CropLife e-News

New Soybean Rust Host Found In U.S.

To paraphrase a popular slogan: Rust -- it’s not just for soybeans and kudzu anymore.

Now a new plant can be added to the list of Asian soybean rust hosts in the U.S.

"Soybean rust was confirmed by USDA on a new host, Erythrina herbacea (common name coral bean or Cherokee bean), collected in Marion County, FL," according to USDA's Pest Information Platform for Extension and Education Web site, commonly known as PIPE.

"It's a new host for the continental United States," says Carrie Harmon, a University of Florida plant pathologist and associate director of the Southern Plant Diagnostic Network, in a report by DTN. No Asian soybean rust had been found on U.S. coral bean before, but closely related plants have infected with the other species of rust in Puerto Rico.

"It (coral bean) is widespread in Florida and possibly in other southern states," says Harmon. DTN notes that coral bean is blooming in Florida right now and can be observed along roadsides, old homesteads, abandoned lots, and gardens. The plants, which are about 3 feet tall, have bright red flowers. "The bright red beans are noted when the pods dry in the fall," she adds.

A possibly infected sample of Erythrina herbacea, part of the Fabacea -- pea -- family, was found in a central Florida kudzu Asian soybean rust sentinel plot that is monitored year-round and sent for testing in at the National Plant Diagnostic Network hub lab in Gainsville, FL.

The sample tested positive. A positive ASR find on a new host means the sample must then be sent on for federal testing, according to the DTN report, so the coral bean sample headed north to USDA's Systematic Mycology and Microbiology Laboratory in Beltsville, MD, for three tests.

The results of the first test were positive so a preliminary confirmation has been made, Harmon says.

Visit www.floridata.com/ref/E/erythrin.cfm for pictures and more information.

(Sources: DTN, USDA’s PIPE Web site)