelon Varieties
Pickling Cucumber
Slicing Cucumber
Alibi (50) – CMV, PM, S
Bristol (54) – A, ALS, CMV, DM, PM, S
Citadel (52) – A, ALS, CMV, DM, PM, S
Dasher II (58) - A, ALS, CMV, PM, S
Eureka (57) - A, ALS, CMV, PM, PV
General Lee (66) – CMV, PM, S
Supremo (56) - A, ALS, CMV, PM, PV, S
Intimidator (61) - A, ALS, CMV, PM, S
Vlasstar (52) - A, Al, CMV, PM, S
Marketmore 76 (58) - CMV, PM, S, OP
 
Speedway (56) - A, ALS, CMV, PM, S
Protected Culture/High Tunnel Cucumber
 
Corinto (slicing - 48) – CMV, PM, P
Specialty Melon
Excelsior (pickling - 50) – ALS, CMV, PM, S, P
Diplomat (71) - PM
Katrina (beit alpha - 49) - CMV, PM, S, P
Passport (70) 
Lisboa (slicing - 45) – CMV, PM, S, P
San Juan (78) - F012, PM
Noykya (slicing - 55) - PM
Sun Jewel (68) – DM, PM
Socrates (beit alpha - 52) - PM, S, P
 
Tyria (beit alpha - 56) – PM, S, P
Muskmelon
Unistars (pickling - 42) – PM, S, P
Athena (79) - F012, PM
  Divergent (75) - F012, PM
Watermelon - Seeded
Goddess (68) – F012, PM
Crimson Sweet (85)  - A, F012, OP
Gold Star (87) - F012
Sugar Baby (80) - OP
Halona (73) - F012, PM
Sangria (87) – F1, A
Sarah's Choice (76) - F012, PM
 
Sugar Cube (80) - F, PM, PV
 
Wrangler (76) - F012, PM
   
 
Watermelon - Seedless
 
Gypsy (82) - A
 
Sorbet (80) – A, F01

The number in parentheses is the approximate number of days to maturity from seeding.

Resistant or tolerant to: A: Anthracnose; ALS: Angular Leaf Spot, DM: Downy Mildew (current races only), CMV: Cucumber Mosaic Virus, F: Fusarium (races indicated where known), PM: Powdery Mildew, PV: Potyviruses, S: Scab

OP: open-pollinated, P: Parthenocarpic (sets fruit without pollination)

Soil Fertility

Soils that warm up quickly in the spring are preferred over heavier soils that remain cool. Muskmelon should be grown on very well-drained soil for optimum quality. Raised beds provide additional benefits. The soil should be fertile and high in organic matter. On sandy soils, irrigation is necessary. In non-irrigated fields, apply the lower rates of fertilizer recommended.

Apply lime according to soil test to maintain soil pH at 6.0-6.8. Watermelon can tolerate pH as low as 5.5. If the fertilizer cannot be banded at planting, add the band fertilizer amount to preplant broadcast application. If growing plants on plastic mulch, nitrogen can be applied through trickle or overhead irrigation or sidedressed along the edge of the plastic mulch. Nitrogen under the plastic mulch is protected from leaching. Foliar feeding rate is 8-10 lb actual N (4-5 lb urea) per acre. Wet foliage is conducive to disease development, so avoid foliar feeding after the 5 leaf stage.

If using transplants, use of a liquid starter fertilizer at planting time is beneficial. This is especially true with cool soil conditions because P uptake by plants is slow in colder soils. Although the specific analysis of the product is not critical, starter fertilizers usually contain higher amounts of P. Follow the recommend mixing rates on the product.  

Plant Nutrient Recommendation According to Soil Test Results for Cucumbers, Muskmelons, and Watermelons
CUCUMBERS, MUSKMELONS, AND WATERMELON* NITROGEN (N) LB PER ACRE PHOSPHORUS (P) LB P2O5 PER ACRE POTASSIUM (K) LB K2O PER ACRE
Soil Test Results   Very Low Low Optimum Above Optimum Very Low Low Optimum Above Optimum
Broadcast and Incorporate(Transplants) 50 110 60 0 0 150 90 0-40 0
Band-Place when Direct Seeding** 20-40 40 40 25-50 0 30 30 30 0
Sidedress When Vines Start to Run*** 20-40 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 80-130 150 100 25-50 0 180 120 30-70 0
* Watermelon requires a maximum of 100 lbs/A of N; excessive N may cause hollow heart in seedless varieties.
** For direct-seeded cucumbers. For melon transplants, add the band fertilizer amount to pre-plant broadcast application. Total N and K2O in the band should not exceed 5.5 lb./1000' of row. Banded P2O5 may not be of benefit in warm soils.
*** Sidedressing may not be necessary when using plastic mulch, or if organic matter can supply sufficient N; repeat sidedress in 2 to 3 weeks

Planting

Cucumbers may be direct seeded or transplanted. Because of the long season required for muskmelon and watermelon, transplants are used. Transplants are preferred for early crops. The plants should be about 3 weeks old, with just 1-2 true leaves, at transplanting time. Older transplants that have begun to run are difficult to handle and suffer greater transplant shock.

Recommended spacing for slicing cucumbers, muskmelons and watermelons is 2' between plants and 6' between rows. Pickling cucumbers should be direct seeded to 6-8" between plants and 3-6' between rows, depending on the cultivar. Most cultivars should be planted at 3' between rows.

Seedless watermelons require special growing conditions. Seedless cultivars are sterile because they are triploid, and this negatively affects their germination ability. They require high temperatures (85-95° F.) during germination, and excess soil moisture should be avoided. To ensure fruit set, a diploid (seeded) or a “pollenizer”, variety must be planted among seedless watermelons in a ratio of at least 1 pollenizer to 3 seedless plants. Growers have moved to using “pollenizer” varieties because they produce a large amount of male flowers with viable pollen, are less competitive and take up less field space than diploids (seeded) varieties.  Different pollinizer configurations can be used successfully; however, placing pollenizers in row with seedless varieties at like spacing or interplanting pollinizers between every 3rd and 4th seedless plant tends to promote better yields compared to dedicating separate rows of pollinizers. The later may be done for growing triploid (seedless) and diploid (seeded) varieties within the same field. 

In some growing seasons, vine crops that have recently been transplanted or have just germinated suddenly wilt and die. Most often, this situation occurs just following a period of 4-5 days of rainy or cloudy weather. Without sunshine, soil temperatures drop below 55° F-60° F. At these soil temperatures the plant roots cannot absorb water from the soil. Consequently, when the sun does reappear, water transpires from the leaves much more rapidly than the roots absorb water, resulting in sudden wilting and death. There is no control for this problem, except to attempt to manipulate planting around weather forecasts. Earlier planting dates increase the likelihood of this problem.

Field Culture

Early and total yields are increased with black plastic mulch. For summer plantings when day time temperatures are 85° F or greater, more growers are using white plastic mulch to avoid high soil temperatures that develop under black plastic and cause sunburn or crop loss on delicate transplants. Before the plastic is laid, be sure the soil is fertilized and the soil surface is smooth. The plastic should fit snugly against the surface. Do not lay plastic on dry soil; either irrigate or wait for rain to ensure the soil is moist prior to laying the mulch. In conjunction with plastic mulching, using hoops and spunbonded row covers will provide earlier and higher yields, while also helping to control insects such as striped cucumber beetle. Apply the covers at the time of planting and leave on until the time for pollination by bees (bloom). These crops can withstand high temperatures under the covers. A sufficient number of pollinating insects should be present to insure adequate fruit set in cucumber and melons. One strong hive of honeybees per acre as flowers just begin to open is recommended.

High Tunnel Culture

For greenhouse or tunnel production, growers may choose to use varieties that are parthenocarpic, meaning that they set fruit without pollination. Other types can be grown, but will require pollination which could be prevented or limited by the structure and other exclusion techniques employed for pest management. However, if parthenocarpic varieties are pollinated, fruit quality is reduced. In more open high tunnel structures where pollinators are likely to visit, it may be better to use gynoecious varieties, which produced mostly female flowers. 
 
In high tunnel systems, cucumbers are best trellised to use space efficiently, promote an easier harvest and encourage airflow. This can be done by using netting (commonly used with unpruned field types) or by wrapping or clipping to strings (similar to high tunnel tomato production). High tunnel cucumbers can be pruned back to one or two leaders in these systems and subsequent pruning is needed on a regular basis to remove future lateral branches, known as suckers. Cucumbers are vigorous plants and often exceed the height of the trellis system. Growers have managed this by heading the top of the plant above a node and allowing two lateral branches to develop and grow down in an “umbrella” system. Other growers simply allow the single or double leaders to hang and grow back down. 

High tunnel cucumbers have been grown successfully with various spacings. A common spacing is using 18-24” in-row spacing on beds with single rows. However, beds with single rows using 12” in-row spacing and beds with double rows using staggered 24” spacing have both been used. Between row spacing should be 4-6 feet. Match spacing with needs, varieties and management systems. 
 

Harvest and Storage

Cucumber. Harvest on a regular basis (2-4 times per week) to obtain a maximum number of fruits. Cucumbers are sensitive to chilling injury; optimum storage temperature is 50-55° F.  

Muskmelon. Melons change color as they ripen, generally taking on a yellow hue. Harvest cantaloupe and galia-types from half- to full-slip, when the melon receptacle becomes corky and a slight push of the stem will cause the melon to separate from the vine. At half-slip they are less ripe and shelf life is increased, but some flavor may be compromised. 

Only well-netted cantaloupes should be harvested; fruits with poor netting have generally been stunted in growth and lack good flavor. Other muskmelon-types require different harvesting techniques which can be specific to individual varieties. Generally, honeydews lose their fuzzy feel and must be cut from the vine at peak ripeness. Canary and crenshaws are harvested at forced-slip.  Hold muskmelons for 1-2 days at 70° F for final ripening; for longer periods of storage, maintain a temperature of 50-55° F. Long shelve life (LSL) or ‘harper’ style melons have been bred to hold for controlled pick harvests. 

Watermelon. Varieties vary in maturity indicators. The proper time to harvest must be learned by experience (and perhaps by wasting a few fruits). Dried (brown) tendrils and ground spots are two generally reliable indicators of ripeness. When the tendril on the vine at the juncture of the fruit stem turns brown, the watermelon is close to maturity. A bright yellow ground spot on the underside of the fruit also indicates maturity. The thumping method to identify ripe melons can work, after some experience is developed. Store watermelons at 50-55° F.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

PESTICIDE USE IN GREENHOUSES AND HIGH TUNNELS:

Pesticides can be used on high tunnel and greenhouse crops if: 1) the crop and pest/disease is on the label, AND the products specifically says it can be used in the greenhouse; OR 2) the crop and pest/disease is on the label, AND the product is ‘silent’ about use in the greenhouse in the greenhouse. Products that specifically prohibit greenhouse use cannot be used in greenhouses or high tunnels regardless of the crops or pests/diseases listed on the label.

Anthracnose (Colletotrichum), Alternaria Leaf Spot, and Black Rot (Didymella)

Plant only certified disease-free seed. Rotate out of cucurbits for at least 2 years. Control all weeds, especially volunteer cucurbits. Collect and burn or plow down deeply all infected crop debris after harvest. Grow cultivars with resistance if available. Avoid wounding fruit during harvesting. Immerse fruit in clean and fresh water containing 120 ppm chlorine. Chemical control can be obtained through a regular spray program of eradicant or protective fungicides. Coverage of leaf undersides and fruit is crucial to success.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 1d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.

azoxystrobin plus chlorothalonil (Quadris Opti): 3.2 pt/A; PHI 1d, REI 12h, Groups 11 & M05.  See label for tank mix precautions.  

azoxystrobin plus difenoconazole (Quadris Top): 10.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3.

boscalid (Endura): 6.5 oz/A; PHI 0d, REI 12h, Group 7. Not labeled for anthracnose.

chlorothalonil (Bravo Weather Stik): 1.5 to 3.0 pt/A; PHI 0d, REI 12h, Group M05. Bravo WS can cause injury to watermelon fruit; see label.

copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH of less than 6.5 or tank mix with Aliette.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.

famoxadone plus cymoxanil (Tanos): 8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Tank mix with an appropriate contact fungicide with a different mode of action. Not labeled for black rot.

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 14d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides. For Alternaria only.

fluopyram plus tebuconazole (Luna Experience): 6.0 to 17.0 fl oz/A; PHI 7d, REI 12h, Groups 7 & 3. Watermelon only.

mancozeb (Dithane F45): 1.6 to 2.4 qt/A; PHI 5d, REI 24h, Group M03. Some cantaloupe varieties are sensitive.

mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01. 

penthiopyrad (Fontelis): 12.0 to 16.0 fl oz/A; PHI 1d, REI 12h, Group 7. Not labeled for anthracnose.

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium bicarbonate (MilStopOG): 2.5 to 5.0 lb/100 gal; PHI 0d, REI 4h, Group NC. See label for small volume application rates.

pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11.

pyraclostrobin plus boscalid (Pristine): 12.5 to 18.5 oz/A; PHI 0d, REI 12h, Groups 11 &7. Do not make more than one application of Pristine before alternating with a non-Group 11 fungicide.

thiophanate methyl (Topsin M 70WP): For anthracnose and black rot only, 0.5 lb/A; PHI 1d, REI 12h, Group 1. The repeated exclusive use of Topsin M may lead to buildup of resistant strains of fungi and loss of disease control.

Downy Mildew (Pseudoperonospora cubensis)

Pseudoperonospora cubensis infects only members of the cucurbit family and is an obligate parasite. Its survival depends on the presence living of cucurbit hosts, either in climates which permit their growth year round or in greenhouse culture. The source of primary inoculum in cold climates is windblown sporangia from areas where plants survive the cold season. Generally, downy mildew of cucurbits does not arrive in southern New England until September. However, in some seasons it can move up the eastern seaboard early and arrive in July. The progress of downy mildew is tracked by the North American Plant Disease Forecast Center and warnings issued based on disease progression and weather (http://cdm.ipmpipe.org/).  Physiological specialization occurs in P. cubensis and at least 5 pathotypes have been described. Cucumber and melon are susceptible to all pathotypes, while squash and pumpkin cultivars vary in their reactions. Spread of downy mildew within a field can be by air currents, rain splash, workers, and tools. The main means of control are fungicide applications, the use of resistant cultivars, and cultural practices. Maximum control can be achieved only with a combination of these measures. Maximize the distance from potential inoculum sources. Use plant spacing which reduces the density of the plant canopy. Avoid overhead irrigation. Both these practices are aimed at minimizing the length of leaf wetness periods. Some commercial cultivars of cucumber have good levels of resistance to downy mildew. Watermelon and melon cultivars are available with low levels of resistance. Squash and pumpkin cultivars are resistant to some pathotypes but are very susceptible to compatible pathotypes.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin plus chlorothalonil (Quadris Opti): 3.2 pt/A; PHI 1d, REI 12h, Groups 11 & M05. See label for tank mix precautions.     

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group BM02. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

chlorothalonil (Bravo Weather Stik): 1.5 to 2.0 pt/A; PHI 0d, REI 12h, Group M05.

copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH of less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman 400 SC): 2.1 to 2.75 fl oz/A; PHI 0d, REI 12h, Group 21. Alternate sprays of Ranman with a fungicide with a different mode of action.

cymoxanil (Curzate 60 DF): 3.2 to 5.0 oz/A; PHI 3d, REI 12h, Group 27. Use only in combination of a labeled rate of a protectant fungicide (copper, chlorothalonil, mancozeb).

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Apply only in combination with a labeled rate of another non-group 40 fungicide. Do not make more than 2 sequential applications of Forum before alternating to a fungicide with a different mode of action.

famoxadone plus cymoxanil (Tanos): 8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Tank mix with an appropriate contact fungicide with a different mode of action.

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 14d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides.

fluazinam (Omega 500F): 12.0 to 24.0 fl oz/A; PHI 7d and 30d (see label), REI 12h, Group 29. See label for restrictions. 

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. A tank mix with another labeled fungicide with a different mode of action (FRAC #) must be used for resistance management.

fosetyl- Al (Aliette WDG): 2.0 to 5.0 lb/A; PHI 12d, REI 24h, Group P7. Do not tank mix with copper products or apply in a spray solution with a pH less than 6.0.

mancozeb (Dithane F45): 1.6 to 2.4 qt/A; PHI 5d, REI 24h, Group M03.

mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01.

mancozeb plus zoxamide (Gavel 75DF): 1.5 to 2.0 lb/A; PHI 5d, REI 48h, Groups M03 & 22. Apply preventively to control downy mildew. Do not tank mix with other fungicides if the target pest is only downy mildew.

oxathiapiprolin (Orondis Ultra): 5.5 to 8.0 fl.oz/A; PHI 0d, REI 4h, Group 49 & 40. Begin foliar application prior to disease development. Use higher rate when disease is present.

phosphorous acid  (Fosphite): 1.0 to 3.0 qt/20.0 gal (foliar); PHI 0d, REI 4h, Group P7. Do not apply to plants that are heat or moisture stressed. Do not apply directly to copper treated plants within 20-day interval to avoid plant injury. See label for other application methods and additional restrictions.

propamocarb HCl (Previcur Flex): 1.2 pt/A; PHI 2d, REI 12h, Group 28. Alternate with a contact fungicide (copper, chlorothalonil, sulfur).

Reynoutria sachalinensis extract (RegaliaOG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application methods and restrictions 

zoxamide + chlorothalonil (Zing!): 30.0 to 36.0 fl oz/A; PHI 0d, REI 12h, Groups 22 & M05.

Phytophthora Blight and Fruit Rot

Phytophthora capsici cannot be managed by fungicide applications alone; successful disease control is achieved only by a season-long effort to manage water and other cultural practices. The single most effective way to control this disease is to prevent its movement into clean fields by equipment, humans, or infested water. Plant susceptible crops (tomatoes, peppers, eggplant, and all cucurbit species) in fields that have no history of this disease and are well-drained. Plant non-vining crops on raised beds, avoid planting in low areas where water puddles, and improve drainage by sub-soiling after heavy rain events. Promptly disk under small areas where the disease appears along with a border of healthy appearing plants. Avoid working in wet fields and compacting the soil.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40.

cyazofamid (Ranman 400 SC): 2.75 fl oz/A; PHI 0d, REI 12h, Group 21. Addition of a surfactant improves effectiveness when disease pressure is severe. Alternate sprays of Ranman with a fungicide with a different mode of action. Observe a 30-day plant back interval for crops not on label.

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Apply only in combination with a labeled rate of another non-group 40 fungicide. Do not make more than 2 sequential applications of Forum before alternating to a fungicide with a different mode of action.

famoxadone plus cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Suppression ONLY.  Foliar or fruit phase ONLY. Tank mix with an appropriate contact fungicide. Do not alternate with other Group 11 fungicides.

fluazinam (Omega 500F): 12.0 to 24.0 fl oz/A; PHI 7d & 30d (see label), REI 12h, Group 29. See label for restrictions. 

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. A tank mix with another labeled fungicide with a different mode of action is required.

fosetyl Al (Aliette WDG): 2.0 to 5.0 lb/A; PHI 12d, REI 24h, Group P7. Do not tank mix with copper compounds. Mixing Aliette with surfactants or foliar fertilizers is not recommended. Use the high rate when Phytophthora blight is active.

oxathiapiprolin (Orondis Ultra): 5.5 to 8.0 fl.oz/A; PHI 0d, REI 4h, Groups 49 & 40. Begin foliar application prior to disease development.

phosphorous acid (Fosphite): 1.0 to 3.0 qt/20.0 gal (foliar); PHI 0d, REI 4h, Group P7. Do not apply to plants that are heat or moisture stressed. Do not apply directly to copper treated plants within 20-day interval to avoid plant injury. See label for other application methods and additional restrictions. 

Reynoutria sachalinensis extract (RegaliaOG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application methods and restrictions.

Powdery Mildew (Podosphaera xanthii)

Fungicides should be applied at the first sign of disease (or earlier with some products). Begin scouting for powdery mildew at fruit initiation. On cucurbits, powdery mildew fungi attack both the top and bottom of the leaf, and this makes the disease more difficult to control with non-systemic fungicides. However, powdery mildew fungi tend to become resistant to systemic fungicides such as Topsin-M (Group 1); Cabrio, Flint Extra, Quadris and Sovran (Group 11). Resistance to Group1 and Group 11 fungicides have resulted in the removal of these classes of fungicides from recommendations, with the exception of Pristine which is a combination product. Resistance to the DMI fungicides (Rally, Procure) is also widespread; use Rally or Procure at the high labeled rate only. The most effective contact fungicides are sulfur, mineral oil, and chlorothalonil. Begin applying fungicides when powdery mildew is at a low level (threshold is 1 of 50 old leaves with symptoms on either leaf surface) or on a preventative schedule for fields not scouted; do not begin using mobile fungicides when disease is widespread. A seven-day interval is recommended.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group BM02. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

boscalid (Endura): 6.5 oz/A; PHI 0d, REI 12h, Group 7. Suppression only.

botanical extract (EcoswingOG): 1.5 to 5.0 pt/A; PHI 0d, REI 4h, Group BM01. 

chlorothalonil (Bravo Weather Stik): 2.0 to 3.0 pt/A; PHI 0d, REI 12h, Group M05. Use caution when applying to watermelon. See label for restrictions.

copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 1d, REI 12h, Groups 9 & 12.

cyflufenamid (Torino): 3.4 oz/A; PHI 0d, REI 4h, Group U6. 

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Groups 3 & 9.

fluopyram plus tebuconazole (Luna Experience): 6.0 to 17.0 fl oz/A; PHI 7d, REI 12h, Groups 7 & 3. Watermelon only.

flutriafol (Rhyme 2.08 SC): 5.0 to 7.0 fl oz/A; PHI 0d, REI 12h, Group 3.

mineral oil (JMS Stylet-oilOG): 3.0 to 6.0 qt/100.0 gal; PHI 0d, REI 4h, Group NC. Not rejistered for use in NJ. 

metrafenone (Vivando): 10.3 to 15.4 fl oz/A; PHI 0d, REI 12h, Group 50.

potasium dihydrogen phosphate (Nutrol): 10.0 to 20.0 lb/A; PHI 0d, REI 4h, Group P7.

myclobutanil (Rally): 2.5 to 5.0 oz/A; PHI 0d, REI 24h, Group 3.

penthiopyrad (Fontelis): 12.0 to 16.0 fl oz/A; PHI 1d, REI 12h, Group 7.

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium bicarbonate (KaligreenOG): 2.5 to 5.0 lb/A; PHI 1d, REI 4h, Group NC. Not labeled for muskmelon. See label. 

quinoxyfen (Quintec): 4.0 to 6.0 fl oz/A; PHI 3d, REI 12h, Group 13. Melon only. Alternate with other effective fungicides at their recommended rates and spray intervals.

sulfur (Microthiol DisperssOG): 5.0 to 10.0 lb/A; PHI 0d, REI 24h, Group M02. Sulfur can injure plants, especially when temperatures reach 90° F. Do not apply to sulfur sensitive varieties.

triflumizole (Procure 480SC): 4.0 to 8.0 oz/A; PHI 0d, REI 12h, Group 3. Alternate with a protectant fungicide (copper, chlorothalonil, mancozeb, sulfur).

triflumizole (Trionic 4 SC): 2.0 to 4.0 fl oz/100 gal.; PHI 1d, REI 12, Group 3. Apply only as foliar spray. See label for surfactant recommendation. Labeled for greenhouse use.

Scab (Cladosporium cucumerinum)

Scab is a significant problem for summer and winter squash, pumpkin, melon, and watermelon. Resistant cultivars of cucumber are widely available. The pathogen survives in the soil on infected crop debris, may be seedborne, and is capable of saprophytic growth.  Rotate with non-cucurbit crops for 2 to 3 years. Select sites with well-drained soil and good air movement for rapid drying of foliage and fruit.  Avoid overhead irrigation and dense plant canopies.  Fungicide sprays may not be effective during extended cool, wet weather due to the short disease cycle of this pathogen.

acibenzolar-S-methyl (Actigard 50 WG): 0.5 to 2.0 oz/A; PHI 0d, REI 12 h, Group P1. For surpression only. 

chlorothalonil (Bravo Weather Stik): 2.0 to 3.0 lb/A; PHI 0d, REI 12h, Group M05. Use caution when applying to watermelon. See label for restrictions.

mancozeb (Dithane F45): 1.6 to 2.4 qt/A; PHI 5d, REI 24h, Group M03.

mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01. 

polyoxin D (OSO 5%SC): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Seed Decay

Buy treated seed. Do not use treated seed for food, feed or oil purposes.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.01 to 0.4  fl oz/100,000 seeds; PHI 0d, REI 4h, Group BM02. 

fludioxonil (Maxim 4 FS): 0.08 to 0.16 fl oz/100 lb seed; REI 12h, Group 12. For protection against seed and soil-borne fungi.

mefenoxam (Apron XL SC): 0.085 to 0.64 fl oz/lb seed; REI 48h, Group 4. For Pythium damping-off protection.

thiram (Thiram SC): 4.5 fl oz/100 lb seed; REI 12h, Group M03.

Angular Leaf Spot (Pseudomonas syringae pv. lachrymans)

Avoid working in the fields when the foliage is wet. Plow crop residue under promptly after harvest to aid decomposition. Rotate out of cucurbits for 2 years. Plant resistant varieties when possible. Use pathogen-free seed or hot-water treat the seed to kill the bacterium in the seed. Sprays may not be effective if applied too late or if environmental conditions are conducive to spread of the disease.

copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01.  Do not apply in a spray solution having a pH less than 6.5. or tank mix with Aliette.

mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01.  

Bacterial Wilt (Erwinia tracheiphila)

Bacterial wilt is transmitted by cucumber beetles. Cucumber and muskmelon are highly susceptible to wilt; watermelon is not. Seedlings at the cotyledon and 1- to 3-leaf stage are more susceptible to infection with bacterial wilt than older plants. Thus, it is especially important to keep beetle numbers low before the 5-leaf stage. Cucumber beetles must be controlled by appropriate insecticide programs. Please refer to the information on cucumber beetle for managment recommendations. Use crop rotation to reduce beetle numbers. Because this bacterium is transmitted systemically by cucumber beetles, copper sprays are of no value. Rogue infected plants. Resistant cultivars of cucumber are being developed. No resistance has been identified in melon.

Cucumber Mosaic Virus (CMV)

Many different strains of this virus occur and the host range includes plants in more than 31 different families. Many weed species also serve as hosts and the virus is seed-borne in chickweed. The virus is spread by more than 40 species of aphids and 2 beetles. Seed transmission is possible but unlikely in commercial cucumber seed. The abundance of other host plants, their proximity to crops, and the presence of vectors govern the incidence and severity of disease. The use of resistant varieties is the most effective means of control. Reduce weeds, especially chickweed, pokeweed and milkweed, as much as practical. Practice rotation and plant away from previously contaminated fields. Insecticides are not effective.

Watermelon Mosaic Virus (WMV) and Papaya Ringspot Virus (PRSV-W)

Several aphid species transmit these 2 viruses. PRSV-W is only known to occur in the cucurbit family but WMV-II has been reported from alfalfa, vetch, crimson clover, sour clover, snow-on-the-mountain and Malva parviflora. Seed transmission is considered a possibility but remains unproven.

Zucchini Yellow Mosaic Virus (ZYMV)

Zucchini Yellow Mosaic Virus was first discovered in the United States in the early 1980s. Two strains, Connecticut and Florida, are currently recognized. The Connecticut strain produces more severe symptoms than the Florida strain. The virus is transmitted in a nonpersistent manner by aphids. At this time, no weed hosts have been identified. Resistant varieties are not available.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Caution: Insecticides should not be applied when bees are active in the field.  Avoid products with high or moderate bee toxicity during bloom. If application of an insecticide is necessary while the crop is blooming, select products with low bee toxicity or with short residual period; apply in the evening after the bees have left the field. See Protecting Honeybees and Native Pollinators in the Insect Management section for more suggestions on how to avoid harmful effects on pollinators.

Aphids, Green Peach (Myzus persicae ) and Melon (Aphis gossypii)

Aphids found in cucurbits include green peach aphid and melon aphid. See Peppers for more information about green peach aphid. Melon aphid has a wide host range; vegetable crops attacked include cucurbits, asparagus, pepper, eggplant and okra. Among cucurbits, it is more serious on cucumber, muskmelon and watermelon than in squash and pumpkins. Varieties differ in susceptibility. Melon aphid overwinters in the north on woody plants including catalpa and rose of Sharon; more southerly, adults survive on cold tolerant plants including spinach and dock. Life cycle is similar to green peach aphid; winged females colonize crops in early summer, and wingless females produce live young for about 15 days (70 to 80 offspring per female) resulting in multiple generations. The time from birth to reproductive adult can be 1 week. Wingless females are 1 to 2 mm long. Color varies from light green mottled with dark green (most common) to white, yellowish or dark green. The cornicles at the tip of the abdomen are always black, a key diagnostic feature. Melon aphid outbreaks are more common in hot, dry weather.

