New soybean virus found, confirmed in Indiana

MARTINSVILLE, Ind. (WLFI) - Soybean vein necrosis virus, a new disease in Indiana soybeans, was confirmed earlier this month, according to a Purdue Extension plant pathologist.

A sample exhibiting symptoms of the virus, also known as SVNV, was sent to Purdue’s Plant and Pest Diagnostic Laboratory.

The lab sent the sample for further testing, and molecular test results showed the presence of a tospovirus, or a disease causing death, in the plant.

"SVNV is one of our newer viruses that we've confirmed in soybeans," Purdue Extension plant pathologist Kiersten Wise said. "This is the first year that we've confirmed it in Indiana, although we've seen suspect symptoms in the past."

While it doesn’t seem to affect yield, the disease does cause symptoms similar to herbicide injury. That includes yellowing in plant veins and light green patches or mottled green and brown speckled areas.

Leaves will show a blotchy, scorched appearance in shades of yellow and orange, and as the season goes on, the virus could lead to tissue death of the plant.

In the years since the discovery of SVNV in 2008, it’s been reported in 12 states: Arkansas, Delaware, Kentucky, Kansas, Illinois, Maryland, Missouri, Mississippi, New York, Pennsylvania, Tennessee and Virginia. And now joining that list is Indiana.

The virus is spread by insects that infest in a variety of plant species, an insect called “thrips.”

"When those insects are feeding on the soybeans, they may be transmitting this virus as well," Wise said. "We suspect that's why we're seeing more symptoms this year, because we've had more thrips damage in soybeans."

Wise also called the virus an “oddity.” She says farmers are seeing more of it this year than ever before.

"It's all across Indiana from the Kentucky border all the way up to the Michigan border. And growers are concerned about what these blotches are on their soybeans," Wise said.

Wise still doesn’t recommend any treatment, though.

"We are still learning more about this virus, and we're going to continue to monitor it in the future," Wise said. "But at this point in time we wouldn't recommend any changes in production practices."

Wise says growers and crop consultants should inspect any still-green soybean plants for symptoms and email photos or videos of possible cases to her email account .