Spinach

Spinach Evonne Gong Fri, 05/24/2024 - 10:56

Spinach Disease Control Spinach Insect Control Spinach Weed Control

Introduction

Spinach (Spinacia oleracea) is a hardy cool-weather crop, grown for use as a cooked green vegetable or for salad greens. Temperature for optimum production and high quality is 55-60°F with day length of approximately 12 hours. Winter spinach production in unheated high tunnels has expanded in New England to supply greens year-round. Under certain conditions, spinach will bolt (develop a seed stalk and flower), reducing quality. During summer months, high temperatures and long days will result in bolting. For spinach plants overwintered in high tunnels, bolting may occur in early spring as days lengthen. The tendency to bolt varies with the cultivar, some being more resistant than others. Growers who want greens in summer should consider beet greens and/or Swiss chard as substitutes, since they produce better under high temperature and long day conditions. Malabar spinach (Basella alba) is not related to true spinach; it is a vining spinach-like crop native to tropical Asia and is well-adapted to growing in summer New England conditions.

Types and Varieties

There are 2 main types of spinach: smooth leaf and savoy (crinkled leaf). Both grow equally well and are marketed similarly, but the savoy type, because of its crinkled leaf, is more difficult to clean. Asian leaf types are relatively smooth with pointed leaves. Varieties best suited for winter production are often the fastest-growing varieties.

Variety	Type	Season	Disease Resistance
Acadia	semi-savoy	SF	DM 1-13,15,16
Auroch	smooth	SFW	DM 1-12,14-16,19
Bonnethead	savoy	SFW	DN 1-7,9,11-18
Carmel	semi-savoy	SF	DM 1-11,13
Corvair	smooth	W	DM 1-11,13
Flamingo Improved	Asian	SFW	DM 1-11,12,13
Gerenuk	savoy	SFW	DM 1-7,9-19
Giant Winter OP	semi-savoy	FW	DM 1-11
Kolibri	semi-savoy	SFW	DM 1-9,12-15,17
Kookaburra	semi-savoy	SF	DM 1-13
Rangitoto	smooth	W	DM 1-16,19
Red Tabby	smooth	SFW	DM 1-9,11-13
Responder	savoy	W	DM 1-12,14-16
Seaside	smooth	S	DM 1-12,14
Space	smooth	FWS	DM 1-3,5,6,8,11,12
Sunangel	semi-savoy	SFW	DM 1-9,11-17
Winter Bloomsdale OP	savoy	W	CMV
OP = open-pollinated, Seasons: S = spring, F = fall, W = winter. Resistant or tolerant to: DM: downy mildew (races indicated), CMV: cucumber mosaic virus

Soil Fertility

Apply lime according to soil test results to maintain soil pH at 6.5-6.8. Soils with low pH will result in slow growth and chlorotic leaves.

Because of sensitivity to magnesium (Mg) deficiency, older spinach leaves may tend to show yellow color similar to that caused by nitrogen (N) deficiency or downy mildew. Low levels of Mg in the soil can be corrected by using high-Mg lime (dolomitic) or by adding Mg to the fertilizer. Do not automatically apply more N to try to develop the desired deep green color. Rather, fertilize with Mg according to pre-plant soil tests and, if needed, test again mid-season and make a topical application of 10-15 lb magnesium sulfate (Epsom salts) in 100 gal water to correct any Mg deficiency. Spray to wet the foliage. If Mg was deficient, you will see a color change to dark green overnight. Spinach will accumulate excess nitrates if N is used in an attempt to induce green color. Thus, it is always best to check for Mg problems before applying extra N if plants have chlorotic pale green color or yellow lower leaves.

In winter high tunnel production, a single crop may be harvested for 6 months and therefore sidedressing may be necessary. Nitrogen use efficiency of crops is lower in cold temperatures, so more frequent sidedressing of small amounts of N will achieve better results than fewer applications of larger amounts of N. Avoid putting fertilizer directly onto crop foliage. The need for sidedressing will be influenced by pre-plant levels of N in the soil, which can vary widely between farms and high tunnels based on the soil nutrients remaining after the summer crop. Available N levels can be monitored mid-season using pre-sidedress nitrate tests. Sidedress with N if nitrate levels drop below 30 ppm.

