New Insight about Disease Resistance and Management of Sudden Death Syndrome of Soybean

Sudden death syndrome (SDS) is an increasingly important root rot disease of soybean that is caused by blue-pigmented, ‘toxin’ producing strains of Fusarium solani.  The SDS pathogen in the U.S. has recently been designated F. virguliforme replacing the earlier designation of F. solani f. sp. glycines.  Yield losses due to SDS are especially dependent upon growth stage at the time of active colonization of roots, cultivar reaction, interaction with other soybean pathogens, and environment.  SDS is a fungal disease that occurs regularly in a disease complex with the soybean cyst nematode.  These two pathogens combined lead to the most severe yield losses of soybean in the U.S.  It is not uncommon for SDS losses in highly susceptible soybean cultivars to range from 50-80% in individual fields.  Although many questions about SDS resistance are unanswered, utilizing knowledge of SDS to improve disease management can reduce yield losses.  The primary objectives of this presentation are to summarize our current knowledge of SDS and to indicate how this knowledge can be used to manage the disease more effectively.  Information about the SDS fungal pathogen, soil inoculum levels, disease symptoms and influence of soil moisture on disease development, host resistance and cultivar selection, interaction of SDS with other soybean pathogens, and the influence of planting date, crop rotation and tillage practice on SDS severity will be addressed.

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T. Scott AbneyUSDA/ARS Soybean Pathologist & Professor
Purdue University
abney@purdue.edu


My research is to identify and define the role(s) of fungal pathogens infecting soybeans. Host resistance is a major emphasis. The overall objective of the soybean disease research is to increase soybean productivity and profitability through reducing soybean yield losses due to SDS and Phytophthora root rot. Identification of host-plant resistance, environmental conditions and the influence of crop management practices on disease severity are addressed and will improve disease management.