By Eric Jones and Philip Rozeboom et.al
Most of the winter wheat has been harvested in South Dakota and spring wheat harvest is underway. While the growing season is over for the wheat, post-harvest weed management is important to minimize the amount of weeds that are present in the spring. Weeds may continue to grow or emerge after the wheat harvest.
These weeds will likely produce seeds that will have to be managed in future growing seasons. Shortly after wheat harvest, most of the weeds will be summer annuals. However, some winter annual and perennial weeds may also be present. The summer and winter annual weeds can be sprayed with an herbicide any time after harvest but aim to treat weeds 2 to 4” in height.
Perennial weeds, such as Canada thistle, should be treated later in the season.
Source : sdstate.edu