U.S. Soybean Industry Ready to Fight Rust

At this time of year, soybean yields will see minimal impact, if any at all. Jacqui Fatka

Published on: Nov 10, 2004

USDA's Animal Plant Health Inspection Service (APHIS) confirmed today that Asian Soybean Rust (Phakopsora pachyrhizi), has been found on soybean leaf samples collected from two Louisiana State University's research plots near Baton Rouge, Louisiana. APHIS officials report they believe the pathogen was carried to the United States during the recent hurricane season.

USDA will dispatch its soybean rust detection assessment team, composed of scientific experts and regulatory officials, to the site within 24 hours. The assessment team will work closely with Louisiana State Department of Agriculture representatives to assess the situation and conduct surveillance around the detection site to determine the extent of the disease spread.

ASA President Neal Bredehoeft, a soybean producer from Alma, Mo., says, "Potential yield loss from soybean rust starts to diminish as plants begin to reach maturity. At this time of the year, when soybeans in many areas of the United States have already reach full maturity and the crop is ripe, soybean rust will no longer reduce this year's crop yields."

With the case being found in a research farm and having active surveillance, the chances for the disease being widespread are "very high," Plant Protection and Quarantine (PPQ) Deputy Administrator Ric Dunkle says. More should be known once a more thorough assessment of the area is complete. The spores inability to overwinter in many northern regions should benefit disease management.

Proactive Steps Now

While the harvest for this year is nearing completion, during next year’s planting season, producers will need to watch for symptoms of the fungus such as small lesions on the lower leaves of the infected plant that increase in size and change from gray to tan or reddish brown on the undersides of the leaves.

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 soybean production areas should be extremely careful that the disease is not transmitted to their fields.

Dunkle recommends any producers who still have soybeans in the field to contact their local extension office for testing. Dunkle says the entire Gulf coast region will be surveyed.

Growers in areas near the outbreak should survey their fields to inspect for symptoms of soybean rust disease. Inspection consists of a thorough visual examination of soybean plants in the field and of other host plants in the vicinity of the fields being surveyed. A 20-power hand lens will be required to inspect the underside of the lower leaves in the lower crop canopy for uredinial pustules that are powdery, and buff or pale brown in color.

As soybean plants mature and set pods, infection may progress rapidly under favorable environmental conditions to cause high rates of infection in the middle and upper leaves of the plant.

For more on ASA's recommendations, click HERE.

Learning from others

The United States is the last major soybean-producing nation to be affected by this soybean fungus. "We have learned from the experiences of other countries and are better prepared to handle this situation," says American Farm Bureau Federation President Bob Stallman.

"U.S. soybeans should continue to have a solid standing in export markets, now and in the future," Stallman adds. "A number of states have already taken steps to ensure their farmers have access to effective crop protection tools to control soybean rust next year."

For more information about fungicide approval and economics of the disease, click on the Soybean Rust menu option on our left navigation bar.