Eutypella Canker
From Bugwoodwiki
|
USDA Forest Service. 1979. A guide to common insects and diseases of forest trees in the northeastern United States. Northeast. Area State Priv. For., For. Insect and Disease Management., Broomall, PA. p. 123, illus.
Eutypella canker, caused by the fungus Eutypella parasitica, is a common disease of maple tree. All maples are susceptible, sugar maple more so than others. The disease is found throughout the northern half of the range of sugar maple. It attacks primarily saplings or small sawtimber-sized trees, and usually affects only scattered trees within a stand.
The first symptom is a callus formation around an infection point, usually at a branch stub or wound. A sunken, dead area develops in the center of the callus and expands as the fungus grows outward. Broad, slightly raised areas of callus tissue may cause a wave-like appearance on the canker face. In later years the cankered area may form a hump, as the tree responds to invasion of the fungus. Dry, flinty bark normally remains attached to the face of the canker for many years. White mycelial fans can be found by cutting the callus tissue from the canker.
Black fruiting bodies develop in older cankers and release wind-dispersed spores. The spores are thought to infect other trees through openings in the bark such as branch stubs, logging wounds, sucscald and frost cracks.
Gallery
 Photo by Joseph O'Brien, USDA Forest Service, Bugwood.org |
