As waterhemp resistance to Group 15 herbicides continues to challenge Illinois soybean farmers, the second year of a research project is diving deeper into the issue. The study, which is screening waterhemp populations from soybean fields across the state, aims to assess the level of resistance and provide farmers with practical recommendations for integrating Group 15 herbicides into their weed management programs. This project is being led by Travis Wilke, graduate student underneath Dr. Aaron Hager.  

In the first year of the project, research findings were shared with over 250 farmers, agronomists, and weed scientists at major meetings,

including the North Central Weed Science Society Annual Meeting, CCA Annual Meeting, and Field Advisor Forum. These discussions helped clarify the growing concerns over resistance and started important conversations about management strategies. 

This spring, screenings began on March 3, focusing on S-metolachlor, with plans to wrap up screenings by the end of April. The team is also comparing resistant and sensitive populations from fields with suspected resistance and will test additional Group 15 herbicides to further confirm resistance. 

The project is now entering its second year with the goal of identifying the specific genes responsible for metabolism-based resistance in waterhemp populations. 

For more information on this Illinois Soybean Checkoff-funded research, visit the Field Advisor Research Hub. 

The project was presented by Travis Wilke in the student contest portion of the North Central Weed Science Society Annual Meeting. (Photo provided by Wilke)