Less nitrogen fertilizer will be needed if manure or legume sod was plowed down (see Table 1 and Table 2).

Plant Nutrient Recommendations According to Soil Test Results for Spinach

SOIL TEST RESULTS	NITROGEN (N) - LBS PER ACRE	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	60-80	180	120	30-60	0-30	180	120	30-60	0
Sidedress 3-4 weeks after planting	30	0	0	0	0	0	0	0	0
TOTAL RECOMMENDED	90-110	180	120	30-60	0-30	180	120	30-60	0

Planting

Seed will germinate at soil temperatures of 32-60°F. Soil temperatures above 70°F will result in poor germination. Another cause for poor germination is salt accumulation in the top 2" of high tunnel soil. Priming the seed (i.e. soaking the seed in water or another solution to kickstart the germination process prior to seeding) may improve germination, though there is no research-based seed priming protocol specifically designed for spinach. Spinach seed is short-lived and susceptible to damping-off. For good stands, start with new, fungicide-treated seed each year. Taking measures to prepare uniform, well-drained beds and to provide even irrigation can reduce variations in soil moisture that can lead to damping-off as well.

Spinach can be direct-seeded quite densely, at up to 3,000,000 seeds per acre (70 seeds per sq. ft.). Target harvest size may affect seeding density, with “teenage” or larger-sized spinach seeded less densely and baby-leaf spinach seeded at the higher density. Harvest method may also affect preferred seeding density. Growers harvesting by clear-cutting, either by hand or mechanically, may prefer denser seeding rates, whereas those harvesting lower leaves only may prefer wider spacing. After preparing a stale seedbed, denser seeding may help to control weeds. During dry conditions, irrigation may be necessary to germinate seeds. Seed 0.25-0.5" deep depending on soil moisture and temperature. Deeper planting is suggested in a warm, dry soil. Growers should attempt to seed to a stand as thinning is generally not recommended.

Spinach can also be germinated in seed trays and transplanted at the desired site. This method is particularly useful if the site is not yet prepared for the next crop, and to get a head-start in production. Seedlings are typically ready for transplant approximately 3 weeks after initial seeding. Again, plant spacing can vary based on target harvest size and method.

Field Culture

Main Season (Spring and Fall). Spinach can be seeded in the spring as soon as the soil can be worked. Sandy soils are generally preferred because they warm earlier in the spring. Two main crops are generally grown, one in the spring, another in late summer, seeded about 6 weeks before the average first frost.

Winter Season. Winter production of spinach by New England growers is now quite common. Stand-alone low tunnels equipped with heavyweight row cover (1.25 oz/yd²) and plastic (6 mil) result in good winter survival of spinach and allow for separate fall and spring harvests. However, accessing plants during winter months when the ground is frozen is challenging, and leaves may not be saleable during this this period. High tunnel production permits winter access and provides additional insulation, and can result in winter-long harvests if plants are established by late fall. If direct-seeding, a September seeding date is suggested. Higher total yields (fall through spring) will be obtained by the earliest fall planting dates, primarily due to higher fall production. Spring-only yields are less affected by fall planting date.

Plant growth slows with less than 10 hours of light per day, starting around November 10 in southern RI and October 30 in northern ME. Aim to have 4-5 true leaves on plants before you reach this point.

It is important to ensure adequate moisture is available for spinach during the fall, winter, and spring months, either by using drip or overhead irrigation. The majority of irrigation is needed in fall and spring. Little irrigation is needed in winter months when crop growth is slow.

