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

Abstract

The present investigation was carried out during the two successive years of 2006 and2007 on ?Costata? persimmon trees in order to study the influence of foliar sprays of differentchemicals on the fruit retention, fruit quality and yield.Trees were sprayed at pea stage (5mmfruitlet diameter), marble stage (15mm fruitlet diameter) or at both stages with urea, phosphoricacid, 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 significantlyincreased vegetative growth, fruit retention, tree yield in both seasons . GA4 had the highest fruitretention and yield followed by Amcotone and activated dry yeast and then NAA as comparedwith all other treatments in both seasons. All sprayed compounds increased fruit weight ,TSS, totalsugars, reducing sugars, carotene and V.C contents and decreased fruit acidity and tannin contentsas compared with all other treatments in both seasons. GA4 had the highest fruit weight, followedby activated dry yeast and mixture of ascorbic acid + citric acid and then Amcotone. Phosphoricacid 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 allother chemicals in both seasons. Foliar sprays at pea + marble stages recorded the highest valuesof all the investigated parameters in both seasons as compared with pea or marble stage.