[November 18, 2009] Nematodes silent nemesis to soybeans: Parasite can cut yields by 30 percent, with plants showing no obvious symptoms Tweet Nov 18, 2009 (American News - McClatchy-Tribune Information Services via COMTEX) -- South Dakota State University and the South Dakota Soybean Research and Promotion Council are continuing their testing program for soybean cyst nematode. The soybean cyst nematode is a small, plant-parasitic roundworm that feeds on the roots of soybeans and is the most damaging pest of soybeans in the United States, according to a press release. Most nematodes are too small to be seen with the naked eye. Both entities are especially interested in testing more samples from areas where the nematode is not a well-known pest. In South Dakota, it was first detected in Union County in 1995. SDSU's ongoing monitoring shows that, as of this year, the nematode was present in 25 counties in the eastern part of the state. But Larry Osborne, a plant pathologist with South Dakota Cooperative Extension, said that in some counties of northern South Dakota, the nematode has been confirmed in only limited areas. He said it is possible it is more widespread than producers realize and is quietly robbing them of higher yields. Detection may be difficult because soybean cyst nematode can reduce yield by as much as 30 percent with no obvious symptoms. One indication is declining soybean yields in portions or all of a field. Symptoms often include stunting, frequently expressed as a roller-coaster effect. Infected plants may become yellow in July or August, and they have reduced vigor or mature earlier than those in surrounding areas of the field, according to the release. Soil samples can be submitted to the SDSU Plant Diagnostic Laboratory, Box 2108, Plant Science Building 117, Brookings, SD 57007. The South Dakota Soybean Research and Promotion Council subsidizes the costs for testing on in-state samples, so there is no cost to South Dakota producers, Osborne said. Details: See Extension fact sheet 902A, "Soybean Cyst Nematode" at agbiopubs.sdstate.edu/articles/FS902A.pdf or local county Extension offices. To see more of the American News, or to subscribe to the newspaper, go to http://www.aberdeennews.com. Copyright (c) 2009, American News, Aberdeen, S.D. Distributed by McClatchy-Tribune Information Services. For reprints, email [email protected], call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA. [ Back To TMCnet.com's Homepage ]