INTERACTION OF ERWINIA-CHRYSANTHEMI AND FUSARIUM-SOLANI ON SWEET-POTATO

Stem Cuttings of sweetpotato cultivars Jewel and Beauregard were inocu lated with Ewinia chrysanthemi and/or Fusarium solani and then transpl anted in the greenhouse or the field. In the greenhouse tests, stem ro t lesions in plants coinoculated with both pathogens were longer than those in plants inoculated with either pathogen separately. In the fie ld tests, however, stem rot incidence was low, and no interaction effe ct was observed with either cultivar in 1989 or 1990. Neither pathogen , alone or in combination, had a consistent effect on yield. When the pathogens were applied to wounded storage roots, lesions were not sign ificantly larger in coinoculated roots than in roots inoculated with E . chrysanthemi alone.