Horticultural Research Institute, Saharanpur, U.P.
An experiment was conducted to explore the possibilities of growth regulators in improving yield and juice quality of a seeded variety of grape (Motia) under the soil and climatic conditions of Uttar Pradesh. Gibberellic acid at 25, 50 and 100 ppm and Methyl-ester of Naphthalene acetic acid, Para-chloro-phenoxy acetic acid and Ortho-chloro-phenoxy acetic acid at 10, 20 and 30 ppm concentrations were applied on the plants at full bloom and fruit setting stages. Amongst these gibberellic acid at 100 ppm concentration was the best treatment both for improving the weight of berries, weight of bunch and improving the fruit quality by increasing the total soluble solids content and decreasing the acidity of the juice and by reducing the number of seeds per berry. Methylester of naphthalene acetic acid also gave promising results with 20 ppm concentration in respect of improvement in weight of berries and 30 ppm concentration in respect of increase in bunch weight and total soluble solids content of the juice. In all cases, application at full bloom appeared more effective than that at fruit set. The maximum seedless berry (41.85 per cent) was found with GA application at 100 ppm concentration at full bloom stage.
