Minn. detects soybean disease with no cure

Red crown rot, a fungal disease that hides in soil, rots soybean roots away and destroys part of the bean's leaf tissue, has been found in Minnesota. And there’s no cure for it.

Dean Malvick, a University of Minnesota Extension disease researcher, said when a Rock County farmer sent samples for testing in September, he was confounded.

“At first, we were questioning whether it was really [red crown rot],” Malvick said. “Because it hadn't been detected anywhere near that location.”

Red crown rot was previously detected in Missouri last year. How it made its way north without being detected in Iowa or other surrounding states remains a mystery. 

“It's a spreading concern,” Malvick said.

But how the disease spreads remains a question mark. It was first found over fifty years ago in North Carolina and has since spread from state to state, eventually landing in the Midwest in 2018 after the rot was detected in Illinois. 

Because red crown rot is a fungus found in soil, it’s possible that high-speed winds could’ve played a role in the disease’s spread. 

“We really don't know how it's spreading,” Malvick said. “That's a real wide-open question.”

And until that question is answered, Malvick said we won’t know where else the fungus could be or how far it’s spread already. 

“There are many questions here about [red crown rot], as to how important and destructive it will be in Minnesota,” Malvick said. “It could be really important, or maybe not so important.” 

While Malvick is concerned over the rot’s presence in the state, he said there’s no cause for alarm. 

Because the disease was detected in the fall, his team can use winter as an opportunity to continue studying the rot. Most soybeans won’t be planted in the cold anyway, which gives them time to prepare for spring planting season. 

“This will be one of the things we'll be doing: helping people understand what this disease is,” Malvick said. “Following up next year in the summer will be a much bigger effort to look for it, scout for it, survey for it, and try to determine where else it might be occurring.”