Preharvest Weed Control

2,4-D (several trade names)

Rate 0.5 to 1.4 lb ae/a

Time Apply when grain is in the hard dough stage, and the green color is gone from stem nodes.

Remarks Controls weeds that will interfere with harvest, and suppresses perennial weeds. Preharvest interval is 7 days.

Caution Do not apply to winter wheat grown for seed.

Site of action Group 4: synthetic auxin

Chemical family Phenoxy acetic acid

carfentrazone (Aim EC)

Rate 0.016 to 0.031 lb ai/a (1 to 2 oz/a Aim EC)

Time Apply when winter wheat is mature and the grain has begun to dry down.

Remarks A nonionic surfactant, methylated seed oil, or crop oil concentrate is required. Good spray coverage is essential for satisfactory weed control. Repeat application if necessary.

Caution See label for tank mixing guidelines, precautions, and crop rotation restrictions.

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

Chemical family Triazinone

dicamba (several trade names)

Rate 0.25 lb ae/a

Time Apply when grain is in the hard dough stage, and the green color is gone from stem nodes.

Remarks To control weeds that will interfere with harvest or to suppress perennial weeds. Not all dicamba labels include this use. Preharvest interval is 7 days.

Caution Do not apply to winter wheat grown for seed.

Site of action Group 4: synthetic auxin

Chemical family Benzoic acid

dicamba (several trade names) + 2,4-D (several trade names)

Rate 0.25 lb ae dicamba/a + 0.5 to 1 lb ae/a 2,4-D

Time Apply when grain is in the hard dough stage and the green color is gone from stem nodes.

Remarks To control weeds that will interfere with harvest or to suppress perennial weeds. Preharvest interval is 7 days. Not all dicamba labels include this use.

Caution Do not apply to winter wheat grown for seed.

Site of action (both) Group 4: synthetic auxin

Chemical family (dicamba) benzoic acid; (2,4-D) phenoxy acetic acid

flumioxazin (Valor)

Rate 0.0478 to 0.0637 lb ai/a (1.5 to 2.0 oz/a Valor)

Time Valor may be applied as a harvest aid to winter wheat when the grain has reached physiological maturity (hard dough stage), and has no more than 30% moisture. Tank mixing Valor with glyphosate is recommended for harvest aid applications.

Remarks Valor should be applied with an MSO + AMS or UAN adjuvant system in a minimum volume of 10 gal/a to optimize desiccation of the winter wheat and any weeds present.

Caution Winter wheat may be harvested 10 days after a harvest aid application of Valor.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family N-phenylphthalimide

glyphosate (several trade names)

Rate 0.38 to 0.75 lb ae/a

Time Apply when grain is in the hard dough stage, and the green color is gone from stem nodes.

Remarks To control weeds that will interfere with harvest or to suppress perennial weeds. Add an 80% ai nonionic surfactant. Preharvest interval is 7 days. Not all glyphosate labels include this use.

Caution Do not apply to winter wheat grown for seed.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

saflufenacil (Sharpen powered by Kixor herbicide)

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

Time Apply only to wheat that has reached physiological maturity (hard-dough stage; grain contains less than 30% moisture). Allow 7 days for optimum desiccation effect depending on environmental conditions.

Remarks A methylated seed oil plus ammonium-based adjuvant system is required for optimum desiccation activity and weed control. See label for more information on adjuvants and tank-mixes.

Caution Do not apply more than a maximum cumulative amount of 2.0 oz/a of Sharpen per cropping season for desiccation purposes. Do not apply Sharpen on wheat (all types) grown for seed production.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Pyrimidinedione