The United States Department of Agriculture announced on November 10, 2004, that they had confirmed the presence of soybean rust on soybean leaf samples taken from two plots associated with a Louisiana State University research farm. This is the first instance of soybean rust to be found in the U.S. USDA Press Release

In February and March 2005, soybean rust was found on overwintering at two sites in Florida.

Soybean rust is a fungal disease that causes crop loss. Yield losses have been reported from 10-80 percent. Soybean rust was first reported in Japan but because it is spread primarily through windborne spores, the disease is now found in Africa, Asia, Australia, Hawaii and South America.

Until now, soybean rust had not been found in the continental U.S. It is a concern because of the potential for large crop and economic losses for soybean growers. Soybean rust causes distinctive lesions on the leaves. The lesions cause water loss and interfere with photosynthesis. This limits the plant's ability to make its own food and to set soybean pods.

The finding of soybean rust is not completely unexpected. The soybean industry, state and federal agencies, agrichemical companies and soybean specialists at colleges and universities across the country have been doing research, field surveys and making preparations in the event that soybean rust would arrive in the United States.

What's happening in Wisconsin
The Wisconsin Department of Agriculture, Trade and Consumer Protection's Plant Industry Bureau has been actively looking for soybean rust for the past three years. Staff systematically survey between 270 and 280 soybeans fields each year for various soybean diseases, including soybean rust. The number of fields surveyed is based on statistical probability - that is, if we don't find it in these fields, we're 95 percent certain that soybean rust is not present in Wisconsin. To date, we have not found any suspected soybean rust.

If any suspect plants are found (the early stages of another soybean disease has similar characteristics) samples go to the department's Plant Industry Laboratory or to the University of Wisconsin's Plant Disease Diagnostic Laboratory. Further testing to confirm the disease would be handled by plant diagnostic laboratories that are part of USDA's Center for Plant Health, Science and Technology.

Impact on Wisconsin agriculture
Soybean rust needs a living host. The spores cannot survive on plant debris or seeds - that's why harvested soybeans are not a risk to spread the disease. If soybean rust is found next growing season in the southern states, it is possible that fungal spores could reach Wisconsin but it seems unlikely that the spores could overwinter. However, we don't know how far north the disease can survive.

The greatest impact on Wisconsin farmers is the potential for increased production costs associated with the costs of fungicides needed to control the disease.

Soybean rust is not a concern for consumers and the disease presents no risk to people.

Controlling Soybean Rust
The state agriculture department has been working closely with soybean specialists at the University of Wisconsin – Madison preparing a special pesticide registration request for fungicides needed to control soybean rust.

Soybean Facts

• In 2003, Wisconsin was the 15th largest soybean producing state producing 46.76 million bushels of soybeans or 2 percent of total US production. The value of last year's crop was $332.46 million. Wisconsin's share of US soybean exports in 2003 was $159.2 million.
• A good yield for Wisconsin is 45 bushels per acre. Last year it was 28 bushels, due to drought conditions. This year's yield is forecast at 35 bushels per acre.
• The 2004 Wisconsin harvest is forecast at 54.25 million bushels.

Soybean Rust Resources
Soybean Plant Health
Find the latest research-based information from the University of Wisconsin-Madison on all aspects of soybean plant health. You can find soybean rust information under What’s New for 2005. Also check under Soybean Plant Health Topics where you can find further links to soybean rust information including the Soybean Health Soybean Rust Fact Sheet.

USDA Soybean Rust Website
A one-stop federal resource provides timely information on the extent and severity of soybean rust outbreaks in the U.S, Caribbean basin and Central America. The site will provide up-to-date forecasts on where soybean rust is likely to appear in the United States, reports where the disease exists by county, links to county agents nationwide, and links to the National Plant Diagnostic Network laboratories.

Wisconsin Pest Bulletin
The Department of Agriculture, Trade and Consumer Protection's Pest Bulleting will provide state and national updates on soybean rust and survey results from Pest Survey scouting efforts.

USDA Animal and Plant Health Inspection Service (APHIS)
This web page offers press releases, government initiatives and general information on soybean rust.

American Soybean Association
A membership-driven, grassroots policy organization that represents U.S. soybean farmers.

United Soybean Board
The USB is a 62 member board representing growers in 28 states and is funded through the soybean check off. Their Producer Workshop section contains a producer guide to soybean rust.

USDA Animal and Plant Health Inspection Service Pest Alert
Extensive information on soybean rust including the strategic plan to address the disease, risks, symptoms and characteristics.

North American Plant Disease Forecast Center
Generates forecasts of spore movement based upon current infection areas and meteorological data.

Plant Management Network Soybean Rust Page
Agriculture businesses, a great number of universities and plant-related professional groups have joined together for this comprehensive cooperative resource for applied plant sciences.

For more information on soybean rust, contact your County Extension office, your crop consultant or call the Wisconsin Department of Agriculture, Trade and Consumer Protection at 608-224-4592 or send an email.