Chestnut Diseases

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Disease	Symptoms	Pathogen/Cause	Management
Blight	Slightly sunken or slightly swollen cankers on branches or the trunk are yellow-brown, 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 chestnusts 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 leaving 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.