Herbicide-resistant giant ragweed and waterhemp continue to plague Iowa farmers, and the pesky weeds are showing up more frequently in the same field making control with herbicides especially difficult.

Understanding weed biology can be helpful in the battle to control these weeds. “It is one of the most important factors to consider when developing a successful weed management program,” believes Jared Goplen, a University of Minnesota Extension crops educator.  In addition, recent research indicates corn and soybean growers may need to integrate tillage, including cultivation, as part of their weed management strategy.

“Three main factors influence weed control success: weed emergence patterns, the weed seed bank and incorporating sound agronomic practices, including tillage,” Goplen...