A Proactive Approach for Fighting Invasive Pests and Diseases

In the face of increasing risks of invasive pests and diseases from around the world and nation, California’s winegrape growers today can turn to the innovative grower-government partnership created almost two decades ago to help protect their vineyards. The research, outreach and other activities which the Pierce's Disease and Glassy-Winged Sharpshooter Board funds are all geared toward safeguarding California winegrapes.

In 2001, an annual, value-based assessment on winegrapes was established to fund PD/GWSS research and related activities. The PD/GWSS Board, an advisory board composed of winegrape growers and processors, was also established at that time. The Board advises the California Department of Food and Agriculture on the best use of assessment funds, ensuring dollars are spent wisely and productively to find solutions to PD, GWSS, and other designated pests and diseases of winegrapes. Over the years, the assessment rate has averaged $1.39 per $1,000 of crop value. Over $45 million has been spent on research and outreach since 2001.

Projects funded by the PD/GWSS Board are showing promising results. Winegrapes resistant to PD and other control techniques are headed toward commercial availability, and research continues to search for practical and sustainable solutions and control methods for PD, GWSS, and other serious winegrape pests and diseases. Through it all, the PD/GWSS Board, guided by winegrape growers and vintners from around the state, strives to ensure assessment funds are spent wisely and productively.


The PD/GWSS Board consists of at least 14 members who are winegrape growers or grower processors, and one member from the public. Board meetings are held quarterly or more as needed, and open to the public.



  • Jeff Bitter, Allied Grape Growers, Fresno

  • Pam Bond, Swanson Vineyards, Oakville

  • Gregory Coleman, E&J Gallo Winery, Modesto

  • Robert Crudup, BrightView Tree Company, Fillmore

  • William Drayton, Treasury Wine Estates, St. Helena

  • Bill Hammond, Jackson Family Wines, Santa Rosa

  • Rich Hammond, Hammond Family Vineyards, Fresno

  • John “JD” Harkey, Drake Enterprises, Inc., Temecula

  • Randy Heinzen, Vineyard Professional Services, Inc., Paso Robles

  • Keith Horn, Producer-Processor, Central Valley

  • Fredrick R. (Trey) Irwin III, Tejon Ranch Company, Lebec

  • Aaron Lange, LangeTwins Family Winery and Vineyards, Acampo

  • Jim Ledbetter, Vino Farms, Healdsburg

  • Steve McIntyre, Monterey Pacific, Inc., Soledad

  • Domonic Rossini, Fratello Farming, Denair

Pierce's Disease Advisory Task Force

The Task Force is composed of county agricultural commissioners, scientists, agricultural representatives, and other experts. It reviews program progress and develops recommendations for the Secretary of CDFA as well as provides counsel to the PD/GWSS Board.


  • Kevin Andrew, consultant, Bakersfield

  • Cathy Fisher, Santa Barbara County Agricultural Commissioner

  • Deborah Golino, University of California, Davis

  • A. Humberto Izquierdo, Napa County Agricultural Commissioner

  • Jean-Mari Peltier, Consolidated Central Valley Table Grape and Pest Disease District

  • Beth Stone-Smith, United States Department of Agriculture

  • Judy Zaninovich

California Department of Food and Agricu