News Releases

(JACKSON, Tenn.) - It is speculated that the season's recent hurricanes were literally ill winds that blew Asian soybean rust into the United States. As the nation prepared to celebrate Thanksgiving, USDA researchers confirmed findings of soybean rust (Phakopsora pachyrhizi) on soybean leaves located in Louisiana, Mississippi, Alabama, Georgia, Florida and Arkansas.

The disease has not yet been identified in Tennessee, but experts believe it is just a matter of time.

A fungal disease of soybeans and other cultivated legumes such as peas and beans, Asian soybean rust has the ability reduce yields significantly. The USDA estimates financial losses across the nation could range between $640 million to more than $1 billion.

University of Tennessee Extension plant pathologist Melvin Newman says the extent of economic impacts in Tennessee will depend on the timing, spread and severity of rust establishment and outbreaks and on how soybean producers respond.

Soybeans are among the state's top agricultural commodities, with roughly 42 million bushels harvested this year. Depending on the producer's sale price, the 2004 crop could be worth a total of more than $243 million to farmers throughout the state.

"This year's harvest is in, so growers have several months to prepare their rust mitigation plans for the next growing season," Newman said.

Two fungicides are already labeled for use on soybean rust: azoxystrobin (Quadris®) and chlorothalonil (Bravo® or Echo®). A third fungicide, pyraclostrobin (Headline®), is expected to be labeled for use in the next few weeks. Still, Tennessee and several other states have requested that the EPA approve seven additional fungicides and combinations to help control the disease on an emergency basis. Propiconazole (Tilt®, ProiMax® and Bumper®) and myclobutanil (Laredo®) have already been approved, and Newman says the others are likely to be approved before the spring.

To control soybean rust, producers should spray as soon as scouting reports indicate that rust is nearby. Newman says fungicides must be applied before rust infects between 5 and 10 percent of a field's leaf canopy.

"If producers are advised to spray for rust they need to be ready. They should prepare to overcome any number of logistical problems," Newman warned. "Availability of effective fungicides, lack of reliable spray equipment, changing over to hollow cone nozzles, even having enough water tanks and other equipment may be a problem. Producers should not wait until the last minute to get ready because rust can spread very fast."

In early 2005, UT Extension soybean pathologists and specialists will train Extension agents, company representatives and others who work in the field to help scout for rust symptoms. They will be trained to recognize soybean foliar diseases and instructed on how to submit suspect leaf samples to the UT Extension plant disease and pest diagnostics laboratory in Nashville.

Newman recommends that producers keep in touch with their county Extension agents for the latest recommendations on disease prevention and management. They may also check the Web site www.utcrops.com for updated information.

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Contact:

Melvin Newman, 731-425-4718
Patricia McDaniels, 865-974-7141