Vegetable Seed Crops
Tim Miller
Revised December17, 2008

In some seed-producing regions, contracting seed companies or seed associations have secured special local needs labels for members. Authors of this handbook wish to honor the third-party ownership of these labels and their restricted use; these labels are not listed here. If a herbicide is labeled for use in a given crop, that herbicide also may be used in producing seed for that vegetable, unless expressly forbidden in the label. Be sure to check vegetable crop sections of this handbook for additional herbicide listings.
VEGETABLE SEED CROPS—Stale Seedbed Method
Refer to “Stale Seedbeds” in the Vegetables section of this Handbook for information on the following options.
•  flaming		•  carfentrazone
•  glyphosate		•  pelargonic acid
•  paraquat
VEGETABLE SEED CROPS—Beet Seed, red or table
•  cycloate (Ro-Neet 6-E)
Rate  3 to 4 lb ai/A
Time  Apply preplant to soil dry enough to thoroughly mix; immediately incorporate 2 to 3 inches deep by cross-disking or using a rotary tiller.
Remarks  Use on mineral soil only; seed may be planted immediately.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
•  quizalofop (Assure II)
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide. 
Caution  Do not mix with or apply with any other pesticide except as specified on label. Do not apply to plants stressed from lack of moisture, cold, or injury from herbicides, insects, or disease. Do not use any treated part of crop for food or feed. Do not exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  pyrazon (Pyramin DF)
Rate  3.2 to 3.7 lb ai/A
Time  Apply either preemergence after planting beet seed or postemergence after two expanded true leaves and before weeds emerge. Apply on moist soil surface, and follow with light irrigation or shallow incorporation before weeds are 2 inches tall.
Remarks  West of Cascades, preemergence application is preferred if rain or irrigation is adequate. 
Caution  Do not use on sandy or loamy sand soil or on soil with over 5% organic matter. Consult label for replanting table or sugar beets only.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Pyridazinone 
•  phenmedipham (Spin-Aid)
Rate  0.5 to 1 lb ai/A
Time  Apply any time red beets have four to six true leaves and before weeds have two leaves.
Remarks  Avoid applying when daytime weather changes rapidly from cool and cloudy to warm and sunny, or if beets are stressed from insect, disease, or cultivation injury. Tip burn or temporary growth retardation and chlorosis may occur, although plants usually recover within 10 days. 
Caution  Preharvest interval is 60 days. Avoid using more than 7 gal water per quart of herbicide in spray tank; this can cause the herbicide to precipitate. 
Site of action  Group 5: photosystem II inhibitor
Chemical family  Phenylcarbamate
•  phenmedipham + desmedipham (Betamix)
Washington only
Rate  Consult label.
Time  Apply any time red beets are past the two-true-leaf stage. Do not apply after crop begins to form buds.
Remarks  Special local needs label WA-010015. Crop may be injured under unfavorable environmental conditions or if beets are stressed by insect, disease, or cultivation injury. Tip burn or temporary growth retardation, and chlorosis may occur; plants usually recover within 10 days. May be tank-mixed with ethofumesate.
Caution  Do not use any treated portion of crop for food or feed.
Site of action  (both) Group 5: photosystem II inhibitor
Chemical family  (both) phenylcarbamate
•  fluazifop (Fusilade DX)
Washington only
Rate  0.063 to 0.25 lb ai/A (4 to 16 fl oz/A)
Time  Apply to actively growing grasses.
Remarks  Special local needs label WA-040006. Identify grasses; adjust rates for susceptibility and stage of weed growth as label instructs. Results often are erratic on grasses stressed from lack of vigor, drought, high temperature, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment.
Caution  Do not exceed 32 oz/A per season. Do not apply if rain is expected within 1 hr. Rotational grass crops such as corn and cereals may not be planted within 60 days of the last application. Grazing any plant product or residue is prohibited.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  sethoxydim (Poast)
Rate  0.28 to 0.47 lb ai/A (1.5 to 2.5 pints/A)
Time  Apply at optimum growth stage listed on label. 
Remarks  Identify susceptible grasses and add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
•  S-metolachlor (Dual Magnum)
Oregon only
Rate  Consult label
Time  Broadcast preplant with ground application equipment.
