WOOSTER, Ohio — Soybean rust has been reported on soybeans in the southern United States for the first time this year, but it’s unlikely that Ohio soybean growers will have to worry about the disease this growing season.
The first find of soybean rust was reported in Texas on June 10, on the border with Mexico.
Anne Dorrance, an Ohio State University Extension plant pathologist with the Ohio Agricultural Research and Development Center and Ohio’s go-to soybean rust expert, said other southern states won’t begin to detect it for another four weeks, because of unfavorable weather conditions for the disease to spread.
That’s good news for Ohio growers.
“We are at a very low risk for soybean rust to develop this season,” Dorrance said.
Came close last fall
Soybean rust has not yet been reported in Ohio. Last year was the closest it came to the state, with detections in Kentucky in early September, followed a month later on late-planted soybeans in southern Indiana.
“What was most impressive last year was the amount of rust that built up in the southern states at the end of the season,” said Dorrance.
Hit kudzu, too
In addition to soybeans, the amount of kudzu that was also infected is also a growing concern, she added. However, not all kudzu is susceptible to the current strains of soybean rust.
In addition, Dorrance said, this past winter was so cold in the southern states that much of the kudzu was frozen for a long time, thus taking out both kudzu and soybean rust.
Don’t worry
Dorrance said that even if soybean rust were to arrive in Ohio late in the growing season, it might not be much of an issue for growers.
Any potential threat would occur after harvest or well beyond pod-fill.
In addition, soybean rust does not overwinter, so any inoculum would die off.
Since its discovery in the United States in 2004, researchers across the U.S. have learned quite a bit about soybean rust, Dorrance said, and several effective fungicides have been identified for soybean rust control.
