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Researchers want to test soybeans for SDS and dry bean and alfalfa root systems for root rot.

Paula Mohr, Editor, The Farmer

September 5, 2019

2 Min Read
Symptoms of soybean sudden death syndrome
SDS SIGNS: Symptoms of soybean sudden death syndrome include interveinal necrosis and chlorosis, defoliation which leaves petioles attached, and root rot.Dean Malvick

University of Minnesota scientists are asking farmers for help in understanding the spread of certain plant diseases affecting soybeans, dry beans and alfalfa.

Dean Malvick, U-M Extension plant pathologist, wrote in a recent blog post that university scientists are working to understand where fungal pathogens are spreading that cause soybean sudden death syndrome and root rot of edible bean in Minnesota. They want to monitor and map where pathogens are impacting these crops as they continue to spread further north in the state.

Malvick asked that farmers help with this research effort by collecting and mailing plant samples to him. Samples can be sent until the plants start to yellow from maturity in the fields. After that point it is difficult to diagnose the disease properly, he added.

“We are focusing our sampling on areas north of Highway 12,” he said. “We are interested in soybean samples with foliar symptoms of SDS as well as dry edible bean and alfalfa samples with symptoms of root rot from northwest and central Minnesota.”

Samples sent in by farmers will be tested for the soilborne fungus, Fusarium virguliforme, which causes soybean SDS and root rot of edible bean and other legumes. Over the winter, Malvick said they plan to report detection of the pathogen and SDS by county. Locations and results for specific fields will be shared only with the individual who submitted the sample.

Collecting good samples, information

Malvick suggested the following:

Document it. Photograph the plant symptoms in the field.

Collect samples. Collect four to six plants showing SDS leaf symptoms, yellowing, or root rot from individual fields. Try to collect samples by the first week of September.

Uproot it. Dig up the root system, cut off shoots 8 to 10 inches above soil line and place roots in plastic bag wrapped in moist paper towel, leaving stems sticking out of the bag.

Take leaf samples. For soybean samples, also send at least three sets of trifoliate leaves showing symptoms. Leaves should be wrapped in paper.

Note location info. Include information for each sample site: County, nearest town, GPS coordinates, description of symptoms and distribution in field, and crop variety, if known.

Send package as soon as possible after collection to Dean Malvick, 1991 Upper Buford Cir, 495 Borlaug Hall, Saint Paul, MN 55108.

Or, contact Dean Malvick by email ([email protected]) to receive a prepaid FedEx label to use for shipping ASAP.

About the Author(s)

Paula Mohr

Editor, The Farmer

Mohr is former editor of The Farmer.

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