Remarks  Uniformly mix into top 2 inches of soil. Inhibits roots and shoots. Special local needs indemnified label OR-060012, available only through the Syngenta Farm Assist website (www.farmassist.com) by completing the following steps.
	1. Visit the website and register as a user. 
	2. Click on Sign-in button; enter your user name and password.
	3. Click on Products, then Syngenta Crop Protection, then Special labels.
	4. Near the top of the page, in very small print, it says “if searching for indemnified labels, click here.” Do that.
	5. On the next screen, enter state (OR) and product (Dual Magnum) on the drop-down menus and click Submit button.
	6. The next screen shows the available Dual Magnum 24C labels. Select the crop (beets, in this case). Click Submit button.
	7. The indemnification agreement will come on the screen. Read it carefully, then click ‘I accept’ or ‘I decline’.
	8. The label(s) you selected will appear on the next screen. Print the label(s), which must be in your possession when you apply the herbicide.
Caution  Crop may be injured if environmental conditions are unfavorable. Do not feed or graze forage or fodder or cut for hay or forage. No part of the treated field, including seed, seed screenings, hay, forage, or stubble, may be used for human or animal consumption. See label for all other precautions and regulations. 
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
•  ethofumesate (Nortron SC)
western Washington only
Rate  Consult label.
Time  Apply preplant incorporated, preemergence, or postemergence tank-mixed with phenmedipham (Spin-Aid). Postemergence treatment may be repeated 4 wk after first application.
Remarks  Special local needs label WA-010002. Crop may be injured under unfavorable environmental conditions or when higher rates are used. 
Caution  Do not feed or graze table beet forage or fodder. No portion of the treated field, including seed, seed screening, hay forage, and stubble, may be used for human or animal consumption.
Site of action  Group 16: unknown
Chemical family  Benzofuran
•  clopyralid (Stinger)
Rate  0.094 to 0.125 lb ae/A (0.25 to 0.33 pint/A)
Time  Apply in 10 gal or more total spray volume when seed crop has at least two true leaves.
Remarks  Special local needs label WA-970033. Use above rates for annual weeds 1 to 2 inches high. Make spot applications up to 0.66 pint/A to Canada thistle. 
Caution  Apply after most thistle basal leaves emerge but before buds form. Re-treat as necessary up to eight-leaf stage of crop growth, but do not exceed 0.66/A pint Stinger per growing season. Crop safety data are limited; use only when crop injury is acceptable. Follow rotational crop restrictions on label. Avoid spray drift to sensitive crops. Do not use any part of the treated field, including seed, seed screenings, hay forage, and stubble, for human or animal consumption.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
VEGETABLE SEED CROPS—Carrot Seed (and other Apiaceae or Umbelliferae seed crops)    
•  trifluralin (several trade names)
carrot seed only
Rate  0.5 to 1 lb ai/A
Time  Apply from 3 wk to immediately before planting; incorporate 2 to 3 inches deep within 24 hr by cross-disking or using a power take-off rotary tiller.
Remarks  Spray only once; avoid overlaps. Consult label for restrictions on planting sensitive crops within 12 mo.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  pendimethalin (Prowl H2O)
carrot seed only
Rate  0.45 to 1.9 lb ai/A (1 to 4 pints/A Prowl H2O)
Time  Apply at last cultivation (layby) as a directed spray. 
Remarks  Adequate rain or irrigation after application, before weed seedlings emerge, provides the most effective weed control. Inhibits mitosis in roots and shoots.
Caution  Do not spray broadcast over the top of carrots, or crop may be injured. Refer to main labels for crop rotation restrictions. Preharvest interval is 60 days. Do not use any plant residue or product for food or feed. Rotate to tolerant crops other than winter wheat or barley if rates exceed 1.5 lb/A.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  S-metolachlor (Dual Magnum)
Oregon only—carrot and parsnip seed
Rate  Consult label
Time  Broadcast preplant with ground application equipment.
Remarks  Uniformly mix into top 2 inches of soil. Special local needs labels OR-060012. This indemnified label is available only through the Syngenta Farm Assist website (www.farmassist.com). Follow the steps listed in “Beet seed” section of this chapter to acquire the indemnified label.
