THE EFFECT OF DORMANT SEASON SURVIVAL OF XYLELLA FASTIDIOSA IN GRAPEVINES

• Author(s): Hill, Barry; Hashim, Jennifer; Peacock, William;
• Abstract: The two California Pierces disease (PD) epidemics associated with population outbreaks of glassy-winged sharpshooter, at Temecula in the mid 1990s and in Kern County peaking in 2002, differed dramatically in the number of vineyards lost and the grapevine varieties affected. It is postulated that vine-to-vine (secondary spread) of infections occurred throughout all vineyards in both areas but the survival and progression to disease of these infections differed between the two areas. In Temecula, many of the resulting infections survived vine dormancy and progressed to chronic disease resulting in the loss of half or more of the areas vineyards of all varieties. In Kern County only some of the infections in only two varieties, Redglobe and Crimson Seedless, survived vine dormancy and progressed to disease, and vineyards of all other varieties were unaffected. A hypothetical explanation of this epidemiological pattern is presented and experiments are begun to test this hypothesis. The benefit to grape growers in the southern San Joaquin Valley will be to provide reliable ways to reduce risk of loss by PD epidemics.
• Publication Date: Dec 2005
• Journal: 2005 Pierce's Disease Research Symposium