April 8, 2004

 

 

US Soybean Farmers Prepare For Asian Rust Invasion
 

Government agencies and agribusinesses this week stepped up efforts to arm US farmers with tools to fight Asian soybean rust, the devastating fungus-caused disease that can cut crop yields by half or more.

 

On Tuesday, the Environmental Protection Agency (EPA) approved emergency use of the fungicide myclobutanil in South Dakota and Minnesota to treat soybean rust. Under EPA rules, states and agencies can make requests for Section 18 quarantine exemptions that allow use of chemicals that have been well tested by scientists. Other states are working to receive the Section 18 exemption, according to Dow AgroSciences, which sells formulations of myclobutanil called Laredo EC and Laredo EW.

 

"This action will provide farmers some fungicide tools to use should soybean rust ever occur in the United States," EPA media representative David Deegan told Agriculture Online Wednesday. "The emergency situation is not in question," he said.

 

EPA also is reviewing several other fungicides for use against soybean rust, Deegan said. Two chemicals, azoxystyrobin and chlorothalonil, are already registered for use, but have limitations that narrow their effectiveness, Deegan said.

 

EPA's action is prompted not only by the potentially severe economic impact of the disease, but also because Asian soybean rust has been identified by the US government as a possible biological weapon, Deegan said.

 

Soybean rust, which originated in Asia and Australia, is moving northward from South American where it was first reported in 2001. It's probably only a matter of time before wind-blown rust shows up in US growers' fields, USDA researchers say.

 

"This (soybean rust) is likely a problem we will be facing," Bryan Hieser, a director of the United Soybean Board, told farmers attending the Commodity Classic in Las Vegas last month. Hieser, an Illinois farmer who chairs the USB production committee, said that for the first time, the rust was found north of the equator this y ear. "Most experts believe it's not a matter of if but when soybean rust will arrive in the US," Hieser said.

 

Southern US conditions are "very susceptible" to soybean rust, Morris Bonde, a USDA soybean rust researcher told farmers at the Commodity Classic. "Sentinel plots" have been established in the South to help provide an early warning.

 

Multiple applications of fungicides have been used in South America and elsewhere in the world to fight soybean rust. Brazilian farmers lost an estimated $1.1 billion in production this year due to it, according to the country's National Confederation of Agriculture. Farmers have spent about $41 per hectare (about $16.60 per acre) in controlling soy rust, the Brazilian agency told Reuters in March. Costs have been as low as $6 an acre in South America and as high as $15 to $16, Hieser said.

 

Early detection of the problem by farmers will be critical, researchers say. But early detection is "very very difficult," according to USDA's Bonde. "That's why if you hear that they're having it two or three hundred miles south of you, then you better start watching for it. It's pretty easy to wait a little too long."

 

The disease can show up anytime, and soybeans are susceptible at any stage, Bonde said.

 

Soybean rust can can look like early spider mite damage, or SDS in the early stages, according to Hieser.

 

Soybean checkoff funded research is focused on developing tolerant or resistant varieties, and on creating new tools to help diagnose the disease. But, the plant screening efforts so far have been "somewhat disappointing," Hieser said.