Gardening - Fruit: Pests & Diseases
Bacterial spot, known also as bacteriosis, bacterial shothole, or shothole, is caused by the bacterium Xanthomonas campestris pv. pruni. Although primarily a peach and nectarine problem, this disease also occurs on apricots, plums and, to a lesser degree, cherries.
Losses due to bacterial spot occur from affected fruit and from the devitalization of trees caused by frequent defoliation. Such weakened trees are more subject to winter injury. Losses are greatest in light, low-fertility soils. Trees low in vigor are more susceptible to bacterial spot than vigorous trees.
"SP277-I-Bacterial Spot of Peach," The University of Tennessee Agricultural Extension Service, , http://trace.tennessee.edu/utk_agexgard/71