Caution  Crop may be injured if environmental conditions are unfavorable. Do not feed or graze forage or fodder or cut for hay or forage. No part of the treated field, including seed, seed screenings, hay, forage, or stubble, may be used for human or animal consumption. See label for all other precautions and regulations. 
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
•  quizalofop (Assure II)
carrot seed only
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A product)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.
Caution  Do not mix with or apply with any other pesticide except as specified on label. Do not apply to plants stressed from lack of moisture, cold, or injury from herbicides, insects, or disease. Do not use any treated portion of crop for food or feed. Do not exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  sethoxydim (Poast)
Rate  0.28 to 0.47 lb ai/A (1.5 to 2.5 pints/A)
Time  Apply for barnyardgrass and other grass control at 3- to 12-inch stage of growth. Add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption.
Remarks  Control often is erratic on grasses stunted or stressed by drought, heat, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
•  fluazifop (Fusilade DX)
carrot seed only
Rate  0.063 to 0.25 lb ai/A (4 to 16 fl oz/A)
Time  Apply to actively growing grasses.
Remarks  Identify grasses and adjust rates for susceptibility and weed growth stage as on label. Results often are erratic on grasses stressed by lack of vigor, drought, heat, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment. Do not exceed 48 oz/A per season.
Caution  Do not apply if rain is expected within 1 hr. Do not rotate to grass crops such as corn and cereals within 60 days of last application. Grazing any plant products or residue is prohibited. 
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  prometryn (Caparol 4L)
Washington—carrot, parsley, parsnip, and dill seed; 
Oregon—carrot, coriander, and parsley seed
or 
•  prometryn (Prometryne 4L)
Washington and Oregon—dill seed only
Rate  0.5 to 1 lb ai/A (1 to 2 pints/A)
Time  Apply postemergence when crop has three to five true leaves, when weeds are not more than 2 inches tall, or as a layby treatment, preferably as a directed spray.
Remarks  Special local needs labels WA-960014 or WA-980005 and OR-040002 or OR-050018. Use in at least 30 gal/A spray volume. Use adjuvants only with layby applications. 
Caution  Do not use any part of the crop for food or feed. Do not exceed 4 pints/A per crop. To reduce the chance of injuring rotational crops, disk the field deeply and irrigate at least twice soon after harvest. Using prometryn on soils with excess salts or that are highly calcareous may injure crop.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
•  linuron (Lorox DF)
carrot and parsnip seed
Rate  0.75 to 1.5 lb ai/A
Time  Apply postemergence when carrots are at least 3 inches tall, when grass weeds are not more than 2 inches tall, and when broadleaf weeds are not more than 6 inches tall.
Caution  Do not exceed 40 psi spray pressure. Weed control may be poor if daytime highs are below 50°F. Crop may be injured if linuron is mixed with surfactants, nitrogen, or fertilizer solutions, or applied at temperatures above 85°F. Applications may be repeated, but do not exceed 1.5 lb ai/A per season. Do not apply on sandy, loamy sands, gravelly soils, or soils with less than 1% organic matter. See label for planting rotation crops within 12 mo.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Substituted urea
•  oxyfluorfen (Galigan 2E)
Washington and Oregon—carrot seed only
Rate  0.25 to 0.5 lb ai/A
Time  Begin applications in early spring when carrots are 8 to 10 inches tall and weeds are in the two- to four-leaf stage.
Remarks  Special local needs labels WA-030012 and OR-070003. Maintain a 25-ft vegetative buffer between treated areas and water. Reduce crop injury potential by using lower rate, by not applying soon after or in combination with linuron, and by applying to large carrots. Grazing crop residue or treated fields prohibited.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether
•  bensulide (Prefar 4-E)
parsley and cilantro seed
Rate  5 to 6 lb ai/A
Time  Apply preplant or preemergence.
Remarks  Use lower rates on light, coarse soils and on soils with low organic matter. Application to cold, wet soils, due to rains or poor drainage, during germination period may reduce crop stands or yields. Do not exceed 6 lb ai/A per season.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
VEGETABLE SEED CROPS—Cole Crop Seed
•  simazine (Simazine 4L)
Washington—cabbage seed only
Oregon—broccoli, Brussels sprouts, cabbage, kale, and kohlrabi seed
Rate  Consult label.
