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Growers Needed for Tree Carbohydrate Study

Producers are invited to participate in carbohydrate research that will advance their understanding of bloom time, irrigation management and yield prediction


Almond Bloom carbohydrate study


Maciej Zwieniecki, Ph.D., and his research team from the University of California Davis have conducted nearly a decade of research on tree non-structural carbohydrates (CHO). CHO (sugars and starch) are products of photosynthesis that allow for physiological processes to occur in a plant. Carbohydrate levels greatly influence overall tree performance, including growth, health and survival. These are the source of energy that trees have to perform key physiological processes such as bloom, fruit set, and final yield (more information on carbohydrate research).

Framed by a large-scale project called the Carbohydrate Observatory, the team is studying the roles that these carbohydrates play in tree and orchard performance in the Central Valley. The ultimate goal of this project is to add analysis of carbohydrates to the ‘toolbox’ of orchard management practices. Considering current and predicted reductions in water availability, researchers are currently looking at the link between carbohydrate contents, water application and changes in orchard yield potential versus real yield. The study goal is to understand if there are ways to mediate limited water availability under prolonged drought conditions.

The Almond Board of California is supporting this research project and invites growers who are interested to participate.

Grower Qualifications & Involvement

  • The ideal setup would include situations where the grower is planning to reduce irrigation in some of their orchards/blocks with respect to previous years while maintaining typical irrigation in adjacent similar orchards/blocks. Orchards should be more than 5 years old and yield information is available. Orchards whose water allocation this year is lower than normal are also ideal candidates.
  • The grower is responsible for collecting and mailing twig samples from the studied orchards once a month for a period of at least two years (however, in case of emergency, researchers would assist with collection). Sampling protocol is simple and relatively fast, needing to visit each orchard and spending there few minutes for the collection once a month. See the sampling protocol.
  • The grower shares management practices and yield of the studied orchards with the research team (information is considered to be confidential and will not be released without the grower’s permission).

Grower Incentives

  1. Growers will have access to data on carbohydrates as affected by levels of irrigation.
  2. Growers will have access to yield and bloom time prediction tools using their orchard-specific data.
  3. Growers will receive periodic updates as the research team advances their understanding of tree productivity.

Applications from potential collaborators are open now and can be done by filling out a quick form. The application window is open now through the fall of 2021 and will be prioritized by order of completion.

For further details please contact Dr. Paula Guzmán-Delgado, researcher at Dr. Zwieniecki’s lab. Email:, Phone: 530-400-6912