Researchers at the University of Nebraska, Lincoln, have confirmed a population of kochia that is resistant to glyphosate herbicide.
As a result, a group of multi-state researchers have encouraged growers to adopt integrated weed-management stragies, according to a grower newsletter.
These include rotating crops and herbicide modes of action as well as using tankmixes with multiple herbicides.
The researchers were Andrew Kniss, University of Wyoming; Phil Stahlman, Kansas State University; Robert Wilson, University of Nebraska; Phil Westra, Colorado State University; and Mike Moechnig, South Dakota State University.
The most recent population of glyphosate-resistant kochia is located in Keith County, Neb.
Growers for the past two years had reported weed-control failures in the area.
Laboratory tests shows resistance in the population may be 10 to 15 fold.
The development is not a surprise because glyposate-resistant kochia was first reported in the United States in Kansas in 2009.
Although the latest development is tied to the Roundup Ready production system, herbicide resistance can develop elsewhere, too.
In addition, cases of kochia resistant to triazine, ALS and growth-regulator herbicides have been reported within the United States.
For a complete list of herbicide-resistant weeds, visit the Weed Science Society of America.