IMPACT OF IRRIGATION WATER MANAGEMENT AND SILICON SPRAYING ON AVOIDING COLD INJURY AND IMPROVEMENT YIELD OF KITT MANGOS

The present study was carried out during 2015 and 2016 seasons on Kitt mongo  trees to evaluate the effect of three irrigation water management (4000  m3 of irrigation water were applied to the four physiological stages of mango tree growth as 15 & 20 & 40 & 25 % ,  30 & 15 & 35& 20 % and  35 & 20 & 30& 15 % m3 / tree/ year,  respectively) as well as  four concentrations  of potassium silicate on avoiding cold injury and  improvement yield of kitt mango .                 Irrigation Mango tree by  the second program water management (30, 15, 35 , 20) recorded The highest values of vegetative growth in terms of number of shoot /tree  and lower values of leaves percentage   affected with cold injury, Also, an evident increase in the content leaves of N  & K elements , C/N ratio  and final fruit set % total yield by divided  irrigation water at the four physiological stages of mango  trees  (30, 15, 35, 20) was recorded compared with  the other two water managements. No significant differences between the second and third irrigation water management programs (30%,  15%, 35%, 20% and  35%,  20%,  30%, 15%) on values of  leaf area, P% and  total carbohydrates as well as on TSS,  acidity and L-ascorbic acid content  of fruits .                 Spraying trees with potassium silicate in three times during the period from October to January at the rate of 1000 ppm  give the highest values of quality characteristics at mango trees and their fruits. While sprayed with potassium silicate at 2000 ppm achieve moderate values of the mentioned characteristics                 It could be recommended from the obtained data that irrigation water management at the four physiological stages (30, 15, 35, 20) of Kitt mango  trees and spraying 1000 ppm potassium silicate in dormancy period is considered  a good treatment to avoid cold damage on leaves and fruits as well as in giving the highest yield and quality of kitt fruit.