New Diseases and Epidemics Canker of Japanese Maple Caused by Colletotrichum acutatum. V. L. Smith, Assistant Scientist, Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven 06504. . Plant Dis. 77:197-198. Accepted for publication 12 October 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0197.

Colletotrichum acutatum was identified as the pathogen causing a canker and dieback of Japanese maple (Acer palmatum) in propagation at a Connecticut nursery. Symptoms and signs included cankers frequently associated with wound sites, abundant acervuli, prominent masses of spores under conditions of high humidity, and death of cuttings. The fungus was consistently isolated from affected plants, and similar symptoms were expressed on inoculated seedlings in a greenhouse. One isolate from maple incited bitter rot of apple cv. Granny Smith fruit. This is the first report of C. acutatum causing a disease on a woody plant in North America.