Postharvest Quality Maintenance of Table Grapes cv. ’Alphonse Lavallée’ by Exogenous Applications of Salicylic Acid, Oxalic Acid and MAP

Treating the grape with elicitors such as jasmonic, oxalic or salicylic acid can reportedly activate several defense mechanisms, including the accelerated expression of defense genes, enhances in the cell wall composition, and the accumulation of antimicrobial compounds such as phytoalexins. Salicylic acid (SA) and oxalic acid (OA) with or without MAP (Modified Atmosphere Packaging) were tested for their effects on extending storage life of grapes cv. ’Alphonse Lavallée’. After treatments (control, MAP, 5 mM OA, 2 mM SA, SA + MAP, OA + MAP) grapes were stored at 1 °C, 90% R.H. up to 60 days. Overall, all the treatments had significant positive effects on postharvest quality of grapes. SA + MAP was the most effective treatment with the lowest weight loss and decay incidence, the greatest rachis chlorophyll content and berry detachment force at the end of 60 d storage. Effects of SA were also very close to those obtained by the combined treatment. SA alone or SA + MAP treatment may be recommended as an environmental friendly, healthy and sustainable method for extending postharvest quality of grapes up to 60 d, without significant adverse effect on produces. Considering the cost and ease of application, SA alone could be preferred as an effective alternative strategy for traditional chemical treatments.