Effect of Irrigation and Fertigation Strategies on Growth, Yield, Quality and Water Use Efficiency of Drip Irrigated Grapevine

Grapevine irrigation and fertigation are becoming important practices to ensure grape yield and yield quality in regions affected by limited water availability. Therefore the present study aimed to determine water requirement for Superior seedless grapevine under environmental conditions of Nubaria area, and to determine the effect of different water regime and fertigation practices on vine growth, fruit yield and quality and water use-efficiency. There are three irrigation treatments i.e. 60, 80 and 100% of reference evapotranspiration (I1, I2 and I3) and two fertigation programs i.e. farm fertigation program (F1) and new proposed fertigation program (F2). Irrigation was applied through surface drip irrigation and fertilization was supplied throughout irrigation system as nutrient solution in irrigation water. The results of vegetative growth are significantly affected by irrigation and fertigation treatments. The irrigation treatment (80% of ET0) reached the maximum value of all vegetative parameters in which increased by 53.76, 29.85, 59.97, 57.17, 62.50, 12.45 and 19.53% for Cane No, Spure No, Buds No, Shoots No, Bunch No., Bud Break and Fertility. The proposed fertigation program (F2) was superior over the farm fertigation program (F1). The results indicated that irrigation regime significantly affected these characters. Increasing irrigation up to 80% of potential evapotranspiration (ET0) increased the cluster weight by about 20.28% with the farm fertigation program (F1) and by about 49.00% with proposed fertigation program (F2) as compared to the farm irrigation and fertigation practices (IF1). The present results recommended irrigation of grapevine with 80% of ET0 and fertigation with proposed fertigation program (F2) to obtain the best grapevine yield. The proposed fertigation program (F2) was superior over farm fertigation program (F1) by 6.53, 14.69, 37.71, 8.11, 8.88 and 14.75 %, for TSS, total sugar, reducing sugar, weight of 100 berries, volume of 100 berried and volume of juice, respectively. It is clear that WUE has increased in case of water deficit compared with farm irrigation practice, and it is increased significantly with 80% of ET0 in comparison with non-stressed treatment (100% of ET0). The results illustrated that irrigation and fertigation treatments significantly affected the grapevine petioles nutrients content except for sodium content. All nutrients content were found to be adequate for plant and grapevine did not suffer from nutrients deficiency according the standard values. The results of the present study recommend irrigation of grapevine at 80% of reference evapotranspiration to save about 24% of irrigation water. Also recommends fertigation of grapevine with new proposed fertigation program to obtain an increase of yield by about 46.89%.