This project examines farmer decision-making in the context of disease management, including the influences of policy, learning, cooperation, economic factors, and individual characteristics. We are using semi-structured interviews, quantitative surveys, and behavioral experiments to better understand farmer decision-making with respect to the adoption of preventative disease-management practices in wood-canker diseases of grape, pistachio, and almond. The research is in collaboration with plant scientists developing new diagnostic tools and disease-resistant cultivars as well as economists modeling the long-term costs and benefits of the adoption of preventative management practices.

Wood-canker diseases significantly limit production and the longevity of grape, pistachio, and almond. With no eradicative controls, prevention is essential. This is attempted primarily through fungicides and preventative pruning, but grower adoption of such practices in mature vineyards and orchards comes too late for effective control. This is in spite of the fact that these diseases are widespread across the entire acreage of these crops and that these diseases are the main depreciable driver of crop longevity. Gaps in our ability to detect the pathogens in the nursery and the field, insufficient knowledge of disease-resistant cultivars, and a weak understanding of the socioeconomic factors that limit grower adoption of preventative practices contribute to a high disease incidence. Accordingly, we propose the following objectives: (i) to develop new detection tools for use by diagnosticians, nurserymen, and growers, (ii) to identify sources of resistance in the germplasm, and (iii) to encourage adoption of preventative control practices in young vineyards and orchards. These objectives are the main priorities for wood-canker disease research, as identified by an SCRI planning grant-funded series of meetings and workshops with an advisory board of commodity representatives, and with research and extension agents from across the US. Together, our goal is to combine innovative methodology and approaches to deliver sustainable and economically-feasible controls to effectively manage canker diseases in the orchard, vineyard, and nursery.

Other project collaborators:

• Kendra Baumgartner, USDA-ARS
• Jonathan Kaplan, California State University, Sacramento

Project partners:

• University of California at Davis
• USDA Specialty Crops Research Initiative