Considerations for Small Grain Weed Control

Mark VanGessel, Extension Weed Specialist;

There has been an interest in using herbicides at planting (or shortly after planting) for weed control in small grains. There are few effective herbicides labeled for preemergence applications. Sharpen is labeled for wheat and barley but provides limited control. Valor or Afforia can be used with the burndown application, but there must be a 7-day period between application and planting wheat. We have seen injury with Afforia or Value used on coarse-textured soils, particularly if rain occurs shortly after planting or if seed is planted less than 1 inch deep.

Axiom, Anthem Flex and Zidua can be used after wheat emergence, typically spike stage. These products are only labeled for winter wheat, not barley. They do not provide control of emerged weeds, but can have utility in situations where application can be made after wheat emergence but before weed emergence. These three herbicides require rainfall or irrigation to activate, so if we experience a dry spell after application, control can be compromised.

Axiom, Anthem Flex, Zidua, Valor and Afforia all specify that the seed must be planted at least 1 inch deep. None of these products are compatible with wheat planted by “spinning the seeds” on the soil surface and shallow incorporation with a disk or turbo-till.