Clover Seed

CLOVERS—Red, White, Crimson, and Arrowleaf

Preplant

benefin (Balan DF)

Rate 1.2 to 1.5 lb ai/A (2 to 2.5 lb/A Balan DF)

Time Before planting clover, benefin must be incorporated into the top 2 to 3 inches of the seedbed.

Remarks Controls annual grasses and certain annual broadleaf weeds. Application rates are based on soil texture. Use the 2.5 lb/A rate on fine clay soils, use the lower 2 lb/A rate on coarse sandy soils.

Caution Weed control may vary if incorporation is delayed more than 4 hours after application. Do not apply benefin to soils that are subject to prolonged flooding, because poor weed control may result. In arid, irrigated areas, do not rotate to a small grain or other grass crop for 10 mo to avoid crop injury due to herbicide carryover. See label for additional crop rotation restrictions.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

EPTC (Eptam 7E or Eptam 20G)

Rate 2 to 4 lb ai/A (2.25 to 4.5 pints/A Eptam 7-E or 15 to 20 lbs/A Eptam 20-G)

Time Apply to a clean, residue-free seedbed before final disking and harrowing. Immediately incorporate into the top 2 to 3 inches of soil to prevent losing the herbicide. Whenever possible, apply and incorporate in the same operation. Incorporation in two directions is recommended for heavy soils and perennial grass weed control. Clovers may be seeded any time after EPTC is incorporated into the soil.

Remarks Controls annual and perennial grasses (e.g., quackgrass and common and German velvetgrasses) and certain broadleaf weeds.

Caution Temporary crop stunting and sealing of the first leaves will occur if clover germination conditions are not optimum. Do not use if a grass or small-grain nurse crop is to be planted with the clover. Do not use on white Dutch clover.

Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor

Chemical family Thiocarbamate

Established clover—soil residual

pendimethalin (several trade names)

Oregon and Idaho only

Rate 0.95 to 3.8 lb ai/A

Time Apply to established clover before weeds emerge and before clover is more than 6 inches high. Herbicide is most effective when incorporated into the weed germination zone by rain or irrigation within 7 days of application.

Remarks Special local needs labels ID-060017 and OR-070025 (for Stealth). Controls dodder, most annual grasses, and certain broadleaf weeds as they germinate, but will not control established weeds.

Caution Do not apply to seedling clover. Do not feed or graze clover after applying. Do not cut treated clover for hay or forage. Do not use harvested seed for sprouting. The seed producer must give a copy of the label to the seed conditioner. Processed seed must be labeled “not for human or animal consumption.” Refer to main labels for crop rotation restrictions.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

pronamide (Kerb 50 W or Kerb SC)

Rate 0.5 to 2 lb ai/A (1 to 4 lbs/A Kerb 50 W or 1.25 to 5 pints/A Kerb SC)

Time Apply after clover reaches the trifoliolate leaf stage. Results are best when applied under cool conditions (55°F or cooler) with rain following. Apply before soil freezes, and to fields where crop residues have been removed or evenly dispersed.

Remarks Controls annual grasses and volunteer cereals in new or established stands. Use higher rate for well-established grasses or volunteer grains. Does not control groundsel, hawksbeard, mayweed, and other members of the Asteraceae family.

Caution A restricted-use herbicide. Do not graze treated field, or harvest for forage, for 120 days after treatment. Do not plant field to cereals or to a grass crop immediately following clovers that were winter killed. See Kerb labels for crop rotation restrictions.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Benzamide

Dormant and semi-dormant applications

diuron (several trade names)

Western Oregon
Red clover only

Rate 1.6 lb ai/A

Time Apply when red clover is semi-dormant, from October 15 to December 15.

Remarks Controls annual grass and broadleaf weeds such as annual bluegrass, chickweed, hawksbeard, rattail fescue, annual ryegrass, and seedling velvetgrass.

Caution Apply to red clover only. Stands should be established at least 9 months and in vigorous condition. Do not replant to any crop within 1 year after application to limit potential for rotational crop injury.

Site of action Group 7: photosystem II inhibitor

Chemical family Substituted urea

oxyfluorfen (Goal 2XL)

Oregon (OR-050028) and Idaho (ID-100004) only, red and white clover

Rate 0.03 to 0.09 lb ai/A (2 to 6 fl oz/A Goal 2XL)

Time Apply to established dormant clover from December 1 to February 15.

Remarks Controls broadleaf weeds including common mallow, groundsel, filaree, henbit, and speedwell.

