Disease Note.

Xylaria Root Rot of Urban Trees Caused by Xylaria polymorpha. T. J. Proffer, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824. . Plant Dis. 72:79. Accepted for publication 14 September 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0079A.

Xylaria root rot affects a variety of landscape trees with basal wounds on the campus of Michigan State University. In 1986, mature stromata were collected from crabapple (Malus 'Snowdrift'), thornless honeylocust (Gleditsia triacanthos L. var. inermis Willd.), eastern redbud (Cercis canadensis L.), and hedge maple (Acer campestre L.). Based on ascospore and stromata characteristics, the fungus was identified as Xylaria polymorpha (Pers.:Fr.) Grev. X. polymorpha has been reported on other Malus and Acer species (2). This report extends the host range within those genera and to the genera Cercis and Gleditsia. Honeylocust was previously noted as a host of X. mali Fromme (I). Xylaria root rot appears to playa role in the decline of a variety of urban trees, and management practices minimizing basal trunk and root injuries are warranted.

References: (I) J. D. Rogers. Mycologia 76:23, 1984. (2) J. D. Rogers and B. R. Callan. Mycologia 78:391, 1986.