La. farmers should scout for soybean rust disease

(06/10/16) BATON ROUGE, La. – Louisiana farmers need to make sure they’re scouting their fields for signs of diseases, including Asian soybean rust, which was found Thursday (June 9) in Iberville Parish.

The disease, which causes lesions on plants and can result in major yield losses, was observed in soybeans at the R2 growth stage in LSU AgCenter research plots near St. Gabriel, said Clayton Hollier, an AgCenter plant pathologist.

But there is no need for alarm if farmers take time to check their fields for possible problems, Hollier said. Soybean rust can have devastating effects, but the disease is manageable with timely fungicide applications.

“Scout thoroughly and often,” he said. “Decisions on management should be based on growth stage of the soybeans, the disease incidence and severity, predicted weather conditions and the susceptibility of the varieties grown.”

The fungicides that most soybean farmers already apply to manage other common diseases will also manage soybean rust, Hollier said. If growers apply fungicides for other diseases during the R3 and R4 stages, soybean rust will be managed too, he said.

Soybean rust was first observed in Louisiana in 2004. Unlike in other parts of the word, Hollier said, the disease overwinters in Louisiana on kudzu.

“This past winter was mild,” Hollier said. “With that, we expect higher-than-normal soybean rust buildup, but it should decline soon.”

High summertime temperatures reduce buildup of the pathogen, he said.

More information about soybean rust and other common soybean diseases is available in the AgCenter’s Soybean Field Guide at

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Closeup of soybean rust disease on a soybean leaf. Photo by Bruce Schultz

6/10/2016 7:41:04 PM
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