Preplant and Preemergence Weed Control

carfentrazone (Aim EC)

Rate 0.008 to 0.031 lb ai/a (0.5 to 2 fl oz Aim 2EC)

Time Apply before, during, or after grain has been planted.

Remarks May be applied as a preplant burndown (up to 1 day before seeding), foliar broadcast or as a harvest-aid. Use a nonionic surfactant (NIS) at 0.25% v/v (2 pints/100 gal spray solution) having at least 80% active ingredient. 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. Tank-mixes with other herbicides will increase spectrum of control. Apply to actively growing weeds not more than 4 inches tall, or rosettes 3 inches in diameter. Thorough coverage is essential for good control. To avoid significant crop injury, do not apply within 6 to 8 hours of rain or irrigation or when heavy due is present. Restricted entry interval (REI) is 12 hours.

Caution Do not use Aim EC with crop oil concentrates (COC), methylated seed oil (MSO), or silicone-based adjuvants. Do not exceed 0.031 lb ai/a (2 fl oz Aim EC or EW) per crop season. Do not harvest for forage within 7 days after application.

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

Chemical family Triazolinone

glyphosate (several trade names)

Rate 0.375 to 0.75 lb ae/a

Time Apply before, during, or after planting barley but before barley emerges.

Remarks Prepare seedbeds as far ahead of application as possible to permit maximum weed emergence. Be aware that glyphosate is formulated as 3, 4, 4.17, 4.5, and 5 lb ae/gal; be sure to use the correct amount of herbicide depending on the formulation. Glyphosate may only be used as a spot treatment before heading in barley fields. Do not treat more than 10% of the field to be harvested. Some glyphosate products require adding a nonionic surfactant (NIS); be sure to check the product label. The addition of 1 to 2% ammonium sulfate (AMS) by weight or 8.5 to 17 lb/100 gal of water may increase the performance of glyphosate, particularly with hard water or when spraying during drought conditions. Restricted entry interval (REI) is 4 hours.

Caution Carefully check the entire field to ensure that no barley has begun to emerge. Do not allow glyphosate to drift off target.

Site of action Group 9: inhibits EPSP synthase

Chemical family Organophosphorus

paraquat (Gramoxone Inteon)

Rate 2 to 4 pints/a (0.25 to 1 lb ai/a Gramoxone Inteon 2SL)

Time Apply before, during, or after planting barley but before barley emerges.

Remarks It is essential to obtain complete coverage of target weeds to get good control. Results are best if a delay between tillage and planting allows weeds to emerge. Controls only annual weeds. Weeds 1 to 6 inches in height are the easiest to control. Always use a nonionic surfactant (NIS), crop oil concentrate (COC), or methylated seed oil (MSO) with the application. Restricted entry interval (REI) is 24 hours.

Caution Restricted-use herbicide. Do not mix or store in containers, spray tanks, nurse tanks or such systems made of aluminum or having aluminum fittings. May be fatal if swallowed or inhaled. See label for correct protective equipment. Applicators, mixers and loaders must wear long-sleeve shirt and long pants, shoes plus socks, protective eyewear (applicator), face shield (mixers and loaders), Category A chemical resistant gloves, chemical resistant apron (mixers and loaders), and a dust mist NIOSH-approved respirator with an N, R, P, or HE filter. Dry, dusty conditions will decrease herbicide's activity. Do not apply if barley has already emerged.

Site of action Group 22: photosystem I electron diversion

Chemical family Bipyridilium