Informational table showing disease name, symptoms, pathogen/cause, and management of Chestnut diseases. Disease Symptoms Pathogen/Cause Management Blight Slightly sunken or slightly swollen cankers on branches or the trunk are yellow-brown and oval or irregular in shape. As the stems are girdled, the leaves yellow and brown but remain attached to the branch. Water sprouts may develop below the canker. During wet weather, yellowish masses of spores ooze from orange pimple-like fruiting structures that pepper the surface of the canker. Cryphonectria parasitica (formerly Endothia parasitica) American and European chestnuts are susceptible. Chinese and Japanese chestnuts are not immune but have some resistance. Remove infected trees. Leaf spot Small, circular, yellow to brown spots have concentric rings within them. Spots may drop out and leave a shot hole, or leaves may fall prematurely. Marssonina ochroleuca No control is recommended. Twig canker (Chinese and Japanese chestnuts) Cankers on any part of the tree girdle and kill the tissue. Cryptodiaporthe castanea Prune infected wood.

Chestnut blight cankers

Prepared by Gary W. Moorman, Professor of Plant Pathology