|Grower perceptions of preventative practices for management of trunk diseases of grape|
K. BAUMGARTNER (1), R. Travadon (2), V. Hillis (2), J. Kaplan (3), M. Cooper (2), M. Lubell (2). (1) USDA ARS, Davis, CA, U.S.A.; (2) UC Davis, Davis, CA, U.S.A.; (3) California State University, Sacramento, Sacramento, CA, U.S.A.
Trials on prevention of trunk diseases (e.g., Eutypa dieback) show that three practices [delayed pruning, double pruning, pruning-wound protectants] prevent pruning-wound infections by 25-100%. Nonetheless, they are often not adopted until disease incidence is >20% in mature vineyards. There are no eradicative controls. Our goal is thus to encourage adoption in young vineyards. We surveyed 350 grape growers in five California regions (Napa-Sonoma, Central Coast, N. San Joaquin, S. San Joaquin, N. California) using the audience-response software Turning Point, in extension meetings. Growers answered questions on practice usage (never to always), vineyard age when practice was adopted (0-3, 4-7, 8-12, and 13+ years), and perceptions of disease-control efficacy and cost-effectiveness (ineffective to effective). In all but one region (Napa-Sonoma), preventative practices were adopted in vineyards >8 years old, with mean disease incidence of 15%. Delayed pruning was most common except in Sonoma, where pruning-wound protectants were most common. Growers who adopt a practice in vineyards <8 years old also had positive perceptions of efficacy and cost-effectiveness, suggesting that timing the practice before symptoms appear does indeed maintain yields and is cost-effective. With a clear understanding of their usage and perceptions, we will develop new extension tools that better communicate to growers the case for preventing trunk diseases in young vineyards.