Infestations occur on undersides of leaves where aphids extract plant sap with their piecing sucking mouthparts. Feeding causes yellowing, puckering, leaf curling, and leaf death at high numbers along with shiny honeydew deposits and buildup of sooty mold. Viruses transmitted by melon aphid include cucumber mosaic, watermelon mosaic, and zucchini yellow mosaic. Because transmission occurs within 15 seconds of feeding, insecticides may not prevent initial virus infection though they may reduce its spread in the crop. Oils may reduce virus transmission but test for phytotoxicity.

Use of reflective or row covers to prevent early infestation and virus transmission. Reflective mulch confuses aphid orientation and reduces their ability to locate and infest plants.  Direct seeding is recommended in reflective mulch for maximum effectiveness. When using row cover, apply immediately after setting transplants or seeding, and be sure transplants were not infested while in the greenhouse. Cultivars differ in susceptibility to aphid buildup and to virus; plant resistant varieties if they are available. Separate early and late plantings.

Scout for aphids beginning in mid-June by searching undersides of leaves on runners. If 20% of runners or more have live aphids treatment may be needed. Good coverage of undersides of leaves is needed with materials that require direct contact with pest; translaminar products help to reach aphid feeding sites. Use selective insecticides for other pests to conserve natural enemies.

alpha-cypermethrin (Fastac* EC): 3.4 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

acetamiprid (Assail 30 SG): 2.5 to 4 oz/A; PHI 0d, REI 12h, Bee: M, Group 4A.

afidopyropen (Sefina): 3 fl oz/A; PHI 0d, REI 12 h, Group 9D.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group UN.

bifenthrin (Brigade* 2EC): 2.6 to 6.4 oz/A (PHI 3d, REI 12h, Bee: H, Group 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A cotton and melon aphid, 10 to 13.5  oz/A gren peach aphid; PHI 1d, REI 4h, Bee: H, Group 28. For soil applicationes at planting, or drip chemigation during first half of crop growing cycle.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

dimethoate (Dimethoate 4EC): 0.5 to 1 pt/A for watermelon; 1 pt/A for other melons; PHI 3d, REI 48h, Bee: H, Group 1B. Do not use on cucumbers.

dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. Cucumber and melon transplants only, while in greenhouse. Not for use on field or greenhouse grown crops.

dinotefuran (Venom): 1 to 4 dry oz/A foliar or 5 to 7.5 dry oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip. Do not apply to vegetables grown for seed.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; 2.8 to 4.28 oz/A or 0.065 to 0.1 oz/1000 sq ft for greenhouse cucumbers; PHI 0d, REI 12, Bee: L, Group 9C.

flupyradifurone (Sivanto): 7 to 12 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 11d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil; 0.44 fl oz/10,000 plants on seedling transplants in greenhouse; PHI 21d, REI 12h, Bee: H, Group 4A. Planthouse applications only provide short-term protection; an additional field application must be made within 2 weeks following transplanting to provide continuous protection. Not for foliar applications.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May require repeated applications. Apply with a labeled companion insecticide on green peach aphids; on other aphids, use of a companion insecticide is recommended for enhanced and residual control.

lambda-cyhalothrin (Warrior* II): 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

malathion (Malathion 57 EC): 1.5 pt/A; PHI 1d, REI 24h cucumber, 12h melons, Bee: H, Group 1B. Do not apply unless plants are dry.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d for 1.5 pt/A; PHI 3d for over 1.5 pt/A, REI 48h, Bee: H, Group 1A. For melon aphid.

oxamyl (Vydate* L): 2 to 4 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9A. Selective control of aphids including melon and green peach aphid. Translaminar. Apply before populations build up.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. DO NOT apply as a foliar spray.

tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1d, REI 12 h, Bee: H, Group 21A.

Cucumber Beetle, Striped (Acalymma vittatum) and Spotted (Diabrotica undecimpunctata)

Striped cucumber beetle is a key pest of all cucurbit crops in New England, one that requires cultural and often chemical controls to prevent direct feeding damage and transmission of bacterial wilt.  Adult beetles are 7 mm long, are yellow with 3 black stripes that reach the end of the forewings, and have a yellow thorax and black head. Adults overwinter primarily in field edges near last year's crop, with a small proportion remaining in the field. With the onset of warm days (> 50° F), beetles feed on pollen in early-blooming wild plants. High tunnel and greenhouse cucumbers draw beetles first, followed by early field crops. Eggs are laid in soil at the base of the stem, and larvae feed on roots. After pupation in the soil, 'summer adults' emerge, generally in late-July and August. Summer adults feed until early fall, when they move to overwintering sites. Some may produce a second generation which emerges in the fall. There one generation per year in northern New England and a partial second generation in southern New England.

Beetles can colonize a field very rapidly. Adults cause direct feeding damage to cotyledons (often as gouges on underside), leaves (ragged holes) and the base of the stem (wounds and scars). Wounds on the stem allow entry of soil-borne pathogens. Once flowering begins, beetles congregate in flowers.  At high numbers, adults may cause pits and scars on fruit. Larval root feeding, hidden but important, reduces plant vigor and yield. The striped cucumber beetle also vectors Erwinia tracheiphila, the causal agent of bacterial wilt. The pathogen overwinters in the beetle gut, and is transmitted through fecal material deposited in feeding wounds. The bacteria then invade the vascular system of the plant. Non-infected beetles can become infected by feeding on infected plants. Cucumber and muskmelon are highly susceptible to wilt; watermelon is not. Seedlings at the cotyledon and 1- to 3-leaf stage are more susceptible to infection with bacterial wilt than older plants. Thus, it is especially important to keep beetle numbers low before the 5-leaf stage.

Use crop rotation, moving spring crops as far as possible from last year’s fields and overwintering areas. Exclude beetles by using use row covers, supported by hoops to prevent abrasion; remove at flowering to allow pollination. Use transplants so that plants reach at least the 3- to 4-leaf stage before beetles arrive. Some repellents or systemic insecticides may be applied to transplants outside the greenhouse before setting in the field, and some may be applied through drip irrigation. See cucumber beetle in the insect control section of Pumpkin, Squash and Gourds for information on using trap crops to protect a main crop of cucumbers and melons from beetle damage.

Scout twice per week from emergence to 3-leaf stage, then weekly. Count beetles per plant and note damage to leaves and stems. The economic threshold depends on the crop. To prevent bacterial wilt in highly susceptible crops such as cucumber, muskmelons, summer squash, and zucchini, treat when there is 1 beetle for every 2 plants. Less wilt-susceptible crops (butternut, watermelon, most pumpkins) will tolerate 1 or 2 beetles per plant without yield losses. Spray within 24 hours after the threshold is reached. Timely and effective early control will prevent the need for sprays during flowering when bees are active in the crop. There are few options for bee-friendly insecticides to use during flowering; if sprays are needed, apply in the evening after bees have stopped foraging. 

Spotted cucumber beetle does not overwinter here but disperses from more southern areas, reaching New England in mid to late-summer.  Also known as southern corn rootworm, it feeds in a very wide range of crops and weeds and is often found in flowers. Adults are yellowish green with 12 black spots and a black head.  Immature stages are in the soil. This pest rarely builds up to damaging levels in New England.

acetamiprid (Assail 30 SG): 2.5 to 5.3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.

alpha-cypermethrin (Fastac* EC): 3.0 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

beta-cyfluthrin (Baythroid* XL): 2.4 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2 EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A. Do not apply when foliage is wet.

cryolite (Prokil Cryolite): 8 to 16 lb/A; PHI 14d, REI 12h, Bee: L, Group UN. Melons only.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

dinotefuran (Venom): 1 to 4 oz/A foliar; PHI 1d, REI 12 hr, Bee: H, Group 4A. Do not apply to vegetables grown for seed.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24, Bee: H, Group 3. Control may be improved by the addition of a non-ionic surfactant. Do not apply during bloom or if bees are actively foraging.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 7 to 10.5 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.

kaolin (Surround WPOG): 25 to 50 lb/A or 1/4 to 1/2 lb/gal for backpack sprayer; PHI 0d, REI 4h, Bee: L. Suppression and repellence only. May be applied to transplants prior to setting in field. Use on seedlings and young plants. Product residue may need to be washed off if applied after fruit set. White residue may be minimized if applications stop when fruit is 1/4 of its expected harvest size. Follow label instructions for mixing. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

malathion (Malathion 57 EC): 2 pt/A for watermelons, 1.6 pt/A for all other melons; PHI 1d, REI 12h, Bee: H, Group 1B. Melons only.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d for 1.5 pt/A, PHI 3d for over 1.5 pt/A, REI 48h, Bee: H, Group 1A.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Actara): 3 to 5.5 oz/A; PHI 0d, REI 12h, Bee: H, Group 4.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. DO NOT apply as a foliar spray. Suppression only.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Cutworms

See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

alpha-cypermethrin (Fastac* EC): 1.4 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

deltamethrin (Delta Gold*): 1 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Seedling spray only.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 1.5 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For variegated cutworm.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft; PHI 1d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants; reapply after heavy rain or at least every 2 to 4 weeks but not more than 3 times per 30 days.

zeta-cypermethrin (Mustang*): 1.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.  

Seedcorn Maggot (Delia platura)

See seedcorn maggot in the Beans insect control section for more information.

cyantraniliprole (Verimark): 10 to 13.5 oz/A soil; PHI 1d, REI 4h, Bee: H, Group 28. Apply as in-furrow spray or transplant tray drench no earlier than 72 hours prior to planting in field, or as transplant water treatment, hill drench, or surface band.

dimethoate (Dimethoate 4EC): 0.5 to 1 pt/A for watermelon; 1 pt/A for other melons; PHI 3d, REI 48h, Bee: H, Group 1B. Do not use on cucumbers. 

Squash Bug (Anasa tristis)

See squash bugs in the insect control section of Pumpkin and Squash for more on life cycle, monitoring, and management.

acetamiprid (Assail 30 SG): 5.3 oz/A; PHI 0d, REI 12h, Bee: M, Group 4A. Most effective on newly laid eggs and nymphs.

alpha-cypermethrin (Fastac* EC): 3.0 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

bifenthrin (Brigade* 2EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A. Do not apply when foliage is wet. Apply sufficient spray volume for thorough coverage; time sprays for early morning or late afternoon. Repeated application may cause plant injury. For squash bug only.

dinotefuran (Venom): 1 to 4 dry oz/A foliar or 5 to 7.5 dry oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. For squash bug only. Do not apply to vegetables grown for seed.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A Danitol 2.4EC; PHI 7d, REI 24, Bee: H, Group 3. Do not apply during bloom or if bees are actively foraging.

flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar; PHI 1d, REI 4h, Bee:L, Group 4D. Foliar applications only. 

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Use high rate for squash bugs.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.  

Two-spotted Spider Mite (Tetranychus urticae)

Also known as Red Spider Mite. Outbreaks are often caused by the use of broad-spectrum insecticides that kill beneficial insects that normally keep two-spotted spider mites (TSSM) populations in check. Watch for white speckling on the upper surface of leaves or webbing on the undersurface around leaf veins. Avoid early-season, broad-spectrum insecticide applications for other pests. Use selective products whenever possible.  With most miticides (not bifenazate), use 2 applications, approximately 5 to 7 days apart, to help control immature mites that were in the egg stage and protected during the first application.  TSSM are prone to developing pesticide resistance so be sure to alternate between products after 2 applications to help prevent or delay resistance. For more information on TSSM, see the Eggplant section.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading and/or penetrating spray adjuvant; do not use binder or sticker type adjuvant.

bifenazate (Acramite 50WS): 0.75 to 1 lb/A; PHI 3d, REI 12h, Bee: L, Group 25.

bifenthrin (Brigade* 2 EC): 5.1 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

etoxazole (Zeal): 2 to 3 oz/A; PHI 7d, REI 12h, Bee: L, Group 10B. Do not apply more than once per season.

fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24, Bee: H, Group 3. Control may be improved by the addition of a non-ionic surfactant.

fenpyroximate (Portal XLO): 2 pt/A; PHI 3d, REI 12 hr, Bee: L, Group 21A. A selective contact miticide. Melons only.

gamma-cyhalothrin (Declare*): 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May require repeated applications. Use of a companion labeled insecticide is recommended for enhanced and residual control.

malathion (Malathion 57 EC): 1.5 pt/A; PHI 1d, REI 12h, Bee: H, Group 1B. Melons only.

Metarhizium anisopliae Strain F52 (Met 52 EC): 40 to 80 oz/100 gal (drench), 8 to 64 oz/A (foliar); PHI 0d, REI 0h, Bee:L, Group UN.

neem oil (TrilogyOG): 0.5 to 2% solution in 25 to 100 gal water/A; PHI 0d, REI 4h, Bee: M, Group 18. Avoid mid-day applications and ensure good coverage.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 23. Complete coverage is necessary; an adjuvant may be used to improve coverage and control. Effective against egg and nymphal stages.

Whiteflies

See whiteflies in insect control section of Tomato for more information.

afidopyropen (Sefina): 14 fl oz/A; PHI 0d, REI 12 h, Bee: L, Group 9D.

Chenopodium extract (Requiem EC): 2 to 3 qts/A; PHI 0d, 4h REI, Bee: L. Apply before pests reach damaging levels.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 10oz/A chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, or drip chemigation during first half of crop growing cycle.

dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. Cucumber and melon transplants only, while in greenhouse. Not for use on field or greenhouse grown crops.

dinotefuran (Venom): 1 to 4 dry oz/A foliar or 5 to 7.5 dry oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Do not apply to vegetables grown for seed.

fenpyroximate (Portal XLO): 2 pt/A; PHI 3d, REI 12 hr, Bee: L, Group 21A. A selective contact miticide. Melons only.

flonicamid (Beleaf 50SG): 2.8 dry oz/A; 4.28 oz/A or 0.1 oz/1000 sq ft for greenhouse cucumbers; PHI 0d, REI 12, Bee: L, Group 9C. Suppression only.

flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil; 0.44 fl oz/10,000 plants on seedling transplants in greenhouse; PHI 21d, REI 12h, Bee: H, Group 4A. Planthouse applications only provide short-term protection; an additional field application must be made within 2 weeks following transplanting to provide continuous protection. Not for foliar applications.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May require repeated applications. Use of a companion labeled insecticide is recommended for enhanced and residual control.

Metarhizium anisopliae Strain F52 (Met 52 EC): 40 to 80 oz/100 gal (drench), 8 to 64 oz/A (foliar); PHI 0d, REI 0h, Bee: L, Group UN.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

pyriproxyfen (Knack): 8 to 10 oz/A; PHI 7d, REI 12h, Bee: L, Group 7. Does not control adults. Apply when whiteflies reach economic threshold.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 23. Complete coverage is necessary; an adjuvant may be used to improve coverage and control. Effective against egg and nymphal stages.

thiamethoxam (Actara): 3 to 5.5 oz/A; PHI 0d, REI 12h, Bee: H, Group 4.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. DO NOT apply as a foliar spray.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107) for information on the use of these herbicides.

carfentrazone (Aim EC): REI 12h, Group 14. Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2– 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Growing on plastic mulch

Many growers choose to grow cucumber, muskmelon, and/or watermelon on plastic mulch. Herbicides can be applied before laying down plastic to help control weeds that may grow underneath the plastic or in planting holes.  Herbicides can also be used between rows of plastic.  Some herbicides can not be used under plastic, even if they are registered for use in the crop. Read labels carefully! See notes on specific herbicides in the following section for more infomation on use and timing.

Labeled for preemergence weed control under plastic:

  • bensulide (Prefar)
  • halosulfuron (Sandea) (not labeled on muskmelons)

Labeled for preemergence weed control between plastic rows (directed and shielded band app)

  • bensulide (Prefar)
  • clomazone (Command)
  • ethalfluralin (Curbit)
  • halosulfuron (Sandea) (not labeled on muskmelons)
  • pendamthalin (Prowl) (not labeled for cucumbers)

Labeled for postemergence application between plastic rows

  • halosulfuron (Sandea) (not labeled on muskmelons)
  • paraquat (Gramoxone SL 2.0)
  • clethodim (Select Max)
  • sethoxydim (Poast)

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): May be used under plastic. REI 12h, Group 0.  Apply 5 to 6 qt/A.  Can be used as a broadcast treatment (no plastic), between rows of plastic, or under plastic.  Preplant incorporate by shallow cultivation (1-2”), or apply preemergence and incorporated thoroughly by irrigation/rainfall within 36 hours of application. Used primarily where grasses are a serious problem. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

clomazone (Command 3ME): REI 12h, Group 13. 

For cucumbers: 30d PHI. Apply 6.4 to 16.2 fl oz/A.  Make one application after seeding but before cucumber emergence.

For melons: apply 6.4 to 10.7 fl oz/A. For direct seeded melons apply after seeding but before melon emergence. For transplanted melons apply before transplanting and place roots of transplant below the chemical barrier when planting.

Use the lower rate on coarse-textured soil and the higher rate on fine-textured soil.  Can be used as a broadcast treatment (no plastic) or between rows of plastic.  Do not use under plastic. Use lower rate on coarse soil. Will control annual grasses and many broadleaf weeds including common lambsquarters, velvetleaf, and jimsonweed. Combining with Curbit (tank mix or sold as premixed product “Strategy”) will also control pigweed species.  Some temporary crop injury (partial whitening of leaf or stem tissue) may be visible after crop emergence. Complete recovery will occur from minor early injury without affecting yield or earliness. See label for replanting restrictions.

DCPA (Dacthal W-75): REI 12h, Group 3.  Not labeled for cucumber.  For melons, apply 6 to 14 lb/A preemergence to weeds, but after crop emergence (after crop has 4 to 5 true leaves, is well established, and growing conditions are favorable for good growth).  If weeds have emerged, crop should be cultivated and weeded prior to application. May also be banded to weed-free soil between rows of plastic mulch.

ethalfluralin (Curbit EC): REI 24h, Group 3.  Do not use under plastic. Can be used as a broadcast treatment or between rows of plastic. Do not soil incorporate prior to planting or crop loss will occur. Apply at seeding or up to 2 days after (before the crop emerges), or apply as a banded spray between rows after crop emergence.  A minimum of ½" of irrigation water (within two days after application) or ½” of rainfall (within five days of application) is required for activation. Use 3 to 4.5 pt/A, based on soil texture.  See label for rate selection. Use during cold, wet weather can result in crop injury or stunting.

ethalfluralin + clomazone (Strategy): REI 24h, Group 3 and 13. Use 2 to 6 pt/A, based on soil texture.  See label for rate selection. Can be used as a broadcast treatment (no plastic) or between rows of plastic.  Do not use under plastic. Do not soil incorporate prior to planting. Apply to seeded crop at time of seeding or up to two days after seeding, or apply as a banded spray between rows after crop emergence.  A minimum of ½" of irrigation water (within two days after application) or ½” of rainfall (within five days of application) is required for activation.

pendimethalin (Prowl H2O): REI 24h, PHI 35d, Group 3. Not labeled for cucumber. Row middles only.  Apply up to 2.1 pt/A as a shielded application between rows with 6 inches on either side of row middles (before melon transplanting or before a seeded crop has emerged) or between rows covered with plastic mulch (before holes are punched in plastic for melon planting). Make a second shielded application up to 2.1 pt/A per between rows with a minimum of 6 inches on either side of stem or vines or between plastic mulch before melon vine running. Applications must be at least 21 days. Avoid spray contact with melon foliage or running vines because crop injury will occur.  DO NOT apply more than 2.1 pt/A in a single application or more than 4.2 pt/A per acre per season.

s-metolachlor (Dual Magnum): REI 12h, Group 15.  MASSACHUSETTS AND NEW HAMPSHIRE ONLY. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge.

Herbicides Used Pre- and/or Postemergence to Weeds

halosulfuron (Sandea): May be used under plastic. PHI 14d cucumber, PHI 57d watermelon and other melon, REI 12h, Group 2.

Can cause temporary stunting. Heavy rains following applications will increase the potential for crop injury. Use of organophosphate insecticides can increase crop injury from halosulfuron.  See the label for other precautions and a list of weeds controlled. Consider using Sandea as a supplement to Strategy (ethafluralin + clomazone) in cases where Strategy has not provided sufficient weed control and when a postemergence application is not practical.

For cucumber, cantaloupe, honeydew, and crenshaw melon: Apply 0.5 to 1 oz/A uniformly with ground equipment in a minimum of 15 gal of water per acre. Use the lower rate on lighter textured soils with low organic matter

Preemergence

  • Direct seeded - Grown on bare ground: Apply after planting, but prior to soil cracking for direct seeded crops. Grown on plastic mulch: Apply following final bed shaping and just prior to the installation of the plastic mulch. Crop may be seeded into this treated area no sooner than 7 days after application and the installation of the plastic mulch unless local conditions demonstrate safety at an earlier interval.
  • Transplanted - Grown on bare ground: Can be used as a pre-transplant application. Crop may be transplanted into this treated area no sooner than 7 days after application unless local conditions demonstrate safety at an earlier interval. Limit movment of soil into transplant holes while planting. Grown on plastic mulch: Apply following final bed shaping and just prior to the installation of the plastic mulch. Crop may be transplanted into this treated area no sooner than 7 days after application and the installation of the plastic mulch unless local conditions demonstrate safety at an earlier interval.

Postemergence

  • Direct seeded - Grown on bare ground and mulch: Apply Sandea after the crop has reached at least 3 to 5 true leaves but before first female flowers appear. May be applied as an over-the-top application, a directed spray application, or with crop shields to minimize contact of the herbicide with the crop. Grown on plastic mulch: Additional phytoxicity may occur when applications are made over plastic due to concentration of product in holes.
  • Transplanted - Grown on bare ground: Apply to transplants that are established and actively growing and in the 3 to 5 true leaf stage or no sooner than 14 days after transplanting unless local conditions demonstrate safety at an earlier interval.  May be applied as an over-the-top application, a directed spray application, or with crop shields to minimize contact of the herbicide with the crop.
  • Transplanted - Grown on plastic mulch: Over-the-top applications not allowed. May be applied as a directed spray application or with crop shields to minimize contact of the herbicide with the crop.
  • Row middles - Apply between rows of direct-seeded or transplanted crop. Avoid contact of the herbicide with the planted crop. If plastic is used on the planted row, adjust equipment to keep the application off the plastic.

Split applications for nutsedge control:

A preemergence application followed by a postemergence application.  Use a spot treatment method, treating only areas of emerged nutsedge. Application rate should not exceed 1.0 oz/A.  Avoid contact of the herbicide with the planted crop.

A postemergence followed by a postemergence. It may be necessary to use a second postemergence spot application to areas where the nutsedge has emerged or regrown. For these situations, use a spot treatment method treating only those areas of emerged nutsedge. Allow a minimum of 21 days between applications.

For watermelon : apply 0.5 to 0.75 oz/A in a minimum of 20 gallons of water per acre.  Use the lower rate on lighter textured soils with low organic matter. Where soil is fumigated prior to planting, allow at least five days after soil fumigation before an application of Sandea.

  • Grown on bare ground: For direct seeded crop, apply after planting, but prior to soil cracking.  For transplanted crop, watermelons should be transplanted into this treated area no sooner than 7 days after application unless local conditions demonstrate safety at an earlier interval. Care should be taken to limit movement of herbicide treated surface soil during the transplant process to avoid injury.
  • Grown on plastic mulch: Pre-seeding/pre-transplant – Apply following final bed shaping and just prior to the installation of the plastic mulch. Watermelons should be seeded or transplanted into this treated area no sooner than 7 days after the application and the installation of the plastic mulch unless local conditions demonstrate safety at an earlier interval. Use the lower rate on lighter textured soils with low organic matter. Care should be taken to limit movement of herbicide treated surface soil during the transplant process to avoid injury.
  • Row Middle Applications: Apply between rows of direct-seeded or transplanted crop, while avoiding contact of the herbicide with the planted crop. If plastic is used on the planted row, adjust equipment to keep the application off the plastic. Reduce rate and spray volume in proportion to area actually sprayed. Runners that come in contact with the plastic can pick up residual Sandea and may exhibit a visual crop response. Do not apply more than 2 applications or 1 oz/A of product per 12 month period. (includes applications to the crop and to row middle).

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max): PHI 14d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 14d (3 day PHI for cucumber and muskmelon), REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 3 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Eggplant

Introduction

Eggplant (family Solanaceae; Solanum melongena) is thought to have originated in Southern to Southeastern Asia. Eggplant is closely related to pepper, tomato, tobacco and potato, and shares diseases with some of these crops. Cultivation methods are similar to those for pepper, but it is more heat tolerant and cold sensitive.  Deep, well-drained sandy loam soils are ideal for eggplant. Southern slopes that warm early in the spring may yield better.

Types and Varieties

Eggplants come in a diverse array of shapes, colors and sizes, and preferences vary widely among markets. The most common type is large, oblong, and deep purple with a green calyx. Asian types are long and slender, often deep purple with purple calyxes. Specialty varieties include finger-sized eggplants, small round eggplants, and different colors in all shapes and sizes. Some varieties are marketed specifically for tunnel or greenhouse production.

Eggplant Varieties
Oblong Large-Fruited Slender Long Asian
Angela (striped) - GH Orient Express
Aretussa (white) - GH Millionaire
Beatrice  
Black Bell Slender Finger
Black Beauty Diamond
Classic Hansel 
Clara (white) Gretel (white)
Dancer (pink) Fairy Tale (striped)
Dusky  
Falcon  
Jaylo - GH  
Michal - GH  
Nadia  
Nubia (striped)  
Traviata  
White Lightning (white)  
GH: developed for tunnel or greenhouse production

Soil Fertility

Apply lime according to soil test results to maintain soil pH at 6.5-6.8.

Use a liquid starter fertilizer at transplanting, especially with cool soil conditions. Use a high phosphorus starter fertilizer mixed according to label directions (typically 3 lb/50 gal of water). Apply 8 fl oz (1 cup) per transplant. If plants are to be grown on plastic mulch, the amount of nitrogen fertilizer to be sidedressed can be reduced, since leaching is minimized. Nitrogen can be applied through drip/trickle or overhead irrigation. Drip fertigation is especially advantageous with plastic mulch. Too much nitrogen fertilization will lead to plants that are bushy, leafy and slow to bear fruit. See Plastic Mulch and Row Covers and High Tunnels for more information.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR EGGPLANT
EGGPLANT NITROGEN (N) LB PER ACRE PHOSPHORUS (P) LB P2O5 PER ACRE POTASSIUM (K) LB K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 50 150 100 25-50 0 150 100 50 0
Sidedress 3-4 Weeks after Planting 30-50 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 80-100 150 100 25-50 0 150 100 50 0

Planting

Eggplant is normally grown from transplants. Between 2 and 4 ounces of seed are required to produce plants for one acre. Germinate seeds in flats at 70-75º F. Move to 50-cell trays after emergence. Sowing directly into 50-cell trays will shorten the time needed to produce transplants by approximately 1 week. Good transplants are 6-8 weeks old, fairly large and slightly hardened. Transplant in the field with 18" (small plant types) to 30" (large plant types) between plants. This requires from 66-40 plants per 100' of row respectively. Allow 36-42" between rows. Eggplants are much less cold hardy than tomatoes. Plant eggplants out after overnight low temperatures are consistently above 50º F.

Field Culture

The use of black plastic mulch will usually result in increased early growth and yield with less damage from Verticillium wilt, perhaps because the plant is more healthy and vigorous at the time of infection. Eggplant benefits from irrigation during the period of flowering and fruit set. If soil moisture is limited at this time, yields will be reduced. Large plants may benefit from being staked. Use one 4.5' stake per plant. Temperatures above 90º F, and night temperatures below 60º F or above 70º F, can cause poor flowering and flowers drop. Fruit are also vulnerable to sunburn so enough leaf coverage is critical. 

When growing eggplant in a high tunnel or greenhouse, consider trellising to prevent plants from toppling and improve ease of harvesting later in the season.  Pruning to a two- or four-leader system may improve yields, although labor cost tradeoffs should be considered for your farm.

Harvest and Storage

Fruit should be harvested by clipping them off with sharp shears when the outside color is a glossy purple, the fruit is firm and before the seed changes color. Soft fruit, loss of glossy color and dark colored seed are signs of over-maturity. Harvest fruit as they mature to ensure continued fruit set. Fruit can be stored up to 10 days at 50-54º F and 90-95% relative humidity. Eggplant are susceptible to chilling injury if held in temperatures that are too cold. 

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Anthracnose (Colletotrichum coccodes)

Start with certified, disease-free seed, fungicide treated seed, or treat seed with hot water to disinfest. Rotate with non-solanaceous crops for at least 3 years to allow infested crop residues to decompose completely. Keep fields free or solanaceous weeds and volunteers.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Do not apply more than 1 application or other Group 11 fungicides before alteration with a non-Group 11 fungicide.

azoxystrobin plus difenoconazole (Quadris Top): 8.0 to 14.0 fl oz/A; PHI 0d, REI 12h, Groups 11 & 3. 

chlorothalonil (Bravo Weather Stik): 1.5 pt/A; PHI 3d, REI 12h, Group M5.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

flutriafol (Rhyme): 7.0 fl oz/A; PHI 0d, REI 12h, Group 11.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 0d, REI 12h, Group 11.  Do not apply more than 1 application or other Group 11 fungicides before alteration with a non-Group 11 fungicide.

tetraconazole (Mettle 125ME): 6.0 to 8.0 fl oz/A; PHI 0, REI 12, Group 3. Apply no more than twice before alternating to a fungicide with a different MOA (Group 3).

trifloxystrobin (Flint Extra): 3.0 to 4.0 oz/A; PHI 3d, REI 12h, Group 11. Do not apply more than 1 application or other Group 11 fungicides before alteration with a non-Group 11 fungicide.

