imazethapyr (Pursuit and others)
Rate 0.0469 lb ai/A (3 fl oz/A Pursuit)
Time Preplant incorporate within 1 week before planting. May apply up to one month before no-till planting.
Remarks Apply only once per year. Do not incorporate deeper than 3 inches. Crop rotation is 18 months for sweet corn, oat and sorghum, 26 months for potato.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
pendimethalin (several trade names)
Rate 0.7 to 1.4 lb ai/A (1.5 to 3.0 pints/A Prowl)
Time Apply and incorporate up to 60 days before planting. Rate depends on soil texture.
Remarks Thoroughly mix previous crop residue into soil 4 to 6 inches before applying.
Caution Do not apply more than once per season. Do not apply to pea forage, pea silage, pea hay, or pea straw grown for livestock feed.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
saflufenacil (Sharpen)
Rate 0.017 lb ai/A (0.75 fl oz/A Sharpen)
Time Apply preplant incorporated up to one week before planting. Do not incorporate deeper than 3 inches.
Remarks There are no university data for use of this product in the PNW. Methylated seed oil (MSO) or crop oil concentrate (COC), at 1% v/v + ammonium sulfate (AMS) at 8.5 to 17 lb per 100 gal, are required for satisfactory control of emerged weeds. 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. 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
triallate (Far-Go)
Rate 1.25 to 1.5 lb ai/A (2.5 to 3 pints/A)
Time Apply within three weeks of planting. Incorporate immediately, using a disk or spike-tooth harrow.
Remarks Controls wild oat and annual ryegrass. See label for crop rotation restrictions.
Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family Thiocarbamate
trifluralin (Treflan, Trust, and several others)
Rate 0.5 to 0.75 lb ai/A (1 to 1.5 pints/A), depending on soil texture
Time Apply preplant, and incorporate 1 to 2 inches deep within 24 hr, by cross-disking, rototilling, or cross-tilling with a field cultivator.
Remarks Spray only once per season. Avoid overlapping. Use lower rate on coarse soils. Peas have been stunted when maximum labeled rates were applied uniformly in fields with slight variations in soil type. Consult label for planting sensitive crops within 12 months.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline