University of Illinois

No. 8/May 15, 1998

Soybean Cyst Nematode Educational Program

Even though soybean planting has yet to begin in much of the state due to weather problems, it's not too early to think about the soybean cyst nematode (SCN), one of the most serious pest problems on soybeans. This planting season marks the beginning of a 3-year educational program to increase awareness among soybean producers for managing SCN. SCN is the most destructive soybean pest found in both the Midwest and the Southeast. If not properly managed, it can reduce yields from 5 to 15 bushels per acre. With the size of the Illinois crop, losses in a single year can be as high as $100 million.

The educational program has a major goal of increasing the level of soil testing for SCN. Funding comes from two checkoff sources. The North Central Soybean Research Program is coordinating the overall operations, and the Illinois Soybean Checkoff Board is assisting in the state program. Both agencies are funded from producer checkoff monies, and this programis an excellent example of how these funds benefit not only the local producer but also soybean producers throughout the region.

Soil testing is the only definite method of detecting SCN. Throughout much of the northern half of Illinois, SCN-infested plants tend not to show any above-ground symptoms. The deep, rich soils and normally adequate rainfall help keep plants growing, although they may set fewer pods. Producers realize that they have a problem only after harvest--when yields are unexpectedly low. After eliminating obvious pest and agronomic problems, a soil test typically shows above-threshold SCN levels (greater than 3 mature cysts/100 cc of soil or 150 eggs/100 cc). At this stage, proper management using crop rotation and resistant varieties can reduce threat of further SCN damage.

The 3-year program in Illinois is a cooperative effort among Extension staff, the Illinois Soil Testing Association (ISTA), the Illinois Soybean Checkoff Board, private industry, and other state agencies. Soil-sample processing will be handled by members of the ISTA. All Illinois soybean producers are encouraged to participate in this program and should contact any soil-testing lab for more information. A list of participating labs will be available within a few weeks.

H. Walker Kirby (kirbyw@mail.aces.uiuc. edu), Extension Plant Pathology, (217)333-8414