Pierce’s disease (PD), caused by the bacterium Xylella fastidiosa, is quite prevalent in many locations this year. The cold winter this last year has not made up for the two previous warm winters, so the bacterium has survived and prospered over the last 2-3 years. Unfortunately, once vines are infected and symptomatic, the vines need to be destroyed immediately or as soon as possible to prevent further spread. Accurate identification is important, as one does not want to destroy vines with chemical damage or some other issue which mimics PD. We are starting a pilot program in which select county agents will use kits to confirm PD if questions exist. If you need help with identification, please contact your local county agents. They will be glad to help — making sure that you know all the symptoms of PD and confirming that Xylella is the cause of the symptoms you observe. If you can’t destroy vines now, you need to flag vines for destruction as soon as harvest has been completed.
Pierce’s disease on Vitis vinifera vine in northern Georgia (2018).
Phil Brannen is a Professor in the Plant Pathology Department at the University of Georgia. He attended the University of Georgia for his undergraduate degree in Plant Protection and Pest Management, where he also received an M.S. in Plant Pathology, followed by a Ph.D. in Plant Pathology from Auburn University. He has extensive experience with disease management programs in numerous cropping systems. He serves as the extension fruit pathologist for Georgia – conducting research and technology transfer for multiple fruit commodities. His efforts are directed towards developing IPM practices to solve disease issues and technology transfer of disease-management methods to commercial fruit producers. He also teaches the graduate level Field Pathology Course, the History of Plant Diseases and their Impact on Human Societies Course, team-teaches the IPM Course, coordinates the Viticulture and Enology in the Mediterranean Region Course (Cortona, Italy), and guest lectures in numerous other courses throughout the year.
