Effect of Some Natural Stimulants on Fruit Set,yield and Fruit Quality of Costata Persimmon at Harvest and After Cold Storage

Abstract

This research work was carried out in 2013 and 2014 seasons on "Costata" persimmon trees at Kafr Ashma farm (Menoufeya Governorate),to test the effectiveness of foliar sprays of some stimulants (Ascopin, GA 3 , Glycine, Chitosan, Azolla, Yeast and Kaolin), on tree yield parameters and fruit quality of fruits, especially tannin content. Each treatment was carried out on a separate row of 10 trees. Five monthly sprays were applied starting from 2 weeks after full bloom (mid April), till mid August. Application of these stimulants had good and variable effects, as they caused a significant increase in fruit set %, number of fruits/tree, yield, fruit weight, dimensions, TSS, acidity, TSS/acidity and firmness compared to the control. Samples of fruits at maturity were picked and placed 4 weeks at 4 ºC, and 90 RH and their quality criteria were estimated weekly. Chitosan, Azolla and Yeast achieved the best results in this respect. Yeast treatment resulted in the least content of tannins during fruit growth at harvest and after cold storage, but Ascopin had no positive effect on other quality attributes contrary to the noticeable effects of Chitosan, GA 3 , Azolla and Yeast on increasing T.S.S. % vitamin C, and on decreasing acidity % of fruits and decreasing their weight loss after storage. Fruits from Yeast treatment had the best taste . It is recommended to use any of these stimulants on persimmon orchard, especially Yeast, GA 3 . Azolla and preferably Yeast, because it is highly effective in getting high yield and reducing tannins as well as being a cheap natural material.