Time  Apply in fall after cabbage plants are established and after winter rains begin but before most winter weeds emerge.
Remarks   Special local needs labels WA-900005 and OR-050017. In Washington, repeat application in spring after last cultivation before cabbage begins active growth. 
Caution  Do not use on sandy, loamy, or gravelly areas of fields or where water pools. Avoid crop rotations to susceptible crops. Do not use crop, crop residues, or seed screenings for food or feed, or apply through any type of irrigation system. 
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
•  quizalofop (Assure II)
Chinese cabbage seed only
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.
Caution  Do not mix with or apply with any other pesticide except as specified on label. Do not apply to plants stressed from lack of moisture, cold, or injury from herbicides, insects, or disease. Do not use any treated portion of crop for food or feed. Do not exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  oxyfluorfen (several trade names)
transplanted winter cauliflower and cabbage seed 
Rate  0.25 to 0.5 lb ai/A
Time  Apply soon after final soil preparation and before transplanting through the treated layer with minimal soil disturbance.
Remarks  Use lower rate for coarse soils with less than 1% organic matter. Leaves that contact treated soil may be injured temporarily. Injury may be severe if transplants are stressed by temperature, disease, fertilizer salts, nematodes, insects, pesticides, and storage conditions or if planting small transplants grown in 1-inch cells. After transplanting, apply at least 0.25 inch overhead moisture. Plant only crops listed on label within 10 mo after treatment. Grazing crop residue or treated fields prohibited.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether
•  clopyralid (Stinger)
broccoli, cauliflower, and cabbage seed
Rate  0.094 to 0.125 lb ae/A (0.25 to 0.33 pint/A)
Time  Apply in 10 gal or more total spray volume when seed crop has at least two true leaves. Spot applications up to 0.66 pint/A may be applied to Canada thistle. Apply after most thistle basal leaves emerge but before buds form.
Remarks  Special local needs label WA-970033. Use for annual weeds 1 to 2 inches high. Re-treat as necessary up to eight-leaf stage of crop growth; do not exceed 0.66 pint/A Stinger per growing season. Crop safety data are limited; use only where crop injury is acceptable. Follow rotational crop restrictions on label. Avoid spray drift to sensitive crops. 
Caution  Do not use any part of treated field, including seed, seed screenings, hay forage, or stubble for human or animal consumption.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
•  fluazifop (Fusilade DX)
Washington only—cabbage, kale, and Chinese cabbage seed
Rate  0.063 to 0.25 lb ai/A (4 to 16 fl oz/A)
Time  Apply to actively growing grasses. 
Remarks  Special local needs label WA-040006. Identify grasses and adjust rates for susceptibility and stage of weed growth as label instructs. Control often is erratic on grasses stunted or stressed by drought, heat, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment. 
Caution  Do not exceed 32 oz/A per season. Do not apply if rain is expected within 1 hr. Do not plant rotational grass crops such as corn and cereals within 60 days of the last application. Grazing any plant product or residue is prohibited.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  clomazone (Command 3ME)
cabbage seed only
Rate  0.25 to 0.5 lb ai/A  (0.67 to 1.3 pints/A)
Time  Apply to soil before transplanting cabbage. Place plant roots below the herbicide barrier when transplanting.
Remarks  Use lower rate for coarse soils and higher rate for fine soils. See label for crop rotation restrictions and application requirements to avoid crop injury or vapor drift to sensitive plants. Cabbage may be chlorotic temporarily. Before using, ask seed company whether the cultivar has good tolerance to Command. Avoid overlaps while spraying.
Caution  Do not mix or apply within 300 ft of landscapes, orchards, vegetable or berry plots, or property lines to prevent chemical trespass. Do not graze cover crops. Preharvest interval is 9 mo for food or feed. Do not let livestock graze on treated pea vines or vine trash.
Site of action  Group 13: inhibits DOXP synthase
Chemical family  Isoxazolidione
•  S-metolachlor (Dual Magnum)
Oregon only—rutabaga and turnip seed 
Rate  Consult label
Time  Broadcast preplant with ground application equipment.
