Response of Vine Water Status and Berry Sugar Accumulation in Grapes under Regulated Deficit Irrigation

Abstract

The optimization of irrigation strategies in viticulture is essential for balancing water conservation with fruit quality, particularly under water-limited conditions. This study investigates the response of vine water status and berry sugar accumulation in grapes under regulated deficit irrigation (RDI) to enhance water use efficiency and improve fruit quality. The proposed methodology involves controlled field experiments with varying irrigation levels applied at specific phenological stages, combined with data-driven analytical approaches. Key parameters, including vine water status indicators (such as leaf water potential and stomatal conductance), soil moisture levels, berry growth, and sugar accumulation (°Brix), are monitored using sensor-based measurements and standard viticultural techniques. The collected data are preprocessed through cleaning, normalization, and statistical validation to ensure accuracy and consistency. Advanced analytical and machine learning models, including regression analysis, Random Forest, and Artificial Neural Networks, are employed to evaluate the relationship between water stress and berry development. Experimental results indicate that regulated deficit irrigation effectively controls vine vigor while promoting enhanced sugar accumulation in berries. Moderate water stress during key growth stages leads to improved fruit quality without significant yield reduction, whereas excessive water deficit adversely affects berry size and overall productivity. The study also demonstrates that precise timing of irrigation deficits is critical for optimizing both water use efficiency and fruit composition. The findings highlight the effectiveness of integrating controlled irrigation strategies with data-driven analysis in viticulture. The study concludes that regulated deficit irrigation provides a sustainable and efficient approach for improving grape quality, optimizing water usage, and supporting high-value crop production under limited water availability.