Grapevine Red Blotch Disease

Abstract

Grapevine red blotch disease (GRBD) is a recently recognized viral disease. It was first described on Vitis vinifera cv. Cabernet Sauvignon at the University of California Oakville Research Field Station in 2008, but the causative agent was not characterized until 2012. The disease, GRBD, is caused by a DNA virus named Grapevine red blotch-associated virus (GRBaV). Infected red wine grapevines exhibit symptoms similar to those associated with leafroll disease, with red blotches forming on leaves during the later summer months. Fruit ripening issues have been reported in grapevines diagnosed with GRBD. The symptom similarity to leafroll disease and abiotic factors such as nutrient deficiencies, insect damage, or physical injuries makes visual diagnosis difficult and explains the delay in recognition and characterization of the disease.