Remarks  Uniformly mix into top 2 inches of soil. Special local needs labels OR-060012. This indemnified label is available only through the Syngenta Farm Assist website (www.farmassist.com). Follow the steps in “Beet seed” section of this chapter to acquire the indemnified label.
Caution  Crop may be injured if environmental conditions are unfavorable. Do not feed or graze forage or fodder or cut for hay or forage. No part of treated field, including seed, seed screenings, hay, forage, or stubble, may be used for human or animal consumption. See label for all other precautions and regulations. 
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
•  sethoxydim (Poast)
Rate  0.28 to 0.47 lb ai/A (1.5 to 2.5 pints/A)
Time  Apply at optimum growth stage listed on label. 
Remarks  Identify susceptible grasses and add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed by drought, heat, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.  
Caution  Do not exceed 3 pints/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
VEGETABLE SEED CROPS—Onion Seed 
•  sethoxydim (Poast)
Rate  0.19 to 0.28 lb ai/A (1 to 1.5 pints/A)
Time  Apply at optimum growth stage as on label. Add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption.
Remarks  Control often is erratic on grasses stunted or stressed by drought, heat, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.
Caution  Do not exceed 5 pints/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
•  quizalofop (Assure II)
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.
Caution  Do not mix with or apply with any other pesticide except as specified on label. Do not apply to plants stressed from lack of moisture, cold, or injury from herbicides, insects, or disease. Do not use any treated part of crop for food or feed. Do not exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  oxyfluorfen (several trade names)
Rate  0.125 lb ai/A
Time  Apply postemergence to onions with at least three true leaves and to weeds in the two- to four-leaf growth stage.
Remarks  Although multiple applications may be necessary to control late weed flushes, do not exceed 0.5 lb ai/A total per year. Do not mix with oils, surfactants, fertilizers, or other pesticides. Do not apply to onions under stress.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether
VEGETABLE SEED CROPS—Radish Seed
•  quizalofop (Assure II)
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.
Caution  Do not mix with or apply with any other pesticide except as label specifies. Do not apply to plants stressed by drought, cold, or injury from herbicides, insects, or disease. Do not use any treated part of crop for food or feed or exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  S-metolachlor (Dual Magnum)
Oregon and Washington only
Rate  Consult label
Time  Broadcast preplant with ground application equipment.
Remarks  Uniformly mix into top 2 inches of soil. (Inhibits roots and shoots). Special local needs labels OR-040010 (includes daikon radish) and WA-990005 (excludes daikon radish). The Oregon label is available only through the Syngenta Farm Assist website (www.farmassist.com). Follow steps in “Beet seed” section of this chapter to acquire the indemnified label.
Caution  Restricted-use pesticide in Washington, to protect groundwater. Crop may be injured if environmental conditions are unfavorable. Do not feed or graze radish forage or fodder or cut for hay or forage. No part of treated field, including seed, seed screenings, hay, forage, or stubble, may be for human or animal consumption. See label for all other precautions and regulations.
Site of action  Group 15: Inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
VEGETABLE SEED CROPS—Spinach Seed
•  phenmedipham (Spin-Aid)
Rate  0.5 to 1 lb ai/A
Time  Apply when seedling weeds have germinated and spinach has four to six true leaves.
Remarks  Temperature must be below 75°F, and spinach should not be stressed. Avoid applying when weather changes rapidly from cool, cloudy to warm, sunny days. Tip burn or temporary growth retardation and chlorosis may occur, but plants usually resume normal growth within 10 days. Do not exceed 7 gal water for each quart of herbicide, to prevent precipitating the herbicide. 
Site of action  Group 5: photosystem II inhibitor
Chemical family  Phenylcarbamate
•  cycloate (Ro-Neet)
western Washington only
Rate  3 lb ai/A
Time  Apply preplant to soil dry enough to thoroughly mix; incorporate immediately by cross-disking or using a rotary tiller.
Remarks  Special local needs labels WA-020003A and WA-020003C. Use on mineral soils only. Seed may be planted immediately. Inhibits shoot growth.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
•  quizalofop (Assure II)
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses, and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.
