Soybean farmers in Illinois face a big problem: waterhemp weeds are becoming resistant to many different herbicides. The confirmation of resistance to Group 15 herbicides in 2019 has made managing these weeds even more challenging.

Identifying resistance in this group is also particularly challenging due to their residual nature, exhibiting as a shorter duration of control rather than lack of control common with other classes of chemistry.

To evaluate how widespread Group 15 herbicide resistance is, a project funded by the Illinois Soybean Association checkoff program will collect and analyze waterhemp populations from soybean fields across Illinois. Results from this project will be used to provide farmers with recommendations on how best to incorporate these herbicides into integrated weed management programs. Resistant populations will be used in subsequent research to identify the gene(s) conferring the metabolism-based resistance.

This research is led by the University of Illinois Urbana-Champaign Crop Sciences Department, spearheaded by Dr. Aaron Hager, Professor & Weed Science Extension Specialist, along with Dr. Patrick Tranel, Professor, UIUC, and Travis Wilke, a master’s student at UIUC.

To learn more about this project, visit ILSoyAdvisor.com/Research.