With Missouri's crop harvest winding down, thereâ€™s no reason to be concerned about possible soybean rust infection this season. However, producers are encouraged to begin monitoring early for detection of symptoms in next year's crop.
"Increasing education and awareness about the disease has become a primary focus of our efforts," says Dale Ludwig, executive director, Missouri Soybean Association. "We will continue funding research to develop new technologies that will provide us with rust-resistant varieties."
USDAâ€™s Animal and Plant Health Inspection Service (APHIS) recently announced confirmation of the first case of soybean rust to hit the United States. It was found on leaf samples taken from two test plots at a Louisiana State University research farm. Asian soybean rust, the source of Louisiana's outbreak, is the most aggressive species.
Soybean rust is a fungal disease spread primarily through wind-borne spores capable of traveling long distances very quickly. APHIS believes the massive hurricane season may be a contributing factor in the appearance of soybean rust in America.
Rust research efforts
The soybean checkoff approved funding for research on soybean rust in 2001, shortly after the disease was first identified in Brazil. Through this research, USDA-APHIS scientists have been screening soybean lines that may offer resistance to rust and working to determine the most effective ways to manage the disease and minimize its impact.
Studies are underway at the University of Missouri to develop a value-added soybean that is exclusively resistant to soybean rust. The plan is to use new technology to identify and deliver defense peptides that bind to infective structures of ASR and halt its development.
"Our first job will be to determine rust resistance in our soybean germplasm," says David Sleper, MU soybean breeder. "When the U.S. outbreak occurred, Henry Nguyen, MU endowed soybean research scientist, was in Vietnam, his native country, arranging for test plots. Missouri varieties planted there will be under pressure from the more virulent Asian Soybean Rust."
Once resistance is found, plant breeders can transfer those genes into current commercial varieties with yield and other disease-resistance genes.
Producersâ€™ plan of action
To detect soybean rust, look for small abrasions, on the lower leaves of your plants, that increase in size and change from a grayish color to a tan or reddish brown on the underside of the leaves. Although lesions are most commonly found on the leaves, they may also appear on petioles, stems and/or pods.
MU Extension state and regional agronomists will hold educational meetings this winter. New publications, including a pocket ID guide, are being printed.
Soybean rust can be treated with fungicides, but yield loss is still a possible threat. Depending on the extent of damage, two or more applications of fungicide may be required during the growing season, at a cost of approximately $20 to $25 per acre.
Earlier this spring, MDA petitioned EPA to approve the use of 10 trade name products to help combat Asian soybean rust. To date, there are four products still awaiting approval from EPA.
For more information on soybean rust click on Soybean Rust on the left or visit the following Web sites: