Leafspot of Black Cherry

United States
Department of
Agriculture

Forest Service

Northeastern Area

NA-PR-01-92

Leafspot of Black Cherry
A leafspot caused by the fungus Blumeriella jaapii can damage black cherry seedlings in both forests and nurseries. The disease was formerly know as Coccomyces leafspot (from the genus of synonyms for the causal fungus). Affected leaves bear spots that initially are purple. In moist conditions, light-colored spore masses may ooze from fruiting bodies in these spots on lower leaf surfaces. Spots can enlarge and develop necrotic brown centers that sometimes drop out to result in "shot holes." As numerous spots develop, leaves can become chlorotic or necrotic and be prematurely shed. Defoliation of seedlings in forests is associated with mortality which might contribute to delays or failures of natural regeneration. Defoliation in nurseries can result in stunting that reduces numbers of acceptable seedlings.


Figure 1. Nursery seedlings defoliated by leafspot (left), and protected from disease by applications of a fungicide (right).	Figure 2. Symptoms on forest seedling including small, purle spots on recently infected leaf (arrow).

Figure 3. Range of spots, chlorosis, and necrosis on leaves from nursery seedlings.	Figure 4. Fruiting bodies of the asexual state, Phloeosporella padi, in spot on lower leaf surface.

Authors:

Glen R. Stanosz, University of Wisconsin-Madison

Mary L. Torsello, USDA Forest Service

For additional information, contact:

USDA Forest Service
Forest Health Protection
180 Canfield Street
Morgantown, WV 26505
(304) 285-1541 USDA Forest Service
Forest Health Protection
271 Mast Road
Durham, NH 03824-0640
(603) 868-7704 USDA Forest Service
Forest Health Protection
1992 Folwell Avenue
St. Paul, MN 55108-1099
(612) 649-5261