Damping-Off

Buy treated seed. Do not use treated seed for food, feed or oil purposes.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi. Does not control Pythium and Phytophthora.

thiram (Thiram 42 S): 8.0 lb/100.0 lb seed; REI 24h, Group M3

Phytophthora Crown and Fruit Rot (Phytophthora capsici)

Phytophthora capsici cannot be managed by fungicide applications alone; successful disease control is achieved only by a season-long effort to manage water and other cultural practices. The single most effective way to control this disease is to prevent its movement into clean fields by equipment, humans, or infested water. Plant susceptible crops (tomatoes, peppers, eggplant, and all cucurbit species) in fields that have no history of this disease and are well-drained. Plant non-vining crops on raised beds, avoid planting in low areas where water puddles, and improve drainage by sub-soiling after heavy rain events. Promptly disk under small areas where the disease appears along with a border of healthy appearing plants. Avoid working in wet fields and compacting the soil.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 4d, REI 12h, Groups 45 and 40.

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Must be applied in a tank mix with a  fungicide with a different mode of action.

fenamidone (Reason 500 SC): 8.2 fl oz/A; PHI 14d, REI 12, Group 11. For suppression only.

fluazinam (Omega 500): 1.0 to 1.5 pt/A; PHI 30d, REI 12, Group 29. First application can be made as a soil drench at transplanting.

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Must be applied in a tank mix with a fungicide with a different mode of action.

mefenoxam (Ridomil Gold SL): 1.0 pt/A preplant or at planting; PHI 7d, REI 48h, Group 4. For crown rot phase only. Apply as a drench at planting or as a banded application. Must be moved into soil mechanically or by irrigation. Use as a preventative, will not cure infected plants.

phosphorus acid (Fosphite): 1.0 to 3.0 qts/A; PHI 1d, REI 4h, Group 33. Best efficacy when tank mixed with fungicides with a different mode of action.

Verticillium Wilt

Verticillium species can persist in the soil for many years in the absence of susceptible plants. Follow a 4- to 5-year crop rotation with non-solanaceous crops to reduce inoculum levels in fields.  Include grain crops in the rotation. Control weeds as many weeds are susceptible to Verticillium. Remove and destroy infected plant material after harvest. Resistance to Verticillium species in pepper and eggplant is poor. Fumigate in fall with Vapam as directed on the label. Mulching plants with black plastic may reduce disease severity. See Soil Fumigation Outdoors (page 89).

Trichoderma asperellum, T. gamsii (Bio-tam 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group NC.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Floating row covers can exclude beetles, increase yield and produce earlier harvests. Plants should be free of aphids and whiteflies before setting in the field. Apply covers immediately after setting transplants. Completely seal edge of the material with soil, leaving enough slack to allow for plant growth. Use wire hoops to prevent damage to growing tips. Use in conjunction with crop rotation to prevent Colorado potato beetles from emerging underneath. Remove row covers at bloom to prevent plants from becoming leggy and lodging. See Plastic Mulch and Row Covers (page 31), and High Tunnels (page 33) for more information.

Aphids, Green Peach (Myzus persicae ) and Melon (Aphis gossypii)

See melon aphid in the insect control section of Cucumber and green peach aphid (GPA) in the insect control section of Pepper for more information on each of these aphid species.

Aphids generally colonize eggplant during the first 2 weeks of July, and good control at this time with a selective insecticide will prevent the need for sprays later in the season. Good coverage of the underside of leaves is important. Treat when 1 to 2 aphids per leaf are observed. Be aware that broad-spectrum insecticide applications can cause aphid and mite outbreaks by reducing the populations of beneficial organisms.

Reflective mulch, where 50% of the surface area is reflective, will repel colonizing aphids. Even black plastic mulch has been shown to reduce aphid infestations to some extent compared with bare-ground culture.

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

afidopyropen (Sefina): 3 fl oz/A; PHI 0d, REI 4 h, Bee: L, Group 9D.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee:L, Group UN.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, drip chemigation, or soil injection. Suppression only.

dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. For transplants while in greenhouse. Not for use on greenhouse or field grown crops.

dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. For green peach and potato aphids only. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip.

flonicamid (Beleaf 50SG): 2.8 to 4.28 oz/A; PHI 0d, REI 12, Bee: L, Group 9C. Begin applications before populations begin to build, and before damage is evident. Use higher rate for building populations or dense foliage.

flupyradifurone (Sivanto): 7 to 12 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, 45d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil, 1.3 to 2.2 oz/A foliar, 0.44 oz/10,000 plants on seedling transplants in greenhouse; PHI 21d soil, PHI 0d foliar, REI 12h, Bee: H, Group 4A. Planthouse applications only provide short-term protection; an additional field application must be made within 2 weeks following transplanting to provide continuous protection.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with companion labeled aphicide.

methomyl (Lannate LV*): 12 to 48 oz/A; PHI 5d, REI 48h, Bee: H, Group 1A. For green peach aphid.

oxamyl (Vydate* L): 2 to 4 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For foliar treatment by ground equipment when insects first appear.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9B. Green peach and potato aphids only. Translaminar. Apply when aphids first appear, before populations build up.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spirotetramat (Movento): 4 to 5 oz/A; PHI 1d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 1d, REI 12h, Bee: H, Group 4C. Do not apply any time between 3 d prior to bloom and until after petal fall. 

thiamethoxam (Actara): 2 to 3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seedling root zone during or after transplanting operations. DO NOT apply as a foliar spray.

tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1d, REI 12 h, Bee: H, Group 21A.

Blister Beetles (Epicauta funebris and E. vittata)

See Blister Beetles in the Beets and Swiss chard section for more information on these two species of blister beetles. Note that both species feed on flowers and foliage in eggplant. A single spot spray with a broad-spectrum insecticide that is registered for blister beetles or flea beetles on this crop will control blister beetles.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. For beetle larvae only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Colorado Potato Beetle (Leptinotarsa decemlineata)

See Potato for more details on Colorado potato beetle (CPB), including cultural controls and resistance management. In eggplant, CPB feeding may occur in June on young transplants, or later in the season when plants are full grown and fruit is developing. Watch for emergence of summer adults in late July and August, as they can damage leaves, flowers, petioles, including clipping flower buds. This reduces fruit formation and marketable yield. Scout to determine number of adults, egg masses, small and large larvae and to assess feeding damage. The following action thresholds have been established from seedling to fruiting stage: 2 small larvae or 1 large larvae per plant (if plant is 6 inches). Avoid using insecticides from the same resistance group more than once per year.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading and/or penetrating spray adjuvant; do not use binder or sticker type adjuvant.

acetamiprid (Assail 30SG): 1.5 to 2.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group un.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

Bacillus thuringiensis subsp. tenebrionis strain SA-10 (TridentOG): 3 to 6 qt/A; PHI 0d, REI 4h, Bees: M, Group 11. Only use 3 qt/A rate when light populations of larvae of uniform age or size are present. Use of an adjuvant may improve efficacy, but avoid mixing with silicone-based surfactants. Do not apply while pollinators are actively visiting the treatment area.

Beauveria bassiana (Mycotrol ESO): 0.5 qt to 1 qt/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. See label for application rates when used through drip chemigation, or soil injection applications. For foliar applications, may be combined with a labeled adjuvant for improved leaf adhesion or control in dense foliage. For soil applications, must be applied uniformly in the root zone.

cyantraniliprole (Exirel): 7 to 13.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: H, Group 28. See label for application rates when used through drip chemigation, or soil injection applications.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 12 h, Bee: H, Group 28.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 7 to 10.66 oz/A; PHI 3d, REI 24, Bee: H, Group 3. Do not apply during bloom or if bees are actively foraging. May be combined at with Belay for control of other pests. See label for rates.

flupyradifurone (Sivanto): 10.5 to 14 oz/A; PHI 1d, REI 4h, Bee:L, Group 4D. Foliar applications only.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil, 1.3 to 2.2 oz/A foliar; PHI 21d soil, PHI 0d foliar, REI 12h, Bee: H, Group 4A.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

novaluron (Rimon 0.83EC): 9 to 12 oz/A; PHI 1d, REI 12h, Bee: L, Group 16B.

oxamyl (Vydate* L): 2 to 4 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For foliar treatment by ground equipment when insects first appear.

permethrin (Pounce* 25WP): 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. For beetle larvae only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Do not apply Group 5 insecticides to consecutive generations of CPB, and do not make more than 2 applications to a single generation.

thiamethoxam (Actara): 2 to 3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seedling root zone during or after transplanting operations. DO NOT apply as a foliar spray.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

tolfenpyrad (Torac): 14 to 21 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

Cutworms

Black cutworm is the most common of the many cutworm species that damage eggplants in New England. The dark-grey or black caterpillars hide under the soil surface adjacent to the plant stem during the day and feed after dark. On rare occasions, large larvae switch from leaf feeding to cutting stems of seedlings. Certain fields tend to have a history of repeated cutworm damage. Scout fields weekly through June after transplanting. Check at least 100 plants for cut stems, especially near field margins. Spot spray damaged areas or edges of the field if 1% or 2% of the plants have been cut down. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Hardening seedlings before transplanting toughens stems and reduces damage. See cutworms in the Pepper section for more information on this pest.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M. Group UN.

carbaryl (10% Sevin Granules): 20 lb/A; PHI 3d, REI 12h, Bee: H, Group 1A. Apply evenly to the soil surface.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 10.66 oz/A; PHI 3d, REI 24, Bee: H, Group 3. Do not apply during bloom or if bees are actively foraging.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.9 to 1.6 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft; PHI 1d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants.

tebufenozide (Confirm 2F): 6 to 16 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Must be ingested. Use lower rate for early season applications to young, small plants. Begin applications when first signs of feeding damage appear. Use higher rate for later season applications and heavier infestations. Use of a spreader-binder adjuvant is recommended.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Flea Beetle, Potato (Epitrix cucumeris)

Potato flea beetle feeds primarily on solanaceous crops (eggplant, tomato, pepper and potato), solanaceous weeds (jimsonweed, ground cherry, black nightshade), and other weeds including redroot pigweed and lambsquarters. It does not feed in brassica crops. Adults are 1.5 to 2.0 mm, dull black, short and broad, with a pitted and hairy body. Adult beetles spend the winter protected under leaf litter in field edges near the crop where they were feeding in late summer, and search out weed and crop plants in the spring. Eggs are laid in the soil, larvae feed on roots, and after a pupal stage in the soil, a new generation of adult beetles will emerge. These ‘summer adults’ feed heavily and then move to a protected spot for the winter. Thus, there are 2 major flushes of adults – one in late May and early June, and the second from mid-July to mid-August. Leaves that are heavily damaged may be riddled with small round ‘shot holes’ that stunt or kill plants. Potatoes, once well established, can withstand considerable feeding damage. Eggplants are vulnerable even at later stages, especially when summer adults emerge and fruit is forming.

Management practices include clean cultivation, crop rotation, removing or avoiding spring weed hosts, using row covers, and applying spot treatments targeting eggplants along the field edges. Scout to observe beetles and damage. Treat newly set transplants if they have 2 flea beetles per plant, seedlings 3" to 6" tall if they have greater than 4 beetles per plant, and plants over 6" tall if they have 8 beetles per plant. Most insecticides registered to control CPB, including spinosad, will control FB. Systemics applied to the soil at transplanting may control both flea beetle and Colorado potato beetle; avoid using the same chemical group for both soil and foliar treatments.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

beta-cyfluthrin (Baythroid* XL): 2.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 0.66 oz/A; PHI 3d, REI 24, Bee: H, Group 3. Do not apply during bloom or if bees are actively foraging. May be combined at with Belay or Dipel DF for control of other. See label for rates.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil; PHI 21d, REI 12h, Bee: H, Group 4A. Only soil applications allowed for flea beetle control.

kaolin (Surround WPOG): 12.5 to 50 lb/A or 0.125 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression and repellence only. May be applied to transplants prior to setting in field. Use on seedlings and young plants. Product residue may need to be washed off if applied after fruit set. White residue may be minimized if applications stop when fruit is 25% of its expected harvest size. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

permethrin (Pounce* 25WP): 6.4 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. For beetle larvae only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Suppression only. Do not apply to seedlings for transplant.

thiamethoxam (Actara): 2 to 3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seedling root zone during or after transplanting operations.

tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Pepper Maggot (Zonosemata electa)

Some farms with high population of pepper maggot experience damage on eggplant, especially when peppers are rotated out of the field. Perimeter trap cropping can help limit damage to eggplant. Plant 1 or 2 rows of cherry peppers around the perimeter of the eggplant and spot spray the trap crop (only) when the first stings (egg-laying scars) occur on the peppers or adult flies are captured on traps. See pepper maggot in Pepper section for more details and for effective insecticides for peppers.

Potato Leafhopper (Empoasca fabae)

Potato leafhopper feeding is toxic to eggplant. Leaf margins and tips turn yellow and curl up. Feeding can reduce yield before damage is visible. Damage is often confused with Verticillium wilt, where leaves turn yellow and droop down. Treatment is recommended if there is an average of more than 1 to 1.5 leafhoppers per leaf. See potato leafhopper in the Potato section for more information.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A.

deltamethrin (Delta Gold*): 1 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip.

fenpropathrin (Danitol* 2.4EC): 10.66 oz/A.; PHI 3d, REI 24h, Bee: H, Group 3. Do not apply during bloom or if bees are actively foraging. 

flupyradifurone (Sivanto): 7 to 10.5 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 45d soil, REI 4h, Bee:L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil, 1.3 to 2.2 oz/A foliar; PHI 21d soil, PHI 0d foliar, REI 12h, Bee: H, Group 4A.

kaolin (Surround WPOG): 12.5 to 50 lb/A or 0.125 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression and repellence only. May be applied to transplants prior to setting in field. Use on seedlings and young plants. Product residue may need to be washed off if applied after fruit set. White residue may be minimized if applications stop when fruit is 25% of its expected harvest size. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Actara): 2 to 3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Stink Bugs

See Tomato section for information on stink bugs, including brown marmorated stink bug.   

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Use higher rate for control of Brown Marmorated Stink Bug.

dinotefuran (Venom): 1 to 4 oz/A; PHI 1d, REI 12h, Bee: H, Group 4A. Foliar applications only. For brown, consperse, green, and Southern green stink bugs only. Coverage is essential for adequate control.

fenpropathrin (Danitol* 2.4EC): 10.66 oz/A. Can be combined with Belay to control brown stink bugs only, but this combination should not be applied during bloom or if bees are actively foraging; PHI 3d Danitol alone, PHI 21d Danitol + Belay, REI 24, Bee: H, Group 3.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

novaluron (Rimon 0.83EC): 12 oz/A; PHI 1d, REI 12h, Bee: L, Group 16B.

Tarnished Plant Bug (Lygus lineolaris)

See Lettuce for information about tarnished plant bug.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

beta-cyfluthrin (Baythroid* XL): 2.1 to 2.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

flonicamid (Beleaf 50SG): 2.8 to 4.28 oz/A; PHI 0d, REI 12, Bee: L, Group 9C. Begin applications before populations begin to build, and before damage is evident. Use higher rate for building populations or dense foliage.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sulfoxaflor (Closer SC): 2.75 to 4.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 4C. Do not apply any time between 3 d prior to bloom and until after petal fall. 

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Tomato Fruitworm (Helicoverpa zea)

This is another common name for the corn earworm. Caterpillars may attack tomatoes and other solanaceous crops late in the season, especially if moth numbers are high and fresh corn silk is relatively scarce. Use selective insecticides to avoid disrupting natural enemies that control secondary pests, such as mites and aphids.  For more information, see corn earworm in the Sweet Corn section.   

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

azadirachtin & pyrethrins (AzeraOG): 16 to 56 oz/A foliar, drench, and greenhouse applications; PHI 0d, REI 12h, Bee: M, Groups UN & 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M. Group UN.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. See label for application rates when used through drip chemigation, or soil injection applications. For foliar applications, may be combined with a labeled adjuvant for improved leaf adhesion or control in dense foliage. For soil applications, must be applied uniformly in the root zone.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 7 to 13.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, drip chemigation, or soil injection.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

emamectin benzoate (Proclaim*): 2.4 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Apply when larvae are first observed.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 10.66 oz/A; PHI 3d, REI 24, Bee: H, Group 3. Control may be improved by the addition of a non-ionic surfactant. 

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

indoxacarb (Avaunt): 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

methomyl (Lannate LV*): 24 to 48 oz/A; PHI 5d, REI 48h, Bee: H, Group 1A.

methoxyfenozide (Intrepid 2F): 10 to 16 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Suppression only. Apply at first sign of feeding damage, or when threshold levels are reached.

novaluron (Rimon 0.83EC): 9 to 12 oz/A; PHI 1d, REI 12h, Bee: L, Group 16B.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Do not apply to seedlings for transplant.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Two-spotted Spider Mite (Tetranychus urticae)

Two-spotted spider mite (TSSM) is the most common mite species that attacks vegetable crops in New England and feeds on tomato, eggplant, potato, beans, vine crops such as melons and cucumbers, and other crops.  In eggplant, TSSM is a key insect pest. Adult females are approximately 1/50" long, slightly orange or pale green in color with 2 dark spots on their body, and lay up to 100 eggs over their 3 to 4-week lifespan. Eggs are globular and amber red when viewed with a 10X hand legs. Eggs hatch in about 3 days and immediately begin feeding. Following two brief nymphal stages, they become adults and start laying eggs in 1 to 3 days. The life cycle can be completed in 7 to 14 days, depending on temperature.

Foliar damage results from piercing plant tissue with their mouth-parts and removing plant fluids. Feeding injury often gives the top leaf surfaces a mottled or speckled, dull or bronzed appearance. Mites cover the leaves with fine webbing. Other symptoms include distorted leaves, stunting and overall loss of plant vigor (in spite of adequate moisture and nutrition), whitening or spotting of leaves, yellowing of the plant or some of the leaves, and in some cases loss of foliage and death. Spider mites are favored and by hot, dry, dusty conditions, which also aggravates injury by stressing the plant, and by excess nitrogen which fosters succulent growth. Damage is often underestimated or goes unnoticed since the wounds and the pest are not easy to see without close inspection.

Overhead irrigation or prolonged periods of rain can help reduce populations. Do not over-fertilize. Avoid weedy fields and do not plant eggplant adjacent to legume forage crops. Avoid planting eggplant near dusty, high-traffic farm roads. Scout by searching leaves for symptoms and webbing, and using a 10- to 15X hand lens to identify mites. Use selective products and avoid broad-spectrum insecticides for this and other pests wherever possible, because outbreaks are often caused by the use of broad-spectrum insecticides that interfere with the numerous natural enemies that help to manage mite populations. With most miticides (except those with a long residual such as bifenazate), use 2 applications, approximately 5 to 7 days apart, to help control immature mites that were in the egg stage and protected during the first application. Alternate between products after 2 applications to help prevent or delay resistance. Preventative releases of the predatory mite, Phytoseiulus persimilis, may suppress TSSM populations, as they do in strawberry fields. Releases must be made when TSSM numbers are low. Amblyseius fallicis is a predatory mite that is widely used in greenhouses. See Vegetable Transplant section on insect and mite management and on scouting guidelines and biological control for information.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading and/or penetrating spray adjuvant; do not use binder or sticker type adjuvant.

acequinocyl (Kanemite 15SC): 31 oz/A; PHI 1d, REI 12h, Bee: L, Group 20B. Do not use less than 100 gal water/A. Use of an adjuvant or surfactant is prohibited.

bifenazate (Acramite 50WS): 0.75 to 1 lb/A; PHI 3d, REI 12h, Bee: L, Group 25. Long residual; not systemic, ensure complete coverage of upper and lower leaf surfaces and fruit.

bifenthrin (Brigade* 2EC): 5.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

etoxazole (Zeal): 2 to 3 oz/A; PHI 7d, REI 12h, Bee: L, Group 10B. Do not apply more than once per season.

fenpropathrin (Danitol* 2.4EC): 10.66 oz/A; PHI 21d, REI 24, Bee: H, Group 3.

fenpyroximate (Portal XLO): 2 pt/A; PHI 1d, REI 12hr, Bee: L, Group 21A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

insecticidal soap (M-PedeOG): 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

neem oil (TrilogyOG): 0.5 to 2% solution in 25 to 100 gal water/A; PHI 0d, REI 4h, Bee: M, Group 18. Avoid mid-day applications and ensure good coverage.

oxamyl (Vydate* L): 2 to 4 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For foliar treatment by ground equipment when insects first appear.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

soybean oil (Golden Pest Spray OilOG): 2 gal/10 to 80 gal water/A; REI 4h, Bee: L, Group 25. Apply once a week beginning when mites first appear.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 1d, REI 12h, Bee: M, Group 23. Effective on all developmental stages, but juvenile stages more susceptible than adults.

tolfenpyrad (Torac): 14 to 21 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

Whiteflies, greenhouse (Trialeurodes vaporariorum) and sweet potato (Bemisia tabaci)

Transplant clean plants to the field. Because whiteflies can go from egg to adult in a few days, it is important to make 2 to 3 applications 4 to 5 days apart. Alternate chemical groups to prevent development of resistance. See whiteflies in the Outdoor Tomato section for more information. 

acetamiprid (Assail 30SG): 2.5 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

afidopyropen (Sefina): 12 fl oz/A; PHI 0d, REI 12h, Bee: L, Group 9D.

beta-cyfluthrin (Baythroid* XL): 2.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. For suppression of adults only.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Chenopodium extract (Requiem EC): 2 to 3 qts/A; PHI 0d, 4h REI, Bee: L, Group UN. Apply before pests reach damaging levels. For silverleaf whitefly.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, drip chemigation, or soil injection.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Suppression only.

dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. For transplants while in greenhouse. Not for use on greenhouse or field grown crops.

dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Whiteflies only. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress or through drip.

flonicamid (Beleaf 50SG): 2.8 to 4.28 oz/A; PHI 0d, REI 12, Bee: L, Group 9C. Begin applications before populations begin to build, and before damage is evident. Use higher rate for building populations or dense foliage. For greenhouse whitefly suppression only.

flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 45d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

imidacloprid (Admire Pro): 7 to 10.5 oz/A soil, 1.3 to 2.2 oz/A foliar, 0.44 oz/10,000 plants on seedling transplants in greenhouse; PHI 21d soil, PHI 0d foliar, REI 12h, Bee: H, Group 4A. Planthouse applications only provide short-term protection; an additional field application must be made within 2 weeks following transplanting to provide continuous protection.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with a companion labeled insecticide.

lambda-cyhalothrin (Warrior* II): 1.3 to 1.9 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9A. Suppression only. Apply when whiteflies first appear.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

pyriproxyfen (Knack): 6 to 10 oz/A; PHI 1d, REI 12h, Bee: L, Group 7. Does not control adults. Translaminar.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spirotetramat (Movento): 4 to 5 oz/A; PHI 1d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

sulfoxaflor (Closer SC): 4.25 to 4.5 oz/A.; PHI 1d, REI 12h, Bee: H, Group 4C. Do not apply any time between 3 d prior to bloom and until after petal fall. 

thiamethoxam (Actara): 3.0 to 5.5 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used in an in-furrow, banded, drench, or drip irrigation application to the seedling root zone during or after transplanting operations.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 1d, REI 12h, Bee: M, Group 23. Most effective on immature stages.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107).

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): REI 12h, Group 0.  Apply 5 to 6 qt/A.  Can be preplant incorporated by shallow cultivation (1-2”) or applied preemergence and incorporated by irrigation within 36 hours or application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions. Can be used under plastic mulches.

DCPA (Dacthal W-75): REI 12h, Group 3.  Crop should be well established before use.  Apply 6 to 14 lb/A 4-6 weeks after transplanting or on direct seeded plants at 4-6 inches in height. Can be sprayed over transplants without injury. Will not control emerged weeds.  If weeds have emerged, the crop should be cultivated or weeded prior to application. See label to select rate based on target weeds and soil texture.

napropamide (Devrinol 2-XT): REI 12h, Group 0. Apply 2 to 4 qt/A to weed-free soil surface. Use the lower rate on light soil (coarse-textured/sandy) and the higher rate on heavy soil (fine-textured/clay). Incorporate thoroughly with irrigation if adequate rainfall does not occur within 24 hours of application. Can be applied broadcast before transplanting (transplants on bare soil) or as a preplant incorporated under plastic mulch. If soil is dry, irrigate with sufficient water to wet to a depth of 2 to 4” before covering with plastic. Apply plastic over treated soil same day as treatment.  Can be applied at 4 qt/A to weed free soil surface between rows of plastic.

pendimethalin (Prowl H2O): PHI 70d, REI 24h, Group 3. Apply 1 to 3 pt/A, either as preplant incorporated or to the soil surface PRIOR to transplanting. Rate based on soil textture; see label for more information.  If applied to the soil surface, excessive treated soil falling into the transplant hole may delay crop growth. Can be used under plastic mulch. Can also be applied as a post-directed spray on the soil at the base of the plant, beneath plants, and between rows. Avoid direct contact with foliage or stems or injury will occur.  Apply before weed germination. Emerged weeds will not be controlled.

trifluaralin (Treflan 4E): REI 12h, Group 3. Transplant eggplant only. Use caution as eggplant my be sensitive to trifluralin. Select rate based on soil texture, see label for details. Apply 1 to 1.5 pts/A and incorporate Treflan HFP before transplanting or apply post-transplant and incorporate. When applied post-transplant, direct liquid sprays to the soil between rows and beneath plants.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 20d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

halosulfuron (Sandea): PHI 30d, REI 12h, Group 2. Can be used in row middles/furrows only.  For direct seeded and transplants, apply 0.5 to 1 oz/A to the area between rows as a banded shielded application while avoiding contact with the crop. If plastic is used on the planted row, adjust equipment to keep the application off the plastic. Reduce rate and spray volume in proportion to area actually sprayed. It is recommended to add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray) to the spray solution for applications where susceptible weeds are present. Provide both preemergence and postemergence control of many weed species, such as nutsedge and many broadleaf weeds. See the label for other precautions and a list of weeds controlled.

paraquat (Gramoxone SL 2.0*): REI 12h, Group 22.  For use between rows after crop establishment as shielded application. Apply up to 2 pt/A to emerged weeds between rows when weeds are succulent and weed growth is less than 6”. Include a nonionic surfactant at 0.25% v/v in the spray solution.  Maximum 3 applications per year. Allow 14 days between applications.  Use precision directed spray application equipment adjusted to prevent spray contact with crop plants. Crop contact by the spray will cause severe injury or death. Do not exceed 30 psi nozzle pressure or spray under conditions which may cause excessive drift. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 20d, REI 12h, Group 1.  Carrots only. Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 4.5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Garlic

Introduction

Garlic (Allium sativum L.) is in the onion family. For thousands of years it has been grown for culinary and medicinal uses.  Garlic grows in a wide range of conditions. While most production is in mild areas, such as California, some varieties grow well in cold climates, often with better flavor. 

Types and Varieties

There are two types of garlic. Hardneck (or topset) garlic produces false flower stalks called scapes, which are also edible. It typically has about a half dozen cloves per bulb. Softneck garlic typically has more than twice as many cloves and generally has a longer storage life than hardneck varieties.  Softneck garlic dominates commodity production, but many growers in New England prefer hardneck types for retail sales due to their flavor and appearance.  Hardneck varieties often have a reddish-purple clove covering versus the white color common in softneck types. 

After centuries of cultivation, garlic has lost the ability to produce seeds. Therefore, it is vegetatively propagated by saving bulbs and planting individual cloves from which new bulbs form. The small bulbils produced on hardneck scapes can be used for propagation, but it takes several years of planting and selection to achieve marketable size bulbs.

Although many different variety names are used in garlic commerce, recent genetic research suggests there are only about 10 major varieties of garlic. These express different characteristics from one location to another, complicating variety identification. Since there is no standardization of varieties, as with potatoes, one must take garlic variety names with a grain of salt. It's a good idea to start out with several different varieties produced in your area, selecting and saving those that perform best.

Soil Fertility

A well-drained soil with good tilth and plenty of organic matter is ideal for garlic.  Garlic has a shallow root system; excess moisture, compaction, or droughty conditions will reduce yields. The optimum soil pH is between 6 and 7. Since garlic commences growth very early in the season, it is important to have soil nutrients available at that time. The table below gives timing guidelines for use of quick-release sources, particularly for nitrogen. Adjust timing if using a slower release material. Since garlic has such an early start, avoid fields that are slow to drain in the spring

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR GARLIC
GARLIC NITROGEN (N) LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate in fall 40 150 100 25-50 0 150 100 50 0
Sidedress in spring when shoots are 6 inches high 40 0 0 0 0 0 0 0 0

Sidedress 3-4 weeks later 

40

0

0

0

0

0

0
TOTAL RECOMMENDED 120 150 100 25-50 0 150 100 50     0

Planting

Garlic is planted in the fall since it requires a cold temperatures to induce bulb formation. Planting typically occurs from October in northern New England to early November in southern areas. The goal is to time planting for good development of roots, but not enough time for the shoots to emerge from soil before winter. Many different planting arrangements are used by growers depending on irrigation, mulching, and weed control systems. Planting cloves too densely can reduce bulb size, while spacing too far apart reduces yield per area of land. Common planting arrangements include 2-row beds 30" apart on center with 6" spacing in and between rows, 3- or 4-row beds with 6-8" in and between rows; single rows spaced 24-30" with 6" in-row spacing. Wide row spacing between rows allows for easy mechanical cultivation for weed control; multiple rows per bed allow for use of plastic much to control weeds.

