RT Journal Article
SR Electronic
T1 Spatial Patterns of Pierce's Disease in the Napa Valley
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP 162
OP 167
DO 10.5344/ajev.1974.25.3.162
VO 25
IS 3
A1 A. H. Purcell
YR 1974
UL http://www.ajevonline.org/content/25/3/162.abstract
AB The spatial pattern of Pierce's disease of grapevines was studiied by mapping diseased grapevines in eight vineyard plots in the Napa Valley, California. The percentage of diseased vines was highest nearest natural riparian vegetation, declining with distance (up to 400 to 500 ft) from natural source areas of the principal leafhopper vector, Hordnia circellata (Baker). The slope of disease dispersal gradients annual changes in apparent infection rate, and the overall incidence of Pierce's disease varied among grape varieties in adjacent plantings with similar exposure to vector source areas.