The Minnesota Department of Agriculture has positively identified the invasive weed Palmer amaranth in Winona County.
MDA was contacted by a crop consultant after they discovered several suspect plants in a soybean field. MDA staff scouted the area and removed 20 Palmer amaranth plants which were confirmed by genetic testing. The field has since been treated with an herbicide application, and follow-up scouting by the MDA did not find any new plants. The site will be monitored for up to three years for any new Palmer amaranth.
MDA is trying to determine the source of the invasive weed.
Farmers asked to scout
Now is the time when Palmer amaranth becomes visible in agricultural fields. MDA officials ask that farmers, crop consultants and agronomists report any suspicious plants to MDA’s Arrest the Pest line at 1-888-545-6684 or at firstname.lastname@example.org.
Since it was first discovered in the state in 2016, Palmer amaranth has been found in nine Minnesota counties, including Winona County. Details of previous finds can be found on the MDA’s website.
Palmer amaranth is listed as a noxious weed in Minnesota. All above- and belowground parts of the plant must be destroyed. It cannot be moved.
The weed is also listed as a prohibited weed seed in the state. This means no Palmer amaranth is allowed in any seed offered for sale in Minnesota.
Left uncontrolled, a single female Palmer amaranth plant typically produces 100,000 to 500,000 seeds. It is resistant to multiple herbicides, can cause substantial yield losses and greatly increases weed management costs in soybeans and corn.