Epidemiology of Diseases Caused by Xylella fastidiosa in California: Evaluation of Alfalfa as a Source of Vectors and Inocula.

Pierce's disease and almond leaf scorch disease have been chronic problems for California grape and almond growers, respectively. Both diseases are caused by the xylem-limited, bacterial pathogen Xylella fastidiosa, which is transmitted by xylem-feeding insects. We evaluated the potential for alfalfa to serve as a source of vectors and inocula in California.