APPLICATION OF SALICYLIC ACID IMPROVES YIELD AND NUTRACEUTICAL QUALITY IN GRAPEVINE

Abstract

Salicylic acid (SA) is a phenolic compound involved in various physiological processes in plants, such as germination, photosynthesis, nutrient absorption, enzyme activity, and the biosynthesis of secondary metabolites, which are essential for interacting with the environment. In this study the effect of foliar application of salicylic acid on yield, antioxidant activity, and nutraceutical quality of Vitis vinifera L. cv. Cabernet Sauvignon was evaluated. Five increasing doses of salicylic acid were tested: 0, 0.5, 1.0, 1.5 and 2.0 mM using a randomized complete block design. Production-related traits, non-enzymatic antioxidant compounds and protein content, as well as the activity of enzymes catalase and peroxidase were measured. Results showed that foliar spraying of salicylic acid 0.5 mM significantly increased yield, titratable acidity, maturity index, and catalase and peroxidase activity. The concentration of secondary bioactive compounds such as phenols, flavonoids and vitamin C increased mainly with the 1.0 mM dose. Despite the reduction in protein content, the enhanced antioxidant enzyme activity raised the presence of elicitors to activate defense mechanisms, even in the absence of stress. Foliar application of salycilic acid is an effective strategy for boosting secondary metabolite biosynthesis and improving the yield of grapevine crops.