There are three common physiological disorders that may occur on winter-grown spinach. Spinach can withstand frost well, as long as leaves are not handled when frozen. Freezing damage can kill and brown leaf tissue. This can be minimized by using row cover. Row cover is not necessary for winter high tunnel spinach production in most of New England but can speed up growth even if not needed to keep plants alive. Oedema results when water pressure causes cells to burst, resulting in scab-like calluses on the leaves. This can be minimized by limiting irrigation and maintaining low relative humidity as temperatures drop and growth slows. Lastly, under winter and spring conditions, spinach leaves often develop glandular trichomes on upper and lower leaf surfaces, which resemble tiny water droplets or insect eggs. They are more common on young leaves. These trichomes are naturally occurring structures produced by the spinach leaves and are harmless.

Harvest

Spinach is usually harvested 37-45 days after seeding, but can take much longer to mature during late fall and winter. Harvesting can be done by hand, either by clipping mature leaves and leaving young leaves uncut, or by clear-cutting just above the growing point. Walk-behind and tractor-mounted mechanical harvesters can be used. Regrowth quality varies by harvest method and the growth habit of the cultivar.

In summer and fall, harvest early in the day and cool immediately to 32°F to maximize shelf life (10-14 days). In the winter, wait until leaves have thawed before harvesting, as handling frosted leaves will cause damage.

Good yields will range from 5-7 tons/A for fresh market and 10-12 tons/A for processing. In winter high tunnel production, growers report producing 0.4–0.6 lbs/sq ft. Spinach is sometimes field packed loose into crates or cartons. Whole plants are sometimes bunched with roots trimmed off for retail sales. Package as bushel baskets or crates containing 20-25 lb, cartons or wire-bound crates with 2 dozen bunches each, or loose leaf 12 film bags (10 oz per bag) in a master carton. Winter spinach is often sold bagged in smaller quantities.

Spinach Disease Control

Spinach Disease Control Evonne Gong Fri, 05/24/2024 - 11:07

Spinach - General Spinach Insect Control Spinach Weed Control

NOTE: For the disease control products listed below, a product trade name and formulation are 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 26 and Fungicides and Bactericides Alphabetically Listed 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.

Cladosporium Leaf Spot (Cladosporium variabile)

Cladosporium leaf spot, caused by Cladosporium variabile, was previously considered to be of minor importance in spinach crops but can be severe in spinach seed production and has become a common problem in winter high tunnel production. Symptoms begin on the foliage as pale/tan lesions that develop olive-green spores. The most conducive environment for disease development is cool and moist with temperatures between 59-68ºF and relative humidity above 80%. However, the fungus can grow under a wide range of temperatures, ranging from 41-86ºF. The epidemiology of this disease is not well-known. Spinach seeds carry the fungus, but it has not been determined whether the disease is transmitted via contaminated seed to soil or seedlings. It is also not known how long the fungus can survive on spinach residues in soil or in weed hosts. C. variabile has been recovered from dried leaves and seed stocks up to 8 years old. Cultural controls rely mainly on sanitation—the removal of infected plants, spinach debris, spinach volunteers, and unused seed. Start with certified, disease-free seed or treat seed with hot water or bleach to reduce seedborne inoculum. Avoid covering wet plants with row covers. Cultivar susceptibility varies but is rarely reported by seed producers or distributors.

Bacillus mycoides isolate J (LifeGard WG^OG): 1.0 to 4.5 oz/A; PHI 0d, REI 4h, Group P06. Apply at first true leaf stage or after thinning. Refer to label for other appropriate rates and application volumes.

Downy Mildew (Peronospora farinosa)

Spinach downy mildew (SDM) is considered the most important disease of spinach and is favored by cool, moist conditions. The pathogen is host-specific to spinach and will not survive without a living host. Incidence of the disease appears to be increasing due to the increased use of high tunnels for winter spinach production. The potential overlap of field spinach and high tunnel spinach can create a “green bridge” for the disease, allowing the pathogen to transfer between fields and high tunnels. SDM begins as irregular yellow patches on upper leaf surfaces with purplish-gray sporulation on the undersides of leaves. Lesions may eventually dry out and turn brown. There are currently 19 numbered races of SDM, along with numerous "novel" races, and new races can emerge every year. SDM management relies on resistant cultivars, as well as managing relative humidity and leaf wetness. Select cultivars with resistance to races 1-19, if possible, and grow multiple cultivars that do not share the same gaps in resistance. Once infected, there is little that can be done to manage SDM. The pathogen can produce long-lived resting spores, called oospores, that can potentially survive in the soil without a living host. However, the role of oospores in season-to-season survival in New England is currently unknown. Rotate out of spinach for at least 2 years.

