How Palmer Amaranth is Sneaking into Minnesota Fields

Some seed mixes used to grow habitat for bees and wildlife have been contaminated with an aggressive and prolific weed that can be a scourge for farmers, including those in Minnesota.

Palmer amaranth was discovered in Minnesota for the first time after weed seeds were accidentally planted on conservation land, the Star Tribune ( reported. Palmer is one of the most harmful weeds in the country for corn, soybeans and other row crops.

"It's probably the most significant agronomic weed that we've seen over the last 30 years," said Tony Cortilet, noxious weed program coordinator for the Minnesota Department of Agriculture.

A western Minnesota farmer reported Palmer in his newly planted conservation land in September. Since then, Minnesota agriculture officials have confirmed the weed in 30 plantings by 13 landowners in Yellow Medicine and Lyon counties.

All were planted with contaminated seed traced to the same company, which officials haven't identified because the investigation is ongoing.

If left untreated, the weeds could take over fields like it has in southern states in as little as three years.

A single female Palmer amaranth plant produces more than 250,000 seeds, grows to a height of 6 to 8 feet and has a woody stem that can damage farm equipment, according to University of Minnesota Extension weed scientist Jeff Gunsolus.

"It's almost chain saw material; it's that strong," Gunsolus said.

The Palmer amaranth issue was addressed in early December by Minnesota

Crews with the Minnesota Department of Agriculture used propane torches in early December to incinerate Palmer amaranth weeds. Cortilet said the incineration of the weeds didn't fix the problem but will prevent Palmer seeds from falling into soil and sprouting into thousands of plants next spring.

"This is a window of opportunity for us to put boots on the ground and try to stop this thing from getting out of control and moving into the row crops," he said.

Minnesota officials are creating a plan to try to eradicate the Palmer amaranth problem at other known locations, both before and after it sprouts.

Contaminated seeds sold and planted in Minnesota, Iowa and Illinois have been sent to the University of Illinois for scientific testing for positive identification of the Palmer amaranth and other weeds.