Mitigating Summer Heat Stress on Cabernet Sauvignon Vines Grown in Central California

Rising temperatures pose a significant threat to grape production in regions like Central California, making it essential to identify sustainable and easily implementable solutions to mitigate these impacts. In this trial, an untreated control (C) was compared to the application of diatomaceous earth (D), pinolene (P), and shoot twisting of the apical portion of the shoots (T). Parameters such as leaf area, light interception, gas exchange, and water potential were monitored, along with quantitative and qualitative production characteristics. T induced desiccation in the upper portion of the shoots, reducing leaf area without overexposing the clusters. Stem water potential measurements indicated that T partially alleviated stress conditions in particularly hot periods. D decreased stomatal conductance without significantly reducing net assimilation, thereby improving water use efficiency. All treatments resulted in higher acidity and lower pH levels, while no difference in crop load was observed. This trial demonstrates the feasibility of using easily mechanizable techniques to mitigate summer heat stress and improve water use efficiency in regions characterized by hot and arid regions, such as California’s Central Valley.