Weed out winter annuals in your winter wheat. Identifying weeds today could increase yield tomorrow.

May 12, 2009

If winter wheat is part of your rotation, now’s the time to scout your fields for fall-germinated winter annual weeds. The proper diligence today could reap bigger dividends come harvest.

Paul Thoroughgood, Regional Agrologist with Ducks Unlimited Canada (DUC) says winter wheat produces 10 to 30% higher yields than spring seeded varieties but proper management is key. “Getting out into the field today and surveying the crop is essential to help your winter wheat achieve its highest yield”, says Thoroughgood. “Otherwise weeds such as narrow-leaved hawks beard, stinkweed, flixweed and shepherd’s-purse will compete with the crop for resources and reduce yield.”

Weed control considerations for winter wheat are similar to other cereal crops. However, producers should be mindful of herbicide selection and timing.


  1. Consult with your crop protection guide for new herbicides, weed spectrum and rates.
  2. Identify the problem weeds, and then select an appropriate product.


  1. In-crop applications in spring generally coincide with pre-seeding glyphosate applications and seeding operations. Delaying an in-crop herbicide application on your winter wheat until after seeding, often results in poor weed control.
  2. Aim to spray when the winter annual weeds are still small, but actively growing, and spray within the proper winter wheat growth stage for the herbicide used.
  3. Crop injury can result if the herbicide application is followed by a frost. Colder temperatures may interfere with the plant’s ability to metabolize the herbicide’s active ingredients. Applications following a frost should be postponed for two to three days depending on the severity of the frost, or until the weeds are actively growing again.
  4. Ensure that any burn-off chemicals have been well rinsed from the sprayer tank, to prevent crop damage.

DUC has been supporting winter wheat production since the early 1990s as the crop provides safe, attractive nesting habitat for waterfowl. In January, DUC and Bayer CropScience launched Winter Cereals: Sustainability in Action, a program which showcases the important role winter wheat plays in sustainable agriculture. The program combines investment in research, working with producers and engaging additional partners to increase winter wheat acreage across the Prairies, and highlights an agricultural practice that is profitable and wildlife-friendly.