Preharvest Weed Control

2,4-D (several trade names)

Rate 0.5 to 1 lb ae/a

Time Apply when barley is in hard dough stage to control weeds that will interfere with harvest.

Remarks Results are best when soil moisture is sufficient for active weed growth. Restricted entry interval (REI) is 12 hours for the low volatile ester (LVE) formulation and 48 hours for the amine formulation.

Caution Do not let 2,4-D drift off target. The preharvest interval is 14 days. Maximum of 1.75 lb ae (3.6 pints/a) per crop cycle. Limited to one preharvest application per crop cycle. Do not apply to fields underseeded to legumes.

Site of action Group 4: synthetic auxin

Chemical family Phenoxy acetic acid

carfentrazone (Aim EC)

Rate Apply up to 0.031 lb ai/a (apply up to 2 fl oz/a Aim 2EC)

Time Apply when crop is mature, and grain has begun to dry down. Do not apply within 7 days of harvest.

Remarks Use MSO or COC at 1 to 2 % v/v (1 to 2 gal/100 gal of spray solution) for harvest aid. A high-quality sprayable liquid nitrogen fertilizer may be used at 2% to 4% v/v (2 to 4 gal/100 gal spray solution) or ammonium sulfate (AMS) at 2 to 4 lb/a in addition to the NIS. Coverage is essential for satisfactory performance. Repeat application if necessary. Restricted entry interval (REI) is 12 hours.

Caution If applied as a tank-mixture, refer to the other product labels for restrictions on tank mixing, and follow all label precautions, instructions, and rotational cropping restrictions.

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

Chemical family Triazolone

glyphosate (several trade names)

Rate 0.75 lb ae/a

Time Apply after feed barley is in hard dough stage (less than or equal to 20% moisture).

Remarks Use on feed barley only. Preharvest application is not recommended for barley grown for seed. Be aware that glyphosate is formulated as 3 lb, 4 lb, 4.17 lb, 4.5 lb, and 5 lb ae/gal; be sure to use the correct amount of herbicide. Do not exceed 0.75 lb ae/a per season. Add 0.5 to 1% v/v (2 to 4 qt/100 gal spray solution) nonionic surfactant (NIS). Apply in 3 to 10 gal/a by air or ground. Preharvest interval is 7 days. Restricted entry interval (REI) is 4 hours.

Caution Do not let glyphosate drift off target. Do not use on malt barley or barley grown for seed because a reduction in germination or vigor may occur.

Site of action Group 9: inhibits EPSP synthase

Chemical family Glycine

metsulfuron (Ally XP) + 2,4-D or glyphosate

Rate 0.0375lb ai/a metsulfuron + 0.25 to 0.5 lb ae/a 2,4-D or 0.77 lb ae/a glyphosate (0.1 oz/a Ally 60XP)

Time Make applications after the crop has reached the hard dough stage, but no later than 10 days before harvest.

Remarks Used in combination with 2,4-D at 0.25 to 0.5 lb ai/a plus surfactant at 0.25 to 0.5% v/v (1 to 2 qt/100 gal spray solution) or glyphosate at 0.75 lb ae/a will typically aid in dry down of many broadleaf weeds. Weeds must be actively growing to be effective. Restricted entry interval (REI) is 4 hours.

Caution Do not use on soils above pH 7.9. Metsulfuron can persist in soil. Carefully follow label instructions regarding crop rotations. Many crops cannot be planted within 2 years or longer after applying. Do not use with glyphosate on malt barley or barley grown for seed because a reduction in germination or vigor may occur.

Site of action Group 2: acetolactate synthase (ALS) inhibitor

Chemical family Sulfonylurea

saflufenacil (Sharpen)

Rate 0.022 to 0.045 lb ai/a (1 to 2 fl oz/a Sharpen 2.85SC)

Time Apply only to barley that has reached physiological maturity (hard-dough stage; grain contains less than 30% moisture) or according to Extension Service recommendations in the use area. Allow up to 7 days for optimum desiccation effect depending on environmental conditions.

Remarks A methylated seed oil (MSO) plus ammonium-based adjuvant system is required for optimum desiccation activity and weed control. See label for more information on adjuvants and tank-mixes. Pre-harvest interval is 3 days. Restricted entry interval (REI) is 12 hours.

Caution Do not apply more than a maximum cumulative amount of 2.0 fl oz/a of Sharpen per cropping season from desiccation uses. Do not apply Sharpen on barley (all types) grown for seed production. Do not apply to barely grown for malting purposes.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Pyrimidindione