|The role of pest control advisors in managing grapevine trunk diseases: a survey of perceptions of practice efficacy and trends in recommendations|
K. BAUMGARTNER (1), D. Doll (2), V. Hillis (3), J. Kaplan (4), M. Lubell (3). (1) USDA-Agricultural Research Service, Davis, CA, U.S.A.; (2) University of California Cooperative Extension, Merced, CA, U.S.A.; (3) Department of Environmental Science and Policy, University of California, Davis, CA, U.S.A.; (4) Department of Economics
Trunk diseases (Botryosphaeria dieback, Esca, Eutypa dieback, Phomopsis dieback) significantly limit vineyard productivity. The causal fungi establish chronic wood infections, which accumulate over time. Symptoms do not become obvious until the vineyard is 6-8 years old. Post-infection practices (vine surgery, replanting vines) are labor intensive. Effective preventative practices (delayed/double pruning, fungicide applications to pruning wounds) are less costly in the long run if started when the vineyard is young (and healthy), but convincing growers to adopt these practices in the absence of symptoms is difficult. To help guide a new outreach plan, we surveyed California pest control advisors (PCAs). Our online survey revealed that PCAs recommend post-infection practices as frequently as preventative practices. High disease incidence was correlated with a higher frequency of recommendation for all practices, suggesting no preferences for recommending certain practices in young vs. mature vineyards. Instead, PCAs recommended more frequently practices (both preventative and post-infection) they perceived as more effective and less costly. PCAs rated other PCAs, university publications, and field trials as their most frequently-used sources of disease management information. Our findings underscore the importance of communicating to PCAs the widespread prevalence of trunk diseases and the fact that preventative practices are effective, if adopted in young vineyards.