Evaluating the Response of Grapefruit (Citrus paradisi) Juice Quality to Rootstock Selection and Saline Water Irrigation

Abstract

Salinity stress is a major constraint in citrus production, affecting both yield and fruit quality, particularly under limited freshwater availability. This study evaluates the response of grapefruit (Citrus paradisi) juice quality to different rootstock selections under saline water irrigation conditions. Field experiments were conducted using grafted grapefruit trees on multiple rootstocks subjected to varying salinity levels to assess their combined influence on fruit development and juice characteristics. Key parameters measured included fruit yield, juice content, total soluble solids, titratable acidity, sugar–acid ratio, vitamin C content, and ion accumulation in plant tissues. Results indicated that rootstock selection significantly influenced the plant’s ability to tolerate saline irrigation and maintain juice quality. Salt-tolerant rootstocks exhibited improved ion regulation, limiting sodium and chloride accumulation in fruit tissues, which contributed to better juice composition and flavor balance. These rootstocks maintained higher total soluble solids and favorable sugar–acid ratios compared to more sensitive rootstocks under saline conditions. While increasing salinity generally reduced yield and quality, tolerant rootstocks mitigated these effects and sustained acceptable fruit characteristics. The study highlights the importance of selecting appropriate rootstocks as a practical strategy to manage salinity stress in citrus orchards. While analytical methods were used to evaluate physiological and quality responses, the primary focus remains on horticultural performance and orchard management. These findings provide actionable insights for growers to optimize rootstock selection and irrigation practices, improve fruit quality, and sustain grapefruit production under saline water conditions.