Reminders About Herbicides at Planting for Small Grains

Mark VanGessel, Extension Weed Specialist;

The mantra of “Starting Clean” is important for all crops, including small grains. Relying on mechanical implements to prepare a weed-free seedbed requires selecting the appropriate one. Most vertical tillage implements are not aggressive enough to kill weed seedlings. These fields that receive the vertical tillage also need to be sprayed with a burndown herbicide.

Paraquat (Gramoxone) or glyphosate are commonly used prior to planting, with glyphosate being the better option when grasses such as annual bluegrass or Italian ryegrass have already emerged. Sharpen or Reviton can included with glyphosate if horseweed has emerged; or Reviton can improve control of emerged primrose plants. Neither Sharpen nor Reviton will help with residual control.

Anthem Flex and Zidua is often used in fields with bluegrass and Italian ryegrass control. Remember, both of these products are labeled only for winter wheat (there is no barley label). Wheat needs to be seeded at least 1-inch deep. Anthem Flex label allows an application when “at least 80% of the seeds have at least ½ inch shoots”. My concern is how best to stage this over the whole field. I like to wait until you can see the crop in the spike stage, when you can make out the rows. That way you know if there was uniform germination across the field. Seeds that have not sprouted yet when these products are sprayed can result in lost stands.