Foliage of affect limbs is sparse and leaves can be small. Dry, thin bark will crack and split to reveal black, powdery spores.
Branches die back to the canker.
Can occur anywhere on the tree. This fungus can only infect its many hosts via a wound. Pruning often opens the door, either directly through the pruning cuts, or indirectly by exposing the stems to sun scald . Sapsuckers or rubbing branches in the canopy can also provide entryway. Apply a broad spectrum fungicide to the wound.