Preplant surface, preplant incorporated, or preemergence
sulfentrazone + pyroxasulfone (Authority Supreme)
Rate 0.141 to 0.5 oz ai/A (4.3 to 15.4 oz/A Authority Supreme)
Time May be applied in the fall for crops planted in the fall or for crops planted the following spring. In spring, may be applied from 30 days before planting up to 3 days after planting.
Remarks In early preplant and fall applications, Authority Supreme can be applied in sequential programs, but do not exceed the maximum use rate per year. Where weeds are emerged, use appropriate tank mixtures for control of the weed species present. Crop seeds must be planted at least 1 inch deep. Do not incorporate greater than 2 inches deep.
Caution Some adverse crop response may occur on coarse textured soils with low organic matter (less than 1.5%) and pH of 7.8 or higher, or on highly eroded soils, or in areas of calcareous outcroppings. Authority Supreme use rates should be reduced in those areas. Inadequate seed furrow closure or shallow planting (less than 1 inch) may result in undesirable crop response. Verify selectivity of Authority Supreme on your variety before applying to avoid injury to sensitive varieties.
Site of action (sulfentrazone) Group 14: protoporphyrinogen oxidase inhibitor; (pyroxasulfone) Group 15: inhibits very long chain fatty acid synthesis
Chemical family (sulfentrazone) Aryl triazinone; (pyroxasulfone) Isoxazoline
Preplant incorporated
ethalfluralin (Sonalan HFP)
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 Not all pea varieties are tolerant. 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.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
imazethapyr (Pursuit and other trade names)
Rate 0.047 lb ai/A (3 oz/A 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 3.3 EC, Prowl H2O, and other trade names)
Rate 0.75 to 1.5 lb ai/A (1.8 to 3.6 pints/A Prowl 3.3EC; 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
pendimethalin + metribuzin (Tripzin ZC)
Rate 0.91 to 1.375 lb ai/A (29 to 44 oz/A Tripzin ZC).
Time Apply up to 60 days preplant and incorporate within 7 days of application. Do not apply more than once per cropping season. Do not apply when the air temperature is below 45°F.
Remarks Apply in 10 to 40 gal/A water.
Caution Do not use on coarse-textured soils, sandy soils, or soils with less than 1.5% organic matter.
Site of action (pendimethalin) Group 3: microtubule assembly inhibitor; (metribuzin) Group 5: photosystem II inhibitor
Chemical family (pendimethalin) Dinitroaniline; (metribuzin) Triazine
triallate (Far-Go or Avadex MicroActiv)
Rate 1.5 lb ai/A (1.5 quarts/A Far-Go or 15 lb/A Avadex MicroActiv))
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 HFP and other trade names)
Rate 0.5 to 0.75 lb ai/A (1 to 1.5 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 MicroActiv)
Rate 0.3 to 0.36 lb ai/A trifluralin + 1 to 1.2 lb ai/A triallate (10 to 12.5 lb/A Buckle MicroActiv)
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
Preplant incorporated or preemergence
S-metolachlor (Dual Magnum and other trade names)
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 Do not exceed an incorporation depth of 2 to 3 inches. Preharvest interval for hay is 120 days.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide
sulfentrazone (Spartan 4F and other trade names)
Rate 0.07 to 0.25 lb ai/A (2.25 to 8 oz/A Spartan 4F)
Time Apply preplant incorporated (spring only) or early preplant in the fall or spring up to 3 days after planting as a preemergence application.
Remarks See current label for appropriate use areas. Use rate depends on soil texture and organic matter. Consult label for use rates for specific soil type. PNW data suggest that use rates above 4.5 oz/A may cause injury to dry peas.
Caution Do not exceed 8 oz/A per 12-month period. See label before planting subsequent crops. 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.
Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor
Chemical family Aryl triazinone
Preplant surface or preemergence
sulfentrazone + carfentrazone (Spartan Charge)
Rate 0.074 to 0.251 lb ai/A sulfentrazone + 0.008 to 0.028 lb ai/A carfentrazone (3.0 to 10.2 oz Spartan Charge)
Time Apply fall or spring as preplant or preemergence.
Remarks Consult label to determine rate for soil pH, percentage of organic matter, and texture. Consult label for specific crop rotation restrictions.
Caution Do not exceed 0.28 lb ai (10.2 oz) Spartan Charge per 12-month period. Do not apply after crop emerges or if seedlings are near soil surface. Do not apply on sandy soils with less than 1% organic matter. Do not apply to frozen soil. Do not incorporate as this can destroy the herbicide barrier.
Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor.
Chemical family Aryl triazinone
sulfentrazone + S-metolachlor (Spartan Elite and other trade names)
Rate 0.1 to 0.2 lb ai/A sulfentrazone + 0.94 to 1.88 lb ai/A S-metolachlor (19 to 38 oz/A Spartan Elite)
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 (sulfentrazone) Group 14: protoporphyrinogen oxidase inhibitor; (S-metolachlor) Group 15: inhibits very long chain fatty acid synthesis
Chemical family (sulfentrazone) Aryl triazinone; (S-metolachlor) Chloroacetamide
Preemergence
diuron (Diuron 4L and other trade names)
Austrian field pea only and only in western Oregon
Rate 1.2 to 2.6 lb ai/A (1.2 to 2.6 quarts/A Diuron), depending on soil type
Time Apply as soon as possible after planting and before crop emerges.
Remarks Diuron will only control certain weeds, consult label. Do not apply on sand, sandy loam, or gravelly soils. Aerial application is prohibited.
Caution Crop injury may result if soil organic matter is less than 1%. Consult label for other restrictions.
Site of action Group 7: Photosystem II inhibitor
Chemical family Urea
imazethapyr (Pursuit and other trade names)
Rate 0.047 lb ai/A (3 oz/A Pursuit)
Time Apply from immediately after, or up to 3 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
linuron (Lorox DF)
Rate 0.5 to 1.0 lb ai/A (1 to 2 lb/A Lorox DF)
Time Apply after planting but preemergence to the crop.
Remarks Use lower rates on coarse-textured soils and higher rates on heavier-textured soils. For Idaho and Washington only: winter wheat and winter barley may be planted 4 months after application; do not apply more than 1.25 lb/A Lorox DF if the field will be rotated to winter wheat or winter barley in the fall or winter and average annual precipitation is less than 16 inches; do not plant any other crop (including spring wheat, spring barley, or canola) until 12 months after the last Lorox DF application as crop injury may result.
Caution Do not apply to sand or loamy sand soil types or to soils with less than 1% organic matter.
Site of action Group 7: photosystem II inhibitor
Chemical family Urea