Palmer amaranth, an aggressive pigweed species similar in appearance to waterhemp, has been positively identified for the first time in North Dakota.
A farmer in Mcintosh County reported the suspect plant to his county extension agent. DNA analysis confirmed the plant as Palmer amaranth.
The weed is native to the southwestern U.S. but was accidentally introduced to other areas of the country and has devastated crops in the South and Midwest. It had not been identified in North Dakota until now.
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.
“Early detection is the key to effectively eradicate or manage this weed,” Agriculture Commissioner Doug Goehring said. “We are thankful it was found and encourage farmers and the public to learn to identify Palmer amaranth in order to react quickly to control the weed.”
Palmer amaranth may spread through multiple channels, including:contaminated seed mixes; equipment and machinery movement; animal feed and bedding; and wild birds.
“We do not believe the plants originated from contaminated seed mixes in this case, but believe it may have been introduced by wildlife,” Goehring said. “We are working with the North Dakota State Seed Department and NDSU Extension to identify other sources.”
More information on Palmer amaranth and other noxious and invasive weeds is available at https://www.nd.gov/ndda/plant-industries/noxious-weeds.