acibenzolar-S-methyl (Actigard 50WG): 0.5 to 0.75 oz/A; PHI 7d, REI 12h, Group P01. Do not apply to plants that are stressed or when extended cold or/and cloudy conditions are expected. May cause crop injury to young seedlings. See label for other restrictions.
ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40. Do not apply to greenhouse or high tunnel crops.
azoxystrobin (Quadris F): 12.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Rotate with a non-Group 11 fungicide. Phytotoxicity may occur. Proceed when using tank mixes. See label for restrictions. Do not apply to greenhouse or high tunnel crops.
Bacillus amyloliquefaciens strain D747 (Double Nickel LC^OG): 1.0 to 6.0 qt/A; PHI 0d, REI 4h, Group BM02. Suppression only. See label for other application methods and rates.
copper hydroxide (Kocide 3000): 0.75 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Flecking may occur.
copper oxychloride plus copper hydroxide (Badge X2^OG): 0.75 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Flecking may occur. See label for precautions.
cyazofamid (Ranman 400SC): 2.75 fl oz/A; PHI 0d, REI 12h, Group 21.
cymoxanil (Curzate 60 DF): 5.0 oz/A; PHI 1d, REI 12h, Group 27. Use only in combination with a protectant fungicide.
famoxadone plus cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide from a different FRAC Group. Do not alternate or tank mix with other Group 11 fungicides.
fenamidone (Reason 500 SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h, Group 11. Do not apply to greenhouse or high tunnel crops.
fluopicolide (Presidio 4SC): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Must be used in a tank mix with a fungicide with a different mode of action. Do not apply to greenhouse or high tunnel crops.
fluxapyroxad plus pyraclostrobin (Merivon Xemium): 6.0 to 11.0 fl oz/A; PHI 1d, REI 12h, Groups 7 & 11. Suppression only. Do not apply as tank mix with other pesticides or anything other than water. Do not apply to greenhouse or high tunnel crops.
fosetyl aluminum (Aliette WDG): 2.0 to 5.0 lb/A; PHI 3d, REI 24h, Group P07. Lower rate of 2-3lb/A may be used when tank mixed with another fungicide labeled for downy mildew (do not mix with copper). See label for instructions.
mandipropamid (Revus): 8.0 fl oz/A; PHI 1d, REI 4h, Group 40. Addition of adjuvant is recommended.
mefenoxam (Ridomil Gold SL): 0.25 pt/A; PHI 21d, REI 48h, Group 4. Must be applied pre- and post-plant for effective control of downy mildew. Incorporate into soil mechanically or with irrigation. See label for instructions and precautions. Do not apply to greenhouse or high tunnel crops.
oxathiapiprolin (Orondis Gold 200): 1.2 to 2.4 fl oz/A (foliar); PHI 0d, REI 4h, Groups 49. Do not apply to greenhouse or high tunnel crops.
oxathiapiprolin plus mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 1d, REI 4h, Groups 49 & 40. Apply with an adjuvant.
phosphorous acid (Fosphite): 1.0 to 3.0 qt/20 gal foliar; PHI 0d, REI 4h, Group P07. Do not apply to plants that are heat- or moisture-stressed or recently treated with copper products.
pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11. May cause leaf injury. Do not apply with anything other than water. See label for precautions. Do not apply to greenhouse or high tunnel crops.