Caution  Do not mix with or apply with any other pesticide except as label specifies. Do not apply to plants stressed by drought, cold, or injury from herbicides, insects, or disease. Do not use any treated part of crop for food or feed. Do not exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  fluazifop (Fusilade DX)
Rate  0.063 to 0.25 lb ai/A (4 to 16 fl oz/A)
Time  Apply to actively growing grasses. Results often are erratic on grass stressed from lack of vigor, drought, high temperature, or low fertility.
Remarks  Special local needs label WA-040006. Identify grasses and adjust rates for stage of weed growth and susceptibility as label instructs. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment.
Caution  Do not exceed 32 oz/A per season. Do not apply if rain is expected within 1 hr. Do not plant rotation grass crops such as corn and cereals within 60 days of the last application. Grazing any plant product or residue is prohibited.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  sethoxydim (Poast)
Rate  0.28 to 0.47 lb ai/A (1.5 to 2.5 pints/A)
Time  Apply at optimum growth stage listed on label. 
Remarks  Identify susceptible grasses and add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed by drought, heat, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.
Caution  Do not exceed 3 pints/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
•  ethofumesate (Nortron SC)
western Washington only
Rate  0.75 to 1 lb ai/A
Time  Apply preemergence at or shortly after planting but before weeds germinate. 
Remarks  Special local needs label WA-010001 for use only by members of Puget Sound Seed Growers Association. One-half inch of rain or irrigation soon after treatment is important to activate herbicide. If rain is marginal, incorporate ethofumesate 1 to 2 inches before planting.
Caution  Do not apply through any type of irrigation system. Do not rotate with any crops other than sugar beets or ryegrass for 12 mo. Do not cultivate deeper than 2 inches; this may reduce effectiveness of ethofumesate.
Site of action  Group 16: unknown
Chemical family  Benzofuran
•  S-metolachlor (Dual Magnum)
Washington only
Rate  0.32 to 0.64 lb ai/A (0.33 to 0.67 pint/A)
Time  Apply preemergence at or shortly after planting but before weeds germinate.
Remarks  Special local needs label WA-030039. Apply in at least 15 gal/A water with ground equipment; 0.5 inch of rain or irrigation soon after treatment is important to activate herbicide. Use lower rate on coarse soil and higher rate on medium- or fine-texture soils. 
Caution  Restricted-use pesticide in Washington, to protect groundwater. Do not mechanically incorporate. Do not apply through any type of irrigation system. Crop may be damaged if excess rain after seeding washes Dual Magnum into the root zone.
Site of action  Group 15: Inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
• asulam (Asulox) 
Oregon and Washington only
Rate  0.62 to 1.25 lb ai/A (1.5 to 3 pints/A)
Time  Apply postemergence; works best if weeds are small. If applied once per season, use 1.5 pint/A on spinach with two to four leaves, or 3 pints/A on spinach with four to six true leaves. If applied twice per season, use 3 pints/A on spinach with four to eight true leaves and 3 pints/A 7 days later (typically 8 to 12 true leaves).
Remarks  Special local needs label OR-070016 and WA-080001. A nonionic surfactant at 0.25% v/v may be added to the spray to increase efficacy. Crop oils and other adjuvants such as urea ammonium nitrate are not recommended. Suggested dilution rate is 20 gal/A water. Spinach may be somewhat stunted, especially with two applications at 3 pints/A. 
Caution  No pesticide residue tolerance has been established for this crop, and so no portion of this seed crop (including screenings) may be used or distributed for food or feed. Grazing the crop field or stubble is not permitted. Asulam is known to leach through soil into ground water under certain conditions. Using asulam where soils are permeable, particularly where the water table is shallow, may contaminate ground water. Avoid surface water contamination.
Site of action  Group 18: inhibits DHP synthase step
Chemical family  Carbamate
VEGETABLE SEED CROPS—Swiss Chard Seed
•  fluazifop (Fusilade DX)
Washington only
Rate  0.063 to 0.25 lb ai/A (4 to 16 fl oz/A)
Time  Apply to actively growing grasses.
Remarks  Special local needs label WA-040006. Identify grasses and adjust rates for susceptibility and stage of weed growth as label instructs. Results often are erratic on grasses stressed by lack of vigor, drought, heat, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment. 
