Indian Institute of Horticultural Research, Bangalore-560080.
Two fortnightly sprays of gibberellic acid at concentrations of 10, 25, 50, 100, 250 and 500 ppm and control were applied to rose cultivar ‘Queen Elizabeth’. Highly significant increase in stem length were obtained at 100 and 250 ppm. There were increased internode length at all concentrations except control and !0 ppm. Increase in peduncle length were observed with 100, 250 and 500 ppm. The concentration of 100 ppm was effective in increasing the number of branches. More number of flowers were obtained between concentrations of 10–100 ppm. There was a corresponding increase in fresh wood weight at 100 ppm along with increased stem length, whereas at 250 ppm where there was maximum increase in stem length, no corresponding weight increase in fresh wood was observed. It may be concluded that in cv. ‘Queen Elizabeth’, GA causes increased branching (at 100 ppm) and more number of flowering (at 10, 25, 50 and 500 ppm) which are two important characters in roses.
