PRE-HARVEST FOLIAR APPLICATION OF VEGETABLES EXTRACT IMPROVES THE QUALITY OF HARVESTED GRAPE

Abstrakt

This study focused on examining the effect of vegetables extract foliar application on storage quality of the grapes grape (Vitis vinifera L. cvs. ‘Perlette’ and ‘King’s Ruby’). The vines were sprayed after fruit set twice at 15 days interval at concentrations of 0, 0.20%, 0.30% and 0.40%. Fruit were harvested and kept under cold-storage at 0.5 ±0.5°C and 90% RH for 28 days. The physicochemical properties of treated and untreated berries were analyzed at 7 days intervals during the cold storage. The results showed that the pre-harvest application of vegetable extracts reduced the weight loss and inhibited the fruit decay. Treated grape also had higher ascorbic acid contents, total phenolics, 2,2-diphenyl-1-picrylhydrazyl-radical (DPPH) scavenging activity, and higher soluble solid contents, titratable acidity, and reduced sugar:acid ratio. The concentration of 0.30% and cultivar ‘Kings Ruby’ gave the best result as compared to untreated control. In conclusion, pre-harvest vegetables extract application on berries showed higher antioxidant activities in grape berries, and maintained their post-harvest quality. These results indicated that foliar spray of vegetables extract could effectively improve the fruit quality, mainly through the reduction of phenolic content.