Fall Herbicide Options in Wheat and Barley

 

As fall weeds compete with wheat and barley establishment, below are some herbicide options to consider.

 

Dense populations of winter annual weeds can compete with wheat and barley in late fall and early spring and slow the rate of crop development potentially reducing yield. If winter annual weeds like common chickweed, henbit, marestail, winter annual grasses, and others emerge with the small grain and are left unchecked, the potential impact on yield could be great. In these situations, it may make sense to kill these weeds in the fall rather than early spring. Harmony Extra is the most broad spectrum herbicide for broadleaf control, but resistant populations of common chickweed are becoming evident in parts of the state. In addition, there are several herbicides labeled for grass control in wheat and fall is typically the best time to make an application. Make sure to include the necessary spray adjuvants. Remember that cool (less than 50oF) cloudy days can reduce herbicide activity. Also, if you plan to frost-seed or drill a companion crop such as red clover in early spring it may be best to make a fall herbicide application to avoid certain issues with herbicide residuals affecting their establishment. However, even if products such as PowerFlex HL, Osprey, Dimetric, and others are applied in the fall, their recrop restrictions still prevent seeding of certain crops next spring. Burndown herbicides for no-till small grains include dicamba, Gramoxone, glyphosate, Harmony Extra, and Sharpen. Refer to the specific product label for more application information. The legitimate use of 2,4-D for burndown in wheat and other small grains is uncertain. None of the 2,4-D ester or amine labels specify application just prior to small grain seeding or emergence. Some research suggests a minimum delay of 7-10 days after application at rates up to 1 pint/A 2,4-D ester. Since 2,4-D burndown in small grains is ambiguous at best, if injury occurs liability rests with the consultant or applicator. The following table summarizes some fall herbicide options for small grains. Check a current herbicide label for the latest use information.