Annual and Perennial Grass Weeds


clethodim (Select Max and other trade names)

Rate 0.068 to 0.121 lb ai/a (9 to 16 oz/a Select Max)

Time Apply postemergence to actively growing grasses. See label for details.

Remarks Apply with an approved nonionic surfactant at 0.25% v/v.

Caution Do not exceed 16 oz/a per season. Do not apply more than one application per season. 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

pronamide (Kerb SC and other trade names)

Winter pea only

Rate 0.75 to 1.5 lb ai/a (2 to 3.5 pints/a Kerb SC)

Time November to January, when peas are in the second node (2 to 3 inches).

Remarks Ground sprayer only; apply in at least 20 gal/a water. If weeds are larger than 3 inches, use the higher rate.

Caution A restricted-use herbicide. Protective measures required for applicator. Do not feed, or allow animals to graze vines, after treatment. Do not make more than one treatment per season.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Benzamide

quizalofop-P (Assure II and other trade names)

Rate 0.04 to 0.08 lb ai/a (6 to 12 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 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 Aryloxyphenoxypropionate

sethoxydim (Poast and other trade names)

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