LANSING -- The winds of hurricane Ivan are believed to have brought a foreign crop disease to the United States.

Soybean rust was discovered recently in Louisiana and could potentially spread throughout the country. The disease causes early leaf defoliation, which ultimately results in crop loss. The disease has no known effects on humans or animals.

Gail Frahm, executive director of the Michigan Soybean Promotion Committee in Frankenmuth, said that the state's soybean producers should be aware of soybean rust but not alarmed.

"I'm sending out a four-page brochure with pictures to approximately 10,000 growers across the state to educate them," Frahm said. With about 2.1 million acres in production, Michigan ranks 12th in the nation in soybean acreage. The five leading producers are Lenawee, Monroe, Saginaw, Sanilac and Shiawassee counties.

Wind currents are responsible for spreading rust spores, which originated in Asia and Africa, but have since spread throughout the world.

"The spores can't survive in winter," said Dechun Wang, a soybean geneticist at Michigan State University. "Soybean rust thrives in moist, warm conditions, and is entirely dependent upon the wind and the weather."

Soybean rust was detected in 2001 in South America, where it caused yield losses of up to 80 percent, Wang said.

"Fortunately, we have the materials to combat the disease," said Bob Boehm, a public information officer for the Michigan Farm Bureau. "There fungicides that can treat the infected spores. We can control it, but it'll be more costly."

Boehm said early detection is important. A task force of representatives from the Farm Bureau, Department of Agriculture, Michigan State's crop and soil science department and the soybean committee are working to educate growers about how to detect the disease.

The group hopes to create a soybean rust action plan to better prepare for a potential outbreak in the spring.

"With the majority of U.S. soybeans having reached full maturity, we have from now until spring to educate growers on strategies to manage soybean rust should Michigan be infected," said Keith Reinholt, the committee's director of field operations.

Early and frequent scouting is critical, Reinholt noted.

"If soybean rust becomes widespread in U.S. soybean production areas, it could cause large crop and economic losses to soybean growers and associated industries. Growers returning from, or hosting visitors from, rust-infected production areas should be extremely careful that the disease is not transmitted to their fields," he said.

Currently there are no rust-resistant or tolerant soybean varieties, but researchers like Wang at Michigan State are looking for them. However, Reinholt said that the discovery of such varieties is five to 10 years away.