Preplant Incorporated

imazethapyr (Pursuit)

Rate Consult labels.

Time Apply only once per year. Preharvest interval is 6 days for peas. See label about planting rotation crops.

Remarks Registered only in certain eastern Oregon and Washington counties, and in Idaho.

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)

Supplemental label (Oregon, Washington, Idaho)

Rate 0.017 lb ai/a (0.75 fl oz/a Sharpen)

Time Apply early preplant, preplant incorporated or preemergence for limited residual broadleaf weed control.

Remarks There are no university data for use of this product in the PNW. 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 lb per 100 gal, are required for satisfactory control of emerged weeds. An early preplant application of Sharpen at 0.75 fl oz/a can be made prior to 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

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

triallate (Far-Go) + trifluralin

Rate 1.25 lb ai/a + 0.375 lb ai/a, respectively

Time Apply within three weeks of planting. Incorporate within 24 hr, using disk or spike-tooth harrow.

Remarks Provides better control of wild oat at a lower rate of trifluralin.

Caution Do not use foliage from treated peas for feed or forage. Peas may show leaf crinkling and delayed maturity, particularly on heavy soils.

Site of action (triallate) Group 8: lipid synthesis inhibitor but not an ACCase inhibitor; (trifluralin): Group 3: microtubule assembly inhibitor

Chemical family (triallate) thiocarbamate; (trifluralin) dinitroaniline

triallate + trifluralin (Buckle)

Rate 10 to 12 lb/a granular

Remarks Follow label directions and note comments above.

Site of action (triallate) Group 8: lipid synthesis inhibitor but not an ACCase inhibitor; (trifluralin): Group 3: microtubule assembly inhibitor

Chemical family (triallate) thiocarbamate; (trifluralin) dinitroaniline

trifluralin (several trade names)

Rate 0.5 to 0.75 lb ai/a (1 to 2 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