- Author: Jeannette E. Warnert
Napa and Sonoma county winegrape producers saw an increasing incidence of Pierce's disease during the 2015 growing season, reported Lynn Alley in the Wine Spectator.
Pierce's disease is caused by Xylella fastidiosa bacteria, which can be spread by a variety of sharpshooter insects. The outbreak in Napa and Sonoma counties is associated with blue-green sharpshooters.
There's been a “huge increase in traditional (Pierce's disease) hotspots and in sites not normally affected,” said Rhonda Smith, UC ANR Cooperative Extension viticulture advisor in Sonoma County....