SOYBEAN SUDDEN-DEATH SYNDROME - CULTIVAR REACTIONS TO INOCULATION IN A CONTROLLED ENVIRONMENT AND HOST-RANGE AND VIRULENCE OF CAUSAL AGENT

Reactions of 27 soybean cultivars to inoculation with Fusarium solani form A, the cause of sudden death syndrome, were determined under grow th chamber conditions. Significant differences in susceptibility occur red among the cultivars. Selected comparisons between cultivar reactio ns in the growth chamber and in the field indicated close corresponden ce, but some inconsistencies occurred. Of 21 nonwounded and wounded pl ant species inoculated in a host range test, the only nonwounded speci es developing symptoms were soybean and mung bean; green bean, lima be an, and cowpea became infected only after wound inoculation. In virule nce tests, some of the 31 isolates tested differed; but most, 24, were equally virulent. Virulence was not related to substrate or geographi c origin.