Benomyl-Resistant Strains of Botrytis cinerea on Apples, Beans, and Grapes. R. C. Pearson, Assistant Professor, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456. D. A. Rosenberger, Assistant Professor, and Cheryl A. Smith, Research Technician III, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, Highland, NY 12528. Plant Dis. 64:316-318. Accepted for publication 29 October 1979. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-316.

Strains of Botrytis cinerea resistant to benomyl were isolated from apples, beans, and grapes where the fungicide had been used primarily for control of other disease organisms. The level of resistance for each Botrytis isolate from the three hosts could not be related to the history of benomyl usage on those crops. Benomyl-resistant isolates from the three hosts were pathogenic on each of the other two hosts, and more variation in aggressiveness was observed among isolates from the same host than among isolates from different hosts. Since apples, beans, and grapes may be grown in neighboring fields, spread of benomyl-resistant pathogenic isolates from one host to another can be expected to complicate control strategies.