Garlic varieties differ in size and weight of cloves; generally, there are about 50 cloves in a pound. Large cloves tend to produce the most vigorous plants and largest bulbs; therefore, small cloves are often not planted. Bulbs should be separated no more than a day or two before planting so they do not dry out. Cloves should always be planted with the root side down, so the top of the clove is 1" below the soil surface. Plant only healthy-looking cloves to avoid disease and nematode problems.

Field Culture 

A layer of clean straw mulch is typically applied to garlic at planting to avoid drastic soil temperature fluctuations and heaving in the winter and early spring. The garlic will grow through the mulch in the spring. Alternatively, garlic can be planted into plastic mulch. Either will conserve soil moisture and suppress weeds. It may be advisable to remove straw mulches in very wet springs to allow soil to dry out and thus reduce the threat of soil borne diseases. In very cold growing areas, removing mulch can also speed soil warming and garlic growth in the spring. Because garlic is shallow-rooted, irrigation is very beneficial during dry periods. 

Clipping scapes from hardneck garlic once fully curled, just below the curl, has been found to improve bulb size. Scapes are edible, and can be sold and used as a garlic-flavored vegetable similar to scallions.

Harvest and Storage

Although variable depending on variety and growing conditions, 1 lb of garlic 'seed' bulbs will usually yield 4-8 lb at harvest. Garlic may be ready to harvest over several weeks during July. When the lower third of leaves turn brown, it is advisable we pull several bulbs to check for maturity. Cut the bulbs in half width-wise, and check whether cloves have fully filled out within the skins. If so, they are ready to harvest. Pull, dig, and/or undercut the bulbs to remove them. Unless a lot of soil is adhered to the bulbs, they do not need to be washed at harvest (although some markets may demand it). Place the harvested plants on wire racks or tie in bundles for hanging to cure for several weeks in a dry area with good ventilation. After curing, tops can be cut to leave about an inch remaining, and root should be trimmed closely. If necessary, bulbs may be brushed or the outer skin gently rubbed off to clean them.

Seed garlic should be stored at 50º F with relative humidity of 65-70%. Cloves sprout most rapidly between 40-50º F. Garlic for table stock should be stored at 32º F and 65-70% relative humidity. Well-cured bulbs stored at proper conditions should keep for 6-7 months. Relative humidity in storage is lower than for most vegetables because high humidity causes root growth and mold.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

The most common controls for leek and garlic diseases include the use of disease-resistant cultivars and pathogen-free seed and bulbs, as well as cultural practices including crop rotation and crop residue management that restrict the pathogens. 

Blue Mold (Penicillium spp.)

Blue mold is typically most problematic as a storage disease, although it can cause infect seed cloves as well, and cause poor stands. Several Penicillium species cause blue mold, and these species are common in soil, on plant and animal debris, and in senescing plant tissues. Some species may be carried on infected cloves or seed. The mold presents as a mass of blue-gray fungal growth on the bulb, and in the field yellowed and stunted plants may be observed. These pathogens typically invade bulbs through wounds, mechanical bruises, or freezing injury. Control other diseases in the field to prevent avenues for infection. Harvest bulbs with a minimum of bruising and wounding, and dry promptly. Store bulbs at 40° F with low relative humidity. Some countries recommend treating with fungicides before storage.

thiophanate methyl (Topsin M 70WP): 1.0 lb/100 gal; REI 72h, Group 1. Pre-plant treatment by immersion of garlic cloves in suspension for at least 5 minutes.

Damping-off and seed rot (Pythium and Rhizoctonia)

Avoid excessive soil moisture by improving soil drainage or planting on raised beds. Seed and soil treatments with fungicides are a recommended practice.

mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lbs seed; REI 48h, Group 4. Not effective for Rhizoctonia.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi. Does not control Pythium or Phytophthora.

Downy Mildew (Peronospora destructor)

During extended periods of cool, humid weather, this disease can be highly destructive, causing losses in both yield and bulb quality. Practice a 3- to 4-year rotation. Plant on well-drained soil and orient rows in the same direction as prevailing winds. Avoid overhead irrigation. A regular program of fungicide spraying based on climatic conditions and disease forecasts should be followed.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.  Do not make more than 1 application of Quadris before alternating with fungicides that have a different mode of action.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.6 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions. 

azoxystrobin plus propiconazole (Quilt Xcel): 17.5 to 21 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Can cause phytotoxicity to leaves.

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide that has a different mode of action. Apply in adequate water.

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not make more than one application of Reason before alternating to a fungicide from a different resistance management group

fluazinam (Omega 500): 1.0 pt/A; PHI 7d, REI 12h, Group 29. Use sufficient water for thorough coverage, but not less than 5 gal./A. 

mancozeb (Dithane F45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

mandipropamid (Revus): 8.0 fl oz/A; PHI 7d, REI 4h, Group 40.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 7d, REI 48h, Groups 4 & M5.

mefenoxam and mancozeb (Ridomil Gold MZ): 2.5 lbs/A; PHI 7d, REI 48h, Groups 4 & 18. Use sufficient water to obtain thorough coverage. Do not apply Ridomil Gold more than 4 times.

oxathiapiprolin & mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 7d, REI 4h, Group 49 & 40.

phosphorous acid  (Fosphite): 1.0 to 3.0 qt/in a minimum of 20 gal/A; PHI 0d, REI 4h, Group 33. Do not apply to plants that heat or moisture stressed. Do not apply directly to copper treated plants within 20-day interval to avoid plant injury.

pyraclostrobin (Cabrio EG): 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides.

Bulb and Basal Plate Rot (Fusarium spp.)

Bulb and basal plate rot of garlic is caused by Fusarium culmorum and F. roseum. Symptoms include pre-emergence decay of cloves and seedlings, decay of the stem plate and storage leaves during the growing season, and postharvest decay of cloves in stored bulbs. Infected cloves will have sunken, circular brown lesions on their outer surface and/or basal plate. Foliar symptoms include curving, yellowing and necrosis of leaves beginning at tips, and wilt.  Infection occurs mainly from the soil through the stem plate. Incidence of the disease increases with injury by onion maggot or other insects. Cloves may remain infected but non-symptomatic. The pathogen is disseminated in seed, soil, infected debris, and irrigation water. Hot water seed treatment has reduced garlic clove infection by 50%, but is not enough to provide commercially-acceptable control when clove infection is severe. Excess soil N favors Fusarium infection; take care to account for soil organic matter and cover crop N credits and not to over apply fertility. Long (4-year) rotations to non-susceptible crops may minimize losses. Storage at 40° F also helps. The most important control measure is the planting of resistant cultivars.

Purple Blotch (Alternaria porri)

Alternaria porri is most likely to become problematic when temperatures are warm (77-85° F) with high humidity. Small lesions will form on stems or leaves, eventually enlarging and becoming tan or purple. Purple blotch is easily confused with Stemphylium leaf blight, which tends to produce darker lesions. While laboratory diagnoses are needed for proper identification, these two pathogens can be managed in the same way. Practice long rotations with unrelated crops, and use practices that reduce hours of leaf wetness, e.g. plant spacing and good air drainage. Plant resistant or tolerant varieties. Plow under crop residues promptly after harvest. Rotate fungicides throughout the growing season.

azoxystrobin (Quadris): 6.0 to 12.0 fl oz/A; PHI 7d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions. 

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Do not make more than 2 consecutive applications before rotating to a fungicide with a different mode of action.

chlorothalonil (Bravo Weather Stik): 1.0 to 3.0 pt/A; PHI 7d, REI 12h, Group M5. When disease is present, use the higher rate.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Do not make more than 2 consecutive applications before rotating to a fungicide with a different mode of action. 

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 plus 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides. 

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides. 

mancozeb (Dithane F45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

polyoxin D (OSO 5%SC): 3.75 to13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

propiconazole (Tilt): 4.0 to 8.0 fl oz/A; PHI 14d, REI 12h, Group 3.

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides (Quadris).

pyraclostrobin plus boscalid (Pristine): 10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7. Do not make more than 2 applications of Pristine before alternating with a fungicide with a different mode of action.

pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9.

Bloat Nematode (Ditylenchus dipsaci)

Ditylenchus dipsaci is a nematode species that infects germinating garlic seed and is primarily borne in seed cloves. The nematode itself has limited mobility, but can be easily spread in infested soil, on equipment, and in infected seed and plant material. D. dipsaci is common in all temperate regions. It is an obligate parasite of plants; populations of the nematode exhibit marked host preferences. The nematodes aggregate into a mass called nematode wool and with slow drying can persist in infested fields for long periods. Symptoms of garlic bloat include leaf yellowing, erratic stands, stunting, looping and bending of leaves, twisting, and growth deformities. Bulb damage can be mistaken for Fusarium basal plate rot with decay occurring both at the neck and the basal plate. Infected bulbs will lack roots. D. dipsaci can be controlled with long crop rotations including the elimination of volunteer onions, garlic, and host weeds. The primary method of controlling nematodes is hot water treatment of seed cloves. The standard regime is 30 to 45 minutes at 100º F, 20 minutes at 120º F, and then 10 to 20 minutes at 64º-72º F. Hot water treatment must be performed carefully to prevent damage to cloves. Chemical, physical, and cultural methods have been used to restrict damage, but most chemical treatments are no longer registered for use.

White Rot (Sclerotium cepivorum)

White rot is caused by Sclerotium cepivorum, which persists for a long time in soil. It is “activated” by root exudates produced by Allium crops. Affected plants will show yellowing older leaves and stunting, and small black sclerotia can be seen on the bulb. Disease development is favored by cool, moist soil conditions. There is little to be done once a field is infested with S. cepviorum, and crops should be rotated out of Alliums for as long as possible. Some fungicides (iprodione) provide protection for the establishment of garlic, but fungicide control is marginal for full-season crops. Soil fumigation may provide partial control. In general, neither fungicides nor fumigation have provided consistent, reliable, full-season control of white rot. Hot water treatment of garlic seed can reduce the potential to spread white rot sclerotia. Winter flooding and soil solarization can reduce the number of sclerotia. White rot symptoms are less severe on leeks. 

azoxystrobin plus propiconazole (Quilt Xcel): 17.5 to 26 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickel 55OG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Apply in-furrow at planting.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

fludioxonil (Cannonball WP): 0.5 oz/1000 ft.; PHI 7d, REI 12h, Group 12. Apply in-furrow at planting.

iprodione (Rovral): 4.0 pt/A; REI 24h, Group 2. Apply in-furrow at planting. Do not make more than 1application per year.

tebuconazole (Orius 3.6F): 25.0 fl oz/A; PHI 7d, REI 12h, Group 3. Apply in-furrow at planting or over the top in a 4 to 6 inch band.

thiophanate methyl (Topsin M 70WP): 2.0 lb/A; REI 72h, Group 1. Apply in furrow.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Allium Leaf Miner (Phytomyza gymnostoma)

For more information on this pest and for cultural and chemical controls, see Allium Leaf Miner in the leek section.

Bulb Mites

Two genera of mites are known to infect species of Allium - a dry bulb mite, Aceria tulipae, and species in the genus Rhizoglyphus. Mites can survive in soil on decaying vegetation. Infected seed may fail to germinate. Plants grown from infected seed may lack vigor and produce stunted, deformed leaves. Plants may outgrow the damage if the infestation is not heavy, but mites may increase in number over the growing season and will remain in the harvested garlic. They are particularly troublesome in storage, causing desiccation and creating wounds that allow for entry of secondary pathogens.

Bulb mites are favored by mechanical injury, disease, cool soil temperatures, and soils with high organic matter content. Avoid adding manure and use fallow periods to eliminate crop residue. In smaller plantings, removing culls from the field immediately after harvest will reduce overwintering populations. Dark plastic mulch will increase soil temperatures and control mites. Plant clean seed and rotate out of Alliums for at least four years after an infestation. Avoid planting Allium crops directly after brassicas, corn, grain, or grass cover crops.

Onion Maggot (Delia antiqua)

For more information on this pest and for cultural and biological controls, see onion maggot in the Onion section.

diazinon (Diazinon* AG500): 2 to 4 qt/A; REI 3d, Bee: H, Group 1B. Broadcast and incorporate just before planting. Will not control organophosphate-resistant onion maggots. DO NOT make more than one application per year.

Onion Thrips (Thrips tabaci)

Thrips are favored by hot, dry weather. Thrips typically feed under leaf folds and in protected inner leaves, although when populations are high they may feed on exposed leaf surfaces. This causes white scars on leaves that can reduce plant growth when severe, as well as provide entry points for foliar diseases. In severe infestations, the field may appear silvery in color. Both adults and nymphs cause damage. 

Heavy rain or overhead irrigation can lower populations quickly. Lacewing larvae, pirate bugs, and predatory thrips are important natural enemies. Reduce populations by cleaning up crop residue after harvest to limit overwintering sites. Do not plant garlic near other Allium crops or alfalfa, clover, cucurbits, or brassicas, as these can harbor large populations of thrips that can migrate to garlic when these crops are cut or harvested. The most common controls for leek and garlic diseases include the use of disease-resistant cultivars and pathogen-free seed and bulbs, and cultural practices such as crop rotation and crop residue management that restrict the pathogens.

Begin applications when damage is first noticed. Repeat applications at 7- to 10-day intervals. Use a shorter interval in hot, dry weather. Use spreader-sticker for better coverage. Apply in early evening, using high pressure and 100 gal water/A for best results. See onion thrips in the Onion [9] section for more information.

acetamiprid (Assail 30 SG): 5 to 8 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

Beauveria bassiana (Mycotrol ESO): 0.25 qt to 1 qt/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.

Burkholderia spp. strain A396 cells (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: MGroup UN. Suppression only.

Chenopodium extract (Requiem EC): 1.5 to 3 qts/A; PHI 0d, REI 4h, Bee: L, Group UN. Begin application as soon as thrips are seen. Thoroughly cover foliage.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Suppression only.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

dinotefuran (Venom): 3 to 4 fl oz/A foliar, 5 to 6 fl oz/A soil; PHI 1d foliar, 21d soil, REI 4h, Bee: H, Group 4A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 14 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression/repellence only. Good coverage into plant crown is essential. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.

malathion (Malathion 57 EC): 1.5 to 2 pt/A; PHI 3d, REI 24h, Bee: H, Group 1B.

permethrin (Pounce* 25WP): 9.6 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Suppression only. Use adjuvant for better control.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Thorough coverage is essential. Efficacy improves with the addition of an adjuvant.

spirotetramat (Movento): 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

zeta-cypermethrin (Mustang*): 3.2 to 4.3 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107).

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3% -10% solution (3 to 10 gallons per 100 gallons).

Garlic is not very competitive, so good weed control is critical. Mulch will control weeds and conserve moisture.  If the mulch is removed, cultivation will likely be needed.  It should be shallow so as not to damage roots. 

Herbicides Used Preemergence to Weeds   

bensulide (Prefar 4E): REI 12h, Group 0.  Apply 5 to 6 qt/A.  Can be preplant incorporated by shallow cultivation (1"-2”) or applied preemergence and incorporated by irrigation within 36 hours of application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

dimethenamid (Outlook): PHI 30d, REI 12h, Group 15.  This herbicide is a root and shoot growth inhibitor that controls susceptible germinating seedlings before or soon after they emerge from the soil. Do not apply until garlic has reached the 2 true-leaf stage or significant crop injury can occur. May be applied as a single application (up to 21 oz/A) or used in split applications.  For split applications do not exceed a total of 21 oz/A per season. An initial application of 10 to 14 oz/A can be followed by another application of the remaining 7 to 11 oz/A.  Applications must be a minimum of 14 days apart. Application rates are influenced by soil organic matter content. See label for info on application rates depending on soil type and organic matter content. See label for info on tank mixing with other herbicides.

flumioxazin (Chateau SW)REI 12h, Group 14.   Apply up to 6 oz/A with 3 days of planting garlic and before garlic has emerged.  Must be sprinkler or rainfall incorporated (0.5" – 0.75” of water) for preemergence weed control.  Will control many broadleaf weeds and some grass species. 

s-metolachlor (Dual Magnum): REI 12h, Group 15.  MASSACHUSETTS AND NEW HAMPSHIRE ONLY. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge.

pendimethalin (Prowl H2O): PHI 45d, 24 hr REI, Group 3. Apply 1.5 to 3.2 pt/A.  Select rate based on soil texture.  See label for detail.  Can be used preemergence after planting but before crop emergence, after crop emergence when garlic is in the 1 to 5 true leaf stage, or at both timings. Emerged weeds will not be controlled.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 45d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 32 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3%-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI 45d, REI 12h, Group 1.  For grass weed control only. Apply up to 24 fl oz/A.  See label to select rate based on grasses targeted for control. Can make up to 2 applications per year. Allow for minimum 14-days between applications, and not to exceed 48 oz/A per year.  Apply to actively growing grasses (see product label for susceptible stage). Add either crop oil concentrate (0.5%-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25%-0.5%, 1-2 qt per 100 gal of spray).

oxyfluorfen (Goal 2 XL): PHI 60d, REI 48h, Group 14. Provides early postemergence and residual control of many broadleaf weed species. For direct seeded garlic, apply 2 to 4 oz/A to garlic that has at least 3 fully developed true leaves. For transplanted garlic, apply 2 to 4 oz/A to garlic transplants as soon as possible after transplanting. Multiple treatments may be applied up to a maximum of 32 fl oz per acre preseason. For optimum postemergence control, apply when susceptible weeds are in the 2 to 4 leaf stage and actively growing. Application to weeds at later than 4 leaf growth stage may result in reduced weed control. Adjust nozzles for minimum spray contact with garlic plants, directing the spray to the soil at the base of garlic plants and adjacent bed top and furrow area.  Do not tank mix or add adjuvants unless directed to do so on Dow supplemental labeling.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3% -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 4.5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1%-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Globe Artichoke

Introduction

Globe artichoke (Cynara cardunculus var. scolymus) is a plant in the Asteraceae family native to the Mediterranean region.  The harvested portion of artichokes is the immature inflorescence, or bud, of which the fleshy bases of the bracts and the heart can be eaten.  Globe artichoke is a domesticated variety of cardoon, which has edible stems instead of buds, and which is still eaten in many regions of the world.  Unharvested artichoke buds will mature into stunning composite flowers that make excellent bee forage or additions to fresh and dried flower arrangements.

Types and Varieties

In mild climates where temperatures do not remain below 50º F for prolonged periods, globe artichoke is a perennial crop that is propagated vegetatively.  In perennial systems, artichokes will produce in their first year but yields will be improved thereafter.  In colder regions like New England, artichoke can be grown annually from seed.  While most if not all varieties can be grown as annuals, some varieties have been bred that reliably produce many buds in their first year after a vernalization period (see Planting section).  

Globe Artichoke Varieties
Colorado Star (A) Romanesco
Emerald Tavor (A)
Green Globe Improved Violetto
Imperial Star (A) Wonder
Imperial Star Purple (A)  
A: bred for annual production

 

Soil Fertility

Apply lime according to soil test results to maintain soil pH between 6.5 and 7.0. Artichokes can be grown on a wide range of soils but produce best on deep, fertile, well-drained soils. Lighter soils having poor water-holding capacity should be avoided. Artichokes are moderately salt-tolerant. 

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR Globe ARTICHOKE
Globe ARTICHOKE   PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS NITROGEN (N) LBS PER ACRE VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate in fall 100 75 50 0-25 0 150 100 50 0

Sidedress 3-4 weeks later 

0-50

0

0

0

0

0

0
TOTAL RECOMMENDED 120 75 50 0-25 0 150 100 50  0

 

Planting

Artichokes should be seeded 8-12 weeks before transplanting into 50-cell trays or 3-4” pots.  Seeds take 8-12 days to emerge. Germinate at 70-80º F, using heating mats if needed. If initially seeded into smaller cell trays, they can be potted up at two true leaves.  Plants require vernalization, i.e. exposure to cold temperatures to induce budding.  The most foolproof way to vernalize plants is to move them to a cooler set to 45-50º F for at least ten days, although the amount of chilling required varies by variety.  Alternatively, transplanting can be timed so that transplants get their chilling time outdoors (use row cover if frost is expected).  However, this is less reliable than artificial vernalization and coolers should have ample space in spring for seedlings. 

Field Culture

While the vernalization process is somewhat involved, this crop is mostly trouble-free in the field with few pests, and offers New England customers a unique Mediterranean treat. Artichokes are large plants and require ample space: 2-3' between plants in 4-6' rows.  Straw mulch may reduce soil temperatures (which can benefit plants in hot weather), but recent research on straw and plastics mulch effects on artichoke production have mixed results.  Plants need an inch of water per week, for which drip irrigation is useful. Artichoke buds should begin to form in late July.  If desired, the healthiest artichoke plants with several side shoots can be split at the end of the season and planted into unheated high tunnels under row cover for an early June harvest the following year. 

Perennial artichokes have been successfully overwintered in experimental settings (see Northeast SARE project FNE 14-809) in northern New England with a combination of straw mulch and low tunnels.  While it is possible that refinement of this system could result in earlier harvests and higher yields, it is unclear whether the proportion of plants that survive winter would be large enough to warrant overwintering versus annual production. 

Harvest and Storage

Yields vary based on variety and cultural practices.  Plants commonly produce 10-20 buds each, but only 2 – 3 of these will be primary buds.  Primary buds are typically of a large enough size to market individually, greater than 3” in diameter.  The remainder of the buds are “secondaries” and will form at plant axials further down in the plant.  While these are smaller, they are equally delicious and can be sold by weight, quart container, etc.  Secondary buds can be eaten much like larger sizes, but are often more tender with a larger proportion of the bud being edible.  Artichokes are marketed in 22 lb cartons, and buds are graded in the following classes: 18s are larger than 4.5" in diameter; 24s are 4-4.5"; 36s are 3.5-4"; and 48s are 3-3.5".  Average diameters in New England tend to fall between 3 and 4". 

Buds are ready to be harvested when they feel fairly compact for their size when squeezed.  Bracts of overmature buds will begin to splay apart, and become bitter and tough.  Clip buds with 2-3” of stem attached.  Wearing gloves is recommended for guarding against spines, and because artichoke plant residue can be difficult to wash off.  After harvest, buds should be cooled quickly and stored at temperatures close to 32º F, but should not be allowed to freeze.  Artichokes can last 2 weeks or longer in storage. Weekly or biweekly harvests are sufficient, depending on size classes of the buds being produced and the time in the growing season.  Plants will continue producing (mostly secondary buds) up until a hard frost.

Disease Control

Gray Mold (Botrytis cinerea)

Botrytis is most problematic in wet conditions and as a secondary pathogen.  Infection of bracts will appear as somewhat sunken brown lesions, with characteristic gray mold sometimes developing on the inside of bracts.  Preventing insect feeding and other wounds can help mitigate gray mold.
 

Insect Control

Aphids, primarily Green Peach (Myzus persicae)

Green peach aphid overwinters in the egg stage on woody plants in the Prunus species (peach, wild cherry, etc), where nymphs feed in spring. Field vegetable crops are colonized in June by winged females who produce live young (nymphs), resulting in multiple generations of wingless females. Generation time from birth to reproductive adult is 1 to 2 weeks depending on temperature; each female produces 30 to 80 live young. If food quality declines, winged females develop and leave in search of new plants. In fall, both male and female winged aphids develop and return to woody plants to mate and lay eggs.

Winged green peach aphids have a black head and thorax and yellow-green abdomen. Wingless adults and nymphs are usually pale yellow-green including the cornicles (a pair of tubes near the tip of the abdomen) but may be pink. Adults reach 2 mm long. Aphids feed on leaves and excrete a sugary, sticky substance called "honeydew", which fosters growth of black sooty mold fungus.  If using plasticulture, this honeydew will be apparent on the plastic.  Scout the underside of leaves for aphids as plants establish.

Numerous crop families (including solanaceous crops, cucurbits, brassicas, spinach and chard, and carrot families), as well as broadleaf weeds, support green peach aphid. Feeding on young tissue causes curling, wilting, stunted growth, and contamination of harvested crop. The major damage caused by this aphid is the transmission of many different plant viruses. It is also a pest in greenhouses; see Vegetable Bedding Plants and Greenhouse Tomato for greenhouse management.

Aphids are usually controlled by natural predators and parasites, such as lady beetles, lacewings, spiders, syrphid fly larvae, wasps, and beneficial fungi, unless the populations of these beneficials are disrupted by chemical sprays. Preserve natural enemies by using selective/microbial pesticides for other pests whenever possible. Occasionally green peach aphid (GPA) or, less commonly, melon aphid (MA) and potato aphid (PA) populations build up and require controls. Early-season, broad-spectrum sprays will destroy beneficials and lead to aphid population buildup.

Begin to examine plants in early July for aphids and the presence of beneficial species. Spray only when aphids are increasing and building up to high numbers. Coverage of leaf underside is important. Add a spreader-sticker. Plant crops away from Prunus species. Spray effectiveness may vary depending upon the species present. Reflective plastic mulch may help to repel aphids. 

Tarnished Plant Bug (Lygus lineolaris)

See Lettuce for information about tarnished plant bug. In artichoke, bugs may feed on leaves, leaving behind a shothole appearance.  More significantly, they may feed at the base of buds and, in extreme cases, cause buds to turn black and rendering them unmarketable.

Thrips

The piercing-sucking mouthparts of thrips cause twisting and curling of leaves.  Occasionally, thrips may also feed on bracts of buds, which can become deformed and thus unmarketable.
 

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Herbicides Used Preemergence to Weeds

pendimethalin (Prowl H2O)PHI 60 or 200 d (based on rate), REI 24h, Group 3. Must be applied at least 1 to 2 days before transplanting artichoke. Apply up to 3 pt/A so soil surface for 60 day PHI, or a higher rate of 3.1 to 8.2 pt/A can be used but requires a 200 day PHI.

Herbicides Used for Pre- and Postemergence Weed Control

oxyfluorfen (Goal 2 XL): PHI 5d, REI 48h, Group 14. Used for both pre- and postemergence weed control.  Apply 4 to 6 pt/A as a directed spray to the soil surface between the rows and at the base of artichoke plants.  Do not apply over-the-top. Contact with direct spray or drift will cause injury to artichoke fronds or severe injury to buds or flowers. Do not apply more than 6 pints of Goal 2XL per acre per season as a result of a single application or multiple applications.

Herbicides Used Postemergence to Weeds

clethodim (Select Max)PHI 5d, REI 24h, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

paraquat (Gramoxone SL 2.0*): REI 12h, Group 22.  For use between rows after crop establishment. Apply up to 2.5 to 4 pt/A as a directed and shielded spray to emerged weeds between rows when weeds are succulent and weed growth is less than 6”. Maximum 3 applications per year, not to exceed a total of 8 pt/A per season.  Use precision directed spray application equipment adjusted to prevent spray contact with crop plants. Crop contact by the spray will cause severe injury or death. Do not exceed 30 psi nozzle pressure or spray under conditions which may cause excessive drift.

sethoxydim (Poast): PHI 7d, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 2.5 pt/A per application, minimum 14-days between applications.  Do not exceed 5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Leek

Introduction

Leeks are root vegetables that look quite similar to onions, to which they are related. Their flavor is onion-like but much milder.  Unlike onions, leeks don't form much of a bulb on the end of the root. Instead, they remain cylindrical, with perhaps a slight bulge at the end.  The leek is a vegetable that belongs, along with onion and garlic, to the genus Allium, currently placed in family Amaryllidaceae, subfamily Allioideae. Historically many scientific names were used for leeks, which are now treated as cultivars of Allium ampeloprasum.

Types and Varieties

Leek Varieties
Summer/Fall
Fall/Over-winter
Belton
Lancelot
King Richard (open pollinated)
Lexton
Lincoln (open pollinated)
Megaton
Surfer
Tadorna
   
Summer
 
Rally  
Runner  

Soil Fertility

See the Soil Fertility sections for Onions.

Planting

For best results, leek seeds should be sown in the greenhouse about 2.5 months before field setting. About 2-3 lb of seed are needed to raise enough plants to set an acre at average spacing (0.25-0.5 oz per 100 feet of row). Plant seeds no more than ½” deep in 288 deep cell trays. Before setting, clip plants to a height of 3" to reduce wind damage in the field. Set plants in the field from late April to late May depending on location and earliness desired. Plants can be set in early July for a late fall harvest, or in milder locations, growers may wish to try overwintering the more cold tolerant leek varieties using  straw mulch or row covers. Rows can be from 15-30" apart depending on equipment; plants should be about 3-6" apart (200-400 plants per 100 feet of row).

