2011 Annual Report
1a.Objectives (from AD-416)
1. Develop sustainable water management strategies for wine, table, raisin, and juice grape production using limited water supplies.
2. Develop sustainable water and soil management strategies for minimizing the impacts of drought and salinity on the root zone environment, grape yield and quality.
3. Establish rootstock recommendations based on drought resistance and salinity tolerance.
4. Quantify the effects of various water management strategies on fruit and product composition, and sensory qualities.
5. Quantify the economic impacts of drought and salinity on grape production under different biophysical soil and water characteristics and alternative management strategies.
6. Disseminate study findings via web based education and farmer outreach.
1b.Approach (from AD-416)
This research will be conducted using both laboratory and field research sites. The field research will be conducted in the Central Valley and Paso Robles, CA and in Washington State. Laboratory studies will be conducted at UC Davis and the Salinity Laboratory in Riverside, CA, as well as a Washington State University in Pullman, Washington. Specialty Crops Research Initiative.
This Reimbursable Agreement supports Objective 1 under the parent project. Research sites were identified for table grapes, wine grapes, and raisin grapes in California and juice grapes in Washington. The plots were laid out and the drip systems installed on all the grape plots in both California and Washington. Three California field sites were selected for leaching trials these included two sites on the central coast of California (red wine grapes) and one site in the Coachella Valley (table grapes). Water management strategies for table and wine grapes is significantly different. Wine grapes are managed to induce some water stress at certain growth stages, thus there is essentially no leaching during the growing season. Salt buildup is controlled by winter leaching, primarily winter rain, and some leaching via irrigation. In contrast, table grapes are well watered throughout the growing season. Rainfall is negligible in the Coachella Valley, transpiration requirements are much greater than those in the Central Coast and leaching is undertaken in the summer after harvest. These sites provide large differences in climate and management. UC Davis personnel initiated a variety of experiments to screen rootstock material for salt tolerance including a study of five hybrid populations and one V. vinifera cv. Colombard selfed population for the trait of chloride exclusion. Several conclusions were drawn, both basic and applied, and will serve to guide our marker development for chloride exclusion. Significant progress has been made on development of an intra-seasonal model of grape production that evaluates the economic impacts of different leaching and deficit irrigation strategies on grape production within a single season, and development of an inter-seasonal model of grape production that evaluates the economic impacts of different leaching and deficit irrigation strategies on sustainable grape production across seasons. Our mathematical model of grape production represents production as a function of water applications, crop age, and soil salinity in a way that keeps track of the effects of field management on yields and profits over time. Project-related information was delivered to the target grower community with presentations related to the project given at the UC Davis Current Topics in Vineyard Reserch Conference in February 2011, and also at the Western Nutrient Management Conference in Reno, NV in March 2011.