Palmer Amaranth Found in Lincoln County, Minnesota

St. Paul, MN: The Minnesota Department of Agriculture (MDA) has positively identified the invasive weed Palmer amaranth in Lincoln County.

A field had been planted with a cover crop seed that was contaminated with Palmer amaranth. The weed is listed as a Prohibited Weed Seed in Minnesota as well as in Iowa, North Dakota, and Wisconsin. This means no Palmer amaranth is allowed in any seed offered for sale in the state.

The seed company that sold the contaminated seed self-reported this violation to the MDA. While the investigation into the issue continues, the seed company assisted the farmer and applied a herbicide recommended by the University of Minnesota Extension to destroy this infestation.

The MDA Palmer amaranth team will monitor the site for up to three years for any new plants.

Companies that sell seed in Minnesota are required to do genetic testing to look for Palmer amaranth. However, the wet spring and the inability to get intended crops planted led to a demand for other types of seed not typically sold in large quantities in Minnesota.

“Seed was brought into the state and sold prior to all the testing being completed,” said Denise Thiede, MDA’s Seed Unit Supervisor. “It’s fortunate in this case that when the testing was completed, this field had been the only one planted and all other seed could be removed from the marketplace.”

Now is the time when Palmer amaranth becomes visible in agricultural fields. The MDA is asking farmers, crop consultants, and agronomists to report any suspicious plants to the Minnesota Department of Agriculture’s Arrest the Pest line at 1-888-545-6684 or arrest.the.pest@state.mn.us.

Since it was first discovered in the state in 2016, Palmer amaranth has been found in seven Minnesota counties, including Lincoln. It was discovered in conservation plantings in Lyon and Yellow Medicine counties in 2016, and Todd and Douglas counties in 2017. The MDA confirmed the weed in row crop fields in Redwood and Jackson counties in 2018. Details of previous finds can be found on the MDA website.