Seedbed Preparation

carfentrazone (Aim EC)

Rate Up to 0.031 lb ai/A (0.5 to 2 fl oz/A Aim EC)

Time Before planting or up to 24 hours after planting. Apply to actively growing weeds up to 4 inches tall and to rosettes less than 3 inches across.

Remarks See label for specific tank-mixes and adjuvant recommendations. Good spray coverage is essential for control.

Caution Do not exceed 0.093 lb ai/A of Aim EC per growing season.

Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor

Chemical family Triazinone

glyphosate (several trade names)

Rate 0.5 to 3.75 lb ae/A

Time Apply to actively growing weeds.

Remarks Use higher application rates if weeds are over 6 inches tall. Apply 1.5 to 3.75 lb ae/A for perennial weed control. Delay tillage 3 days after treating annual weeds, at least 7 days after treating perennials. Refer to specific product label for direction on adding surfactants and for plant-back restrictions for grass seed crops.

Caution Do not graze or use feed from treated areas for 8 weeks after application.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

paraquat (several trade names)

Rate 0.5 to 1 lb ai/A

Time Apply from late November to December, in preparation for planting grasses in the spring. Seed between February 15 and March 15 on non-irrigated land.

Remarks Use 1 to 2 pints of nonionic surfactant or 1 gallon of crop oil concentrate per 100 gal spray mixture. If weather prevents treating in December, applications may be made into January (two applications may be needed for large weeds). If more weeds germinate after December treatments, paraquat may be applied up to the time the crop emerges if seed is well covered by soil. Apply to weeds in the three- to five-leaf stage.

Caution A restricted-use herbicide. Treatment controls only seedling weeds. Cultivate fields up to October 15 to mechanically control established weeds. Do not graze treated areas for livestock feed. Do not use straw from treated areas for animal bedding or feed. Use 2,4-D, dicamba, or bromoxynil for weed control later in the crop year.

Site of action Group 22: photosystem I electron diversion

Chemical family Bipyridilium

pyraflufen (several trade names)

Rate 0.001 to 0.006 lb ai/A

Time Apply to seedling weeds that are less than 4 inches tall or less than 3 inches in diameter if in the rosette stage 30 days before planting grass seed crops. The higher rate will be needed for difficult-to-control species such as kochia or field bindweed.

Remarks May be tank mixed with synthetic auxin herbicides and glyphosate to broaden the weed control spectrum. Always apply with a crop oil concentrate or nonionic surfactant for optimum activity.

Caution Do not exceed three applications of product during the preplant burndown period. Separate applications by 30 days. Do not graze treated areas.

Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor

Chemical family Phenylpyrazole

saflufenacil (Sharpen)

Rate 0.022 to 0.045 lb ai/A (1 to 2 fl oz/A Sharpen)

Time Apply preplant, preplant incorporated, or preemergence for burndown and residual broadleaf weed control while establishing cool-season grasses in the fall or spring.

Remarks A methylated seed oil plus ammonium sulfate or urea ammonium nitrate is required for burndown activity. See label for more information on adjuvants and tank-mixes.

Caution Do not exceed 6 fl oz/A per year. Sharpen may cause transitory injury to cool-season grasses under certain conditions.

Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor

Chemical family Pyrimidindione