(PWV) - New DNA sequencing technology has been used to discover the grapevine red blotch-associated virus (GRBaV) in grapevines affected by “red blotch,” a disease that discolors grape leaves in early fall and reduces sugar levels in grapes.

 Nursery managers received the new information during an annual industry update at the University of California, Davis, Feb. 20, 2013. The virus is of particular concern to wine grape growers, whose grapes must reach a certain sugar content level before they are suitable for winemaking.

 “The most urgent research need now is to determine how the virus spreads,” says Deborah Golino, director of the University of California, Davis-based Foundation Plant Services and a cooperative extension plant disease specialist. “Due to the distribution of the virus in many parts of the United States and evidence that it can be transmitted by grafting, we suspect that red blotch disease is widespread wherever grapes are grown.