Please Help with Waterhemp Seed Collection Survey

Please help UW Extension Weed Scientist Dr. Rodrigo Werle by completing a survey and submitting seed samples that are vital to understanding and limiting aggressive waterhemp.

Here’s is Dr. Werle’s request that gives you the complete details of what he needs from you:

Please Collect and Submit Samples of Waterhemp in Your Fields

“According to our recent SURVEY, waterhemp has become the most concerning weed in row crop production in Wisconsin. Thus, we invite Wisconsin farmers and agronomists to collect waterhemp seeds this fall from their row crop production fields and submit them to UW-Madison for herbicide resistance screenings (we ask farmers to collect samples from only one of their fields; preferably the one with the most troublesome infestation level).

We intend to screen samples in the greenhouse for resistance to glyphosate (Group 9) and also to PPO-inhibitor (e.g., Cobra, Flextar, Cadet; Group 14), ALS-inhibitor (e.g., Pursuit, Classic, FirstRate; Group 2), HPPD-Inhibitor (e.g., Callisto; Group 27), PSII-inhibitor (e.g., Atrazine; Group 5) and Growth Regulator (e.g., dicamba, 2,4-D; Group 4) herbicides. Results will be made available to those who submit the samples after the greenhouse screenings are completed.

There is no cost associated to the herbicide resistance screening. The only cost will be your time to collect the seed samples and mailing them to:

Rodrigo Werle
1575 Linden Drive
Madison, WI 53706

Send Your Waterhemp Seed Samples Here Along with This Form

Please download and print the attached SEED COLLECTION FORM for information on how to collect the seeds and fill out the information necessary for the project. Please submit the form with the seed sample. Samples will only be included in the herbicide resistance screening if the information requested herein is provided by the farmer/agronomist.

For questions, contact Dr. Rodrigo Werle via e-mail: or phone: 608-262-7310.

We thank the Wisconsin Soybean Marketing Board for providing partial funding to support this project and also those submitting samples.

Best wishes,


Rodrigo Werle, PhD
Assistant Professor & Weed Specialist
Department of Agronomy
University of Wisconsin-Madison
1575 Linden Drive, Madison, WI 53706
Office: 608-262-7130
 Twitter: @WiscWeeds
Departmental Webpage:
WiscWeeds Blog: