Experts weigh whether soybean rust warnings were warranted

Sunday, January 8, 2006

URBANA, Ill. -- Government and industry spent millions of dollars last winter to prepare farmers for soybean rust, a fungus that could cost them thousands of dollars to control. But while the disease was found in southern states for a second straight year, it never reached the Midwest.

Soybean experts say all the Web sites, brochures and seminars weren't a waste of time and money because farmers need to be wary again this summer.

"Just because we didn't have soybean rust all the way up into the central part of the United States doesn't mean that it won't eventually get here," Suzanne Bissonnette, a soybean rust expert with University of Illinois Extension, told farmers and chemical applicators at the university's annual Crop Technology Conference on Thursday. "We're in the early stages and I urge you to continue to pay attention to rust."

Asian soybean rust causes premature leaf loss, leading to fewer bean pods, fewer seeds per pod and early maturity, all of which adds up to lost crop yield. It arrived in the southern United States from South America in late 2004.

Fungicides that can control the rust could cost farmers $20 to $35 per acre and must be sprayed soon after infection. A research field in Alabama, where rust was found in 33 counties last summer, showed what can happen if they aren't used.

The field, which was intentionally left untreated, was fully infected within two weeks of detection and completely defoliated within seven weeks, said Edward J. Sikora, a plant scientist at Auburn University.

"If the disease is at mid-canopy in your field and you haven't sprayed yet, you might not bother spraying because there's not going to be any benefit," he said.

Crop scouts found soybean rust in Alabama, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina and Texas last year. The northernmost discovery was in Caldwell County, Ky., where it was found in November on kudzu that has since been killed by frost, according to the USDA.

Because the rust cannot survive the winter cold, some farmers question whether it can migrate to the major soybean-producing states early enough each year to severely affect crop yield. Bissonnette thinks it can.

"Considering we just had the initial infection of soybean rust in November 2004, we had pretty significant movement of the pathogen in this season," she said. "I don't think we're crying wolf given the implications of what could happen when the disease gets here."

Neither does Dale Atkins, who grows about 400 acres of soybeans on his farm near Chenoa in central Illinois.

"I feel like we're lucky that we didn't have the exponential fast explosion of it that they've talked about," he said. "We've had a chance to get some development and get organized."

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