Interaction of Erwinia chrysanthemi and Fusarium solani on Sweetpotato. V. Duarte, Former Graduate Student, Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Louisiana Agricultural Experiment Station, Baton Rouge 70803-1720. C. A. Clark, Professor, Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Louisiana Agricultural Experiment Station, Baton Rouge 70803-1720. Plant Dis. 77:733-735. Accepted for publication 29 March 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0733.

Stem cuttings of sweetpotato cultivars Jewel and Beauregard were inoculated with Erwinia chrysanthemi and/or Fusarium solani and then transplanted in the greenhouse or the field. In the greenhouse tests, stem rot lesions in plants coinoculated with both pathogens were longer than those in plants inoculated with either pathogen separately. In the field tests, however, stem rot incidence was low, and no interaction effect 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 significantly larger in coinoculated roots than in roots inoculated with E. chrysanthemi alone.