Location: Water Management Research2011 Annual Report
1a. Objectives (from AD-416)
Determine the effects and limits of deficit irrigation strategies on the yield and quality of wine and juice grape.
1b. Approach (from AD-416)
The research will be a combination of field studies on cooperating farms, laboratory studies at Washington State University.
3. Progress Report
This Grant Agreement supports Objective 1 of the parent project. Thus far our efforts have concentrated on the development and implementation of project parameters specific to our site location. Per the project guidelines, we worked with a local grower, Mike Miller from Airfield Ranches, to select a Concord and Cabernet Sauvignon block of grapes suitable for this trial. The treatment parameters for both the Concord and Cabernet Sauvignon grapes were determined based on guidelines set forth in the original proposal with consideration given for local climatic constraints, current irrigation infrastructure, and grower input. Stakeholder input from a representative of the National Grape and Wine Initiative was also included. The four treatments for the Concord grape block were determined to be; 1) Control – current vineyard practice (>100% evatranspiration (ET)), 2) 100% ET, 3) 85% ET and, 4) 70% ET. These irrigation deficits would be induced from bloom to veraison. Prior to this treatment period and post treatment irrigation would be set based on the grower’s current practices. For the Cabernet Sauvignon grape block the treatments are as follows; 1) Control – current vineyard practice (extreme deficit, about 50% ET all season), 2) 1/3 increase in irrigation all season, 3) 1/3 increase in irrigation until fruit set, stop, then a 1/3 increase again at veraison, and 4) a 1/3 increase at 50% veraison. Within each vineyard, there were four replicate blocks containing each treatment, one through four, in a randomized block design. This was done to ensure that any differences in soil and microclimate characteristics were minimized. The soil on both sites is mapped as a Warden silt loam. Once the sites were determined and treatment plots marked, the irrigation system was modified to provide for the treatments in both grape varieties. Neutron probe access tubes were inserted between the 2nd and 8th data vines in each plot. Additionally, four watermark soil moisture sensors were place in each vineyard, one per treatment, to have a consistent form of measurement between all of the vineyards in the study. Paso Panels for measuring the shaded area under the grapevine canopy were constructed and other equipment (leaf pressure bomb) was purchased. Monitoring will begin at bloom, which currently is 3 weeks late in central Washington due to cold weather. The lead scientitst monitors the operation of the project through email exchanges, conference calls and annual progress reports and yearly project team meetings.