chestnut blight

chestnut blight

Plant disease caused by the fungus Endothia parasitica. Accidentally imported from East Asia and first observed in 1904 in New York, it has killed almost all native American chestnuts (Castanea dentata) in the U.S. and Canada and is destructive in other countries. Other blight-susceptible species include the European chestnut (C. sativa), the post oak (Quercus stellata), and the live oak. Symptoms include reddish brown bark patches that develop into sunken or swollen and cracked cankers that kill twigs and limbs. Leaves on such branches turn brown and wither but remain attached for months. Gradually the entire tree dies. The fungus persists for years in short-lived sprouts from old chestnut roots and in less susceptible hosts. It is spread locally by splashing rain, wind, and insects, and over long distances by birds. Chinese (C. mollissima) and Japanese (C. crenata) chestnuts are resistant.