2017 ASHS Annual Conference

The grapevine trunk-disease complex limits grape production and vineyard longevity worldwide. Every vineyard in California eventually is infected by one or more trunk diseases. The causal fungi, which are taxonomically unrelated Ascomycetes, infect and then degrade the permanent woody structure of the vine; some species also attack almond and pistachio. With a grant from the USDA Specialty Crop Research Initiative, we addressed shared priorities of tree crop and grape industries: developing new detection methods, identifying sources of resistance in the germplasm, and encouraging disease prevention in young plantings. New molecular tools from pathogen-specific studies (genome sequences, genetic transformation protocols, host biochemical and transcriptomic responses to infection) established a foundation for unifying experiments on mixed infections that typically occur in the field. By expanding the search for sources of resistance to table grapes and to new pistachio cultivars, we accelerated the availability of resistant plant material as a long-term disease-management approach. Studies on grower usage and perceptions of preventative practices brought new perspectives to disease management and helped shape outreach materials in economic terms, which resonate more clearly with growers. New online resources (disease-management plans, economic tools, DNA sequence database) now target a wider range of practioners; not just growers, but also pest control advisers, diagnosticians, and extension agents, all of whom influence disease management.