Susceptibility varies among species, with white and bur oaks usually the most severely affected. Leaf distortion caused by oak anthracnose lesions. The first symptom seen in the spring is usually shoot blight, which can develop suddenly following rain. Young leaves and shoots appear brown and shriveled. Some leaf drop may occur.
Mature leaves are fairly resistant and infection causes only small necrotic spots.
The fungus also infects twigs, producing cankers and causing twig dieback during the winter and early spring. Maple Anthracnose Several species of fungi cause maple anthracnose. The most prevalent one, Kabatiella apocrypta , attacks Norway, red, silver and sugar maples, and boxelders. Leaf lesions and distortion caused by maple anthracnose. The symptoms caused by K. apocrypta appear following infection during cool, wet weather throughout the spring and summer.