Field Culture

To develop a long, white stem, leeks can be planted in a trench 3-4" deep. The trenches are gradually filled as the leeks grow and then soil is hilled around stems to a height of 3-4". Several hillings may be required per season.  Self-blanching varieties are grown without trenching and hilling and require less cleaning.

Harvest and Storage

Leeks can be harvested once the base reaches at least 1" diameter. Soil often clings to freshly harvested leeks. Carefully using a pressure washer or hose nozzle with a strong jet of water may be required to sufficiently clean soil particles from leeks for storage or market. Optimum storage conditions are 32º F with 95-100% relative humidity to prevent wilting. Leeks typically maintain quality in storage for two to three weeks. Under ideal conditions, up to eight weeks is possible. Store separately from ethylene-producing crops.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

The most common controls for leek and garlic diseases include the use of disease resistant cultivars and pathogen–free seed and bulbs, and cultural practices such as crop rotation and crop residue management that restrict the pathogen. 

Damping-off and seed rot (Pythium and Rhizoctonia)

Avoid excessive soil moisture by improving soil drainage or planting on raised beds. Seed and soil treatments with fungicides are a recommended practice.

mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lbs seed; REI 48h, Group 4. Seed treatment.

fludioxonil (Maxim 4FS): 0.08-0.16 fl oz/100 lb seed; REI 12h, Group 12. Does not control Pythium and Phytophthora

Downy Mildew (Peronospora destructor)

During extended periods of cool, humid weather, this disease can be highly destructive causing losses in both yield and bulb quality. Practice a 3- to 4-year rotation. Plant on well-drained soil and orient rows in the same direction as prevailing winds. Avoid overhead irrigation. A regular program of fungicide spraying based on climatic conditions and disease forecasts should be followed.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.  Do not make more than one application of Quadris before alternating with fungicides that have a different mode of action.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions. 

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide with a different mode of action.

famoxadone & cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 plus 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides. 

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 14d, REI 48h, Groups 4 & M5. 

pyraclostrobin (Cabrio): 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not make more than one application of Cabrio before alternating to a fungicide with a different mode of action. Do not rotate with Quadris or Cabrio.

Purple Blotch (Alternaria porri)

Practice long rotations with unrelated crops and practices that reduce hours of leaf wetness, i.e., plant spacing and good air drainage. Use of a single fungicide throughout the growing season is not recommended.

azoxystrobin (Quadris): 6.0 to 12.0 fl oz/A; PHI 0d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions. 

azoxystrobin plus propiconazole (Quilt): 14 to 27.5 fl oz/A; PHI 14d, REI 12h, Groups 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide. 

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7.

chlorothalonil (Bravo Weather Stik): 1.5 to 3 pt/A; PHI 7d, REI 12h, Group M5. When disease is present, use the higher rate.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WDG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus benzovindiflupyr (Aprovia Top): 10.5 fl oz/A; PHI 7d, REI 12h, Groups 3 & 7. No more than 2 sequential applications before alternating to a non-Group 7 fungicide.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d (dry bulb); PHI 14d (green), REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage. 

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 plus 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides. 

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not alternate with other Group 11 fungicides.

fluxapyroxad plus pyraclostrobin (Merivon): 5.5 to 11 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 14d, REI 12, Groups 33 & M5.

propiconazole (Tilt): 4.0 to 8.0 fl oz/A; PHI 0d, REI 12h, Group 3. 

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not exceed six applications or 72 oz/A. Do not rotate with other Group 11 fungicides.

pyraclostrobin plus boscalid (Pristine):  10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7.

pyrimethanil (Scala SC Fungicide): 9.0 to 18.0 fl oz/A; PHI 7d, REI 12h, Group 9.

tebuconazole (Orius 3.6F): 4.0 to 6.0 fl oz/A (for dry onion); PHI 7d, REI 12h, Group 7.

White Rot (Sclerotium cepivorum)

Avoid planting in infested fields. Destroy infected plants and spot treat the soil around the plants with fumigants. Warm season production of host crops may greatly reduce sclerotial inoculum. Practice crop rotation. Soil fumigation may provide partial control. In general, neither fungicides nor fumigation have provided consistent, reliable, full-season control of white rot. Hot water treatment of seed can reduce the potential to spread white rot sclerotia. Winter flooding and soil solarization can reduce the number of sclerotia. White rot symptoms are less severe on leeks.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Allium Leaf Miner (Phytomyza gymnostoma)

The Allium Leaf Miner (ALM) is a relatively new invasive pest species associated with many allium hosts. The ALM is a true fly species. It was first detected in Lancaster County, PA in 2015. Currently the distribution of the fly is limited within New England. However, the northern expansion of the fly has been rapid with several positive identifications in MA in 2019.

Within the Northeast, ALM populations exhibit two flights per season. These flights are separated by a summer aestivation (“summer hibernation”) period that often precludes the fly from causing significant damage in crops grown and harvested during the summer months (i.e. garlic and bulb onions). The first flight (overwintering population) begins in mid-to-late April, ending in May. The second flight does not begin until September and typically extends into early October. Female flies will make multiple punctures on leaves with their ovipositor (apparatus for laying eggs) that leaves a distinct line of easily visible white dots. These oviposition “scars” are the primary diagnostic indicator for the presence of the pest. Eggs are laid singly inside of leaves where the oviposition marks are made. When ALM eggs hatch, larvae enter the leaves and actively “mine” the plant tissue. After several days, larvae move towards the center and base of plant. After several weeks of active feeding, larvae typically pupate near the base of the plant within the foliage or may exit the plant and pupate in the soil. 

The most vulnerable allium hosts plants tend to be those plants harvested during the early spring and fall (primarily leeks and scallions). The removal of infected host plants and other allium residues from earlier harvested alliums is an important practice for reducing potential outbreaks in fall allium crops. Insect exclusion netting or other types of row covers can effectively exclude ALM flies if securely applied before the second flight begins. Foliar chemical applications have also been shown to be effective for reducing ALM damage. 

acetamiprid (Assail 30SG): 5 to 8 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

dinotefuran (Scorpion 35SL): 5.25-7 oz/A; PHI 1d, REI 12h, Bee: H,  Group 4A. Do not apply more than a total of 10.5 fl oz/A per season. 

methomyl (Lannate* LV):  48 oz/A; PHI 7d, REI 48h, Bee: H, Group 1A. Add wetting agent to improve coverage. 

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Efficacy improves with the addition of an adjuvant.

spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Use adjuvant for better control.

Leek Moth (Acroleopiosis assectella)

Though leek moth feed upon most cultivated alliums, leeks are the most preferred and susceptible host species. Because garlic and onions are generally harvested for their bulbs, leek moth feeding damage tends to be less of a concern in these crops, as even moderate damage to the above-ground foliage typically does not lead to significant reductions bulb size or yield.

There are three flight periods of leek moth per season. The first flight (the overwintering generation) begins in mid‐late April, ending in mid‐May. The second flight period (the first generation) begins in mid‐June, ending in early to mid‐July. The third flight period begins in late July, ending in mid‐to late August. Although leek moth activity slows down after the last flight period, the damage can still develop on remaining allium vegetables, especially leeks, in the field. These larvae are considered to be the third generation and become the overwintering adults or pupae.
Eggs are laid singly on lower leaf surfaces whenever night temperatures are above 50-54°F.  Females lay up to 100 eggs over a 3-4-week period. After hatching larvae begin to burrow into the stem and move towards the center of the plant where young leaves are formed. In onions, leek moth larvae enter the hollow leaves and continue to feed on the inner cuticle of the leaf leading to the characteristic “window-paning” damage. After several weeks of active feeding, larvae exit the foliage and initiate pupation on the outside of leaves. Pupation lasts about 12 days, depending on weather conditions. 

Pre-harvest strategies: For smaller plots, insect exclusion netting can be an effective strategy for reducing leek moth damage by directly reducing exposure to egg laying female moths. Chemical applications are typically well-suited for larger growing areas and are best applied 1-2 weeks following peak moth flights, which can be monitored using traps baited with pheromone lures. In addition, research has shown that the timely release of the parasitoid wasp, Trichogramma brassiceae, can significantly reduce leek moth damage in leeks and other alliums. 

Post-harvest strategies: The primary concern for garlic and onion growers is the potential damage that may occur during post-harvest curing and/or storage. Damage during curing and storage are generally the result of larvae being brought into curing and storage area following harvest. A simple low-risk strategy for reducing the prevalence of leek moth larvae in these areas is to remove as much of the foliage as possible prior to curing. This “topping” strategy leaves larvae in the field where they no longer can access the bulbs. Research has also shown that topping prior to curing or storage does not affect bulb quality or shelf life.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.60 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 3 pt/A; PHI 7d, REI 48h, Bee: H, Group 1A. For green and dry onions. Add wetting agent to improve coverage. Begin application before populations reach 3 to 5 thrips per plant.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Thorough coverage is essential. Efficacy improves with the addition of an adjuvant.

spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Use adjuvant for better control.

Onion Maggot (Delia antiqua)

For more information on this pest and for cultural and biological controls, see onion maggot in the Onion section.

diazinon (Diazinon* AG500): 2 to 4 qt/A; REI 3d, Bee: H, Group 1B. Broadcast and incorporate just before planting. Will not control organophosphate-resistant onion maggots. DO NOT make more than one application per year.

Onion Thrips (Thrips tabaci)

Thrips are favored by hot, dry weather. Heavy rain or overhead irrigation can lower populations quickly. Lacewing larvae, pirate bugs and predatory thrips are important natural enemies. Reduce populations by cleaning up crop residue after harvest to limit overwintering sites. Do not plant leeks near other Alliums (onion family) or alfalfa, clover, cucurbits or brassica crops that can harbor large populations of thrips, which may migrate to leeks when these crops are cut or harvested. Begin applications when damage is first noticed. Repeat applications at 7- to 10-day intervals. Use a shorter interval in hot, dry weather. Use a spreader-sticker for better coverage. Apply in early evening, using high pressure and 100 gal water/A for best results. See onion thrips in the Onion section for more information.

acetamiprid (Assail 30SG): 5 to 8 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

Beauveria bassiana (Mycotrol ESO): 0.25 qt to 1 qt/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN. Suppression only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

dinotefuran (Venom): 3 to 4 fl oz/A foliar, 5 to 6 fl oz/A soil; PHI 1d foliar, 21d soil, REI 4h, Bee: H, Group 4A.

imidacloprid (Admire Pro): 14 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression/repellence only. Good coverage into plant crown is essential. Generally compatible as a tank mix with other insecticides.

malathion (Malathion 57 EC): 1.5 to 2 pt/A; PHI 3d, REI 24h, Bee: H, Group 1B.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Thorough coverage is essential. Efficacy improves with the addition of an adjuvant.

spirotetramat (Movento): 5 oz/A; PHI 7d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

zeta-cypermethrin (Mustang*): 3.2 to 4.3 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

See section on Soil Fumigation Outdoors (page 89). Proper use of Vapam can provide control of most weed species.

Stale Seedbed

See Stale Seedbed Technique (page 107).

glyphosate (Roundup Power Max): REI 12h, Group 9.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

DCPA (Dacthal W-75): REI 12h, Group 3.  Select rate for preemergence use based on soil type and weeds targeted for preemergence control.  Good control of most annual grasses; fair on redroot pigweed, lambsquarter, and purslane.  Apply to weed-free soil; will not control existing weeds.  Can be applied at seeding or transplanting and/or at layby.  Can be sprayed directly over transplants without injury. A layby application can be made on onions either alone or in addition to a Dacthal preemergence treatment up to 14 weeks after planting at rates up to 14 lb/A on any soil type. If weeds emerge prior to layby, the onions should be cultivated or weeded prior to application.

dimethenamid (Outlook): PHI 30d, REI 12h, Group 15.  Do not apply until transplants are in the ground and soil has settled around transplants with several days to recover. This herbicide is a root and shoot growth inhibitor that controls susceptible germinating seedlings before or soon after they emerge from the soil. May be applied as a single application (up to 21 oz/A) or used in split applications.  For split applications do not exceed a total of 21 oz/A per season. An initial application of 10 to 14 oz/A can be followed by another application of the remaining 7 to 11 oz/A.  Applications must be a minimum of 14 days apart. Application rates are influenced by soil organic matter content. See label for info on application rates depending on soil type and organic matter content. See label for info on tank mixing with other herbicides.

pendimethalin (Prowl H2O): PHI 30d, REI 24h, Group 3.  Apply 2 pt/A to the soil surface as preemergence after planting but before crop emergence, or after crop emergence when leeks are at the 2 to 3 true-leaf stage, or at both timings. Emerged weeds will not be controlled.  If applied as both pre- and postemergence, applications must be at least 30 days apart. Do not exceed 2 pt/A per application, and do not apply more than 4 pt/A per season. 

Herbicides Used Postemergence to Weeds

clethodim (Intensity One)PHI 14d, REI 24h, Group 1.  Leeks are NOT on the Select Max label, but are on other clethodim product labels (such as Intensity One).  Will control grass weeds only. Apply to actively growing grasses.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Intensity One and 0.25% v:v nonionic surfactant (0.33 fl oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 4.5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Lettuce, Endive, and Escarole

Introduction

Lettuce (Lactuca sativa), endive and escarole (both Cichorium endivia) are members of the Asteraceae plant family, and all originated in the Mediterranean region. Their closest crop relatives are artichoke, chicory and sunflower. 

Lettuce grows best at cool temperatures, making spring and fall the major production seasons in New England. While endive and escarole are also cool-season crops, they are more tolerant of high temperatures than lettuce and therefore make a good substitute for lettuce during the warmer mid-summer weather. 

Types and Varieties

There are five common types of lettuce.  Crisphead or iceberg is commonly found in produce markets. The leaves are thin and crisp, often with curled or serrated edges, and the head should be firm. Butterhead or bibb lettuce has a loose-leafed head with green or red outer leaves and cream or yellow inner leaves. Butterhead type lettuce requires careful handling as it bruises and tears easily. For this reason, it is best suited to local market sales. Cos or romaine is an upright plant with the smooth outer leaves and green inner leaves whitish green. Some think the leaves are crisper than other heading types. The fourth general type is variously named leaf lettuce, loose leaf or loose head. Lettuce of this type does not form a head and the leaves may be serrated, deeply lobed or crinkled. Leaf lettuce color varies from light green to red to green with red speckles, adding attractive color to salad mixes. The fifth type is “one-cut” lettuce. Several different proprietary lines of one-cut lettuces, sold through various seed distributors. This lettuce type has a high leaf count and narrow leaf attachment, so can be harvested easily as a whole head (by cutting at the base) or loose-leaf (by cutting just above the base). Unlike most leaf lettuces, one cut lettuces are usually transplanted, which allows for quicker bed turnover. One-cut lettuces can have variable leaf shapes (smooth, lobed, serrated), colors (green, red) and textures (tender/butter-like, crisp/romaine-like).

Endive and escarole encompass many diverse types. Escarole and Frisée are types of endive (Cichorium endivia), both of which form loose and leafy heads. Radicchio and Belgian endive are forms of chicory (Cichorium intybus) that form small, tight heads. Belgian endive is grown in two stages: during spring/summer, the seeds produce large dandelion-like leaves and a large taproot, similar to carrot. In the fall, the taproots are dug, and potted and placed in the dark. The new growth from the roots produces small tight heads called chicons, which are marketed. Italian (or "culinary") dandelions form long leaves that are usually bunched.

Lettuce, Endive and Escarole Varieties
Lettuce - Butterhead Lettuce - Crisphead
Adriana - DM, LMV Caretaker - TB
Buttercrunch - DM, LMV Crispino
Milagro - DM, LMV  
Skyphos (red) Lettuce - Leaf
  Bergam's Green
Lettuce - Romaine New Red Fire (red)
Coastal Star Starfighter - DM, HT
Green Forest Tropicana 
Sparx - DM Two Star
Winter Density Muir - DM, LMV
Rouge d'Hiver (red)  
  Belgian Endive
Endive Totem
Green Curled  
Salad King Radicchio
  Leonardo
Escarole Sirio
Full Heart Perseo
Resistant or tolerant to: DM: Downy Mildew; LMV: Lettuce Mosaic Virus; TB:Tipburn

Soil Fertility

In general, lettuce, endive and escarole have the same fertility, spacing and seeding requirements. Apply lime according to soil test results to maintain soil pH at 6.5-6.8 and maintain soil calcium levels.  Low soil calcium levels may increase the incidence of tip burn. Tipburn is a disorder that causes the margins of leaves to turn black and decay. It is of particular concern with iceberg and romaine types where tipburn on internal leaves may not be immediately obvious. Over-application of nitrogen on fertile soil can result in very rapid growth which can trigger tipburn.  Banding the preplant fertilizer at planting is preferable, but if not possible, then broadcast and incorporate the initial application. Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR LETTUCE, ENDIVE, AND ESCAROLE
LETTUCE, ENDIVE, AND ESCAROLE NITROGEN (N) LBS PER ACRE PHOSPHORUS (P) LBS P2O5  PER ACRE  POTASSIUM (K) LBS K2O      PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 50-75 180 120 30-60 0-30 180 120 30-60 0
Sidedress 3-4 Weeks after Planting 30-50 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 80-125 180 120 30-60 0-30 180 120 30-60 0

Planting

Generally lettuce, endive, and escarole have the same spacing and seeding requirements. Final spacing on crisphead lettuce, endive, and escarole should be 12-18" between plants (67-100 plants per 100 feet of row) and 12-24" between rows. Other types of lettuce can be 10-16" apart (75-120 plants per 100 feet of row) in 10-18" rows. Spacings should allow good air movement around the plants to minimize disease development. Many growers raise lettuce, endive, and escarole on 4' wide, raised, 4" high beds with 3 to 4 rows per bed. Crop rotation within and between seasons is recommended for disease management. For direct seeding, 10 to 18 oz of seed are needed per acre (0.0625-0.125 oz per 100 feet of row).

Lettuce will germinate at soil temperatures of 32º F, but the optimum and maximum soil temperature is 75º F. Temperatures above 80º F will inhibit seed germination and cause bolting in lettuce. Temperatures below 70º F will promote bolting in endive and escarole. Lettuce seed requires light to germinate and so should be seeded to a shallow depth. 

For once-over harvesting, uniformity at harvest is essential. Producers for direct retail markets and CSA might prefer variable maturity. Precision seeding with modern planters and coated seed can enhance uniformity. Irrigation immediately after seeding also promotes uniform emergence.

Since lettuce matures quickly (40-50 days), and temperature affects days to harvest, plant several successions to get consistent production into the summer. 

Lettuce is often started from transplants, which can be planted all season, from mid-April to August 1. Some growers use floating row covers over beds with early transplants for earlier crops. Hardened transplants should be set out when they are 3-4 weeks old. Hardening is accomplished by withholding water and gradually reducing temperatures for 10 days before the planned transplant date. Use of a liquid starter fertilizer at transplanting time can reduce shock and provide immediately available nitrogen and phosphorus in cold soil. Use a dilute solution to avoid injury to roots. In hot summer conditions, starting transplants in the greenhouse or shade house provides better germination than in the field.

Field Culture 

Hot temperatures cause lettuces to develop a bitter flavor and promotes bolting. White on black plastic mulch (white above, black below) can be used to cool soil temperatures and reduce development of bitterness and bolting. Shade cloth can also be used to reduce heat stress in lettuce. Choose heat-tolerant varieties for mid-season production. 

Harvest and Storage 

Head lettuces should be harvested when heads are well-formed and solid by cutting at the base. A few wrapper leaves should be left on each plant to protect during packing. Leaf lettuces can be harvested by hand or mechanically; a single crop can be harvested multiple times.

Food safety issues from microbial contamination are often linked to leafy greens that are eaten raw. It is important to follow some basic practices that are in accord with the guidance outlined in the Food Safety section of this guide.

Lettuce, escarole, and endive are fragile and highly perishible. Heading lettuces, endive, and escarole are more easily stored than leaf lettuces. Cool to 32-34º F as quickly as possible after harvest and store at 98-100% relative humidity. These crops are damaged by freezing temperatures (32º F).

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Bottom Rot (Rhizoctonia solani)

Rotate crops with non-hosts. Do not plant into fields having significant undecomposed crop residues. Plant in well-drained sites and avoid over-irrigation. Cultivars with upright growth habits are less susceptible.

azoxystrobin (Quadris): 0.40 to 0.80  fl oz/1000 row feet; PHI 0d, REI 4h, Group 11. Apply in-furrow or as a banded application.

Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 14d, REI 12h, Group 7. Suppression only.

iprodione (Rovral 4 F): 1.5 to 2.0 pt/A; PHI 14d, REI 24h, Group 2. Lettuce only.  Direct application to soil and plant base.  Do not cultivate after application.

polyoxin D (OSO 5% SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Trichoderma asperellum, T. gamsii (Bio-tam 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group NC.

Gray Mold (Botrytis cinerea)

Avoid close planting and orient rows in the direction of prevailing winds. Do not plant in poorly drained areas. Plant on raised beds. Minimize damage to lettuce by cultural practices or other pathogens and pests. Avoid overhead irrigation. Do not plant where excessive plant residues are present. Transplanting mature plants results in more breakage. Romaine types are especially susceptible.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 14d, REI 12h, Group 7. Apply at seeding or transplant. A protective fungicide barrier is needed to maximize control.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 0d, REI 12h, Groups 9 & 12. 

penthiopyrad (Fontelis): 14.0 to 24.0 fl oz/A; PHI 3d, REI 12h, Group 7.

polyoxin D (OSO 5% SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Ulocladium oudemansii (BotryStopOG): 2-4 lbs/A; REI 4h, Group not applicable. Begin application when conditions are conducive to disease development.

Downy Mildew (Bremia lactucae)

Lettuce downy mildew is favored by cool, rainy weather. Night temperatures of 43°F to 50°F and day temperatures of 55°F to 70°F with 100% humidity are ideal for disease development. As temperatures increase, the disease disappears. Plant resistant cultivars. Use irrigation practices that reduce leaf wetness and humidity. Protect greenhouse grown transplants with fungicides so that the disease is not introduced into the field.

acibenzolar-S-methyl (Actigard 50 WG): 0.75 to 1.0 oz/A; PHI 7d, REI 12h, Group 21. Apply preventively on a 7-10 day schedule. See label for details.

ametoctradin & dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40.

azoxystrobin (Quadris): 12.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Proceed with caution with regard to tank mixes and adjuvants. Do not rotate with other Group 11 fungicides.

copper compound (Badge X2OG): 1.75 to 3.5 lb/A; PHI 0d, REI 48h, Group M1. Rate and REI vary with product.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette. Injury may occur to sensitive lettuce cultivars.

cyazofamid (Ranman): 2.75 fl oz/A; PHI 0d, REI 12h, Group 21.

cymoxanil (Curzate 60 DF): 3.2 to 5.0 oz/A; PHI 3d (head) and PHI 1d (leafy), REI 12h, Group 27. Must be applied as tank mix with a protectant fungicide.

dimethomorph (Forum):  6 fl oz/A; PHI 0d, REI 12h, Group 40. Must be applied as tank mix with another fungicide with a different mode of action.

famoxadone & cymoxanil (Tanos): 8 to 10 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Tank mix with appropriate contact fungicide with a different mode of action. Do not make more than one application before alternating to a fungicide with a different mode of action.

fenamidone (Reason 500 SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h, Group 11. Do not make more than one application before alternating to a fungicide with a different mode of action. Do not alternate with Quadris.

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Must be tank mixed with a fungicide with a different mode of action.

fluxapyroxad & pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A. PHI 21d, REI 12h, Groups 7 & 11.

mancozeb (Dithane F45): 1.2 to 1.6 qt/A; PHI 10d (head) or PHI 14d (leaf), REI 24h, Group M3.

mancozeb plus copper hydroxide (ManKocide): 1.0 to 2.0 lb/A; PHI 10d, REI 48 h, Groups M3 & M1. 

mandipropamid (Revus): 8 fl oz/A; PHI 1d, REI 4h, Group 40. Addition of a spreading/penetrating adjuvant is recommended.

oxathiapiprolin (Orondis Ultra A): 2.0-4.8 fl.oz/A; PHI 0d, REI 4h, Group 49. Begin foliar application prior to disease development.

propamocarb HCl (Previcur Flex): 2.0 pt/A; PHI 2d, REI 12h, Group 28.

pyraclostrobin (Cabrio EG): 16.0 oz/A; PHI 0d, REI 12h, Group 11.

Drop, White Mold (Sclerotinia minor)

Do not plant seed contaminated with sclerotia (small black hardened fungal survival structures). Avoid planting into severely infested fields. Rotate with non-host crops like grasses. Avoid excessive nitrogen fertilization and irrigate in the morning or with sub-surface drip irrigation to provide dry soil. Deep plow after harvest to bury sclerotia. Soil sterilization with chemicals, steam, or heat (solarization) treatments can significantly reduce inoculum levels. Biofumigation with mustard crop may provide a suppressive effect.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 14d, REI 12h, Group 7. Apply at seeding or transplant. A protective fungicide barrier is needed to maximize control.

Coniothyrium minitans (Contans WGOG): Apply 1 to 4 lb/A in 20 to 50 gal water; REI 4h, Group NC. Spray on the soil surface and incorporate into the top 2" of soil. Fall application is best or 3 to 4 months before planting to allow for the biocontrol agent to infect the sclerotia of Sclerotinia.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 0d, REI 12h, Groups 9 & 1.

fludioxonil (Cannonball WG): 7.0 oz/A; PHI 0d, REI 12h, Group 12.

fluxapyroxad & pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A. PHI 21d, REI 12h, Groups 7 & 11.  

iprodione (Rovral 4F): 1.5 to 2 pt/A; PHI 14d, REI 24h, Group 2. Lettuce only. Direct application to lower stems and branches and adjacent soil surface.  Do not cultivate after application.

penthiopyrad (Fontelis): 16.0 to 24.0 fl oz/A; PHI 3d, REI 12h, Group 7.

polyoxin D (OSO 5% SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Trichoderma asperellum, T. gamsii (Bio-tam 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 4h, Group NC.

Ulocladium oudemansii (BotryStopOG): 2.0-4.0 lbs/A; REI 4h, Group not applicable. Begin application when conditions are conducive to disease development.

Seed Decay

Use treated seed. Do not use treated seed for food, feed or oil purposes.

mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping-off protection.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi. Does not control Pythium or Phytophthora.

thiram (Thiram SC): 8.0 fl oz/100 lb seed; REI 24h, Group M3.

Mosaic (Lettuce and Cucumber Mosaic Viruses)

Certified LMV- and CMV-free seed available. Plant certified disease-free seed away from old lettuce fields.

Yellows

Do not plant lettuce or other sensitive crops in fields or areas having a history of this disease. Control weeds in the Asteraceae family. Control leafhoppers, which carry the disease-causing organism (phytoplasma).

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aphids, Lettuce (Nasonovia ribisnigri)

The most common aphid present on lettuce is the lettuce aphid, of European origin, which overwinters on Ribes species including gooseberries and currants. Winged aphids that colonize lettuce are dark, while wingless females that reproduce on lettuce are pale yellow to green, sometimes reddish, with darker patches. Unlike other aphid species, they feed in the interior of the head, making them difficult to detect and to reach with insecticides. Scout plants at the seedling stage and before heads form. Check field margins, where infestations begin. If one planting becomes infested, use tillage to incorporate crop residue and prevent spread to later succession plantings. Potato aphid, green peach aphid or lettuce root aphid may also occur. See Potato for more information on potato aphid, and Pepper for more information on green peach aphid.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. Green Peach Aphid only. For head lettuce (crisphead) only.

