Cytospora can infect branches through wounds and branch stubs, but does not actively develop a Cytospora canker unless the tree is stressed by drought. Small fungal structures, in which thousands of spores form, develop in the canker. However, during wet weather, the spores ooze out in long yellowish threads. Rain splashes the spores to other branches and branch killing proceeds up the tree.
- Select the planting site carefully, avoiding drought prone sites.
- Prune out and destroy infected branches, disinfecting the tools between cuts.
- Cytospora Canker enters a tree through wounds. Therefore, avoid damage to the bark from lawn mowers, tools, etc.