California Ag Network

Tag: GWSS

  • Pierce’s Disease Investment Saves Wine Grape Growers $56M Annually

    According to a new economic impact study, the California Department of Food and Agriculture’s Pierce’s disease (PD) and glassy-winged sharpshooter (GWSS) prevention, control and research efforts save California winegrape growers $56 million annually by reducing losses from the fatal grapevine disease. Without the program’s efforts, growers’ losses would more than double from $48 million to $104 million. The study found that if GWSS spread unchecked, outbreaks of PD could cost winegrape growers an additional $56 million a year in lost production and vine replacement.

    The Costs of Pierce’s Disease in the California Grape and Wine Industry

    “This study highlights the serious threat Pierce’s disease and the glassy-winged sharpshooter pose to our industry and reinforces the importance of grower-funded research,” said Randy Heinzen, a Paso Robles winegrape grower on the Pierce’s Disease and Glassy-Winged Sharpshooter Board. “The public-private partnership led by the Pierce’s Disease Control Program is vital, allowing grower assessment funds to drive research that improves pest and disease management and to develop practical, sustainable solutions for the long-term viability of our industry.”

    The unique funding partnership the winegrape industry forged between growers, the state and federal government and industry fuels the essential research and control operations that have significantly blunted the most severe impacts of PD and GWSS. Even with these efforts, PD still costs an estimated $110 million annually in California, including $45 million for control, prevention and research, $48 million in lost winegrape production and vine replacement and $17 million in lost table and raisin grape production and vine replacement. Without these critical programs, the industry’s losses in production and vine replacement would be even higher, putting greater financial strain on growers and threatening the long-term stability of California’s vineyards.

    With industry and government support keeping PD and GWSS in check, grower-funded research continues to drive advancements in pest and disease management while supporting field trials for promising solutions. According to the study’s authors, the economic burden of PD and GWSS could decrease as this research yields practical, vineyard-ready innovations.

  • Glassy-Winged Sharpshooter Infestation Detected in Solano County

    A local infestation of the glassy-winged sharpshooter (GWSS) has been detected in a residential area of Vacaville in Solano County. The pest is primarily a threat to grapevines because it can spread a fatal bacterium that causes Pierce’s disease (PD); however, the pest and disease can also impact susceptible types of citrus crops. Five adult GWSS were found Oct. 1 in traps set as part of a broad array designed specifically to detect this pest throughout areas of the state that are not infested. Additional traps have since been deployed at a higher density near those two initial detection sites, detecting approximately 35 additional GWSS. Visual surveys of plant material in the area have also detected egg masses in the same neighborhood. No GWSS or egg masses have been detected outside this immediate area.

    Working with the Solano County Agricultural Commissioner’s office and others in the region, the California Department of Food and Agriculture (CDFA) is continuing to survey the area, inform local growers and the broader community, and develop appropriate next steps to eradicate this infestation.

    If agricultural officials determine that pesticide treatments are necessary to eradicate this infestation, treatments would be made by ground equipment only and would consist of applications to the root zone and leaves/branches of the host plants to target adult GWSS and provide long-term, systemic protection against re-infestation. In previous eradication projects for this pest, properties with host plants within a 150-meter radius around each detection site were treated.

    Residents of affected properties will be invited to a public meeting with officials from CDFA, the county agricultural commissioner’s office, the Department of Pesticide Regulation and the Office of Environmental Health Hazard Assessment to address residents’ questions and concerns. Residents would be notified in writing at least 48 hours in advance of any treatment.

    GWSS is an invasive and aggressive vector of PD, which is considered one of the most devastating diseases of grapevines in the world. It currently infests 12 California counties, with established populations across Southern California. While grapevines are the pest’s most famous target, other crops and ornamental plants such as almonds, citrus, stone fruit and various shade trees are also at risk from the PD’s strain of the bacterium.

    For additional information and details on the infestation, please visit CDFA’s website here. — Citrus Pest & Disease Prevention Program