Vol. 14, Issue 8 (2025)

Author(s):
Samir Al-Rashid, Leyla Oztürk and Reza Mahdavi

Abstract:

Salicylic acid (SA) has emerged as an important phytohormone involved in regulating plant physiological responses, stress tolerance, and metabolic expression, particularly in fruit crops such as grapevine. Grapevines cultivated under semi-arid and warm climatic conditions often face oxidative stress, reduced phytonutrient accumulation, and variability in berry quality. Enhancing phytochemical and antioxidant profiles through foliar applications of regulatory compounds such as salicylic acid has therefore received increasing scientific attention. The present research investigates the role of SA spray in enhancing the phytochemical richness and antioxidant status of two major table grape cultivars, Halwani and Kamali, widely grown across Middle Eastern and South Asian viticultural environments. Emerging literature indicates that SA significantly influences phenylpropanoid pathway activity, leading to the synthesis of flavonoids, anthocyanins, phenolic acids, and related antioxidant metabolites. However, comparative evaluations between specific cultivars remain limited, and the biochemical responses of Halwani and Kamali grapes to SA have not been comprehensively quantified.

This work aims to assess differential changes in total phenolics, flavonoids, anthocyanin profiles, antioxidant enzyme activities, and radical-scavenging potentials following standardized SA foliar applications. The research also explores cultivar-dependent responses, hypothesizing that Halwani and Kamali grapes may demonstrate distinct biochemical sensitivity to exogenous SA due to variations in their inherent metabolic pathways. By establishing the magnitude of SA-induced improvements in biochemical attributes, the research seeks to provide a low-cost, sustainable strategy for enhancing grape quality without reliance on synthetic agrochemicals. The findings are expected to contribute to improved vineyard management practices, enhanced nutraceutical value of fresh grapes, and greater postharvest stability. Ultimately, this research positions salicylic acid as a practical bio stimulant for elevating both the functional composition and market competitiveness of Halwani and Kamali grapes.