Preharvest application of methyl jasmonate for improving postharvest quality of 'Pusa Navrang' grapes

Exogenous application of elicitors is a good strategy to induce physiological changes in grapevines. Methyl jasmonate is one of the potential elicitor trigger the synthesis of phytochemical compounds in grapes. Therefore, an experiment was conducted to study the influence of preharvest application of methyl jasmonate (MeJA) on nutritional quality of grapes cv. Pusa Navrang (Vitis vinifera L.). The experiment was laid out in factorial RBD with 3 replications the treatments were designated with four levels of MeJA (0, 5, 10, 15 mM) and three time of application. The results clearly showed a negligible effect of MeJA on TSS, titratable acidity, juice pH and TSS/TA ratio. Whereas, significant effect was observed for total phenolics (504.58 GAE, mg/100g), total flavonoids (418.33 QE, mg/100g). and total monomeric anthocyanins (1434 C(3)GE mg/kg fresh weight). with the application of methyl jasmonate (10 mM) at veraison stage. This resulted in the accumulation of higher antioxidant activity in terms of FRAP assay (19.44 TE, mu mol /g) with the same treatment combination.