Asian Soybean Rust Found in SW Ark., Extension Service Says

Arkansas soybean-disease fighters hope to nip in the bud, so to speak, an outbreak of Asian soybean rust that has spread to southwest Arkansas.

Asian soybean rust, a fungus that can defoliate a field in three weeks if left untreated, was found July 23 in a field in Little River County, University of Arkansas plant pathologists say.

The experts said the Asian soybean rust is the biggest threat to the Arkansas crop in years, as it can cause drops of 50 percent or more in yield if not treated. About 2.9 million acres in Arkansas are planted in soybeans this year.

“We felt like it was coming, and we were hoping we’d catch it early,” said Scott Monfort, one of the University of Arkansas Cooperative Extension Service pathologists who located the infected field. “It was just beginning, so it seems like we caught it at the right time. We’re going to do some more searching.”

The plant-disease experts traveled to the area to look for the fungus after it was reported in Paris, Texas, only about 100 miles from where it was found in Arkansas.

“Our weather has been coming out of Texas, so I think everybody knew it was just a matter of time before it got here,” said Joe Paul Stewart, county extension service agent for Little River County.

Monfort said he and pathologist Cliff Coker checked several fields in Little River County – across the Red River from northeast Texas – and found the disease in one of them.

“We found active rust pustules on the leaves of soybeans in the reproductive stage in the southeast part of Little River County,” Monfort said.

Stewart said the extension service recommends that soybean growers in extreme southwest Arkansas – as far east as El Dorado – apply fungicides to head off a possible infection. The university recommends use of Quadris, Headline, Folicur, Laredo, Domark, Topguard or Punch.

“We’re stressing that anyone outside the area shouldn’t apply fungicides,” he said.