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

afidopyropen (Versys): 1.5 fl oz/A; PHI 0d, REI 12h, Bee: L, Group 9D.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

Beauveria bassiana (Mycotrol ESO): 8 to 32 oz/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Green peach aphid only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. For control of green peach and suppression of potato aphid only.

dimethoate (Dimethoate 4EC): 8 oz/A; PHI 14d for escarole types and leaf lettuce, REI 48h, Bee: H, Group 1B. Not for head lettuce.

dinotefuran (Safari 20SG): 0.16 to 0.25 oz/1,000 sq ft or 3.5 to 5.5 oz/100 gal or 7 to 11 oz/A; REI 12h, Bee: H, Group 4. Transplants only while in greenhouse. Not for field use.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress, or through drip. For green peach and potato aphid only.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12, Bee: L, Group 9C.

flupyradifurone (Sivanto): 7 to 10.5 oz/A for foliar application, 21 to 28 oz/A for soil application; PHI 1d foliar, PHI 21d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only.

imidacloprid (Admire Pro): 1.3 oz/A foliar, 4.4 to 10.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. For foliar applications, apply only to fully leafed-up canopies.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with a companion labeled insecticide; for green peach aphid, must use companion insecticide.

malathion (Malathion 57 EC): 1.5 to 2 pt/A endive, 2 pt/A lettuce; PHI 7d for endive, PHI 14d for lettuce, REI 24h, Bee: H, Group 1B. Not for escarole.

methomyl (Lannate LV*): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. For lettuce only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. Lettuce only.

pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9B. Translaminar. Apply when aphids first appear, before populations build up.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils. Lettuce only.

spirotetramat (Movento): 4 to 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 3d, REI 12h, Bee: H, Group 4C.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

Aster Leafhopper (Macrosteles quadralineatis)

See Carrot and Parsnip section for more information on aster leafhopper and the yellows mycoplasm that it vectors.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. Aster leafhopper. For head lettuce (crisphead) only.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A for potato leafhopper; 2.4 to 3.2 for other leafhoppers; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A.

dimethoate (Dimethoate 4EC): 8 oz/A; PHI 14d for escarole types and leaf lettuce, REI 48h, Bee: H, Group 1B. Not for head lettuce.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress, or through drip.

flupyradifurone (Sivanto): 7 to 10.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 1.3 oz/A foliar, 4.4 to 10.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. For foliar applications, apply only to fully leafed-up canopies.

insecticidal soap (M-PedeOG): 1.25 to 5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Lettuce only.

malathion (Malathion 57 EC): 2 pt/A; PHI 14d, REI 24h, Bee: H, Group 1B. For lettuce only. 

methomyl (Lannate LV*): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. For aster leafhopper on lettuce only.

permethrin (Pounce 25WP*): 3.2 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

tolfenpyrad (Torac): 14 to 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Cabbage Looper (Trichoplusia ni)

An occasional pest of lettuce, especially in late season when migratory flights have brought high numbers of looper moths into New England. See Cabbage section for more information on cabbage looper.

acephate (Orthene 97): 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. For head lettuce (crisphead) only.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azazadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.4 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through drip chemigation and as a foliar spray. For soil applications, must be applied uniformly in the root zone.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 10 to 17 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Apply when larvae are first observed.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22.

methomyl (Lannate LV*): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. For lettuce only.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

permethrin (Pounce* 25WP): 3.2 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Not for escarole.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. Lettuce only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils. Lettuce only.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Use low rate for early season applications to young, small plants. Use of an adjuvant is recommended.

zeta-cypermethrin (Mustang*): 3.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Cutworms

Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed on stems after dark. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Synthetic pyrethroids (Group 3A) may work best during cool spring weather. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 1 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythoid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.p

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Lettuce only.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 1d, REI 4 h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Tarnished Plant Bug (Lygus lineolaris)

The tarnished plant bug (TPB) is a small (1/4”) bronze-colored insect with a triangular marking on its back. TPB adults are highly mobile. The immature, or nymph stage is smaller and bright green, resembling an aphid, but much more active. Adults overwinter in weeds and crop residue and become active in early spring, laying eggs in plant tissue. Young tissue such as flower buds, immature fruit, and emerging leaves are preferred feeding sites compared to mature fruit, stems or leaves. There are 2 to 3 generations per year. There are both native and imported predators and parasites of TPB. The sucking injury from adults and nymphs can cause dieback of the growing tip, death and drop of buds or flowers, brown scars on leaf ribs, and distorted or stunted growth of leaves, pods, seeds or fruit. TPB injury in lettuce includes piercing of leaf ribs, which leaves a brown scar; this is especially noticeable on romaine. The range of vegetable and fruit crops affected by TPB is great; field crops such as alfalfa and many weeds are also favored hosts. In this guide, celery, lettuce, bean and eggplant list TPB as a pest, but these are not the only crops that could be affected. In vegetables, TPB is generally not a seriously damaging pest unless the vegetation surrounding crop fields is serving as a source of large populations, and the crop offers more succulent feeding than the surrounding fields. Avoid planting lettuce near abandoned, weedy fields or alfalfa crops.  While alfalfa may serve as a trap crop, mowing alfalfa may cause TPB to leave mowed fields for nearby vegetables causing TPB populations to increase. In strawberries, white sticky traps are used to detect adults and shaking flower trusses is used to detect nymphs; check small fruit alerts for TPB spring activity. Scout plants for signs of injury and for TPB adults or nymphs, especially in favorite, hidden feeding sites. Sweep nets can be used in crops that are not damaged by sweeping. Insecticides are warranted if damage is increasing and the crop stage is such that significant crop injury can be prevented.

beta-cyfluthrin (Baythroid* XL): 2.4 to 3.2 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12, Bee: L, Group 9C.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

insecticidal soap (M-PedeOG): 1.25 to 5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. For lettuce only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Slugs

Damage appears as shredded foliage. Look for silvery slime trails on leaves or turn over soil clods or debris to find slugs during daylight hours. Grow plants away from moist, shaded habitats, use clean cultivation, control weeds, hand pick/crush slugs or scatter baits on the ground near infested plants. See the Cabbage section for more information on slugs.

iron phosphate (Sluggo: Snail and Slug BaitOG): 20 to 44 lb/A; PHI 0d, REI 0h, Bee: L, Group 9B. Apply around perimeter, scatter around base of plants, or band down rows. Apply to moist soil in the evening.

metaldehyde (Deadline Bullets): 20 to 40 lb/A; REI 12h, Bee: L. Soil surface treatment broadcast pre-planting, or band treatment between rows after formation of edible parts. Apply to moist soil in the evening. Do not apply directly to or contaminate edible portions of plants.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

See section on Soil Fumigation Outdoors (page 89). Proper use of Vapam can provide control of most weed species.

Stale Seedbed

See Stale Seedbed Technique (page 107). In place of herbicides, flaming can also be used.

carfentrazone (Aim EC): REI 12h, Group 14. Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A.  Preplant or stale seedbed application. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): REI 12h, Group 8. Apply 5 to 6 qt/A. Can be preplant incorporated by shallow cultivation (1-2”) or applied preemergence and incorporated by irrigation within 36 hours of application. Mainly annual grass control, and should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

pronamide (Kerb SC): PHI 25 to 55d (based on rate used), 24 hr REI, Group 3. Must be applied prior to weed emergence.  Can be applied either pre-plant, post-plant, or postemergence to head or leaf lettuce, endive, escarole or radicchio greens in banded, bed-topped or broadcast applications.  It is necessary to move Kerb into the root zone of germinating weeds to provide effective control (by overhead sprinkler irrigation, by rainfall, or by shallow mechanical incorporation).  See label for rotation restrictions.

The rate required is dependent on soil texture, target weeds, and method of irrigation/incorporation. Read label carefully to select the proper rate based on your farm conditions.  Apply 2.5 to 5.0 pts/A per acre for head lettuce, endive, escarole, and radicchio greens.  Apply 1.25 to 5.0 pts/A per acre for leaf lettuce.  Up to two applications are permitted and must be separated by at least 10 days.  Total product applied must not exceed 5.0 pts/A.

trifluralin (Treflan HFP): REI 12h, Group 3. Endive and escarole only. Apply 1 to 2 pts/A as a soil-incorporated treatment in spring or early summer prior to planting. Rate based on soil texture and crop, see label for details. Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 14d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14 days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI 14d, REI 12h, Group 1.  For lettuce (leaf and head).  For grass weed control only. Apply to actively growing grasses (see product label for susceptible stage). Apply up to 24 oz/A per application. Can use up to 2 applications per year, allow for minimum 14-days between applications (max 48 oz/A per year).  Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d head lettuce; PHI 15d for leaf lettuce, escarole, and endive, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 3 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Physiological Disorders

Tip Burn

This is a physiological condition caused by the plant's inability to obtain sufficient calcium due to rapid plant growth, excessive fertilization rates, or uneven water availability. Resistant varieties are available. Avoid excess fertilization. Provide consistent irrigation via drip irrigation systems. Foliar calcium supplements may have some benefit.

Okra

Introduction

Okra, also called Lady’s fingers, is a heat loving plant in the hibiscus family. Okra plants are drought and heat resistant. The immature pods are used in soups, stir fries, pickles, and stews. The mucilage in okra acts as a thickening agent in soups, such as gumbo. Its nutritive value includes high fiber content; soluble in the form of gums and pectins that lower serum cholesterol, and insoluble fiber which helps maintain a healthy digestive system. 

Okra does best in warm weather and will die with frost. Most varieties have hairs on all parts of the plant that can cause skin irritation, so gloves and long sleeves may be needed for harvest. There are also spineless varieties and red-fruiting varieties. Though okra is often listed on pesticide labels along with eggplants, peppers, and tomatoes, they are not a related species and share few pests.

Types and Varieties

Okra Varieties
Annie Oakley II
Candle Fire
Clemson Spineless
Cajun Delight
Emerald Green
Jambalaya
Silver Queen
Zarah

Soil Fertility

Apply lime according to soil test to maintain a soil pH at 6.0-6.8.

If plants are to be grown on plastic mulch, the amount of nitrogen fertilizer to be sidedressed can be reduced, since leaching is minimized. If using transplants, apply a liquid fertilizer at transplanting, especially with cool soil conditions. Use a high phosphorous starter fertilizer mixed at a rate of 3 lb/50 gal water. Apply 8 fl oz (1 cup) per transplant.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR OKRA
OKRA NITROGEN (N) LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 50 150 100 25-50 0 200 100 50 0
Sidedress 3-4 Weeks after Planting 40 0 0 0 0 0 0 0 0
Sidedress 6-8 Weeks after Planting 40 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 130 150 100 25-50 0 200 100 25-50 0

Planting

Seeds are sometimes soaked in water for 24 hours due to their hard seed coat to encourage germination. Transplants may be started in the greenhouse, preferably on a heat mat kept at 75-90º F, and transplanted to larger pots 6 weeks before planting into the field at the 3- to 4-leaf stage. Okra is generally grown in locations where it will receive full sunlight throughout the day. Okra grows best at 75-90º F and should not be planted outdoors before the soil temperature reaches 65º F at 4" depth, usually in early June. Plastic mulch, row cover and high tunnels can be used to help achieve the heat requirements. Black plastic mulch with drip irrigation will increase yields.

Plant populations range from 7,000-15,000 plants per acre, depending on the variety. Spacing ranges from 12-24" in the row (100-50 plants per 100 feet of row respectively) with 36" between rows.

Harvest and Storage

Flowering will occur as soon as 45 days after seeding, depending on the variety, and pods are ready for harvest 5-6 days after flowering. Pod tenderness (which is desirable) decreases as size increases. Most varieties will lose their tenderness when they exceed 3" in length. For this reason okra plantings must be picked almost every other day. Pods are harvested by twisting them off the plant or cutting with a knife. After harvest, room cool or use forced air to bring the okra down to 50-55º F at 85-90% relative humidity, where it may be stored for 7-10 days. Below 50°F, okra pods are subject to chilling injury.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Okra is a tropical annual with a wide range of adaptation; it is very sensitive to cold temperatures and frost. Do not plant until soil temperatures have warmed in the spring. 

Cercospora Leaf Spots (Cercospora species)

The pathogens survive on infected plant debris; remove and destroy diseased plant material. Plow crop debris under after harvest to speed up decomposition.

azoxystrobin plus difenoconazole (Quadris Top): 8-14 fl oz/A; PHI 0d, REI 12h, Groups 11 & 3.

chlorothalonil (Bravo Weather Stik): 1.5 pt/A; PHI 3d, REI 12h, Group M5.

chlorothalonil plus cymoxanil (Ariston): 2-4.4 pints/A; PHI 3d, REI 12, Groups M3 & 27.

copper hydroxide (Kocide 3000): 0.75 to 1.75 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution with a pH less than 6.5 or tank mix with Aliette.

tebuconazole (Orius 3.6F): 4 to 6 fl oz/A; PHI 3d, REI 12h, Group 3.

sulfur (Microthiol DisperssOG): 3.0 to 10.0 lb/A; PHI 0d, REI 24h, Group M2

Damping-off (Pythium and Rhizoctonia solani)

Damping-off diseases are favored by cool, cloudy weather, wet soils, high humidity, compacted soils, and overcrowding. Sterilize used pots and trays to raise seedlings. Use a heating pad under trays to warm soil to 75-90° F for indoor plant production. Avoid excessive irrigation, improve soil drainage, and relieve soil compaction. Remove and destroy affected plants and avoid transplanting diseased plants into the field. Seed treatments with biological control agents or fungicides are useful.

azoxystrobin (Quadris): 0.40 to 0.80 fl oz/ 1000 row feet; PHI 0d, REI 4h, Group 11.

mefenoxam (Apron XL): 0.16 to 0.64 fl oz/100 lbs seed; REI 48h, Group 4. Seed treatment.

phosphorous acid (Fosphite): 1.0 to 3.0 qt/in a minimum of 20 gal. water/A; PHI 0d, REI 4h, Group 33. Do not apply to plants that are heat or moisture stressed. Copper phytotoxicity may occur if applied in alteration with copper.

thiram (Thiram 42 S): 6.0 lb/100 lb seed; REI 12h, Group M3.

Fusarium and Verticillium Wilts

Avoid planting in fields where these diseases are present. Rotate with non-solanaceous crops. Plant resistant varieties, if available. Consider soil fumigation. Soil solarization, fallowing, flooding, and biofumigation with brassica green manures may reduce soil populations of these pathogens. See Soil Fumigation Outdoors (page 89).

Trichoderma asperellum, T. gamsii (Bioten 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group NC.

Fruit Rot (Choa nephora)

Choanephora is a soilborne pathogen that attacks senescent blossoms and grows into the fruit. No fungicides are labeled for control. Improve air circulation by proper plant spacing.

Powdery mildew (Erysiphe cichoracearum)

Maintain plant health by adequate fertilization as nutrient stressed plants are more susceptible to infection.

azoxystrobin (Quadris): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. 

copper hydroxide (Kocide 3000): 0.75 to 1.75 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution with a pH less than 6.5 or tank mix with Aliette.

sulfur (Microthiol DisperssOG): 3.0 to 10.0 lb/A; PHI 0d, REI 24h, Group M2.

Nematodes

Nematode control is very important for okra production. Fumigate fields in the fall. See Soil Fumigation Outdoors (page 89). Rotate with corn.

Yellow Vein Mosaic Virus (YVMV)

YVMV is the most important virus disease of Okra and it severely reduces growth and yield as well as causing fruit deformity. It is spread by whiteflies. There are no cures or chemical treatments for plant viruses. Remove and destroy affected plants. Plant resistant varieties. Control whiteflies to reduce disease incidence.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aphids,Green Peach (Myzus persicae) and Melon (Aphis gossypii)

For more information see aphids in the Pepper section.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

afidopyropen (Sefina): 3 fl oz/A; PHI 0d, REI 12 h, Bee: L, Group 9D.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, drip chemigation, or soil injection. Suppression only.

flupyradifurone (Sivanto): 7 to 12 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 45d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

imidacloprid (Admire Pro): 7 to 14 oz/A soil, 1.3 to 2.2 oz/A foliar, 0.44 oz/10,000 plants on seedling transplants in greenhouse; PHI 21d soil, PHI 0d foliar, REI 12h, Bee: H, Group 4A. Planthouse applications only provide short-term protection; an additional field application must be made within 2 weeks following transplanting to provide continuous protection.

malathion (Malathion 57 EC): 1.5 pt/A; PHI 1d, REI 12h, Bee: H, Group 1B.

spirotetramat (Movento): 4 to 5 oz/A; PHI 1d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Corn Earworm, also known as Tomato Fruitworm (Helicoverpa zea)

See Sweet Corn section for more information.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN.

carbaryl (Sevin XLR Plus): 1 to 1.5 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 7 to 13.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting, drip chemigation, or soil injection.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

methoxyfenozide (Intrepid 2F): 10 to 16 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Suppression only. Apply at first sign of feeding damage, or when threshold levels are reached.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Do not apply to seedlings for transplant.

Japanese Beetles (Popillia japonica)

Beetles migrate from turf or pastures starting in July and skeletonize leaves.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lb/A (soil applications only); PHI 0d, REI 4h, Bee: M, Group UN.

malathion (Malathion 57 EC): 1.5 pt/A; PHI 1d, REI 12h, Bee: H, Group 1B.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Two-spotted Spider Mite (Tetranychus urticae)

Outbreaks are often caused by the use of broad-spectrum insecticides. Two-spotted spider mites (TSSM) tend to be prone to pesticide resistance. Watch for white speckling on the upper surface of leaves or webbing on the undersurface around leaf veins. Avoid early-season, broad-spectrum insecticide applications for other pests. Use selective products whenever possible. With most miticides (not bifenazate), use 2 applications, approximately 5 to 7 days apart, to help control immature mites that were in the egg stage and protected during the first application. Alternate between products after 2 applications to help prevent or delay resistance. For more information on TSSM see the Eggplant section.

acequinocyl (Kanemite 15SC): 31 oz/A; PHI 1d, REI 12h, Bee: L, Group 20B. Do not use less than 100 gal water/A. Use of an adjuvant or surfactant is prohibited.

bifenazate (Acramite 50WS): 0.75 to 1 lb/A; PHI 3d, REI 12h, Bee: L, Group 25. Long residual, but not systemic; ensure complete coverage of upper and lower leaf surfaces and fruit.

bifenthrin (Brigade* 2EC): 5.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A. Suppression only.

Stink Bugs

See Tomato section for information on stink bugs, including brown marmorated stink bug.  

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. 

carbaryl (Sevin XLR Plus): 1 to 1.5 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 5d, REI 24h, Bee: H, Group 3A.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Suggestions for weed management in okra include use of the Stale Seedbed Technique and use of plasticulture. Plasticulture is preferred for okra since it is such a warm season crop.

Stale Seedbed

See Stale Seedbed Technique (page 107). In place of herbicides, flaming can also be used.

carfentrazone (Aim EC): REI 12h, Group 14. Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A. Include a nonionic surfactant at 0.25% v/v, or crop oil concentrate/methylated seed oil at 1.0% v/v (1 gal/100 gal) of the finished spray volume for maximum efficacy. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Stale seed beds can be used between plastic mulch (be careful with flaming as it melts the plastic). Some hand weeding may be needed in the planting holes as okra grows slowly at first after transplanting. Apply the plastic at least 2 to 3 weeks prior to planting and kill the weeds between the mulch prior to setting the okra plants on the plastic.

Herbicides Used Preemergence to Weeds

trifluralin (Treflan HFP): REI 12h, Group 3. Apply 1 to 2 pts/A as a soil-incorporated treatment prior to planting. Select rate based on soil texture and crop, see label for details. Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation.

Herbicides Used Pre- and Postemergence to Weeds

mesotrione (Callisto): PHI 28d, REI 12h,  Group 27.  Callisto can be applied as a row middle OR a hooded post-direct treatment (but not both) for weed control in okra.  Do not make more than one application of Callisto per okra crop.  Injury risk is greatest on coarse-textured soils (sand, sandy loam or loamy sand). Do not apply Callisto as a broadcast preemergence or broadcast postemergence application to okra or severe injury will occur.  Do not apply Callisto directly over the planted okra row or severe crop injury may occur.  Controls many annual broadleaf weeds, including common lambsquarter and triazine resistant biotypes.  Temporary injury, appearing as whitening of the foliage after emergence, may occur.  Varieties may differ in sensitivity to mesotrione.

Preemergence row-middle application: Apply Callisto at a rate of 6.0 oz/A as a banded application to the row middles prior to weed emergence. Leave one foot of untreated area over the okra row or 6” to each side of the planted row. For banded applications, the application must be made to account for band width, i.e. to deliver 6.0 fl oz per treated acre.

Postemergence hooded application: Apply Callisto at a rate of 3.0 fl oz/A as a postemergence directed application using a hooded sprayer for control or partial control of the weeds listed in Table 28, page 109. Okra must be at least 3” tall at the time of this application. It is recommended that a nonionic surfactant (NIS) type adjuvant at a rate of 0.25% v/v be added to the spray solution. For postemergence hooded applications, the spray equipment must be set up to minimize the amount of Callisto that contacts the okra foliage or crop injury will occur. For best postemergence results, Callisto must be applied to actively growing weeds.

prometryn (Caparol 4L):  PHI 14d, REI 12h, Group 5. Primarily controls annual broadleaf weeds. Annual grasses may only be suppressed. Can be used preemergence and/or post-directed to okra. Make a single preemergence broadcast application of Caparol 4L after planting before crop emergence at the rate of 3.0 pt/A.  For two applications make the first preemergence after planting, before crop emergence at the rate of 1.5 pt/A and the second post-directed when okra plants are at 7-9 leaf stage at the rate of 1.5 pt/A. Apply post-directed before weeds are 2 inches tall.  Do not exceed one preemergence and one post-directed application per crop cycle. Do not exceed 3 pt/A of Caparol 4L per crop cycle.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  For use between rows after crop establishment. Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

halosulfuron (Sandea): PHI 30d, REI 12h, Group 2.  Apply between rows of okra for control of broadleaf weeds.  Avoid crop contact.  If plastic mulch is used, keep the herbicide off the plastic. DO NOT allow Sandea to contact the planted crop or crop injury will occur.  See label for additional precautions.  Excellent on velvetleaf, smartweed, ragweed, pigweed.  Good on yellow nutsedge and morning glory.  Use 0.5 to 1.5 oz/A per application. Do not apply more than 2 times per season and do not exceed 2 oz/A per year. See label for list of weeds and other precautions.  Weed control may be reduced without the use of a surfactant.

paraquat (Gramoxone SL 2.0*): REI 12h, Group 22.  For use between rows after crop establishment as shielded application. Apply up to 2 pt/A to emerged weeds between rows when weeds are succulent and weed growth is less than 6”. Include a nonionic surfactant at 0.25% v/v, or crop oil concentrate/methylated seed oil at 1.0% v/v (1 gal/100 gal) of the finished spray volume for maximum efficacy. Maximum 3 applications per year, not to exceed a total of 8 pt/A per season.  Allow 14 days between applications.  Use precision directed spray application equipment adjusted to prevent spray contact with crop plants. Crop contact by the spray will cause severe injury or death. Do not exceed 30 psi nozzle pressure or spray under conditions which may cause excessive drift. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators. The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a DIRECTED/SHIELDED SPRAY; contact with crop will cause injury. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

Onion, Scallion, and Shallot

Introduction

Bulbing onion, scallion, and shallot, along with garlic and leek, are members of the genus Allium. The characteristic flavors of Allium family members come from sulfur-containing compounds produced by these plants.

The bulbing onion, Allium cepa, appears to have originated near the intersection of Europe and Asia, whereas the bunching onion or scallion, Allium fistulosum may have originated in China. 

Types and Varieties

Bulbing onions form bulbs in response to day length. Only long-day and intermediate-day types are recommended for summer harvest in New England since these types require at least 13 hours of daylight. Short-day onions begin forming bulbs when days are 10-12 hours long and are typically grown in southern regions of the U.S. where they are planted in the winter. Recently, some researchers and farmers in New England have been planting onions in low tunnels in the fall for spring harvest. The University of New Hampshire research report on overwintering onions includes planting details and trialed varieties (see https://extension.unh.edu/resources/files/Resource005477_Rep7652.pdf). Shallots form clusters of bulbs. While shallots have traditionally been propagated vegetatively, hybrid cultivars that can be grown from seed are now available. Scallions a member of the Allium genus that do not form a fully developed bulb. They are planted from seed and commonly sold in bunches.

Onion, SHallot, and Scallion Varieties
Scallion/Bunching Onion Onion - Yellow Storage
Evergreen Hardy White Northstar (80)
Ishikura Improved Bridger (90)
Southport White Bunching New York Early (98)
  Patterson (104)
Shallot Cortland (105)
Ambition Crocket (114)
Conservor  
  Onion - Red Storage
Onion - Sets Red Bull (104)
Ebenezer Red Carpet (114)
Stuttgart Redwing (114)
   
Onion - Sweet, non-storing  Onion - Overwintering
Ailsa Craig (110) Bridger
Candy (85) Gatekeeper
  Hi-Keeper
Onion - Sweet Spanish Electric (red)
Super Star (100) Desert Sunrise (red)
Yellow Sweet Spanish (120) Red Rock (red)
The number in parentheses is the approximate number of days to maturity from seeding.

Soil Fertility

Apply lime according to soil test results to maintain soil pH at 6.5-6.8. Onions and leeks do not tolerate acid soil, especially in early growth stages. If the magnesium level is high, a lime high in calcium (calcitic lime) should be used to maintain a high calcium level.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7). These sources may also result in high soil nitrogen levels late in the season. Excessive nitrogen late in the season from any source can delay maturity and reduce storability of onions.

Onion flavor is determined by cultivar type, temperature and irrigation, and sulfur fertility. Growers wishing to produce mild-flavored onions for retail sale should choose mild cultivar types, irrigate regularly up to harvest, and maintain soil sulfur levels between 35 and 55 lb/A. Excessive sulfur levels in soils or fertilizers will increase pungency. 

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR ONION, Scallion, and Shallot
ONION, Scallion, and Shallot NITROGEN (N) LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 80-100 150 100 25-50 0 175 150 50 0
Sidedress 4-5 Weeks after Planting 50 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 130-150 150 100 25-50 0 175 150 50 0

Planting

Bulbing onion and shallot. Sow transplants in late February or early March, 10-12 weeks before setting in field. Direct seed onions in spring as soon as soil can be worked. Seeding should be completed by late April or mid-May at the very latest to allow time for adequate plant growth before bulb initiation occurs. Plant 2-4 rows per bed, 9-18" between rows and 3-4" apart within rows for transplants. Spacing will affect bulb size. For direct seeding, aim for a stand of 6-9 plants per foot. This can be increased to 9-12 plants per foot if double shoe precision seeders are used. This requires 5-6 lb of seed per acre (about 0.5 oz per 100 feet of row). Instead of transplants, some growers use sets to plant all or some of their crop. Sets are small bulbs (about 1/2") raised the prior year and stored over the winter. This provides for an early harvest (mid-summer), but larger sets can be prone to bolting (premature flowering). Sets should be planted as soon as the soil has dried and can be worked. Spacing is the same as for transplants. Some growers are finding success using black or white-on-black plastic mulch on raised beds for sets or transplants.

Scallion. In addition to early spring planting, mid-summer plantings can be used to produce fall harvests. Even moisture must be maintained throughout germination for direct-sown scallions. Seed in rows 2"-3” wide, spaced 4” apart. 

Harvest and Storage

Bulbing onion and shallot: Late, hard, pungent varieties with good skin retention are preferable for winter storage. Undercutting several days before harvesting can improve keeping quality. It is best to undercut when most of the plants have 2 leaves that are still partially green. Allowing leaves to completely dry down before undercutting can result in excessive loss of skin during harvest. To develop best skin color, onions should be cured for 2 weeks at 75-80º F and 70-80% relative humidity. After curing, lower temperature gradually to as near to 32º F as practical without freezing. Cooling too rapidly, followed by a few warm days, can cause moisture condensation, resulting in bulb staining, sprouting and decay. Maintain storage relative humidity at 65-70%, and maintain sufficient air flow to keep cool air moving around bulbs.

Scallion. Scallions, or fresh bunching onions, can be harvested anytime after they are pencil-sized. To maintain good post-harvest quality, they should be cooled to 39º F within 4-6 hours of harvest. Scallions can be stored for 7-10 days at 32º F.

Sprout Inhibition

For long-term storage of bulbing onions or shallots, select storage varieties. Pungent dry onions can be stored for 6-9 months at 32º F. For very long-term storage, a sprouting inihibitor, maleic hydrazide (2 gal of Royal MH-30/A in a minimum of 30 gal/A), may be applied when about 50% of the tops are down, the bulbs are mature, the necks are soft and five to seven of the leaves are still green. See the label for details.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Botrytis Leaf Blight

Avoid close planting and orient rows in the direction of prevailing winds. Do not plant on poorly-drained areas. Plow under crop debris after harvest. Remove cull piles and practice crop rotation. Avoid excessive nitrogen fertilization as this increases canopies and susceptibility. Plant less susceptible cultivars. Irrigate early in the day to reduce leaf wetness periods. Incorporate crop residues after harvest. Apply fungicides based on a disease forecast system (i.e., BOTCAST). Disease development, based on weather conditions near your farm, can be monitored on-line (www.newa.cornell.edu).

For dry bulb onions:

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 7d, REI 12h, Groups 11 & M5.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 7d, REI 12h, Groups 11 & 3.

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 14d, REI 12h, Groups 11 & 3.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. 

chlorothalonil (Bravo Weather Stik): 1.0 to 3.0 pt/A; PHI 7d, REI 12h, Group M5.  To suppress Botrytis neck rot in storage, a minimum of 3 weekly applications prior to lifting using 1.25 to 1.8 lb/A is recommended.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 12h to 24h (24h for hand weeding), Group 29.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A or 1.0 pt/A (if tank-mixed); PHI 7d, REI 24h, Group 2.

mancozeb (Dithane F45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

penthiopyrad (Fontelis): 16 to 24 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 7d, REI 12, Groups 33 & M5.

propiconazole (Tilt): 4.0 to 8.0 oz/A; PHI 14d, REI 12, Group 3.

pyraclostrobin plus boscalid (Pristine): 14.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7. Do not make more than 2 sequential applications of Pristine before alternating with a fungicide with a different mode of action.

pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9. 

For green onions, or shallots:

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3.

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 0d, REI 12h, Groups 11 & 3.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Use higher rate and shorter interval when disease pressure is high. Do not make more than 1 application of Endura before alternating with a fungicide with a different mode of action (FRAC group).

chlorothalonil (Bravo Weather Stik): 1.5 to 3.0 pt/A; PHI 14d, REI 12h, Group M5. When disease is present, use the higher rate.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WDG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 14d, REI 12h, Group 3 & 9.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4-7 pt/A; PHI 14d, REI 12, Groups 33 & M5.

propiconazole (Tilt): 4.0 to 8.0 oz/A; PHI 0d, REI 12, Group 3.

pyraclostrobin plus boscalid (Pristine): 14.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7. Do not make more than 2 sequential applications of Pristine before alternating with a fungicide with a different mode of action.

pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9.