Seed Decay

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

azoxystrobin(Dynasty): 0.10 to 0.38 fl oz/100 lb seed; REI 12h, Group 11. Not labeled for use in Maine.
fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seedborne and soilborne fungi. Does not control Pythium or Phytophthora.
mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping-off protection. Do not use in greenhouse or enclosed environments. See label for restrictions.
thiram (Thiram 42-S): 8.0 lb/100 lb seed; REI 12h, Group M03.
Streptomyces sp. strain K61 (MycoStop^OG): 0.04 to 4.0 oz/lb seed; REI 4h, Group BM02. Other methods of application listed on label.

Stemphylium Leaf Spot (Stemphylium botryosum)

This relatively new disease of spinach was first detected in California in 2001. It affects both production spinach and spinach seed crops and has become a problem in high tunnel production. Details on the pathogen's life cycle are lacking, although the pathogen is known to be seedborne. In the field, the disease spreads slowly and damage is limited. Symptoms include light gray/tan leaf spots 1/16-1/2" in diameter, with larger spots being more irregular. As spots age they dry up and become papery in texture. Cultural controls rely mainly on sanitation—the removal of infected plants, spinach debris, spinach volunteers, and unused seed. Do not cover wet plants with row covers. Start with certified, disease-free seed or treat seed with hot water or bleach to reduce seedborne inoculum.

Bacillus mycoides isolate J (LifeGard WG^OG): 1.0 to 4.5 oz/100 gal water/A; PHI 0d, REI 4h, Group P06.
fludioxonil plus pydiflumetofen (Miravis Prime): 9.2 to 13.4 fl oz/A; PHI 0d, REI 12h, Groups 12 & 7.

White Rust (Albugo occidentalis)

White rust is a very damaging disease of spinach that is found only east of the Rocky Mountains in the U.S. Plant resistant cultivars and practice crop rotation. Apply preplant and foliar fungicides.

acibenzolar-S-methyl (Actigard 50WG): 0.5 to 0.75 oz/A; PHI 7d, REI 12, Group P01. Do not apply to plants that are stressed or when extended cold or/and cloudy conditions are expected. May cause crop injury to young seedlings. See label for other restrictions.
azoxystrobin (Quadris F): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Quadris may be phytotoxic to spinach. See label for precautions. Do not apply to greenhouse or high tunnel crops.
copper hydroxide (Kocide 3000): 0.75 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Flecking may occur on spinach leaves.
copper oxychloride plus copper hydroxide (Badge X2^OG): 0.75 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Flecking may occur. See label for precautions.
cyazofamid (Ranman 400 SC): 2.75 fl oz/A; PHI 0d, REI 12h, Group 21.
famoxadone plus cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide from a different FRAC Group. Do not alternate or tank mix with other Group 11 fungicides.
fenamidone (Reason 500SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h, Group 11. Do not apply to greenhouse or high tunnel crops.
fluopicolide (Presidio 4SC): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Must be used in a tank mix with a fungicide from a different FRAC Group. Do not apply to greenhouse or high tunnel crops.
laminarin (Vacciplant): 14.0 to 22.0 fl oz/A; PHI 0d, REI 4h, Group P04.
mefenoxam (Ridomil Gold SL): 0.25 pt/A; PHI 21d, REI 48h, Group 4. Must be applied pre- and post-plant for effective control of white rust. Incorporate into soil mechanically or with irrigation. See label for instructions and precautions. Do not apply to greenhouse or high tunnel crops.
pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A. PHI 0d, REI 12h, Group 11. May cause crop injury under certain conditions. Do not apply as tank mix with anything other than water. See label for precautions. Do not apply to greenhouse or high tunnel crops.

Cucumber Mosaic Virus (CMV)

CMV is found worldwide and infects over 800 crop and weed hosts. Symptoms include mosaic, mottling, stunting, and leaf distortion. This disease is transmitted by aphids in a nonpersistent manner; insecticides are of no value in controlling this disease. Start with virus-free seed. Eliminate weeds such as chickweed, pokeweed, and milkweed. Grow resistant varieties such as Winter Bloomsdale and Renegade.

