Bacterial canker is a plant disease which has two other names.
Bacterial canker in cherry trees is also known as bacterial blast and may be referred to as bacterial gummosis. Although it is a prime and severe attacker of cherry trees, bacterial canker also attacks a wide variety of both fruit and nut trees. This disease, whether called bacterial canker, bacterial gummosis, or bacterial blast in your region is caused by the bacterium pseudomonas syringae. Bacterial canker is active in all phases of the growing season for cherry trees but can be most devastating to young trees which are more susceptible to damage from pseudomonas syringae bacterium. The bacterial canker disease first appears as yellow and green leaves discoloring.