Neck Rot (Botrytis alli)

Primarily a storage disease. Do not apply nitrogen late in the season and avoid high-density planting. Undercut bulbs to promote drying. Allow the tops to dry completely and have tight necks before topping.  Avoid condensation on bulbs during storage. Maintain storage environment at 32°F to 33°F and 70% to 75% relative humidity. Fungicides applied to control Botrytis blight may also decrease neck rot.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 14h, Groups 11 & M5.  Suppression only. See label for tank mix precautions.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Suppression only. 

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 48h, Group 29.

fluxapyroxad + pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A or 1.0 pt/A (if tank-mixed); PHI 7d, REI 24h, Group 2.

mancozeb (Dithane M45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

pyraclostrobin plus boscalid (Pristine): 14.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7.

pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9.

Downy Mildew (Peronospora destructor)

The fungus overwinters in infected bulbs or sets and on other host plants, in cull piles, and in fall-seeded onion. Only a few spores are needed to initiate an epidemic. Eliminate cull piles, volunteer onion plants, and wild Allium species. Practice a 3- to 4-year rotation. Plant only on well-drained land. Apply fungicides when mildew is present in the area and weather favors disease increase based upon a disease forecasting system (i.e., DOWNCAST).  Disease development, based on weather conditions near your farm, can be monitored online (www.newa.cornell.edu).

For dry bulb onions:

acibenzolar-s-methyl (Actigard 50 WG): 0.75 to 1.0 oz/A; PHI 7d, REI 12h, Group 21. Actigard acts as a plant activator and should be applied preventatively.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 7d, REI 12h, Groups 11 & M5. See label for tank mix precautions.

copper hydroxide (Kocide 3000): 0.75 to 1.5  lb/A; PHI 0d, REI 48h, Group M1. Can cause phytotoxicity to leaves. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman 400 SC): 2.75 to 3.0 fl oz/A; PHI 0d, REI 12h, Group 21.

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide with a different mode of action.

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides. 

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not make more than 1 application of Reason before alternating to a non-Group 11 fungicide.

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 48h, Group 29.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset. For supression only.

mancozeb (Dithane M45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

mancozeb plus copper hydroxide (ManKocide): 2.5 lb/A; PHI 7d, REI 48h, Groups M3 & M1.

mandipropamid (Revus): 8.0 fl oz/A; PHI 7d, REI 4h, Group 40.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 7d, REI 48h, Groups 4 & M5.

mefenoxam plus copper hydroxide (Ridomil Gold Copper): 2.0 lb/A; PHI 10d, REI 48h, Groups M3 & M1.

mefenoxam plus mancozeb (Ridomil Gold MZ): 2.5 lb/A; PHI 7d, REI 48h, Groups 4 & M3.

oxathiapiprolin plus chlorothalonil (Orondis Opti): 1.75 to 2.5 pt/A; PHI 7d, REI 12h, Groups 49 & M5.

oxathiapiprolin plus mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 7d, REI 4h, Groups 49 & 40.

phosphorous acid (Fosphite): 1.0 to 3.0 qt/100 gal; PHI 0d, REI 4h, Group 33. Do not apply to heat or moisture stressed plants or to plants recently treated with copper.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 7d, REI 12, Groups 33 & M5.

pyraclostrobin (Cabrio EG): 12.0 oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus boscalid (Pristine): 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. For suppression only. Rotate with a downy mildew fungicide with a different mode of action.

zoxamide plus chlorothalonil (Zing!): 30.0 fl oz/A; PHI 7d, REI 12h, Groups 22 & M3.

zoxamide plus mancozeb (Gavel 75 DF): 1.5 to 2 lb/A; PHI 7d, REI 48h, Groups 22 & M3.

Green or bunching:

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions.

copper hydroxide (Kocide 3000): 0.75 to 1.5  lb/A; PHI 0d, REI 48h, Group M1. Can cause phytotoxicity to leaves. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman 400 SC): 2.75 to 3.0 fl oz/A; PHI 0d, REI 12h, Group 21. 

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide with a different mode of action.

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset. For supression only. 

mandipropamid (Revus): 8.0 fl oz/A; PHI 7d, REI 4h, Group 40.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 14d, REI 48h, Groups 4 & M5.

mefenoxam plus copper hydroxide (Ridomil Gold Copper): 2.0 lb/A; PHI 7d, REI 48h, Groups M3 & M1.

oxathiapiprolin plus chlorothalonil (Orondis Opti): 1.75 to 2.5 pt/A; PHI 14d, REI 12h, Groups 49 & M5.

oxathiapiprolin plus mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 7d, REI 4h, Groups 49 & 40.

potassium phosphite + chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 14d, REI 12, Groups 33 & M5.

pyraclostrobin (Cabrio EG): 12.0 oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus boscalid (Pristine): 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. For suppression only. Rotate with a downy mildew fungicide with a different mode of action.

zoxamide plus chlorothalonil (Zing!): 30.0 fl oz/A; PHI 7d, REI 12h, Groups 22 & M3.

zoxamide plus mancozeb (Gavel 75 DF): 1.5 to 2 lb/A; PHI 7d, REI 48h, Groups 22 & M3.

Purple Blotch (Alternaria porri)

The pathogen overwinters in plant residue from onions and onion-related plants. Disease development is favored by warm, moist conditions. Avoid Sweet Spanish onions because they are extremely susceptible. Plow under crop residues after harvest. Rotate with non-hosts. Select sites and practice irrigation to enhance rapid drying of foliage. Apply fungicides as canopy becomes denser and leaf-wetness periods increase. Purple blotch disease development, based on weather conditions near your farm, can be monitored on-line (www.newa.cornell.edu).

azoxystrobin (Quadris): 6.0 to 12.0 fl oz/A; PHI 0d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 7d (dry) and 14d (green), REI 12h, Groups 11 & M5. See label for tank mix precautions.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 7d, REI 12h, Groups 11 & 3. 

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 14d (dry) and 0d (green), REI 12h, Groups 11, 7 & 3).

Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7.

chlorothalonil (Bravo Weather Stik): 1.0 to 3.0 pt/A; PHI 7d (dry) and 14d (green), REI 12h, Group M5.

copper hydroxide (Kocide 3000): 0.75-1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WDG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus benzovindiflupyr (Aprovia Top): 10.5 fl oz/A; PHI 7d, REI 12h, Groups 3 & 7. No more than 2 sequential applications before alternating to a non-Group 7 fungicide.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d (dry bulb); PHI 14d (green), REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage. 

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides. 

fluazinam (Omega 500F): 1.0 pt/A (dry bulb only); PHI 7d, REI 12-24h, Group 29.

fluopyram plus pyrimethanil (Luna Tranquility): 16.0 to 27.0 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 5.5 to 11 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A (dry bulb only); PHI 7d, REI 24h, Group 2. Do not make more than 5 applications per season. If tank-mixing with another chemical registered for purple blotch, reduce iprodione rate to 1 pt/A.

mancozeb (Dithane F45): 2.4 qt/A (dry bulb only); PHI 7d, REI 24h, Group M3.

mancozeb plus copper hydroxide (ManKocide): 2.5 lb/A (dry bulb only); PHI 7d, REI 48h, Groups M3 & M1.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 14d, REI 12, Groups 33 & M5.

propiconazole (PropiMax EC): 4.0 to 8.0 fl oz/A; PHI 14d bulb; PHI 0d green, REI 12h, Group 3.

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not exceed 6 applications per season or 72 oz/A. Do not rotate with other Group 11 fungicides.

pyraclostrobin plus boscalid (Pristine): 10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. Do not rotate with another Group 11 fungicide.

pyrimethanil (Scala SC): 18.0 fl oz (alone) 9.0 fl oz (tank mixed)/A ; PHI 7d, REI 12h, Group 9.

tebuconazole (Orius 3.6F): 4.0 to 6.0 fl oz/A (for dry onion); PHI 7d, REI 12h, Group 7.

Stemphylium leaf blight (Stemphylium vesicarium)

Symptoms appear as target-like brown lesions, lacking the purple margins seen with purple blotch. The pathogen overwinters in plant residues from onions and onion-related plants. Disease development is favored by warm, moist conditions. Plow under crop residues after harvest. Rotate with non-hosts. Select sites and practice irrigation to enhance rapid drying of foliage. Apply fungicides as canopy becomes denser and leaf-wetness periods increase.

difenoconazole plus benzovindiflupyr (Aprovia Top): 10.5 fl oz/A; PHI 7d, REI 12h, Groups 3 & 7. No more than 2 sequential applications before alternating to a non-Group 7 fungicide.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d (dry bulb); PHI 14d (green), REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 5.5 to 11 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A (dry bulb only); PHI 7d, REI 24h, Group 2. Do not make more than 5 applications per season. If tank-mixing with another chemical registered for purple blotch, reduce iprodione rate to 1 pt/A.

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not exceed 6 applications per season or 72 oz/A. Do not rotate with other Group 11 fungicides.

pyraclostrobin plus boscalid (Pristine): 10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. Do not rotate with another Group 11 fungicide.

White Rot (Sclerotium cepivorum)

White rot is associated with soil-borne inoculum; repeated cropping of Allium species results in increased disease over time. The sclerotia can persist in the soil for up to 20 years in the absence of a host. Select fields with no history of this disease. Use only disease-free transplants. Soil fumigation may be useful. Stimulating the sclerotia to germinate with onion exudate mimics (diallyl disulphide) can reduce soil inoculum.

azoxystrobin plus propiconazole (Quilt Xcel): 17.5 to 26 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Apply in-furrow.

cyprodinil plus fludioxonil (Switch 6.25 WG): 7.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Apply at planting as in-furrow spray.

fludioxonil (Cannonball WG): 7.0 oz/A (0.5 oz/1,000 ft row); PHI 7d, REI 12h, Group 12.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

tebuconazole (Orius 3.6F): 20.5 fl oz/A (dry onion); PHI 7d, REI 12h, Group 7. Apply in a 4-6 inch band into/over each furrow. May also be applied by chemigation.

thiophanate methyl (Topsin M 70WP): 2.0 lb/A; REI 72h, Group 1. Apply in furrow.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

All tolerances for chlorpyrifos in food crops were revoked in 2022, therefore products containing chlorpyrifos (e.g. Lorsban) cannot be applied to any food crop and growers CAN NOT use up existing stock.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Allium Leaf Miner (Phytomyza gymnostoma)

For more information on this pest and for cultural and chemical controls, see Allium Leaf Miner in the leek section.

Bulb Mites

Two genera of mites are known to infect species of Allium. The dry bulb mite (Aceria tulipae) is an eriophyid mite that survives on cultivated Allium species. Bulb mite species in the genus Rhizoglyphus can also be troublesome on alliums. Bulb mites overwinter in soil on debris, stored onions and garlic, and in garlic seed pieces.  They are moved from field to field with soil on equipment, boots, etc., and planting infested garlic They are particularly troublesome in storage, causing desiccation and creating wounds that allow for entry of pathogens.

Bulb mites are favored by mechanical injury, disease, cool soil temperatures, and soils with high organic matter content. Avoid adding manure and use fallow periods to eliminate crop residue. In smaller plantings, removing culls from the field immediately after harvest will reduce overwintering populations. Dark plastic mulch will increase soil temperatures and control mites. Plant clean seed and rotate out of alliums for at least four years after an infestation. Avoid planting alliums directly after brassicas, corn, grain, or grass cover crops.

Cutworms

Caterpillars hide under the soil surface adjacent to the plant during the day and feed on leaves after dark. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Synthetic pyrethroids may work best during cool spring weather. All synthetic pyrethroid restricted use (*) insecticides listed to control thrips on onions are also registered to control cutworm on this crop. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

gamma-cyhalothrin (Declare*): .077 to 1.28 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.60 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 3 pt/A; PHI 7d, REI 48h, Bee: H, Group 1A. For green and dry onions. Add wetting agent to improve coverage. For black and variegated cutworm only.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 1d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Leek Moth (Acrolepiosis assectella)

For more information on this pest and for cultural and chemical controls, see Leek Moth in the leek section.

Onion Maggot (Delia antiqua)

Infestations may reduce young plant stands, cause plants to wilt and yellow, or damage bulbs.  There are 3 generations each year.  Effective control of the first generation (mid-May to June), which causes the most destruction, and minimizing mechanical and chemical damage to onions throughout the season, will reduce or eliminate damage by later generations. Rotate crops to keep maggot populations low; greater distances are more effective. Cumulative growing degree days (GDD) can be used to monitor the activity of onion maggot fly in your area: peak flight for the first generation is at 735 GDD, base 40°F. Delay planting until after first flight is finished and soil temperatures are high enough to kill eggs (95°F). Planting in late-May is more likely to be safer than the first half of May. Cover recently seeded or transplanted crops with floating row covers as a barrier against cabbage root maggot flies, placing the cover as soon as the transplants are set. Gathering culls into deep piles will limit reproduction to surface layers and reduce populations more than deep plowing or harrowing after harvest. Biological controls, including naturally-occurring fungal diseases, predaceous ground beetles, and soil applications of the entomopathogenic nematode Steinernema feltiae can all reduce onion maggot numbers. Nematodes can be applied to transplants, in transplant water, or as a post-transplant drench. Rates of 100,000 to 125,000 infective juveniles per transplant have been shown to be needed to achieve reduction in damage. Nematodes need a moist soil environment to survive. If using an insecticide, soil drench applications targeting the seed furrow or base of transplants, using at least 100-200 gal of water per acre to help the insecticide penetrate the root zone are the most effective.

diazinon (Diazinon* AG500): 2 to 4 qt/A; REI 3d, Bee: H, Group 1B. Broadcast and incorporate just before planting. Will not control organophosphate-resistant onion maggots. For bulb and green onions. DO NOT make more than one application per year.

Onion Thrips (Thrips tabaci)

Onion thrips range in color from yellow to black and are only 1/16" in length. They spend the winter as adults in crop remnants, alfalfa, wheat, greenhouses and weeds along the border of crop fields. Thrips have rasping mouth parts which they use to tear open plant cells and feed on inner juices. Feeding occurs in protected areas between leaves. Damage may appear as silver lines, white patches, tip dieback and curling, slowed growth, reduced bulb size and yields, or result in plant death. Populations are favored by hot, dry weather. Plants are most sensitive when bulbs are forming and still small. Heavy rain or overhead irrigation can lower populations quickly. Lacewing larvae, pirate bugs and predatory thrips are important natural enemies. Reduce populations by cleaning up crop residue after harvest to limit overwinter sites. Do not plant onions near alfalfa, clover, cucurbits or brassica crops that can harbor large populations of thrips, which may migrate to onions when these crops are cut or harvested.

Reflective mulch will repel colonizing thrips by confusing invading insects and preventing them from finding their host plants. 

Scout plants along field margins where infestations build early. Begin applications when damage is first noticed or when there are 3 or more thrips per leaf. Repeat applications at 7- to 10-day intervals. From 3 to 6 applications may be necessary, but rotate between insecticide groups after 2 applications to help prevent resistance. Use a shorter interval in hot weather. Use spreader-sticker for better coverage. Apply in early evening, using high pressure and 100 gal water/A for best results.

acetamiprid (Assail 30SG): 5 to 8 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group un.

Beauveria bassiana (Mycotrol ESO): 0.25 qt to 1 qt/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.

Burkholderia spp. strain A396 (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN. Suppression only.

Chenopodium extract (Requiem EC): 1.5 to 3 qts/A; PHI 0d, REI 4h, Bee: L, Group UN. Begin application as soon as thrips are seen. Thoroughly cover foliage.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Suppression only.

deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

gamma-cyhalothrin (Declare*): .1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 14 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.

kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression/repellence only. Good coverage into plant crown is essential. Generally compatible as a tank mix with other insecticides.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.

malathion (Malathion 57EC): 1.5 pt/A; PHI 3d, REI 12h, Bee: H, Group 1B.

Metarhizium anisopliae Strain F52 (Met 52 EC): 40 to 80 oz/100 gal (drench), 8 to 64 oz/A (foliar); PHI 0d, REI 0h, Bee: L, Group UN.

methomyl (Lannate* LV): 3 pt/A; PHI 7d, REI 48h, Bee: H, Group 1A. For green and dry onions. Add wetting agent to improve coverage. Begin application before populations reach 3 to 5 thrips per plant.

permethrin (Pounce* 25WP): 9.6 to 19.2 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. For dry bulb onions only

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

pyriproxyfen (Esteem 0.86EC): 8 oz/A; PHI 3d, REI 12h, Bee: L, Group 7D. Dry bulb onions only. Suppression only.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Suppression only. Use adjuvant for better control.

spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Thorough coverage is essential. Efficacy improves with the addition of an adjuvant.

spirotetramat (Movento): 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

zeta-cypermethrin (Mustang*): 3.2 to 4.3 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107). In place of herbicides, flaming can also be used.

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. Dry bulb onion only. REI 12h, Group 22. Use 2 – 4 pts/A. Include a nonionic surfactant at 0.25% v/v, or crop oil concentrate/methylated seed oil at 1.0% v/v (1 gal/100 gal) of the finished spray volume for maximum efficacy. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): REI 12h, Group 0.  Dry bulb onion and dry bulb shallot only. Apply 5 to 6 qt/A.  Can be preplant incorporated by shallow cultivation (1-2”) or incorporated by irrigation within 36 hours of application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

dimethenamid (Outlook): PHI 30d, REI 12h, Group 15.  Can be used for dry bulb onion and shallot, and also for green onion (leeks, spring onions or scallions, Japanese bunching onions, green shallots or eschalots).  If applications are made to transplanted green onions, DO NOT apply until transplants are in the ground and soil has settled around transplants with several days to recover.  This herbicide is a root and shoot growth inhibitor that controls susceptible germinating seedlings before or soon after they emerge from the soil. Do not apply until onion has reached the 2 true-leaf stage or significant crop injury can occur.  May be applied as a single application (up to 21 oz/A) or used in split applications.  For split applications do not exceed a total of 21 oz/A per season. An initial application of 10 to 14 oz/A can be followed by another application of the remaining 7 to 11 oz/A.  Applications must be a minimum of 14 days apart. Application rates are influenced by soil organic matter content. See label for info on application rates depending on soil type and organic matter content. See label for info on tank mixing with other herbicides.

DCPA (Dacthal W-75): REI 12h, Group 3.  Select rate for preemergence use based on soil type and weeds targeted for preemergence control.  Good control of most annual grasses; fair on redroot pigweed, lambsquarter, and purslane.  Apply to weed-free soil; will not control existing weeds.  Can be applied at seeding or transplanting and/or at layby.  Can be sprayed directly over transplants without injury. A layby application can be made on onions either alone or in addition to a Dacthal preemergence treatment up to 14 weeks after planting at rates up to 14 lb/A on any soil type. If weeds emerge prior to layby, the onions should be cultivated or weeded prior to application. Preplant incorporation not recommended.

s-metolachlor (Dual Magnum): REI 12h, Group 15. MASSACHUSETTS, MAINE, and NEW HAMPSHIRE ONLY. Dry bulb and green onion. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge. All label instructions will be supplied after the application for use is completed.

pendimethalin (Prowl H2O): PHI 45d (PHI 30d for green onions), REI 24h, Group 3. Emerged weeds will not be controlled by Prowl.  Dry bulb onion and dry bulb shallot: Apply 1.5 to 3.2 pt/A.  Select rate based on soil texture.  See label for details.  Can be used preemergence after planting but before crop emergence, after crop emergence when onions/shallots are in the 1 to 5 true leaf stage, or at both timings.  For green onions, use 2 pt/A as preemergence spray or as a postemergence spray to the crop at the 2 to 3 true-leaf stage. If applied sequentially as both a preemergence and postemergence spray, applications must be separated by at least 30 days. Do not exceed 4 pt/A per year on green onions. 

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14.  For use between rows after crop establishment. Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max): PHI 45d, 24hr REI, Group 1.  Dry bulb onions and dry bulb shallots only.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 32 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI varies (45d dry bulb, 14d green onion), REI 12h, Group 1. Dry bulb and green onion only. For grass weed control only. See label to select rate based on grasses targeted for control. Apply up tp 24 fl oz/A. Can make up to 2 applications per year. Allow for minimum 14 days between applications, and not to exceed 48 oz/A per year.  Apply to actively growing grasses (see product label for susceptible stage). Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).

oxyfluorfen (Goal 2 XL): REI 48h, Group 14. Provides early postemergence and residual control of many broadleaf weed species. For direct seeded onions, apply 2 to 4 oz/A to onions that has at least 3 fully developed true leaves.  For transplanted onions, an application of up to 2 pt/A acre may be made within two days after transplanting.  If less than 2 pt/A acre is applied, a second application can be made two weeks or more after transplanting.  Do not exceed the maximum use rate of 2 pt/A per season.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 4.5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Parsley and Cilantro

Introduction

Parsley (Petroselinum crispum) and cilantro (Coriandrum sativum) both belong to the Umbelliferae (Apiaceae) family, along with several other crops such as carrot, celery, fennel, dill, and parsnip. Curly leaf parsley is most often used as a garnish, whereas flat leaf parsley is more often used as an ingredient. The fresh leaves of cilantro are commonly used in Mexican, South Asian, Indian and other cuisines; the dried seeds of the same plant are known as coriander. 

Types and Varieties

Cilantro and Parsley Varieties
Cilantro Parsley - Curly Leaf Parsley - Flat Leaf
Advanced Turbo II (BB) Banquet Dark Green Italian Plain
Calypso Darki Giant of Italy
Caribe Double Curled Laika
Confetti Forest Green Peione (DM)
Cruiser (B) Grune Perle  
Leisure Jade  
Longstanding Katinka  
Marino Krausa  
Pallas Moss  
Santo Wega  
B = Bolting resistant, BB = bacterial blight resistant, DM = downy mildew resistant

Soil Fertility

Maintain soil pH near 6.5, and maintain P and K in the high/optimum range. These crops do best in rich, well-drained soils.

Planting 

Parsley and cilantro can be transplanted or direct seeded. Transplants are recommended for parsley, which can take up to 3 weeks to germinate. For transplant production, seed into 72-cell trays. Transplant at 12-18” between and within rows. Cilantro germinates more rapidly, so direct seeding is recommended. Be mindful of reduced germination rates when using seed older than one year; doing a germination test ahead of planting is recommended so that adjustments to seeding rates can be made if necessary. If direct seeding, do so after the last frost. Direct seed 1/3’” deep at 20-40 lb/A (1-2 oz/100-row ft) into rows 12-18” apart. Cilantro grows well even when thickly sown and does not need to be thinned.

Cilantro seeds actually contain more than one seed each, similar to beets. Some varieties of cilantro are available as “split” or monogerm seed to improve planting precision. Split seeds tend to shed the seed coats more quickly as well, which can be helpful for micro cilantro production.

Culture and Harvest

Rotate away from Apiaceae crops to avoid soil-borne diseases. Parsley can be cut all at once or selectively. Selective cuttings of parsley can prolong harvests, and a well-maintained planting can be cut from three to five times in a season. Parsley can be overwintered in high tunnels. Cut leaves approximately 1" above the soil line to avoid damaging the growing point. Harvesting should begin in early July with a mid- to late April seeding date. Cilantro should be harvested before it begins to bolt, and only one harvest is possible. Sequential seedings can be made to ensure steady supply. 

Store cut parsley and cilantro at 32˚F with very high (95-100%) relative humidity, and in coolers separate from ethylene-producing crops. Stored properly, both crops can keep for 2+ weeks.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Bacterial leaf spot of cilantro (Pseudomonas syringae pv coriandricola)

The initial symptoms of bacterial leaf spot are dark, water-soaked, vein-delimited spots on leaves. The spots rapidly turn dark brown in color, remain angular in shape, and can be seen from both top and bottom sides of leaves. If disease is severe, the foliage can take on a blighted appearance when leaf spots coalesce. The disease progresses rapidly during wet weather. Cilantro crops with significant amounts of this disease will be unmarketable. The causal bacterium is host specific to cilantro and does not infect celery or parsley. The pathogen is seedborne in cilantro. Thus, infested seed is the primary means by which the pathogen gets into the cilantro production system. The bacterium can also survive many years in the soil as an opportunistic bacterium. If bacterial leaf spot has been a problem, rotate out of cilantro for several years. Use management practices that promote airflow and do not work in this crop when wet. For both conventional and organic cilantro, the only foliar treatment available is a copper fungicide.

Bacillus amyloliquefaciens Strain D747 (DoubleNickel 55): 0.25 to 3.0 lb/A; PHI 0d, REI 4, Group 44.

basic copper sulfate (Cuprofix Ultra 40 Disperss): 2.0 lb/A; PHI 0d, REI 48h, Group M1.

Powdery Mildew (Leveillula lanuginosa)

Disease development is favored by high humidity, moderate temperatures, and drought stress. Rain or overhead irrigation reduces disease severity. The pathogen can survive between crop cycles. Control wild and volunteer Apiaceae plants. Maintain adequate fertilizer and irrigation programs to ensure plant health. Drought stress may be lessened by mulching. Use resistant cultivars when available.

Root rot (Pythium and Phytophthora spp.)

These pathogens are soil-borne and most severe in cold, wet soils. Look for collapsed plants shortly after emergence. Provide good soil drainage and reduce soil compaction; raised beds may be useful.

mefenoxam (Ridomil Gold SL): 1.0 to 2.0 pt/A; PHI 21d, REI 48h, Group 4.

Trichoderma asperellum, T. gamsii (Bioten 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group NC.

Septoria blight (Septoria petroselini)

Severe disease can destroy crop quality. Symptoms appear as small lesions with small black specks in the center. The pathogen is seed-borne and highly favored by rain and overhead irrigation. Start with certified, disease free seed or treat seed with hot water or fungicides. Inspect transplants before setting in the field and destroy infected plants. Rotate to crops outside of the Apiaceae family. Plant sequential plantings as far apart from one another as possible. Incorporate plant residues promptly after harvest.

White Mold (Sclerotinia sclerotiorum)

Start with certified seed that is free from sclerotia of the pathogen. Infected plants will wilt with a white, cottony fungal mass near the soil line. Rotate with non-host plants. Irrigate in the morning to promote drying of soil and foliage. This pathogen thrives in 50-70 ˚C temperatures and cool, damp conditions. Ten or more days of wet soil promotes infection. Soil sterilization with heat, chemicals, steam, or by biofumigation with brassica crops can reduce, but not eliminate, sclerotia.

Trichoderma asperellum, T. gamsii (Bio-tam 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group NC.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Cabbage Looper, Imported Cabbageworm and Other Caterpillars

For more information, see cabbage looper and imported cabbageworm in the Cabbage section. Parsley worm, the larva of the black swallowtail butterfly (Papilio polyxenes), may invade small plantings but are not abundant enough to reach pest status on larger plantings. Hand picking or selective insecticides provide control.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L, Group UN. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.4 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Parsley only.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A. Not for cabbage looper.

chlorantraniliprole (Coragen): 3.5 to 5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through drip chemigation and as a foliar spray. For soil applications, must be applied uniformly in the root zone. On cilantro, foliar applications only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 10 to 17 oz/A loopers, 13.5 to 20.5 oz/A other caterpillars; PHI 1d, REI 12h, Bee: H, Group 28. Parsley only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. Parsley only.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Cabbage looper only. Apply when larvae are first observed.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A for CL, 3.5 to 6.0 oz/A for beet armyworm and corn earworm; PHI 3d, REI 12h, Bee: H, Group 22. For cabbage looper, beet armyworm and corn earworm only.

malathion (Malathion 57EC): 1 to 2 pt/A; PHI 7d, REI 24h, Bee: H, Group 1B. For imported cabbageworm and cabbage looper.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. Parsley only.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

permethrin (Pounce* 25WP): 3.2 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Not for imported cabbageworm. Parsley only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils. Cabbage looper only.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 1.5 to 8 oz/A parsley, 4 to 6 oz/A cilantro; PHI 1d, REI 4h, Bee: M, Group 5. See label for recommended rates for different caterpillar species.

tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Use low rate for early season applications to young, small plants. Use of an adjuvant is recommended. Parsley only.

tolfenpyrad (Torac): 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A. Suppression of caterpillars only. Parsley only.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A for ICW; 3.4 to 4.3 oz/A for CL; PHI 1d, REI 12h, Bee: H, Group 3A.

Carrot Weevil (Listronotus oregonensis)

Carrot weevil females lay eggs near the base of plants that have 4 or more true leaves, and larvae tunnel into root systems. Aboveground foliage will appear severely chlorotic. Symptoms are easily confused with Pythium; to distinguish, dig up yellowing or wilting plants. Carrot weevil larvae will cause orange gouges near the crown. Alternatively, if the roots appear shortened with reddish to orangish root tips, Pythium is the likely pathogen. See Carrot and Parsnip section for more information.

Cutworm 

Look for missing or cut off plants. When this occurs, cutworms can often be found in nearby soil under clods, debris, or rocks. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

Root-Knot Nematode (Meloidogyne spp.)