Caution Apply to red and white clover for seed only. Apply preemergence or up to six-leaf stage of weeds. Do not feed or graze clover after applying. Do not cut treated clover for hay or forage. Do not use harvested seed for sprouting. Processed seed must be labeled “not for human or animal consumption.” Do not rotate to a small grain crop for 10 months, to avoid crop injury due to herbicide carryover. See label for additional crop rotation restrictions.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Diphenylether

pelargonic acid (Scythe)

Rate Apply a 3% to 10% solution (v/v) in a 75 to 200 gal/A spray solution.

Time Apply when clover is dormant to control actively growing weeds. All partially green foliage will be killed or stunted, but activity may be limited with cool weather after application.

Remarks Use higher rates to control perennial weed species or when maximum vegetative burndown is desired. Adequate spray coverage is essential to maximize activity. Scythe is not translocated throughout plants, and is a nonselective contact material.

Caution Do not apply Scythe through any type of irrigation equipment. There are no grazing, feeding, or plant back restrictions associated with Scythe applications.

Site of action Group 26: unknown

Established clover—postemergence grass control

clethodim (several trade names)

Rate 0.094 to 0.25 lb ai/A

Time Apply to actively growing annual or perennial grasses at the appropriate stage of grass growth as indicated on label.

Remarks For grass weed control only. See label for specific rates, weed species, and weed size. Always add a crop oil concentrate at 1% v/v in the finished spray volume. Control may be erratic on grasses stressed by conditions such as drought, temperature extremes, and insect and herbicide damage. Do not apply if rain is expected within 1 hour of application.

Caution Do not exceed 0.25 lb ai/A of clethodim per season. Adding fertilizer to spray solution is not recommended. Preharvest interval is 15 days. Do not use on clover when soil pH is 5.5 or less. See individual labels for restrictions on livestock grazing and feeding, and cutting for forage or hay.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione

fluazifop-P butyl (Fusilade DX)

Idaho (ID-950006) only

Rate Up to 0.31 lb ai/A (up to 20 fl oz/A Fusilade DX)

Time Make first application (12 fl oz/A) when quackgrass is 6 to 10 inches high. A second application may be made (8 fl oz/A) 2 to 3 weeks after the first, but before quackgrass exceeds 10 inches high.

Remarks For selective quackgrass control in clover grown for seed in Idaho, always add a crop oil concentrate at 1% v/v.

Caution Do not feed or graze clover after applying. Do not cut treated clover for hay or forage. The seed producer must give a copy of the label to the seed conditioner. Processed seed must be labeled “not for human or animal consumption.” Refer to main label for crop rotation restrictions.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxy propionate

sethoxydim (several trade names)

Rate 0.19 to 0.47 lb ai/A

Time Apply to actively growing annual or perennial grasses at growth stage listed on label.

Remarks For grass control only. Most effective on actively growing grasses. See labels for specific rates, weed species, and weed size. Will not control annual bluegrass or fine fescues, and is weak on downy brome and quackgrass. Always add a crop oil concentrate at 2 pints/A.

Caution Control may be erratic on grasses stressed by drought, temperature extremes, insect damage, herbicide injury, or other factors. Do not apply if rain is expected within 1 hour after application. Do not exceed 1.2 lb ai/A per season. See individual labels for restrictions on livestock grazing and feeding, and cutting for forage or hay.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione

Established clover—postemergence broadleaf control

bentazon (Basagran)

Oregon and Washington only

Rate Up to 1 lb ai/A (up to 2 pints/A Basagran)

Time Apply in spring to young, actively growing weeds in crimson, red and white clover grown for seed in Washington and Oregon.

Remarks Controls certain broadleaf weeds and sedges soon after emergence. For consistent control, add a nonphytotoxic crop oil concentrate. Some clover leaf burning may occur, but symptoms generally are outgrown within 10 days of treatment.

Caution Thorough coverage is necessary for adequate weed control. Do not apply to stressed clover. Do not graze livestock or harvest forage or hay for at least 36 days after treatment. Do not exceed 4 pints/A Basagran per year.

Site of action Group 6: photosystem II inhibitor

Chemical family Benzothiadiazole

MCPA amine (several trade names)

Rate See individual product labels for appropriate rate, but generally 0.23 to 0.46 lb ae/A

Time Apply to arrowleaf, crimson, red and white clover (except Dutch). Treat seedling stands after they have 2 or more true leaves (trifoliate stage). Apply in late fall or early spring to established stands when weeds are small and clover is semi-dormant, before active growth starts.

Remarks To control broadleaf weeds in seedling and established stands of clover.

