Early Detection of Group 15 Waterhemp Resistance
Researchers are documenting the extent and distribution of Group 15 herbicide resistance in Illinois waterhemp and using advanced genomic tools to identify the genetic changes responsible. Building on previous Illinois Soybean checkoff-funded research, this project aims to lay the groundwork for a rapid, DNA-based diagnostic test that would help farmers detect resistance and make more informed preemergence herbicide decisions.
Why This Research Is Important
- Reduced sensitivity to Group 15 herbicides, including S-metolachlor (Dual II Magnum), appears to be more widespread than previously recognized.
- Resistance to preemergence herbicides often shows up as shortened residual control rather than complete failure, making it difficult for farmers to diagnose in the field.
- Misdiagnosing resistance as a weather-related issue can lead to repeated use of ineffective herbicides.
- Understanding the genetic mechanisms behind resistance is critical to developing reliable detection tools.
- Early identification of resistance can help preserve the effectiveness of key preemergence herbicide options.
How This Research Benefits the Farmer
- Supports development of a rapid molecular diagnostic assay for Group 15 resistance.
- Enables field-specific herbicide selection based on confirmed resistance status.
- Reduces the risk of investing in products that may no longer provide adequate residual control.
- Helps protect preemergence herbicide programs that are foundational to waterhemp management.
- Builds on previous successful resistance-detection tools already deployed through the University of Illinois Plant Clinic.
Research Team
- Dr. Patrick Tranel, Ainsworth Professor & Associate Head, University of Illinois Urbana-Champaign
- Dr. Aaron Hager, Professor & Extension Weed Science Specialist, University of Illinois Urbana-Champaign
- Dr. Tiffany Jamann, Associate Professor, University of Illinois Urbana-Champaign
Trial Locations
- Waterhemp populations collected from approximately 100 Illinois fields
- Genomic sequencing and analysis conducted at the University of Illinois
About the Lead Researchers
Dr. Patrick Tranel
Ainsworth Professor & Associate Head
University of Illinois Urbana-Champaign
217-333-1531
tranel@illinois.edu
ARE YOU A FARMER OR ADVISOR?
If you’re a farmer or advisor, we invite you to take our Soybean Production Concerns Survey linked below to help guide future ISA research efforts. We also encourage you to contact us below with specific production challenge research ideas.
ARE YOU A RESEARCHER?
If you’re a researcher interested in working with ISA on a project, we encourage you to contact us with your ideas. The RFP will open in early March. Contact us below to be added to the mailing list for more information.
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