Effect of Gibberellic Acid, Naphthalenacetic acid, Calcium and Zinc Spraying on Fruiting of Manfalouty Pomegranate Trees

Abstract

This study was carried out at the Experimental Orchard, Faculty of Agriculture, Assiut University, Egypt, to study the effect of Gibberellic Acid (GA 3), Naphthalenacetic acid (NAA), calcium chloride and zinc sulphate spraying on fruiting of Manfalouty pomegranate during 2017 and 2018 seasons. The experiment was set up in a complete randomized block design with three replicates, one tree per each. GA 3 , NAA, calcium chloride (CaCl 2) and zinc sulphate (ZnSO 4) spraying significantly increased the yield/ tree compared to unsprayed ones. GA 3 spraying gave the highest yield followed by calcium chloride. On the other hand, all treatments significantly decreased the fruit cracking percentage compared to unsprayed ones. The least fruit cracking was recorded due to calcium chloride spraying. All treatments significantly increased fruit weight and fruit dimensions as well as pulp percentage and juice contents compared to unsprayed ones. Moreover, calcium chloride and zinc sulphate as well as combination of GA 3 or NAA with them significantly improved the fruit chemical constituents, whereas, GA 3 spraying alone decreased the chemical fruit constituents compared to unsprayed ones. It could be concluded that spraying Manfalouty pomegranate trees with calcium chloride (CaCl 2) at 2% and zinc sulphate at 0.025% plus GA 3 at 50 ppm or NAA 25 ppm thrice was necessary to get high yield, reduce the fruit cracking percentage and improve fruit quality.