A video has been developed by Jeff Stachler, North Dakota State University  and University of Minnesota Extension  agronomist for sugar beet weed science, about scouting for the presence of glyphosate-resistant weeds .
"Glyphosate resistance  is very different, compared with resistance to ALS (acetolactate synthase) inhibiting (Group 2), ACCase (acetyl coenzyme A carboxylase) inhibiting (Group 1) and triazine (Group 5) herbicides , making it difficult to identify," Stachler says. "In addition, education about how to scout for glyphosate or any type of herbicide resistance has been extremely limited or nonexistent in the past. Pictures and text only go so far in explaining how to scout for glyphosate resistance, while a video is an excellent medium for explaining how to do something."
The video was introduced at NDSU Extension Service winter meetings and is available at http://www.ndsu.edu/weeds/herbicide_resistant_weeds/.
Two versions of the video are available. The longer version introduces the problem and focuses on the response of individual plants, while the short version only focuses on the response of individual plants.
"The most startling difference in the visual response of glyphosate resistance is the complete continuum of responses from dead to normal in appearance and every response in between," Stachler says. "If a single species has a few plants that appear normal, while most other plants are controlled or demonstrate a continuum of responses and all other species have been controlled and other reasons for surviving plants have been ruled out, then resistance is likely occurring."
Glyphosate-resistant weeds continue to increase in North Dakota, Minnesota and across the United States.