Identification, Etiology, and Control of Euonymus fortunei Anthracnose Caused by Colletotrichum gloeosporioides. Matthew J. Mahoney, Shade Tree Laboratories, Department of Plant Pathology, University of Massachusetts, Amherst 01003. Terry A. Tattar, Shade Tree Laboratories, Department of Plant Pathology, University of Massachusetts, Amherst 01003. Plant Dis. 64:854-856. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-854.

A leaf and stem spotting disease on field- and container-grown Euonymus fortunei ‘Emerald ‘n Gold’ and ‘Gaiety’ was found at several nurseries in New England. Colletotrichum gloeosporioides was consistently isolated from diseased leaves and stems. Leaf and stem lesions were discrete, circular, dark brown, and 0.5–3.0 mm in diameter with light tan necrotic centers. Initial infection occurred during late May in Massachusetts and repeated infections occurred throughout the growing season. Under laboratory conditions, lesion development was most severe after 24 hr or more of leaf wetness, and the optimum temperature range for vegetative growth of the fungus and spore germination was 25–30 C. All E. fortunei cultivars tested under laboratory conditions were susceptible to infection, and maneb, mancozeb, and chlorothalonil completely protected leaves from lesion development.