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Soybean rust found in Holmes County
MISSISSIPPI STATE – Soybean rust was found in Mississippi in two fields near Thornton on Thursday, but experts are not recommending producers spray fungicide for the disease.
“This marks the first report of soybean rust in Mississippi this season and the farthest north the disease has progressed in the United States to date,” said Tom Allen, Mississippi State University Extension Service plant pathologist working at the Delta Research and Extension Center in Stoneville. “At this point, it is a very localized infection, and rust has not been detected anywhere else in Holmes County or Mississippi.”
Allen said the producer is aware of the situation and has agreed to treat the fields to likely prevent further spread throughout the Delta.
“There are absolutely no fungicide suggestions at this t ime,” Allen said. “However, growers who already planned to make an R3/R4 fungicide application are encouraged to a pre-mix strobilurin/triazole.”
Allen said the rust was found in an irrigated field that had recently been sprayed with a fungicide. The rust was found on plants growing underneath a power line, so these plants likely did not receive the fungicide application. Rust was found in a second, dryland field directly across the road.
“In both locations, incidence and severity was very low,” Allen said. “Based on the level of infection, it is likely the disease has been present in this location for about four weeks.”
Allen said detection of soybean rust can be difficult. Numerous other soybean diseases have symptoms that look very similar to rust. The key to confirming rust is using a magnifying lens to find pustules on the undersides of soybean or kudzu leaves.
The MSU Extension Service has a Soybean Rust Scouting team that examines the state’s 20 sentinel plots, kudzu stands and commercial fields for soybean rust each week. These scouts began their work in March and will continue until soybeans are harvested. This information is used each year to make management or treatment recommendations anytime rust is detected in the state.
Call the Soybean Rust Hotline at (866) 641-1847 for up-to-date information about soybean rust in Mississippi, Arkansas or Louisiana. The hotline is made possible through the Mississippi Soybean Promotion Board and BASF.