Disease Control

Spinach Insect Control

Spinach Insect Control Evonne Gong Fri, 05/24/2024 - 11:13

Spinach - General Spinach Disease Control Spinach Weed 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 27 and Insecticides Alphabetically Listed 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, primarily Green Peach Aphid (Myzus persicae)

Aphids in spinach are primarily green peach aphids (see Pepper section for more information). Thresholds used in other regions may apply, including 1 aphid/plant on seedlings and 4-10 aphids per plant on older plants. Natural enemies often provide control. Aphid outbreaks can occur after using broad-spectrum insecticides due to the loss of natural enemies, so aphid-selective products should be used whenever possible. Take measures to cover the undersides of leaves if using materials that do not have translaminar or systemic movement.

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A. Do not apply to greenhouse or high tunnel crops.
afidopyropen (Versys): 1.5 fl oz/A; PHI 0d, REI 12h, Bee: L, Group 9D. Do not apply to greenhouse or high tunnel crops.
azadirachtin (Azatin O^OG): 5 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.
Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 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. Do not use adjuvants in tank mix with Exirel in spinach. Do not apply to greenhouse or high tunnel crops.
cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d chemigation, REI 4h, Bee: H, Group 28. Control of green peach and suppression of potato aphid only. Do not apply to greenhouse or high tunnel crops.
cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 28. For best results, use with an effective adjuvant. Use high labeled rate for best perfomance. Melon aphid only. Do not apply to greenhouse or high tunnel crops.
dinotefuran (Venom): 1 to 3 oz/A foliar, 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, as a transplant or post-seeding drench, as a sidedress, or through drip.
flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12h, Bee: L, Group 9C.
flupyradifurone (Sivanto): 10.5 to 14 oz/A for green peach aphid foliar, 7 to 14 oz/A for other aphids foliar, 21 to 28 oz/A for soil; PHI 1d foliar, 21d soil, REI 4h, Bee: L, Group 4D.
imidacloprid (Admire Pro): 1.3 oz/A foliar, 4.4 to 10.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A. For foliar applications, apply only to fully leafed-up canopies. Do not apply to greenhouse or high tunnel crops.
insecticidal soap (M-Pede^OG): 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 57EC): 1.6 pt/A; PHI 7d, REI 12h, Bee: H, Group 1B.
permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
pymetrozine (Fulfill): 2.75 oz/A; PHI 7d, REI 12h, Bee:L, Group 9B. Translaminar. Apply when aphids first appear, before populations build up.
pyrethrin (PyGanic EC5.0^OG): 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. Do not apply to greenhouse or high tunnel crops.
sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 3d, REI 12h, Bee: H, Group 4C. Do not apply to greenhouse or high tunnel crops.
tolfenpyrad (Torac): 17 to 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A. Except lettuce aphids.
zeta-cypermethrin (Mustang*): 2.24 to 4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Aphid control may be variable depending on species present and host-plant relationships.

Blister Beetles

See Blister Beetles in the Beets and Swiss Chard section for more information on blister beetle life cycle and management. A single spot spray with a broad-spectrum insecticide registered for caterpillars on spinach will control the beetles.

pyrethrin (PyGanic EC5.0^OG): 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 Looper (Trichoplusia ni) and Fall Armyworm (Spodoptera frugiperda)

See Cabbage, Broccoli, Cauliflower, and Other Brassica Crops section for more information on cabbage looper (CL) and Sweet Corn section for more information on fall armyworm (FAW).

