Peas (Dry)
PEAS, DRY—Annual Grass and Broadleaf Weeds
Preplant incorporated
ethalfluralin (Sonalan)
Rate 0.56 to 0.75 lb ai/A (1.5 to 2 pints/A Sonalan HFP)
Time Apply preplant and incorporate by following label instructions.
Caution Do not exceed labeled rates because crop may be injured. Do not graze or plant forage crop in treated soil or cut for hay or silage. For use only in dry peas.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
imazethapyr (Pursuit)
Rate 0.047 lb ai/A (3 oz/A of Pursuit)
Time Apply preplant and incorporate within 30 days before planting.
Remarks Do not incorporate deeper than 3 inches. A maximum of 0.047 lb ai/A may be applied to peas.
Caution Do not apply more than once per year. Preharvest interval is 60 days. Consult label restrictions regarding planting subsequent crops.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
pendimethalin (Prowl 3.3EC, Stealth, Prowl H2O, and others)
Rate 0.5 to 1.5 lb ai/A (1.2 to 3.6 pints/A Prowl) or 0.7 to 1.4 lb ai/A (1.5 to 3 pints/A Prowl H2O). Use the lower rate on coarse soils, the higher rate on fine soils.
Time Apply up to 60 days preplant and incorporate by following label instructions.
Remarks Incorporate thoroughly, 1 to 2 inches deep. Apply in at least 10 gal/A water or in 20 gal/A or more liquid fertilizer. Also controls several broadleaf weed species.
Caution Do not apply to pea or lentil forage, silage, hay, or straw grown for feed. Do not apply through any type of irrigation system.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
sulfentrazone (Spartan 4F)
Rate 0.07 to 0.25 lb ai/A (2.25 to 8 fl oz/A Spartan 4F)
Time Apply preplant incorporated or preemergence in the spring before crop germinates.
Remarks See current label for appropriate use areas. Use rate dependent on soil texture and organic matter. Consult label for use rates for specific soil type. PNW data suggest that use rates above 4.5 fl oz/A may cause injury to dry peas. Do not incorporate to depths greater than 2 inches. Do not apply after crop emerges, or if seedlings are near soil surface. Do not apply to frozen soil.
Caution Do not exceed 8 fl oz/A per year. Preharvest interval is 60 days. See label before planting subsequent crops.
Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor
Chemical family Triazinone
triallate (Far-Go)
Rate 1.5 lb ai/A (3 pints/A)
Time Apply preplant or postplant and incorporate.
Remarks Incorporate thoroughly 1 to 2 inches deep. Do not graze treated areas. For control of wild oats, only.
Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family Thiocarbamate
trifluralin (Treflan and others)
Rate 0.5 to 0.75 lb ai/A (1 to 2 pints/A Treflan HFP)
Time Apply preplant and incorporate. May be fall-applied.
Remarks Incorporate thoroughly, 2 to 3 inches deep, immediately after applying. Use lower rate on coarse soils. Controls some broadleaf weeds; weak on nightshade, mustard, and mayweed.
Caution Consult label about planting subsequent crops. Trifluralin may injure stressed crop seedlings.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
trifluralin + triallate (Buckle)
Rate 0.3 to 0.38 lb ai/A trifluralin + 1 to 1.25 lb ai/A triallate as Buckle (10 to 12.5 lb/A Buckle)
Time Apply preplant and incorporate.
Remarks Buckle is a granular formulation of two herbicides. Incorporate thoroughly, 1 to 2 inches deep, immediately after application. Use the lower trifluralin rate for coarse soils. See remarks in trifluralin entry in this section. Do not use foliage from treated peas for feed or forage.
Caution Consult label about planting subsequent crops.
Site of action (trifluralin) Group 3: microtubule assembly inhibitor; (triallate) Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family (trifluralin) dinitroaniline; (triallate) thiocarbamate
Preemergence
imazethapyr (Pursuit)
Rate 0.047 lb ai/A (3 oz/A of Pursuit)
Time Apply from immediately after, or up to three days after planting.
Remarks Do not apply more than once per year. Preharvest interval is 60 days
Caution Consult label restrictions regarding planting subsequent crops.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
S-metolachlor (Dual Magnum or Dual II Magnum)
Rate 0.95 to 1.90 lb ai/A (1 to 2 pints/A Dual Magnum)
Time Apply preplant incorporated or preemergence.
