Bacterial blossom blast of pear
Disease
Bacterial blossom blast of pear
Pseudomonas syringae pv. syringae van Hall
Distribution: Common to all fruit-growing regions in eastern North America; most common in cool and wet climates.
The most common symptoms are wilting followed by browning or blackening of blossoms, often spreading through the entire blossom truss and killing the fruiting spur (A, B). If infection is restricted to the calyx-cup and the blossom is not killed, this may lead to the development of black lesions on developing fruit; many of these fruit drop. Infection of the leaves leads to the development of small lesions and "shot holes"; entire leaves may be killed.