Bacillus thuringiensis aizawai (XenTari^OG): 0.5 to 1.5 lb/A for looper, 0.5 to 2.0 lb/A for armyworms; 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 DF^OG): 0.5 to 2 lb/A looper, 1 to 2 lb/A armyworm; 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 for CL, 2.4 to 3.2 oz/A for FAW; PHI 0d, REI 12h, Bee: H, Group 3A. For FAW, controls 1st and 2nd instar larvae only.
bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 40d, REI 12h, Bee: H, Group 3A.
carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A. FAW 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, or as a foliar spray. For soil applications, must be applied uniformly in the root zone. CL and beet armyworm only. Do not apply to greenhouse or high tunnel crops.
Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.
cyantraniliprole (Exirel): 10 to 17 oz/A loopers, 7 to 13.5 oz/A armyworm; PHI 1d, REI 12h, Bee: H, Group 28. Do not use adjuvants in tank mix with Exirel in spinach. Do not apply to greenhouse or high tunnel crops.
cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d chemigation, REI 4h, Bee: H, Group 28. CL only. Do not apply to greenhouse or high tunnel crops.
emamectin benzoate (Proclaim*): 2.4 to 4.8 oz/A armyworm, 3.2 to 4.8 oz/A CL; PHI 7d, REI 12h, Bee: H, Group 6. Do not apply to greenhouse or high tunnel crops.
indoxacarb (Avaunt): 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22. CL only.
methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 7d, REI 48h, Bee: H, Group 1A. Do not apply if minimum daily temperature is less than 32°F. Do not apply to seedlings less than 3" in canopy diameter. CL may be resistant.
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 CL, 6.4 to 12.8oz/A FAW; PHI 1d, REI 12h, Bee: H, Group 3A.
pyrethrin (PyGanic EC5.0^OG): 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. CL only.
spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Do not apply to greenhouse or high tunnel crops.
spinosad (Entrust SC^OG): 3 to 6 oz/A CL, 4 to 8 oz/A armyworms; PHI 1d, REI 4h, Bee: M, Group 5. Do not apply to seedlings for transplant.
tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. 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 an adjuvant is recommended.
tolfenpyrad (Torac): 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A. Suppression of armyworms only.
zeta-cypermethrin (Mustang*): 3.2 to 4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Leafminer, Beet and Spinach

See Leafminers in Beet and Swiss Chard section for more information on the life cycle, scouting, and management of beet and spinach leafminers.

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. Do not apply to greenhouse or high tunnel crops.
azadirachtin (Azatin O^OG): 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. Leafminer larvae only.
bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 40d, REI 12h, Bee: H, Group 3A.
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, or as a foliar spray. For soil applications, must be applied uniformly in the root zone. Do not apply to greenhouse or high tunnel crops. For leafminer larvae only.
cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Do not use adjuvants in tank mix with Exirel in spinach. Do not apply to greenhouse or high tunnel crops.
cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 6.75 to 10 oz/A chemigation; PHI 1d chemigation, REI 4h, Bee: H, Group 28. Do not apply to greenhouse or high tunnel crops.
cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28. Do not apply to greenhouse or high tunnel crops.
cyromazine (Trigard): 2.66 oz/A; PHI 7d, REI 12h, Bee: M, Group 17. Do not apply to greenhouse or high tunnel crops.
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, as a transplant or post-seeding drench, as a sidedress, or through drip.
emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Suppression only. Do not apply to greenhouse or high tunnel crops.
insecticidal soap (M-Pede^OG): 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.
permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, 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. Do not apply to greenhouse or high tunnel crops.
spinosad (Entrust SC^OG): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Do not apply to seedlings for transplant. Control may be improved with addition of an adjuvant.

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, Broccoli, Cauliflower, and Other Brassica Crops section for more information on slugs.

metaldehyde (Deadline Bullets): 25 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.

Winter Cutworms (Noctua pronuba)

Winter cutworm is a newer, emerging pest in winter high tunnels. They are climbing, foliar-feeding cutworms that are particularly cold-hardy. The adults are large yellow underwing moths and are about 1" long and are active in the summer and fall. They lay eggs in masses on leaves. Winter cutworms vary in color with a dotted line along their backs and have a brown head capsule with black markings. Larvae are usually observed starting in August and feed in high tunnels throughout the fall and winter. Pupation occurs in the spring. They are active during our coldest months, with the worst damage occurring in November and December.

