Palmer amaranth found in 3 ND counties so far in September

Palmer amaranth, considered by some experts to be the most dangerous weed in America, continues to spread in North Dakota. It's now been found in 12 counties, with two more infestations — in Cass and Barnes counties —announced Sept. 9.

But that's no reason to be discouraged or to slack off in efforts against the weed, which can ravage crop yields, Joe Ikley, North Dakota State University extension weed specialist, told Agweek.

"It's better that we're finding it in these counties. People are out looking for it, so we're finding it early and we're able to start controlling it. That's better than it being in those counties and us not finding it," he said.

The North Dakota Department of Agriculture reported Sept. 9 that Palmer had been found in both Cass and Barnes in eastern North Dakota.

In Barnes County, a crop specialist noticed some suspect plants in a field and notified the landowner, who worked with an NDSU specialist. In Cass County, an Extension specialist found it within the city of Fargo, the state's largest city. In both cases, samples were submitted for DNA analysis to the National Genotyping Center, where they were confirmed as Palmer, according to the state ag department.

Landowners involved in the 12 infestations have not been identified publicly, other than by county. Ag officials say that releasing the names of landowners might discourage others from reporting suspicious plants.

Palmer was found along a street in an industrial area in north Fargo, Ikley said.

The weed can establish itself in many places besides cropland, so everyone has a role in fighting Palmer, he said.

The two findings announced Sept. 9, as well as another announced earlier in September, might cause more people to look for Palmer and potentially could lead to additional confirmed sightings this fall, Ikley said.

The state ag department said Sept. 4 that Palmer amaranth had been confirmed in Stutsman County. A county weed officer noticed suspect weeds in a field, notified the landowner and then worked with NDSU. DNA samples confirmed it was Palmer.

The Stutsman infestation was the second finding of Palmer in North Dakota this year; the weed also was found earlier in 2020 in Benson County. Palmer first was found in the state in 2018, and now has been identified in 12 counties. The other eight, all in southern or central North Dakota, are Foster, Morton, Grant, Sioux, Emmons, McIntosh, Dickey and Richland, according to information from the state ag department.

From the beginning, ag officials familiar with the weed stressed that keeping Palmer out of the state altogether would be virtually impossible. As Ikley said, the goal has been identifying infestations early and then getting them under control.

"The main goal is to find it early and eliminate the plants that can go to seed." he said. "It can be managed long term. As long as we stay on top of infestations, it's certainly manageable."

It appears that the infestations identified so far in North Dakota were caught early enough that they can be controlled, Ikley said.

North Dakota officials will continue to educate people about the weed during the upcoming winter meeting season, although those plans aren't finalized because of the COVID-19 pandemic, Ikley said.

"If nothing else, there will be online opportunities this winter" to learn more, he said.

Anyone spotting a suspicious plant in North Dakota or another state should contact his or her state extension service or ag department. In North Dakota, go online to https://www.nd.gov/ndda/pa .

The North Dakota Department of Agriculture has more information on Palmer and other noxious and invasive weeds at https://www.nd.gov/ndda/plant-industries/noxious-weeds .

Palmer amaranth, a huge and long-standing concern in the southeastern United States, is spreading into the Upper Midwest. The weed, which already has been found in Iowa, Minnesota and South Dakota, as well as North Dakota, can damage farm equipment and devastate yields. Yield losses of up to 91% in corn and 79% in soybeans have been reported.

Agricultural officials in Montana have been working to prevent the weed from reaching the state, and so far those efforts appear to be successful.

John Gaskin, a Montana-based botanist/research leader with the U.S. Department of Agriculture's Agricultural Research Center who's been involved in Palmer educational efforts in the state, said he's not aware of any confirmed findings of the weed in Montana.

Palmer is dangerous and difficult to control for a number of reasons, including:

• A single plant can produce as many as 1 million seeds.
  
• The seeds are extremely small, and farmers can spread them unintentionally.
  
• Seeds can lie dormant in the soil for years, waiting to germinate until growing conditions are favorable.
  
• It can grow up to 3 inches per day and is unusually competitive with most crops, including corn and soybeans.
• It develops resistance to herbicides relatively quickly.
  
• Migratory birds can eat Palmer seed in one state and carry it hundreds or even thousands of miles.
• It can be easily mistaken for several other weeds.