Remarks Application rate depends on soil type and organic matter content.
Caution Preharvest interval for hay is 120 days.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide
sulfentrazone + S-metolachlor (Broadaxe)
Rate 0.1 to 0.2 lb ai/A sulfentrazone + 0.94 to 1.88 lb ai/A S-metolachlor (19 to 38 fl oz/A Broadaxe).
Time Apply fall or spring as preplant or preemergence.
Remarks Consult label to determine rate for soil’s percentage of organic matter, and texture. Consult label for specific crop rotation restrictions.
Caution Do not apply to coarse textured soils with less than 1% organic matter. Adequate rainfall is required for herbicide activation from rainfall. If activating moisture is not received within 7 to 10 days after application, a shallow incorporation may be needed to obtain adequate weed control. Do not incorporate to depths greater than 2 inches. Do not apply to frozen soils. Do not use for forage within 60 days after an application. Do not cut for hay within 120 days after application.
Site of action Group 14: protoporphyrinogen oxidase inhibitor; Group 15: inhibits very long chain fatty acid synthesis
Chemical family Triazolinone; Chloroacetamide
PEAS, DRY—Annual and Perennial Grass Weeds
Postemergence
clethodim (Clethodim 2E, Intensity, and other products)
Rate 0.093 to 0.125 lb ai/A (6 to 8 fl oz/A Clethodim 2E)
Time After grasses emerge. See label for details.
Remarks Controls annual and perennial grasses. Always use a petroleum-based crop oil at 1 gal/100 gal.
Caution Do not exceed 8 fl oz/A per season. Do not apply more than one application per season. Do not graze. Apply before bloom but not later than 30 days prior to harvest. Application during bloom period may injure crop.
Site of action Group 1: acetyl CoA Carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione
quizalofop P-ethyl (Assure II or Targa)
Rate 0.04 to 0.08 lb ai/A (6 to 12 fl oz/A Assure II)
Time After grasses emerge. See label for details.
Remarks Controls annual and perennial grasses. Always use either a nonionic surfactant at 1 quart/100 gal, or a petroleum-based crop oil at 1 gal/100 gal.
Caution Do not exceed 14 fl oz/A per season. Preharvest interval is 60 days. Do not graze livestock in treated areas or feed forage, hay, or straw from treated areas.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Aryloxyphenoxy propionate
sethoxydim (Poast)
Rate 0.19 to 0.48 lb ai/A (1 to 2.5 pints/A Poast)
Time Apply to actively growing grasses listed on label. Add 2 pints/A nonphytotoxic crop oil concentrate for ground application to improve leaf penetration.
Remarks Ask knowledgeable people about susceptible grasses in your area. Control may be erratic if grasses are stressed from lack of vigor, drought, or high temperature. Fine fescues and annual bluegrass resist treatment; quackgrass is suppressed.
Caution Preharvest interval is 30 days. Do not exceed 4 pints/A product per year. Do not mix or apply with any other pesticide, additive, or fertilizer except as directed on the label.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione
PEAS, DRY—Annual Broadleaf Weeds
Preemergence
metribuzin (several product names)
Rate 0.1875 to 0.375 lb ai/A (4 to 8 oz of a 75% DF product/A).
Time Apply before or after planting, but before crop emerges.
Remarks Rain or mechanical incorporation is needed to suppress weeds. Under dry conditions, incorporate 1 to 2 inches. Apply in 10 gal/A or more of water for ground equipment or 5 gal/A or more for aerial spray equipment.
Caution Do not apply on seedings less than 2 inches deep. Do not use on clay knobs or poorly covered subsoils. Do not use on coarse soils or soils with less than 1.5% organic matter. Heavy rain after application may injure crop. This treatment may cause some chlorosis or minor necrosis. Preharvest interval is 50 days for dry peas, 120 days for hay.
Site of action Group 5: photosystem II inhibitor
Chemical family Triazinone
saflufenacil (Sharpen)
Rate 0.022 to 0.044 lb ai/A (1.0 to 2.0 fl oz/A Sharpen)
Time Apply early preplant, preplant incorporated or preemergence for limited residual broadleaf weed control.
