Current Research on Pierce’s Disease and Vectors

University of California scientists, specialists and farm advisors have been investigating Pierce’s disease in grapes periodically for at least 50 years.^[1] Researchers from land-grant colleges and universities in states where PD is epidemic also have developed an extensive body of knowledge on the disease and GWSS over the years. Unfortunately for the current situation, sustained research in California on Pierce’s disease and its vectors waned during the past few decades with the gradual decline of periodic epidemics of the disease in the state.

^[1] The December 1946 issue of California Agriculture carried remarks by UC President Robert Gordon Sproul at the annual meeting of the California Farm Bureau Federation. Sproul said, “Some of these agricultural enigmas, like Pierce’s disease of grapevines ... still baffle the scientists.” He went on to report “Pierce’s disease is not new; many years ago it ruined the vine industry of Orange County. Today, several departments of the University ... are bending every effort to see that it shall not destroy the important grape industry that has grown up in other parts of the state.” (Santa Cruz, CA; October 30, 1946).