Plant pathologists and soybean breeders from 7 states hope results from a new, joint effort will lead to the development of soybean lines that can resist two diseases invading the Midwest from the South. University of Missouri-Columbia researchers Grover Shannon and J. Allen Wrather are part of the team.

Supported by a $290,000 grant from the North Central Soybean Research Program and headquartered at Southern Illinois University Carbondale (SIUC), this 2-year project will focus on charcoal rot and frogeye leaf spot, fungal diseases causing mounting yield losses in the region.

"Last year was a really bad year for charcoal rot in Illinois, with soybean yields reduced by an estimated 7 million bushels," said SIUC plant pathologist Jason Bond, who heads the project.

Frogeye leaf spot contributed less damage but has increased in incidence over the last several years.

"These diseases are here and they're getting more severe," said Bond.

The pathogen that causes charcoal rot, the heaviest hitting soybean disease in the Mid-South, appears to be ubiquitous in the north central soybean growing region, too.

"It would be hard to find a field that didn't have it," Bond said.

The fungus, which for some reason does best in hot, dry weather, invades through the roots and settles in soybean plant stems, turning them gray and stunting the plants.

"Irrigating and planting earlier have been suggested as ways of dealing with the disease," said Bond. Yet these management practices run counter to practices suggested to help soybean growers avoid another fungal disease, Sudden Death Syndrome (SDS).

"Irrigating soybeans is not a viable option for most farmers," Bond said. "And as for planting dates, that's a real Catch 22, because one of the strategies for dealing with SDS is to plant later."

Frogeye leaf spot, so named because of the eye-ball lesions that blight the leaves, reproduces easily--mist hanging over a field on a summer morning gives it all the moisture it needs to begin manufacturing spores. The spores travel through air with relative ease.

"It's been hypothesized, though not yet proven, that in addition to the resident inoculum, spores also blow in from the South," said Bond.