A California avocado tree canker that occurs on twigs, branches or trunks is caused by a complex of fungal pathogens which include many species in the Botryosphaeriaceae family. Canker pathogens can enter and initiate infection through wounds on the bark surface, such as pruning, frost damage and mechanical injury wounds. The cankers can result in stem-end rot of avocado trees.
Avocado branch canker symptoms
- Exuding a reddish sap that dries to a brown and white powder.
- Avocado tree bark may be cracked, darkly discolored, or slightly sunken.
- With older cankers, bark may be friable and easily removed from the damaged area.
- Under the canker, inner bark and wood is red-brown to brown.
- When and avocado tree branch is cut, a characteristic wedge-shaped canker extending deep into the xylem may be visible.
- If much of the avocado tree xylem becomes infected, limbs may collapse and leaves may turn brown and show leaf scorch, but remain attached.