Parasitized crops will appear less vigorous, stunted, or nutrient-deficiency in circular patterns in the field. If suspected, carefully dig up the plant and look for galls; if present, send to diagnostic lab for confirmation. If confirmed, rotate with non-hosts such as cereals. Soil solarization or field fumigation in the fall may help reduce nematode populations.
 

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107). In place of herbicides, flaming can also be used.

glyphosate (Roundup Power Max): REI 12h, Group 9.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

bensulide (Prefar 4E): REI 12h, Group 0.  Apply 5 to 6 qt/A. Can be preplant incorporated by shallow cultivation (1-2”) or applied preemergence and incorporated by irrigation within 36 hours or application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

Herbicides Used Pre- and Postemergence to Weeds

linuron (Lorox DF): PHI 30d for parsley, PHI 21d for cilantro, REI 4d for hand-set irrigation activity and REI 24h for all other activities, Group 5. Can be used preemergence or postemergence. Best results are obtained when application is made to moist soil (applied after at least ½ inch of rain or irrigation). Moisture is needed to activate Lorox, and applications should be followed by rainfall or irrigation.

For parsley, do not exceed a total of 3 lb/A per season. 

  • Parsley Preemergence: For mineral and muck soils, make a single broadcast application of 1 to 3 lb/A after planting, but before the crop emerges. Plant seeds at least ½ inch deep. Use lower rates on coarse soils and higher rates on heavier soils (soils high in clay and organic matter). Irrigation or rainfall of at least 1/2 inch prior to making application after planting is necessary for product activation.
  • Parsley Postemergence (Muck Soils Only): Make a single application of 1 lb/A to control emerged weeds. Apply after parsley has a minimum of 3 true leaves or crop injury may result. Apply when weeds are in the 1 to 3 true leaf stage.

For cilantro, varieties may vary in their susceptibility to injury from Lorox. Determine tolerance to Lorox prior to adoption as a field practice to prevent possible crop injury. Do not exceed a total of 4 lb/A per season. 

  • Cilantro Preemergence: Make a single broadcast application of 1 to 2 lb/A after planting, but before the crop emerges. Plant seeds at least ½ inch deep.  Use lower rates on coarse soils and higher rates on heavier soils (soils high in clay and organic matter). Additional postemergence applications may be made as long as the total does not exceed the seasonal maximum.
  • Cilantro Postemergence: Make up to two postemergence applications of 1-2 lb/A to control emerged weeds. Apply after cilantro has a minimum of 3 true leaves or crop injury may result. Apply when weeds are in the 1 to 3 true leaf stage. Early crop injury can occur, however the effect should be transitory, with no yield losses attributable to crop injury. A second application may be made 14 days following the first application but no later than 21 days before harvest.

prometryn (Caparol 4L):  PHI 30d, REI 12h, Group 5. Primarily controls annual broadleaf weeds. Annual grasses may only be suppressed. Use the lower rates on coarse-textured soils and soils low in organic matter; use the higher rates on fine-textured soils and soils high in organic matter. To avoid crop injury, do not use on sand or loamy sand soils, or apply if crop is under water stress.

For parsley, can be applied pre- and postemergence. Do not exceed a seasonal maximum of 3 lb/A. Make a single preemergence broadcast application of Caparol up to 14 days after planting (after seeding, but before crop emergence) at the rate of 1.0 pt/A. Follow with overhead irrigation if rainfall does not occur.

For extended weed control, a second postemergence application can be made at 1.0 pt/A up to 30 days prior to harvest. A third application at 1.0 pt/A can be made to the regrowth up to 30 days prior to the second (cutting) harvest. Do not make more than 3 application per year at a maximum of 1 pt/A per application.

For cilantro, use preemergence only. Make a single application of 2 – 3.2 pt/A of Caparol after seeding, but before cilantro emergence. Use the lower rates on coarse-textured soils and soils low in organic matter; use the higher rates on fine-textured soils and soils high in organic matter.

Herbicides Used Postemergence to Weeds

carfentrazone (Aim EC): REI 12h, Group 14. Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic. Prevent any spray from contacting the crop, or injury will occur. For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control. Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max): PHI 14d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year. Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

pelargonic acid (Scythe)PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 15d, REI 12h, Group 1. Controls grass weeds only. Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications. Do not exceed 3 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions. Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon). Spray to wet, but do not allow runoff of spray solution.

 

Note About Other Labeled Herbicides: Other products are labeled for use but limited local data are available for these and/or they are not recommended in our region due to potential crop injury concerns. These include clomazone (Command 3ME) (cilantro).

Pea

Introduction

Pea (Pisum sativum) belongs to the legume family. It is a cool season crop that may be planted as early in the spring as the soil becomes tillable. Field pea is commonly grown as a cover crop, or, in more arid regions, for its smooth dried seeds used as food or feed crops. Garden pea is more commonly grown in New England for fresh market use. Garden peas contain higher sugar and lower starch contents than field peas and have wrinkled mature seeds. 

Types and Varieties

Three types of garden peas are in demand, all of which come in dwarf and tall vining forms:

  • English Pea - only the seed is eaten.
  • Snow or Edible-Podded Pea- the pod is eaten with undeveloped seeds.
  • Sugar Pea or Sugar Snap - both pod and seed are eaten.

 

Pea Varieties
English Pea Snow Pea
Strike (49) - F Oregon Giant (60)
PLS 534 (58, afila type) - F Avalanche (60)
Knight (62) - CW, PM, PEV Blizzard (61)
Progress #9 (62) Oregon Sugar Pod II (65) - CW, PM, PEV
Maxigolt (62)  
Green Arrow (65) Sugar Snap Pea
Lincoln (67) - CW Sugar Ann (52)
  Sugar Spring (58) - PM, PEV
  Sugar Snap (62)
  Super Sugar Snap (66) - PM, PLR
  SL3123 (70)

The number in parentheses is the approximate number of days to maturity from seeding.

Resistant or tolerant to: CW: common wilt, DM: downy mildew, F: Fusarium wilt, PEV: pea enation virus, PLR: pea leaf roll virus, PM: powdery mildew

Soil Fertility

Apply lime according to soil test results to maintain soil pH at 6.5-6.8.

Most research suggests that 20-30 lb of nitrogen per acre should be available at planting time, but that higher levels are not helpful. Peas can fix anywhere from 50-300 lbs. of nitrogen per acre, depending on plant density and availability of the appropriate species of Rhizobium bacteria. These bacteria, if present, live in root nodules of legumes, including peas, and convert atmospheric nitrogen into forms available to plants (nitrogen fixation). Nitrogen obtained in this manner is used more effectively than applied nitrogen. Therefore, plant vigor and production may be higher when the seed is inoculated with the appropriate species of Rhizobium bacterium. Inoculant can be purchased from most seed companies and should be listed in their catalogs. It is usually applied by mixing it with the seed at planting time. Pea inoculants are the same as those for vetches and lentils. Those used for alfalfa, beans or clovers will not work with peas. If peas or vetch have recently been grown in the field, inoculation may not be necessary. Note that many seed treatments may be toxic to the bacteria.

Nitrogen fixing can be slow in a cool, wet spring, so there may not be adequate nitrogen for high yields through nitrogen fixing alone. In this case, additional nitrogen may help to increase yields. However, applying excess nitrogen may reduce bacterial nitrogen fixation. If Rhizobium is not present, if leaching has occurred, or for early peas, sidedressing with an additional 25 lbs of nitrogen per acre may be beneficial.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR PEA
PEA NITROGEN (N) LBS PER ACRE  PHOSPHORUS (P) LBS P2O5   PER ACRE          POTASSIUM (K) LBS K2O         PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast/Planter 50-75 150 100 25-50 0 150 100 50 0
TOTAL RECOMMENDED 50-75 150 100 25-50 0 150 100 50 0

Planting

Seeding rates for peas vary considerably depending on the size of the seed. For fresh market, peas should be spaced 1.5-2" between seeds and 24-36" between rows at a seeding rate of 90-150 lb/A (about 1 lb per 100 feet of row).

For processing peas, seed 200-250 lb/A at 1" between plants and 7" between rows.

Field Culture

Pea seed will germinate well at soil temperatures as low as 50º F, but germination is slow. Extended periods of cool, wet weather during the germination period may cause rotting of the seed. For this reason, fertile, well-drained, sandy soils are best for early plantings. Finer-textured soils with high moisture-holding capacities are preferred for late spring crops. The use of treated seed is helpful in overcoming the problem of seed decay.

Several root rot organisms that attack peas usually begin at the tips of the feeder roots and progress towards the main roots, or occasionally show on the stem slightly above ground level. Rotation can reduce problems with root rot in peas.

Peas that mature during hot, dry weather frequently show reduced yield and quality. If hot, dry conditions normally occur in your area, pea planting should be suspended in mid-May and resume in July for fall harvest. If hot, dry summer weather occurs for only short periods in your area, plantings can be made throughout the summer using heat-resistant varieties for mid-summer harvest.

Trellising

A trellis should be installed at the time of planting. Nylon mesh netting using twister bands to attach to 2"x 2" stakes makes a good trellis for tall varieties. At least a 6' high trellis is needed for all vining varieties. A double row can be planted for more efficient use of netting.

Harvest and Storage

Pods of shell peas should be rounded and still have a glossy sheen; if dull, they have passed their prime. Snap peas should also be glossy, and swelled, but not rounded. Pods of snow peas should be expanded to their fullest extent but still be flat. Peas should be stored at 32º F with 95-98% relative humidity.

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Damping-Off, Seed Decay, Root Rot, and Stem Canker

Plant early in well-drained and well-fertilized soil. Use a 3- to 4-year rotation.

Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.5 to 4.5 pt/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

fludioxonil (Maxim 4FS): 0.8 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seed-borne and soil-borne fungi.

mefenoxam (Apron XL): 0.16 to 0.64 fl oz/100 lb seed; REI 48h, Group 4 . For Pythium damping-off.  Early season Phytophthora protection (0.64 fl oz/100 lb seed), and systemic downy mildew protection (1.28 fl oz/100 lb seed).

Streptomyces lydicus strain WYEC (Actinovate AGOG):  3.0 to 12.0 oz/A; Group NC. Can be applied to seed.

Trichoderma harzianun Rifai strain T-22: (Root Shield GranulesOG): 5.0 to 12.0 lb/A; Group NC. In-furrow at time of planting.

Rhizoctonia root rot and stem canker

Rhizoctonia stem canker caused by strains of the soil-borne fungus Rhizoctonia solani is common throughout the world. The pathogen survives between crop seasons as sclerotia (survival structures), mycelium in the soil, or on or in infected plant debris.  It is spread in infested soil or plant debris by wind, rain, irrigation water, and machinery. When a soil becomes infested, it remains so indefinitely. Seedlings and young plants are highly susceptible to infection and disease severity is increased by low soil temperatures and soil compaction. Seed decay and damping off can be controlled by using high-quality seed with high germination and vigor, and by practices that encourage rapid germination and emergence.  Seed treatments are not effective against infections later in the season. The disease may be reduced by sowing seed as shallowly as possible in warm, moist soil. Land preparation that minimizes soil compaction and structural damage will lessen disease severity. Rotate crops with a cereal or pasture crop (avoid beets, beans, brassicas and potatoes which increase inoculum). Cover crops and other practices that to increase organic matter and improve soil structure are recommended. Some brassica crops (mustard, rape) used as green manure have been reported to be disease suppressive. Avoid incorporating green manure immediately before planting and damaging roots by shallow cultivation. Fungicides can manage Rhizoctonia root rot on young seedlings if applied as a seed treatment or soil drench.

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

All tolerances for chlorpyrifos in food crops were revoked in 2022, therefore products containing chlorpyrifos (e.g. Lorsban) cannot be applied to any food crop and growers CAN NOT use up existing stock.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Corn Earworm (Helicoverpa zea) and Fall Armyworm (Spodoptera frugiperda)

Generally, these are late-season pests and are likely to only be a problem in fall peas. For more information, see Sweet Corn section.

alpha-cypermethrin (Fastac* EC): 2.7 to 3.8 oz/A; PHI 1d succulent shelled or edible-podded, PHI 21d dried, REI 12h, Bee: H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. For FAW only. Use alone to control light populations, or first and second instar larvae. Add a contact insecticide to control more mature FAW larvae and higher populations. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/APHI 0d, REI 4h, Bee: L, Group 11. Use alone to control light populations, or first and second instar larvae. Add a contact insecticide to control more mature FAW larvae and higher populations. Must be ingested; apply in evening or early morning, before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d fresh, PHI 14d dry, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 0.5 to 1.5 qt/A; PHI 3d fresh; PHI 21d dry, REI 12h, Bee: H, Group 1A. Use high rate for fall armyworm.

chlorantraniliprole (Coragen): 5-7.5 oz/A soil at planting, 3.5-7.5 oz/A foliar; PHI 1d, REI 4h, Bee: L, Group 28.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 7d edible-podded and succulent shelled, PHI 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d fresh, PHI 21d dry, REI 12h, Bee: H, Group 3A. Not for armyworm on dry peas.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d fresh; PHI 21d dry, REI 24h, Bee: H, Group 3A.

indoxacarb (Avaunt): 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 22. Dry Southern peas only.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d fresh, PHI 21d dry, REI 24h, Bee: H, Group 3A. Use higher rates for large FAW larvae.

methoxyfenozide (Intrepid 2F): 4 to 16 oz/A for FAW, 10 to 16 oz/A for CEW; PHI 7d, REI 4h, Bee: L, Group 18. Use lower rates for FAW when plants are small or infestations are light. CEW suppression only.

spinetoram (Radiant SC): 4 to 8 oz/A; PHI 3d fresh, PHI 21d dry, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 4 to 6 oz/A; PHI 3d, REI 4h, Bee: M, Group 5.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A; PHI 1d fresh, PHI 21d dry, REI 12h, Bee: H, Group 3A.

Cutworms

Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed on stems after dark. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Synthetic pyrethroids (Group 3A) may work best during cool spring weather. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

alpha-cypermethrin (Fastac* EC): 1.3 to 3.8 oz/A; PHI 1d succulent shelled or edible-podded, PHI 21d dried, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d fresh, PHI 14d dry, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 to 1.5 qt/A; PHI 3d fresh, PHI 21d dry, REI 12h, Bee: H, Group 1A.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 5 to 8 oz/A; PHI 7d edible-podded and succulent shelled, PHI 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d fresh, PHI 21d dry, REI 12h, Bee: H, Group 3A.

fenpropathrin (Danitol* 2.4EC): 10.7 oz/A; PHI 7d, REI 24, Bee: H, Group 3. Climbing cutworm only.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 7d fresh; PHI 21d dry, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A; PHI 7d fresh, PHI 21d dry, REI 24h, Bee: H, Group 3A.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For variegated cutworm only.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 3d, REI 4h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 1.4 to 4.3 oz/A; PHI 1d fresh, PHI 21d dry, REI 12h, Bee: H, Group 3A.

Pea Aphid (Acyrthosiphon pisum)

The pea aphid is light green with unusually long legs and cornicles (tailpipe-like projections). It is the primary aphid that attacks peas, fava beans and lentils. This aphid overwinters as an egg on alfalfa, vetch, and clover and moves to peas in the spring. Live female nymphs are produced throughout most of the year. Females take 12 days to mature and produce up to 150 nymphs. There are from 13 to 20 generations per year. Populations tend to be lower after cold, snowless winters or springs with persistent wet weather. Infestations during the bloom and early pod stages will reduce yield and crop quality by removing plant sap, impairing pod appearance, reducing seed fill, impairing nitrogen fixation and by the presence of aphid honeydew. Start monitoring when plants begin to flower. Action thresholds include 1 to 2 aphids per leaf, 2 to 3 aphids per stem tip or 9 to 13 per sweep, if a sweep net is being used. Harvest or spray nearby alfalfa, vetch or clover before winged adults are formed in the spring. Varieties differ in their susceptibility to pea aphid damage. Plant varieties less prone to high infestations and damage. There are many natural enemies (lady beetles, lacewings, flower fly larvae, predatory midges, Braconid wasps) that help reduce aphid numbers. Fungi will control high aphid populations during warm, humid or wet weather. A single systemic insecticide application will control this pest.

acetamiprid (Assail 30 SG): 2.5 to 5.3 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A. Not for dry peas.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 3d fresh, PHI 14d dry, REI 12h, Bee: H, Group 3A.

chlorantraniliprole & lambda-cyhalothrin (Besiege*): 6 to 10 oz/A; PHI 7d edible-podded and succulent shelled, PHI 21d dried shelled, REI 24h, Bee: H, Groups 28 & 3A.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

dimethoate (Dimethoate 4EC): 0.3 pt/A; PHI 0d, REI 48h, Bee: H, Group 1B.

esfenvalerate (Asana* XL): 2.9 to 5.8 oz/A; PHI 3d fresh, PHI 21d dry, REI 12h, Bee: H, Group 3A.

flupyradifurone (Sivanto): 7 to 10.5 oz/A; PHI 7d, REI 4h, Bee:L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d fresh; PHI 21d dry, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 1.2 oz/A foliar, 7 to 10.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. Repeated applications or the addition of another insecticide may be necessary.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d fresh, PHI 21d dry, REI 24h, Bee: H, Group 3A.

malathion (Malathion 57 EC): 1.5 to 1.6 pt/A; PHI 3d, REI 12h, Bee: H, Group 1B.

methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.

thiamethoxam (Cruiser 5FS): 1.28 oz/100 lb seed; REI 12h, Bee: H, Group 4A. Systemic seed treatment. Use standard slurry seed treatment equipment which provides uniform coverage. For early-season protection from aphids.

Seedcorn Maggot (Delia platura)

See seedcorn maggot in the Bean section for more information.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

Stale Seedbed

See Stale Seedbed Technique (page 107).

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A. Include a nonionic surfactant at 0.25% v/v, or crop oil concentrate/methylated seed oil at 1.0% v/v (1 gal/100 gal) of the finished spray volume for maximum efficacy. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators. The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence to Weeds

clomazone (Command 3ME): REI 12h, Group 13.  Apply 21.3 fl oz/A to the soil surface after seeding but prior to crop emergence. Place seed, or roots of the transplants, below the chemical barrier when planting. Will control annual grasses and many broadleaf weeds including common lambsquarters, velvetleaf, and jimsonweed. Some temporary crop injury (partial whitening of leaf or stem tissue) may be visible after crop emergence. Complete recovery will occur from minor early injury without affecting yield or earliness. See label for replanting restrictions.

linuron (Lorox DF): REI 24h, Group 5. Make a single application of up to 2 lbs/A after planting but prior to crop emergence. Use lower rates on coarse soils and higher rates on heavier soils.

s-metolachlor (Dual Magnum): REI 12h, Group 15.  English peas and dry peas. Apply either preplant incorporated or to the soil surface just after seeding. See label for specific rates on different soil types and organic matter content (1 to 2 pt/A). NOTE: If soil is cold and wet during pea germination/emergence, use of Dual Magnum can delay maturity and reduce yield. 

pendimethalin (Prowl H2O): REI 24h, Group 3. Apply 2 to 3 pt/A preplant and incorporate into the soil 2" to 3". Do not apply after seeding.  Rainfall or irrigation is required for activation.

trifluralin (Treflan HFP): REI 12h, Group 3. English peas. Incorporate 1 to 1.5 pt/A before planting. Select rate based on soil texture; see label for details.  Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation. Especially effective for annual grass.

Herbicides Used Pre- and Postemergence to Weeds

imazethapyr (Pursuit): PHI 30d, REI 4h, Group 2. English peas and dry peas.  Apply up to 3 oz/A as a preplant incorporated (with 1 week of planting) or as a preemergence up to 3 days after planting. 

Can also be used early Postemergence:  Apply to dry peas and English pea when peas are 3” tall but before 5 nodes and before flowering. Nonionic surfactant must be added to the spray solution for post emergence use.

Herbicides Used Postemergence to Weeds

bentazon (Basagran): PHI 10d, REI 48h, Group 6.  Used postemergence on actively growing weeds.  Rate varies based on weed species targeted (1 to 2 pt/A). Peas are tolerant to after 3 pairs of leaves (or 4 nodes) are present.  Pea injury such as yellowing, bronzing, speckling or burning of leaves may occur under certain conditions.  Temporary injury is generally outgrown without delay of podset, maturity or reducing yields. An effective treatment in an emergency situation to control certain broadleaf weeds and fairly effective against yellow nutsedge when 4" to 6" tall.  Do not apply when peas are in bloom or under stress from root rot.  Do not add oil for use on peas.

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max): PHI 21d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  A single application of 9 to 16 oz/A is permitted.  Apply before bloom. Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

pelargonic acid (Scythe):  PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

quizalofop (Assure II): PHI 60d dry peas, PHI 30d succulent peas, REI 12h, Group 1. Apply to actively growing grasses. Rate based on target weed species, see label for grass growth stage and rate selection.  Multiple applications permitted.  Allow at least 7 days between applications.  Do not exceed 14 oz/A per season.  Apply with either crop oil concentrate or non-ionic surfactant. Do not apply when crop or weeds are under drought stress.

sethoxydim (Poast): PHI 30d dry peas, PHI 15d succulent peas, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 2.5 pt/A per application, minimum 14-days between applications.  Do not exceed 4 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions. Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Pepper

Introduction

Pepper (Capsicum annuum, C. chinense; Family Solanaceae) is a warm-season crop requiring 3-4 months of frost-free growing days. It is started from transplants. Bell peppers are the most commonly grown and are usually harvested green. Fruits left to mature on the plant turn red, orange or yellow, and sugar content increases markedly. Other types of sweet and chili (hot or pungent) peppers are usually elongated and tapered. Varieties grown for green peppers take 55-60 days from transplanting to begin producing fruit; colored fruit takes approximately another 20 days to develop. Hot peppers generally become more pungent as they mature or if grown under stress. Check variety descriptions carefully to obtain the proper peppers for your markets.

Types and Varieties

Pepper Varieties
Field Sweet Bell - Green to Red Hot - Ancho/Poblano
Captain - BLS0-10, P Bastan - TMV
King Arthur - BLS2, PVY, ToMV Baron - BLS123
New Ace - TMV Trident - TMV
Nitro S-10 - BLS0-10, TMV, P, TSWV  
Olympus - BLS123 Hot - Anaheim
Paladin - BLS123, P, TMV, TEV Charger - TSWV
X3R Red Knight - BLS123, PVY Numex Joe E. Parker
Sailfish - BLS123, TMV, P  
Tarpon - BLS0-10, P, TMV Hot - Jalapeno
Turnpike - BLS0-5,7-9, P, TMV Evermand - BLS123
  Jalafuego - BLS12378, PVY
Field Sweet Bell - Specialty Colors Jedi - BLS123
Delirio (orange) - TMV, TSWV Orizaba - BLS123
Flavorburst (yellow)  
Islander (purple to red) - TMV Specialty Hot
  Numex Suave Orange (mild orange habanero)
Greenhouse Sweet Bell Hungarian Yellow/Hot Wax
Abay (yellow) - BLS12345  
Brocanto (yellow) - TMV, TSWV Specialty Sweet
Milena (orange) - PVY, TMV, TSWV, TEV Carmen (frying/Italian, red)
Sprinter (red) - TMV Escamillo (frying/Italian, orange)
  Habanada (mild orange habanero)
Resistant or tolerant to: BLS: Bacterial Leaf Spot (races indicated); CMV: Cucumber mosaic virus, P: Phytophthora crown rot, PVY: Potato virus Y, TEV: Tobacco etch virus, TMV: Tobacco mosaic virus, ToMV: Tomato mosaic virus.

Soil Fertility

Apply lime according to soil test results to maintain soil pH at 6.5-6.8. Sidedress nitrogen can also be applied through a drip irrigation system over the course of the remainder of the season. This is particularly advantageous in soils prone to leaching. See Fertigation for more information. Excess nitrogen has been shown to cause excessive vegetative growth and reduce yields. A pre-sidedress nitrate test (PSNT) can advise on the need for sidedress nitrogen. High P starter fertilizer can be used at transplanting, especially with cool soil conditions.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR PEPPER
PEPPER NITROGEN (N) LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE    POTASSIUM (K) LBS K2O      PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast/Planter
50
150
100
25-50
0
200
150
50
0
Sidedress 2-3 Weeks after Planting
50
0
0
0
0
0
0
0
0
Sidedress after First Fruit Set
40
0
0
0
0
0
0
0
0
TOTAL RECOMMENDED 140 150 100 25-50 0 200 150 50 0

Planting

Growers should produce their own transplants or contract with a reputable local supplier to minimize the potential of importing severe disease and insect problems that are common in other regions. Sow seeds 8 weeks before field transplanting. Peppers are a slow-growing crop and need protection from soil-borne diseases, especially damping-off organisms. Use seed treated with a suitable fungicide or use a biofungicide soil drench (See Table 24, Biological Disease Control Products in the Biorational and Organic Pesticides).  Avoid over-watering. Avoid contamination from the greenhouse floor by lining it with plastic, growing plants on benches, and hanging watering devices when not in use. Do not permit moisture to remain on seedlings for more than 2-3 hours after watering. This may require adjusting watering rates on cloudy days.

One ounce of seed will produce 3,000-5,000 plants. About 8,000-14,500 plants are required per acre, depending on your choice of spacing in the field. Seeds may be sown thickly in flats and later transferred to 72-cell trays. Peppers thrive under warm conditions; seeds germinate best at 85-90ºF, and seedlings develop well at 75ºF during the day and 65ºF at night. Peppers are susceptible to transplant shock. Reduce temperature and water and increase air movement around the plants to condition them for transplanting. A precaution: overly-hardened plants are slow to recover and yields may be reduced. Plants should be set in the field after the danger of frost is over, and the soil temperature is at least 60ºF.

Field Culture

Peppers are commonly grown on black plastic mulch with drip irrigation in the Northeast. Planting into raised beds, especially in heavy or poorly drained soils, can also help prevent root rot diseases. When transplanting into black plastic mulch, center the transplants in holes to avoid burning stems and damaging or killing seedlings as plastic heats up. For best results, 4-8" tall plants should be transplanted on a cloudy, calm day, preferably in the late afternoon.

Space transplants 12-18 in. apart within rows (67-100 plants per 100 feet of row) and 3-3.5 feet between rows. With double rows on plastic, set each row as far apart as the plastic permits, but remember that plants can tip outward (lodge), bringing fruits in contact with bare soil. This spacing requires 8,300-14,500 plants per acre.   

Some smaller pepper varieties produce spindly seedlings and plants that are not as sturdy as bell peppers and can lodge much more readily. Transplanting the seedling so that the cotyledons are at the soil surface (the root ball will be approximately 2 in. deep) will significantly decrease lodging without adversely affecting yield. 

Peppers may require staking to minimize lodging and sunscald. In each row of plants, drive half a tomato stake (18-24 in. long), 6 in. into the soil between every 4-10 plants. Tie polyethylene strings at 8-16 in. heights as plants grow. Run string from stake to stake; first down one side of the plants, looping and tightening it around each stake, and then back on the opposite side of the plants. Leave a 3 ft. gap in the trellis system every 50-100 ft. to facilitate harvesting. In windy locations, it may be helpful to erect temporary windbreaks such as snow fence. Some growers have found improved production with such windbreaks in place.

Research in the Northeast has shown that pruning peppers is not profitable.

High Tunnel Production

Production of peppers in high tunnels has gained popularity in recent years. High tunnel peppers can produce higher yields than field peppers, and while they deliver less revenue than high tunnel tomatoes, they also require significantly less labor because they do not need to be pruned. Quality of colored bell peppers is often higher in high tunnels than in field production. Similarly to field peppers, high tunnel peppers are grown on black plastic with drip irrigation and are planted in single or double rows, 12-18 in. apart. Some varieties are marketed as being for high tunnel production, but may only reach their full yield potentials with pruning, supplemental heat, and long seasons; field varieties have performed as well or better than high tunnel varieties in high tunnels in university trials. Trellising is a common practice in high tunnel peppers—in this protected environment, one string can be run along each side of a double-row bed, with stakes on either side of the bed (as opposed to running one string along both sides of each row as is common in tomatoes).

Harvest and Storage

Green bell peppers normally are harvested in the green (immature) stage after the fruits have reached full size and the walls are firm and have thickened. Colored bell peppers take several additional weeks to turn color. Harvest the crop twice a week to achieve maximum yields, or every 7-10 days for maximum size. Peppers are picked by a twisting, pulling motion with part of the stem adhering to the fruit. Branches can break easily during harvest. Teaching workers the proper harvest technique can help avoid plant breakage and lodging, and extensive losses due to sunscald.

Peppers can be brushed or washed before packing. If peppers are washed, wash water temperature should be as warm or slightly warmer than that of the peppers. Cold wash water reduces the temperature of the pepper and that of the air inside the fruit cavity. This creates a partial vacuum, which draws some of the wash water (and any bacteria that may be in the water) into the fruit. There are commercial sanitizers registered for use in wash water to help prevent bacterial contamination through infiltration and control postharvest rots.

Containers used are wire-bound crates, cardboard boxes, and bushel baskets. Twenty-four pounds per container is an average weight. The wholesale market prefers large peppers (75 or less in a 1 1/9 bu. box).

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