Corn disease spreads in Minnesota

(Photo courtesy of Dean Malvick, University of Minnesota)

Crop scientists are asking Minnesota farmers to help them figure out why the leaves on these corn stalks turned brown.

They know the plants were attacked by a bacterial disease called Goss's leaf blight and wilt, known scientifically as 'clavibacter michiganense subspecies nebraskensis.' But University of Minnesota extension plant pathologist Dean Malvick wants farmers to send his team of researchers diseased leaves so they can study the bacteria in detail.

Malvick wants to know is if the bacteria affecting Minnesota fields is the same one that's wilting corn across the Midwest, or whether it's some sort of variant. He said reports of the disease have increased 'dramatically' this year in the state.

Goss's can reduce ear size, or at it's worst, kill the plant completely. It was first confirmed in Minnesota in 2009, in two fields. Last year there were maybe 40 fields infected.

Malvick said he doesn't have a final tally for this summer, but the number of acres affected will be much higher than 2010. He said researchers don't know why Goss's is increasing so fast, and that's why they've enlisted Minnesota farmers to help solve the riddle.

The disease has a long history in the United States. It was named for University of Nebraska professor R. W. Goss, who first discovered the pathogen in 1969. But it remained fairly isolated for decades, until recently.

Goss's rapid increase over the last few years is something researchers like Malvick are concerned about. And something they want to know more about.

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