Differential response of some seeded grape cultivars of Vitis vinifera to gibberellin application

Several seeded cultivar,s of Vitis vinifera varying in seed content and berry size were tested to see their response to GA application. Oultivars with high seed index number and low seed content like Bhokri, Anab-e-Shahi, Gros Colman (Pusa) and Alamwick did not show any toxic effects due to GA application but responded by producing seedless berries and increasing berry weight with prebloom and postbloom application respectively. Alamwick alone, with high seed index number did not respond to GA by increasing the berry weight but it responded by forming seedless berries. Oultivars like Bharat Early, Black Hamburg and Black Muscat with high seed content per berry and low seed index number did not respond to GA by producing seedless berries and increasing berry weight. This differential response of cultivars to exogenous GA is discussed on the basis of physiological differences in the two groups of cultivars