PROMOTION OF POSTHARVEST INCREASE IN WEIGHT OF ROSE (ROSA X HYBRIDA CV MERCEDES) PETALS BY GIBBERELLIN

The initial postharvest increase in fresh and dry weights of rose petals was promoted by GA(3) treatment. This effect has been measured in petals removed from rose buds (Rosa x hybrida cv. Mercedes) 4 days after harvest and GA(3) treatment, as well as in petals detached immediately after harvest, the bases of which were immersed for 24 h in a GA(3) solution of 20 mg L(-1). The GA(3)-enhanced increase in dry weight was present despite whether petals were kept in light or dark conditions. The promotion of dark fixation of CO2 by GA(3) in addition to the previously described effects of GA(3) on mobilization of assimilates in intact rose buds is proposed.