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By Janet Kubat Willette
ROCHESTER, Minn. — Atrazine works, but it must be used responsibly.
University of Minnesota regional crops Extension educator Lisa Behnken talked about atrazine research trials conducted at the University of Minnesota research site in Rochester during a July field day.
The use of atrazine resulted in improved weed control, faster weed kill and improved yield, Behnken said, but there are areas it can’t be used and producers need to comply with those setbacks.
Products containing atrazine shouldn’t be applied within 50 feet of any well or sinkhole or within 66 feet of the points were field runoff enters perennial or intermittent streams or rivers, applied within 200 feet of natural or impounded lakes or reservoirs or applied within 66 feet of a tile inlet, according to the Minnesota Department of Agriculture.
The exception for tile inlets is if atrazine is immediately incorporated two to three inches or if the entire field is managed using a no-till system.
There are additional restrictions in southeast Minnesota’s karst region, Behnken said. The Best Management Practice for karst geology is no more than 0.8 pounds of active ingredient per acre per year if applied post-emerge. If applied pre-emerge, the BMP rate is 1 pound of active ingredient per acre per year and only on medium or fine textured soils.
Atrazine synergizes many herbicide programs, Behnken said, and a small amount goes a long way to improve performance of other products. Giant ragweed control, for instance, was dramatically better with atrazine.
In this year’s trial, Behnken and other Extension researchers are looking at possible alternatives to atrazine. Buctril, Clarity, Callisto and Hornet are among the products being studied.
Producers are encouraged to stop at the site east of the University Center Rochester and see how products are performing in the herbicide trials.