A disease new to Richland County could have negative impacts on local soybean production.
This comes right when area farmers still are on the lookout for Palmer amaranth after plants were discovered here last summer. Palmer amaranth is an aggressive pigweed.
Agronomists and agriculture agents advise farmers to watch for warning signs of sudden death syndrome. Common in southern Minnesota and South Dakota, the disease has symptoms and pathogens corresponding with plant samples taken from Richland County last year.
It’s not something that we’ve detected in North Dakota until last year, said Chandra Langseth, agriculture and natural resource agent for the NDSU Extension of Richland County.
New disease hits Richland
Sudden death syndrome is commonly observed in a crop’s leaves. Yellow spots between leaf veins, or interveinal chlorosis, is an early symptom. The lesions may expand and turn brown while the spots expand between veins, Crop Protection Network stated. This condition is known as interveinal necrosis. As the disease progresses, leaves die and prematurely fall from the plant, while petioles remain attached to the stem, Crop Protection Network said. Symptoms are similar to those found with diseases like brown stem rot, Langseth said. Because of this, diagnosis of sudden death syndrome requires thorough investigation. Plant samples taken in Richland County have been extensively tested.
Pathologists couldn’t isolate the pathogen that causes sudden death in the plant, Langseth said, who is pretty certain that sudden death is what was found in Richland County. Additional tests are needed before sudden death syndrome is officially announced here.
Pathologists from North Dakota State University surveyed hundreds of fields — largely in eastern North Dakota — in 2018. Plants with typical sudden death symptoms were identified in central Richland County. Samples from that field and other fields in the area were taken and continue to be tested.
Keep on the lookout
Richland County farmers and residents are advised to watch for Palmer amaranth, known for its quick spread, resistance to herbicide and crop-damaging impact. Richland County was one of five Red River Valley counties where Palmer amaranth was positively identified in October 2018.
No additional counties have been added, Langseth said. Now is a great time to search fields because the weeds are bigger and identification is easier, she said.
Palmer amaranth is often mistaken for waterhemp, redroot pigweed and Powell amaranth. Each weed has distinct characteristics, Langseth said. The stem of a Palmer amaranth plant is smooth and hairless. Its petiole, or leaf stem, is long and often longer than the leaf blade. The seed head is open, unbranched and especially long.
Palmer amaranth is capable of separate male and female plants.
Farmers are advised to follow effective practices, closely monitoring components like feed and equipment. If Palmer amaranth is detected it is best to reduce the possibility of seed travel.
The site in Richland County where it was found in 2018 was managed well this year, Langseth said. “It wasn’t perfect, but I have to give kudos to the grower. They kept on top of that particular plant, knowing it was going to be a tough one to manage,” she said.
Keep seeds contained to that field, Langseth said.
For additional information, contact the NDSU Extension’s Richland County office, open from 8 a.m.-5 p.m. at the Richland County Courthouse, 418 Second Ave. N. in Wahpeton. Langseth can also be reached at 701-642-7793.