Management of annual weeds following wheat harvest
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Annual weed densities are very high in wheat stubble this year. These weeds must be managed soon in order to prevent seed production. Several effective options are available for management of annual weeds in wheat stubble. However, these practices must be implemented before seed production to avoid significant additions of seeds to the weed seed bank.
After wheat harvest, weeds take advantage of available resources, especially newfound sunlight, and will grow rapidly, especially in years with adequate soil moisture in July and August. These weeds are capable of producing large amounts of seed prior to a killing frost.
Common ragweed, velvetleaf, common lambsquarters, redroot pigweed and foxtail species are examples of common summer annual weeds in wheat stubble. At this time of the year, these weeds are completing their life cycles by flowering and producing seed. The main goal following wheat harvest is to prevent or reduce weed seed production. Post-harvest weed control options include tillage, mowing and herbicides. In general, management of annual weeds in wheat stubble is not difficult, however timeliness is critical.
Tillage is a viable option for control of both broadleaf and grass weeds. Mowing will reduce seed production of most grass and broadleaf weeds. However, mowing is often less effective on grasses since seeds can be produced on tillers low on the plant. Glyphosate and 2,4-D are common herbicides used for post-harvest weed management in wheat stubble. Refer to the herbicide labels for appropriate rates, adjuvants and tank mixes.