Pest identification
and confirmation—Bacterial canker
Bark infected with Pseudomonas syringae has infected cankers darker than the surrounding, healthy
bark, and the underlying diseased tissue is reddish brown, moist, and may be sour-smelling. Cutting into
infected bark beyond the margin of cankers may reveal small, brown flecks in the inner bark tissue, especially
in apricots and plums. Affected limbs may fail to leaf out in the spring or may produce new growth, which
dies soon after temperatures increase in the summer. If trees are killed by bacterial canker, new shoots
are frequently produced from the rootstock. | 
Red
flecks in wood beneath the main canker |
