Yield management is an important quality control step in winegrape production. A significant body of research exists for the impacts of cluster thinning on vine balance, fruit ripening, and fruit and wine quality, but no clear fruit and wine quality impacts have been found scientifically, largely due to the different climates, cultivars, and production goals under which those studies have been conducted. Furthermore, those studies have not provided clear guidelines that are readily applicable to different cultivars and regions. The Statewide Crop Load Project is a long-term project that was established as a way to develop better yield management guidelines for Pinot noir by conducting research across many vineyards in Oregon. The project uses an industry-participatory research model to investigate yield and vine balance for Pinot noir and is under leadership of a team of researchers at the Oregon Wine Research Institute, including Dr. Patty Skinkis, Dr. James Osborne, and Dr. Elizabeth Tomasino. The project will be conducted for the next six years to help define crop load metrics across different climates, vineyards, and seasons in Oregon. With the growing interest in Chardonnay, the research project has included Chardonnay vineyards since 2015.

Objective:  The main objective of this project is to develop a collaborative model for vineyard-to-winery yield management research to investigate the relationship between yield, vine balance, and fruit and wine quality. Through this model, we will generate a robust data set to address the complex nature of vine balance and quality across different vineyards. We will develop basic vine balance metrics for Oregon Pinot noir and Chardonnay based on the data that is accumulated across seasons. The great benefit of this work is that it is conducted in-house by vineyard and winery collaborators, allowing them to determine real-world interpretation of the results based on their experiences.  The efforts of all collaborators add to the project goal of defining regionally-important vine balance metrics as they relate to wine quality.

Participation:  The more participation from industry collaborators, the greater the information we can gather to understand how vine balance impacts fruit and wine quality.  There are certain criteria that must be met by all research collaborators:

  • Willingness to take an active role in research. Based on the vineyard site and number of yield treatments used, the total investment of labor is ~45-65 man-hours on this project annually.
  • A healthy, uniform vineyard must be used for the trial, and the block must contain the same clone and rootstock throughout the experimental area (Pinot noir or Chardonnay).
  • Ability to use the same vineyard in the trial for at least 3 years.
  • Ability to implement and maintain crop level treatments over the course of the experiment.
  • Ability to collect data as outlined in research protocols. Manual labor hours cited above includes this step.
  • Wine production is not required to be involved in the study, but it is encouraged. For those who make wine, there must be commitment from both vineyard and winemaking partners. Manual labor hours cited above includes wine production.

To apply:  If you are interested in becoming a collaborator in this project, please fill out and return the application form.  Deadline for receipt of applications is June 1, 2016.

More information:  If you questions about the research project, goals, and outcomes, please contact Dr. Patty Skinkis OSU viticulture extension specialist at 541.737.1411, or Michael Kennedy faculty research assistant at 541.556.3141.