Penn State and the state department of agriculture also sponsored a symposium on plum pox, bringing in several European specialists to recommend control strategies. Both the publication and videotapes featuring highlights of the symposium will be available at Penn State Cooperative Extension county offices. The publication is designed to be updated every few months, and the Web site will be updated regularly. In Pennsylvania, the disease will affect primarily peach trees. The state ranks fifth in peach production nationwide.
Sharka symptoms range from minor to severe.
Foliage symptoms at first glance can look like a nutritional deficiency or insect injury. As the disease progresses, lesions can spread to the fruit, making it unsalable. Finally, the disease causes massive drops in yield, ranging from 80 to 100 percent. The Biglerville facility also will be equipped to test samples taken from fruit trees in Pennsylvania for plum pox virus. Tim Gottwald, a USDA statistician, estimates that when spring foliage appears at least 50,000 samples from trees in Adams and surrounding counties must be tested to determine if the virus has spread beyond the initial infected trees.