|Shaner, G - PURDUE UNIVERSITY BOTANY|
|Cochran, A - PURDUE UNIVERSITY BOTANY|
Submitted to: Midwest Soybean Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 7, 2000
Publication Date: N/A
Technical Abstract: Soybean yield losses due to sudden death syndrome (SDS) occur regularly. This relatively new disease caused by a toxin producing form of the Fusarium solani fungus has become a serious disease of soybeans in the southern and Midwestern states. Abundant moisture during the early reproductive stages of the host enhances SDS damage. Root infections are common and occur early, but seldom advance into the taproot prior to the flowering stage. Delayed planting and management practices that improve plant health during the flowering period help reduce disease losses. Results of yield loss and foliar symptom studies with diverse soybean germplasm sources indicate the disease can be very destructive. Most soybeans tested to date are somewhat susceptible to the disease. Only a few soybean varieties derived from a narrow genetic base have been identified as having some degree of resistance. Equally important, variety yreaction to SDS appears to be conditioned to some degree by the soybean cyst nematode (SCN). In addition, SDS evaluations of selected germplasm identified P.I.437654 (resistant to all known SCN races) as highly susceptible to SDS. This information summarizes the cardinal characteristics and disease cycle associated with SDS of soybeans. Diagnostic characteristics associated with the fungal pathogen, soybean disease symptoms, and disease control strategies are included. The information will be useful to extension and crop specialists in diagnosing and recommending control measures for soybean production where the disease is a major problem. It will also permit pathologists and breeders to utilize and evaluate selected germplasm in the development of soybeans with improved resistance to SDS.