Several fungi cause cankers and dieback on branches and trunks. Remove infected branches as they occur and avoid wounding the tree. Fertilizing infected trees may help. Powdery mildew forms a white coating on the leaves but is usually not serious. If control is needed, use benomyl.
Verticillium wilt causes dieback and death of individual branches or the entire tree.
Keep trees healthy to prevent the disease. Fertilizing infected trees with high nitrogen fertilizers helps. This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. This information becomes public property upon publication and may be printed verbatim with credit to MSU Extension.