BISMARCK – Palmer amaranth (Amaranthus palmeri) has been confirmed in Barnes and Cass counties, according to the North Dakota Department of Agriculture on Sept. 9.

A crop specialist noticed some suspect plants in a Barnes County field and notified the landowner. The landowner worked with a North Dakota State University Extension specialist, who submitted samples for DNA analysis to the National Agricultural Genotyping Center, where it was confirmed as Palmer amaranth. In the Cass County case, a NDSU Extension specialist found it within the city of Fargo, and it was confirmed in the same way.

These are the third and fourth findings this year, with the other findings being in Benson and Stutsman counties.

Palmer amaranth, an aggressive pigweed species similar in appearance to waterhemp, is native to the southwestern U.S. but was accidentally introduced to other areas and has devastated crops in the South and Midwest. It is a prolific seed producer that can emerge throughout the growing season. It grows rapidly at 2-3 inches per day in optimum conditions and is prone to herbicide resistance and multiple modes of action. It is a highly invasive weed that can dramatically cut crop yields.

“I strongly encourage agricultural producers to monitor fields for weed infestations. If you have cattle that were fed grain screenings, pay particular attention to where their manure was spread or where they may have foraged. Do not assume it is just pigweed or waterhemp,” Agriculture Commissioner Doug Goehring said. “With harvest season in full swing, farmers are also encouraged to scout fields and clean excess dirt and plant debris off equipment between fields to prevent unintentional spread.”

The public is urged to work with local weed officers, extension agents and other experts to identify and report suspect plants. Palmer amaranth may spread through multiple channels, including: contaminated seed mixes; equipment and machinery movement; animal feed and bedding; and wild birds.

Palmer amaranth has now been found in 12 North Dakota counties. Those sites continue to be monitored for Palmer amaranth. More information on Palmer amaranth and other noxious and invasive weeds is available at www.nd.gov/ndda/plant-industries/noxious-weeds.

To report a suspect plant, go to www.nd.gov/ndda/pa or contact your local county weed officer or North Dakota State University Extension agent.