Effect of foliar sprays on fruit retention, quality and yield of Costata persimmon trees

The present investigation was carried out during the two successive years of 2006 and 2007 on “Costata” persimmon trees in order to study the influence of foliar sprays of different chemicals on the fruit retention, fruit quality and yield.Trees were sprayed at pea stage (5mm fruitlet diameter), marble stage (15mm fruitlet diameter) or at both stages with urea, phosphoric acid, potassium nitrate, Ca-EDTA, Fe-EDTA + Zn- EDTA + Boric acid , NAA, GA4, Amcotone, activated dry yeast and a mixture of ascorbic plus citric acids. All sprayed chemicals significantly increased vegetative growth, fruit retention, tree yield in both seasons . GA4 had the highest fruit retention and yield followed by Amcotone and activated dry yeast and then NAA as compared with all other treatments in both seasons. All sprayed compounds increased fruit weight ,TSS, total sugars, reducing sugars, carotene and V.C contents and decreased fruit acidity and tannin contents as compared with all other treatments in both seasons. GA4 had the highest fruit weight, followed by activated dry yeast and mixture of ascorbic acid + citric acid and then Amcotone. Phosphoric acid recorded the highest values of fruit TSS, total sugars, reducing sugars and carotene contents, whereas activated dry yeast gave the highest V.C and lower tannine contents as compared with all other chemicals in both seasons. Foliar sprays at pea + marble stages recorded the highest values of all the investigated parameters in both seasons as compared with pea or marble stage.