LOCALIZED INFLUENCE OF HETERODERA-GLYCINES ON SUDDEN-DEATH SYNDROME OF SOYBEAN

Half-root tests were established to examine the association between He terodera glycines and the blue strain of Fusarium solani, the causal a gent of sudden death syndrome (SDS) of soybean. Two independent root s ystems were established for soybean 'Coker 156' and inoculated (half r oot/half root) with F. solani, H. glycines, both organisms on opposite root halves, both organisms on one root half, or neither one. Foliar symptoms were more severe for plants inoculated with both organisms on one root half than on opposite root halves or F. solani alone. Root n ecrosis ratings were more severe when both pathogens were combined on one root half than on opposite root halves. Heterodera glycines popula tion development was reduced by the combination of both pathogens on o ne root half compared to opposite root halves or H. glycines alone, re gardless of inoculation time.