Remarks Sharpen controls mainly broadleaf weeds. Methylated seed oil (MSO) or crop oil concentrate (COC), at 1% v/v + ammonium sulfate (AMS) at 8.5 to 17 lbs/100 gal of water, are required for satisfactory control of emerged weeds. An early preplant application of Sharpen at 1.0 to 2.0 fl oz/A can be made prior to a PPI or preemergence application. Sequential applications must be at least 30 days apart.
Caution Do not substitute a nonionic surfactant for MSO or COC as control of emerged weeds will suffer. Do not exceed 2.0 fl oz/A during the cropping season. Do not apply when the peas have reached the cracking stage, or after emergence, because severe crop injury will occur. Legume forage may be fed or grazed 65 or more days after application.
Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor
Chemical family Uracil
Postemergence
bentazon (Basagran)
Rate 0.5 to 1 lb ai/A (1 to 2 pints/A Basagran)
Time Peas tolerate bentazon after three-leaf (or four-node) stage. Apply to small, actively growing annual broadleaf weeds as per label. Do not apply to peas in bloom. For Canada thistle and yellow nutsedge, use higher rate and apply twice, 7 to 10 days apart.
Remarks Avoid applying bentazon during prolonged cold weather; weed control may be nullified. One quart/A (by ground) or 1 pint/A (by air) of crop oil concentrate improves control. Crop may show temporary symptoms under certain environmental conditions. Preharvest interval is 30 days. Do not exceed 2 lb ai/A per year. Do not cultivate within five days before or after applying.
Site of action Group 6: photosystem II inhibitor
Chemical family Benzothiadiazole
imazamox (Raptor)
Rate 0.031 lb ai/A (4 oz/A Raptor)
Time Apply to dry peas with at least three pairs of leaves before blooming.
Remarks Apply with nonionic surfactant at 1 quart/100 gal. In dry peas, always apply 6 to 16 oz/A Basagran to minimize potential for crop response. Only one application of Raptor may be made during the season.
Caution Read and observe all precautions on the label to ensure maximum crop safety. Consult label restrictions regarding planting subsequent crops.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
MCPA sodium salt or dimethylamine salt (Chiptox, MCPA amine 4, or other names)
Rate 0.125 to 0.375 lb ae/A (0.5 to 1.5 pint/A Chiptox; 0.25 to 0.75 pint/A MCPA amine). Lower the rate as temperature increases.
Time Apply when peas are 4 to 6 inches tall and weeds are less than 2 inches wide or 3 inches high.
Remarks Do not apply when peas are blooming. Peas may show slight injury, but usually recover a few days after treatment. Not recommended for use in western Washington.
Caution Do not apply when the temperature is expected to reach 90°F within the next 24 hours. Do not permit MCPA to drift off target. Do not graze or feed.
Site of action Group 4: synthetic auxin
Chemical family Phenoxy acetic acid
metribuzin (several product names)
Rate 0.125 to 0.25 lb ai/A (2.6 to 5.3 oz/A of a 75% DF product)
Time Apply only once per season to susceptible broadleaf weeds less than 2 inches tall or wide.
Remarks Temporary chlorosis of the crop may occur, particularly under moist conditions or if a postemergence application follows a preemergence metribuzin herbicide application. Weed control may be reduced if dry conditions persist after treatment.
Caution Do not use on clay knobs or poorly covered subsoils. Do not use on coarse soils or soils with less than 1.5% organic matter. Heavy rain after application may injure crop. Preharvest interval is 50 days for dry peas, 40 days for hay. Do not exceed 0.5 lb ai/A metribuzin per crop year.
Site of action Group 5: photosystem II inhibitor
Chemical family Triazinone
PEAS, DRY—Canada Thistle and Annual Broadleaf Weeds
MCPB (Thistrol)
Rate 0.5 to 1.5 lb ae/A (2 to 6 pints/A). Use higher rate during cool weather.
Time Apply when peas have six to twelve nodes, but before flower buds form, and Canada thistle is 4 to 10 inches tall.
Remarks Canada thistle is only suppressed and usually re-grows.
Caution Do not permit MCPB to drift off target. Do not feed peas or vines to livestock. Do not apply if temperature is expected to exceed 85°F within the next 24 hours. Do not spray peas under moisture stress.
Site of action Group 4: synthetic auxin
Chemical family Phenoxy acetic acid