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 (HowlerOG): 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 (EcoSwingOG): 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 reduces 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 a post-harvest sanitizer 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.

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 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, before weeds germinate

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

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, after weeds germinate

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.