A Two-Year study of 12 Sustained and Regulated Deficit Irrigation Schedules for Cabernet Sauvignon in Central California
Vincenzo Cianciola, Luca Pallotti, Alessandro De
Rosa, Peyton Peralez, Desiree Hernandez, Luis Ortiz, William
Whalen, Eve Laroche-Pinel, and Luca Brillante*
*Department of Viticulture and Enology, California State
University Fresno, 2360 E Barstow Ave, Fresno, CA, 93740
(lucabrillante@csufresno.edu)
Amidst escalating drought conditions in the San Joaquin Valley, where grapegrowers face an urgent need for effective water management strategies, this study contributes valuable insights for sustainable viticulture practices. Recognizing the pressing importance of optimizing water use in vineyards, particularly in the context of the West San Joaquin Valley, this research aims to unravel the physiological responses of grapevines under varying intensities and timings of sustained and regulated deficit irrigation.
Focused on a singular commercial Cabernet-Sauvignon × 1103 Paulsen vineyard, this study explored the impact of irrigation treatments administered during 2022 and 2023 seasons. Employing a semi-autonomous irrigation approach, actual water quantities were recorded using flow meters. The study incorporates sustained deficit irrigation (SDI) schedules with varying percentages (40, 60, 80 and 100% of ETc) and regulated deficit irrigation (RDI) strategies in both preveraison and postveraison periods (e.g., 100/40, 80/60, 60/100).
Stem water potential and gas exchange were measured from June to harvest, grape composition from veraison to harvest and yield components were also assessed at harvest time. Results show that while the 40% SDI significantly underperformed 100% ETc, it is possible to obtain similar or better results while saving water with RDI and SDI treatments with lower ETc reductions.
This research determined the primary effects of these irrigation regimes on plant water status, gas exchange, berry composition, and yield components. The findings aim to provide a nuanced understanding that can inform advanced developments in water management strategies, offering practical insights for grapegrowers navigating the challenges of water scarcity in the San Joaquin Valley.
Funding Support: American Vineyard Foundation, California State University – Agriculture Research Institute
