Coryneum blight, also called shot hole disease, California blight, peach blight or pustular spot, is caused by a fungus that attacks mainly peaches and apricots, and, less often, sweet cherries.
Early symptoms appear as small, red spots that enlarge and become purple with a white center.
These spots will drop out of the leaf, leaving a shot hole. Numerous shot holes give a tattered appearance to leaves. Coryneum blight also will infect leaf buds, blossom buds and twigs, and cause small, sunken twig cankers. Infection to these areas weakens a tree. More serious damage shows up as blemished or disfigured fruit.