We will soon be observing symptoms of Pierce’s disease in susceptible grape varieties — Vitis vinifera and some hybrids such as Chambourcin. Unfortunately, winter temperatures have now been mild for several years, so we are seeing an uptick in Pierce’s disease at higher and higher elevations in Georgia and throughout the Southeast. Symptoms normally show up in late July or August, especially under dry conditions. North Carolina State recently developed a nice training on Pierce’s disease. See the attached PowerPoints and a link to the training if you are interested. It is particularly important that you identify and destroy infected vines to prevent further spread of this disease. Accurate identification is critical. I am also attaching a guide that we developed here in Georgia. Please contact your local county agents should you need help in confirming this important disease. You don’t want to to remove plants that are showing similar mimics of Pierce’s disease (e.g. drought or nutrient stress), and at the same time, you really do not want to keep Pierce’s disease infected plants in your vineyard — a critical decision for sure.
