Effect of urea and GA sprays on shoot growth and bunch characters in grape (Vitis vinifera L.) variety Arka kanchan

Abstract

A field trial was carried out during 1987-88 on ‘Arka Kanchan’ grape with an aim to increase the berry and bunch size. Effect of 16 treatment combinations of four foliar sprays of urea (during the growth season, fruiting season, during both the seasons and unspread control) and four of GA sprays (at pre-anthesis, full bloom, 10 days after fruit set and unspread control) on berry and bunch size was studied in grape ‘Arka Kanchan’. Urea sprays during both the seasons increased only the vigour of the shoots in vines without any favourable effect on the bunch or berry weight. Urea sprays during fruiting season coupled with GA sprays on the 10th day after fruit set increased the mean berry weight. Urea sprays (0.5%) at fortnightly intervals commencing from 30th days after October pruning coupled with GA sprays on the 10th day after fruit-set may be favourable for increasing the bunch weight of this variety. These investigations also suggested that berry and bunch weight in var. Arka kachan is more dependent on the metabolites during the fruiting season than on the reserves in the canes. In view of the fact GA sprays on the 10th day after fruit set increased the length of berries but not the diameter, with no exchange in the mean berry weight, there is scope to increase the diameter of the berries and there by, the mean berry weight by application of auxin or cytokinin in addition to gibberellic acid. 23