Damage includes large feeding holes and feeding on leaf margins in spinach, Swiss chard, lettuce, and carrots. These cutworms are nocturnal feeders and hide in the soil during the day. They are also highly mobile caterpillars.

Row covers or exclusion netting may work in some situations but needs to be timed with moth flights to prevent egg laying. Products used to target caterpillars may work for insecticides, but they need to be registered for use in high tunnels. Some efficacy has been seen with Bt products and spinosyns, but research is ongoing.

Insect Control

Spinach Weed Control

Spinach Weed Control Evonne Gong Fri, 05/24/2024 - 11:25

Spinach - General Spinach Disease Control Spinach Insect Control

NOTES: 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 in the Weed Management section for information on the use of these herbicides.

carfentrazone (Aim EC): PHI 0d, REI 12h, Group 14.
glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9.
pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0.

Preemergent Herbicides (before weeds germinate)

cycloate (Ro-Neet): REI 48h, Group 15. Apply 0.5 gal/A per application, only 1 application per year. Can be applied before, during, or immediately after planting. Apply in 10-50 gal/A of spray. Incorporate immediately 2-3” into the soil. Use on mineral soils only. Use the lower rate on sandy soils and the higher rate on silt and clay soils.
s-metolachlor (Dual Magnum): REI 24h, Group 15. MA, ME, and NH 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.

Postemergent Herbicides (after weeds germinate)

carfentrazone (Aim EC): PHI 0d, REI 12h, Group 14. Apply 0.5-2 oz/A per application. Do not exceed 6.1 oz/A per season. Can be applied as a preplant burndown no later than 7 days before seeding or immediately before transplanting crops. Can also be applied 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” tall and rosettes less than 3” across.
clethodim (Select Max): PHI 14d, REI 24h, Group 1. Apply 9-16 oz/A per application, up to 4 applications allowed per year, a minimum of 14 days apart. Do not exceed 64 oz/A per year. Apply to actively growing grasses. Add 0.25% v:v nonionic surfactant (1 qt/100 gal of spray). Can also be applied as a spot-spray by mixing 0.33-0.66% (0.44-0.85 oz/gal) Select Max and 0.25% v:v nonionic surfactant (0.33 oz/gal). Spray to wet, but do not allow runoff of spray solution.
clopyralid (Stinger): PHI 21d, REI 12h, Group 4. Apply 4-8 oz/A per application, up to 2 applications allowed per year. Do not exceed 8 oz/A per year. Apply when spinach is in the 2- to 5-leaf stage in 10-20 gal/A of spray. Rate based on weed composition. Some leaf curling may appear, especially at high application rates. Spray additives are not recommended.
glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9. Apply 10 oz to 3.1 qts/A per application, multiple applications allowed per year. Do not exceed 5 qts/A per year. Rate based on target weed species. Can be applied during fallow intervals, prior to planting or transplanting, at planting, or before crop has emerged. Could cause injury when applied prior to transplanting or direct-seeding into plastic mulch. Remove residual product from plastic mulch with a 0.5” of water through irrigation or rainfall prior to planting.
pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0. Apply a 3-10% solution (3-10 gal/100 gal of spray). Apply in 75-200 gal/A of spray. Can use preplant, or as a directed and shielded spray during crop growth. Avoid contact with foliage or crop damage may occur. Spray to wet, but do not allow runoff of spray solution.
sethoxydim (Poast): PHI 15d, REI 12h, Group 1. Apply up to 1.5 pt/A per application, multiple applications allowed per year, a minimum of 14 days apart. Do not exceed 3 pts/A per year. Apply to actively growing grasses. Use with crop oil concentrate (2 pt/A) or methylated seed oil (1.5 pt/A). Crop oil can cause injury under hot and humid conditions. Can also be applied as a spot-spray by mixing 1-1.5% (1.3-1.9 oz/gal) Poast and 1% v:v crop oil concentrate (1.3 oz/gal). Spray to wet, but do not allow runoff of spray solution.

Weed Control