Caution Older, established clover stands may show stem twisting injury after application, which may reduce growth. Do not apply to Dutch white clover or sweet clover. The air temperature at time of application should be above 40°F to maximize weed control efficacy. Do not forage or graze treated areas for 7 days after treatment and review individual product labels for additional feeding and grazing restrictions.

Site of action Group 4: synthetic auxin

Chemical family Phenoxy acetic acid

Established clover—postemergence grass and broadleaf control

imazamox (Raptor) + bentazon (Basagran)

Oregon and Washington only

Rate 0.04 lb ai/A (5 fl oz/A Raptor) + 0.25 to 0.5 lb ai/A (8 to 16 fl oz/A Basagran)

Time Apply when crimson, red or white clover has at least two trifoliolate leaves and most weeds are 1 to 3 inches tall. Imazamox applications to clover grown for seed must be made before bloom.

Remarks Applications of imazamox to clover grown for seed require adding surfactant, nitrogen fertilizer, and Basagran herbicide. Use a nonionic surfactant with at least 80% ai at 0.25% v/v (1 quart/100 gal spray solution). Apply to red, white, and crimson clover only.

Caution Application of more than 16 fl oz/A of Basagran in the tank mix may reduce grass control. When using Raptor plus Basagran, always follow the more restrictive label. Do not apply Raptor more than once per growing season. Imazamox use on crimson, red, or white clover may cause crop injury or loss when applied at the 5 oz/A rate to stressed clover. See additional use cautions on Raptor label including crop rotation intervals.

Site of action (imazamox) Group 2: acetolactate synthase (ALS) inhibitor; (bentazon) Group 6: photosystem II inhibitor

Chemical family (imazamox) Imidazolinone; (bentazon Benzothiadiazole

imazethapyr (Pursuit)

Rate 0.05 to 0.094 lb ai/A (3 to 6 fl oz/A Pursuit)

Time Apply to seedling clover that has at least two to three trifoliolate leaves, and when most weeds are 1 to 3 inches tall. Imazethapyr may be applied to established clover in the fall, and in spring to dormant or semi-dormant clover less than 3 inches tall. Imazethapyr applications to clover grown for seed must be made before bloom.

Remarks Applications of imazethapyr to clover grown for seed require adding surfactant and nitrogen fertilizer. Use a nonionic surfactant with at least 80% ai at 0.25% v/v (1 quart/100 gal spray solution).

Caution Do not feed, graze, or harvest clover within 30 days of applying imazethapyr.

Site of action Group 2: acetolactate synthase (ALS) inhibitor

Chemical family Imidazolinone

paraquat (several trade names)

Rate 0.26 to 0.78 lb ai/A

Time Apply to fall-planted, newly established, or well-established stands between November 15 and January 15, when crop is dormant and before spring growth starts.

Remarks To control winter annual grasses and broadleaf weeds in red and white clover. Add 1 to 2 pints of a nonionic surfactant or 1 gallon crop oil concentrate per 100 gal water. For dense stands of grass, paraquat plus pronamide provides better control than paraquat alone. Green foliage on crop at time of application will be burned.

Caution A restricted-use herbicide. Do not graze or harvest treated forage for 60 days after applying. Do not apply more than once per season. When applying to fall-planted red clover in its first winter, or to red clover planted with a nurse crop the previous spring use the lowest labeled rate. Do not apply if re-growth after grazing or cutting is more than 2 inches tall.

Site of action Group 22: photosystem I electron diversion

Chemical family Bipyridilium

Preharvest foliage desiccation

diquat (several trade names)

Rate 0.37 to 0.5 lb ai/A

Time For preharvest foliage desiccation, when clover seeds are mature.

Remarks Seed crops only. Desiccation is complete in 3 to 10 days.

Caution Do not graze or feed treated forage to livestock. Do not use seed from treated plants for food, feed, or oil.

Site of action Group 22: photosystem I electron diversion

Chemical family Bipyridilium

paraquat (Firestorm)

Idaho (ID-080009) only

Rate 0.64 to 1.0 lb ai/A (1.7 to 2.7 pints/A Firestorm)

Time For preharvest foliage desiccation, when clover seeds are mature. Do not harvest clover seed until at least 4 days after application.

Remarks Do not make more than 2 applications per year.

Caution A restricted-use herbicide. Do not graze or feed treated forage and screenings to livestock. Do not use seed from treated plants for food, feed, or oil. All processed clover seed must be tagged “not for human consumption.” The grower is responsible for informing the processing facility that the clover was treated with paraquat. Do not apply Firestorm through any type of irrigation equipment.

Site of action Group 22: photosystem I electron diversion

Chemical family Bipyridilium