Effect of Gibberellic Acid, Cytofex, and Calcium Chloride as Pre-Harvest Applications on Storability of “Thompson Seedless” Grapes

Document Type : Original Article


 THIS INVESTIGATION was carried out to evaluate the effects of ……spraying two growth regulators, i.e. Cytofex (CPPU) at 6 ppm and Gibberellic acid (GA3) at 20 ppm two times (after fruit set and at 4 mm berries diameter) alone or in combination with calcium chloride 0.5% at berry veraison on "Thompson seedless" grapes quality during cold storage at 0 oC and RH 95 – 98 %. Cluster treated with Cytofex (CPPU) showed the lowest weight loss after 60 days of cold storage. Moreover, the clusters treated by Cytofex combined with GA3 and calcium chloride showed the highest weight loss during shelf life, higher berry removal force, the lowest percent of fruit decay and the highest marketable fruit. CPPU treatment and its combinations with GA3 and or CaCl2 showed the lowest Pectinmethylestraese activity after 60 days of cold storage. Clusters sprayed with GA3+CaCl2 showed the highest berry firmness after 60 days of cold storage. Clusters treated by calcium chloride at 0.5% and control showed the highest SSC: acid ratio. Moreover, it showed the highest total, reducing and non reducing sugars contents after 60 days of cold storage.