Caution  Do not exceed 32 oz/A per season. Do not apply if rain is expected within 1 hr. Rotational grass crops such as corn and cereals may not be planted within 60 days of the last application. Grazing any plant products and residues is prohibited.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  phenmedipham + desmedipham (Betamix)
Washington only
Rate  Consult label.
Time  Apply any time after Swiss chard plants pass the two-true-leaf stage. Do not apply after crop begins to form buds.
Remarks  Special local needs label WA-010015. Crop may be injured under unfavorable environmental conditions or if stressed by insect, disease, or cultivation injury. Tip burn or temporary growth retardation and chlorosis may occur, but plants usually recover within 10 days. May be tank-mixed with ethofumesate. 
Caution  Do not use any treated part of crop for food or feed.
Site of action (both) Group 5: photosystem II inhibitor
Chemical family  (both) phenylcarbamate
•  ethofumesate (Nortron SC)
western Washington only
Rate  Consult label.
Time  Apply preplant incorporated, preemergence, or postemergence. Postemergence treatment may be repeated in 4 wk.
Remarks  Special local needs label WA-010002. Crop may be injured under unfavorable environmental conditions or when higher rates are used. 
Caution  Do not feed or graze Swiss chard forage or fodder. Do not use any part of the treated field, including seed, seed screening, hay forage, and stubble, for human or animal consumption.
Site of action  Group 16: unknown
Chemical family  Benzofuran
•  quizalofop (Assure II)
Rate  0.069 to 0.17 lb ai/A (5 to 12 fl oz/A)
Time  Apply at optimum growth stage listed on label.
Remarks  Identify susceptible grasses and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.
Caution  Do not mix with or apply with any other pesticide except as specified on label. Do not apply to plants stressed from lack of moisture, cold, or injury from herbicides, insects, or disease. Do not use any treated part of crop for food or feed. Do not exceed 25 fl oz/A per season.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  clopyralid (Stinger)
Rate  0.094 to 0.125 lb ae/A (0.25 to 0.33 pint/A)
Time  Apply in 10 gal or more total spray volume when seed crop has at least two true leaves. Spot applications up to 0.66 pint/A may be applied to Canada thistle. Apply after most thistle basal leaves emerge but before buds form.
Remarks  Special local needs label WA-970033. Use above rates for annual weeds 1 to 2 inches high. Re-treat as necessary up to eight-leaf stage of crop growth, but do not exceed 0.66 pint/A Stinger per growing season. Crop safety data are limited, so use only if crop injury is acceptable. Follow rotational crop restrictions on label. Avoid spray drift to sensitive crops.
Caution  Do not use any part of the treated field, including seed, seed screenings, hay forage, and stubble, for human or animal consumption.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
•  sethoxydim (Poast)
Rate  0.28 to 0.47 lb ai/A (1.5 to 2.5 pints/A)
Time  Apply at optimum growth stage listed on label. 
Remarks  Identify susceptible grasses and add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione

VEGETABLE SEED CROPS—Preharvest Desiccation of Beets (red or table), Carrots, Coriander, Radishes, Spinach, and Turnips Grown for Seed
Washington only
•  diquat (Reglone)
Rate  0.375 to 0.5 lb ai/A (1.5 to 2 pints/A)
Time  Apply 3 to 10 days before swathing for harvest, when most seed is harvest ripe (spinach is tan to gray ripe).
Remarks  Special local needs label WA-040011.
Caution  Do not apply through any type of irrigation system. Do not use seed or residues from treated plants for food, feed, or oil purposes. Do not use on daikon radish. Application restricted in Washington; contact Washington State Department of Agriculture before applying.
Site of action  Group 22: inhibits photosystem I electron diversion
Chemical family  Bipyridilium
VEGETABLE SEED CROPS—Sex Expression in Cucumber and Squash
•  ethephon (Florel)
Rate  1 quart/A
Time  Apply within 4 hr of mixing, or activity will be reduced.
Remarks  For uniform plantings, spray once when two true leaves have developed. Spray nonuniform plantings twice: when first true leaf is the size of a quarter and again when third true leaf is expanding. Plant male or pollen rows ahead of seed parent; treatment often causes flowering 7 to 10 days earlier. Growth may be inhibited temporarily because of shortened internodes.
Site of action  Unknown
Chemical family  Ethylene generator