Cankers are irregularly shaped, brown, sunken areas that develop in the bark, twigs, branches, and the tree trunk. Amber-colored sticky gum may exude from the margins of cankers. Orange threadlike structures may also exude from cankers. Leaves may shrivel and die; branches may also die.
Solutions
If trees have been infected, remove entire affected branches in the summer, being sure to eliminate the entire canker and a few inches below. Avoid planting on shallow soils. Where feasible, delay pruning until late winter; prune in dry weather. Avoid overhead sprinklers and excess fertilization. Maintain good tree vigor and avoid problems such as bacterial canker or sunburn as these disorders may make trees more susceptible to cytospora canker. Whitewashing trees may help to seal wounds as well as protect against sunburn.
