EFFECT OF GA3 AND MICRO-NUTRIENTS ON GROWTH AND PHYSICAL AND CHEMICAL PROPERTIES OF THOMPSON SEEDLESS GRAPE VINES IN NOBARIA REGION

Abstract

Thompson seed less is considered the mam grape cultivar in Egypt. However, the productivity as well as fruit quality are not satisfacting in some locations. also, other problem which meet the growers of this cultivar is the short period its fruits stay in the markets . In the other words, the growers not only want to improve their production, but also to e>..'tend the period of marketing. In spite of fertilizer applications which provid the optimum supply of nutrients increased producti vity and quality of grape vines (Campbell et.al. (1980)) foliar nutrition occupies a great position in improving yield and fruit quality . Ohanov et.al. (1975) found that foliar nutrition with include nitrogen and potassium increased vine yield by 71-74% .also, GA3 is suggested to be one of the important ways which can realize the two previous aspects according to available literature which reported that GA3 retarded grape ripening when it was applied after fruit set (Sepulveda and Va lenzuela (1976) and EI-Banna and weaver (1974) . On the other hand, seedless grape vines treated with GA3 at the pre-bloom or full bl oom stage gave the largest cluster with more elongated berries and increased berry and cluster weight (khan, et. al. (1970) ; Jawanda and Vij (1973) ; Dass et.al , (1977); Miele et. al. (1978); Salvador and Manzo ( l984)<md Harrelli anc Williams (1987). However, Mc;e data are needed in wide range of concenuations of Gf .3 applied at various periods of berry development. So, the object of the present investigation was to stud y the effect of some GA3 concentrations and some fol ia r sprays namely Grenzit, libra! Bl\1X and libral Mn on vegetative growth, yield, fruit characters and some macro and micro­ nutrient elements of Thompson seedless grape-vine. Additional to determine the optimum commercial usage regarding concentration and time of application for both GA3 and previous foliar sprays.