Growth and flowering of Chrysanthemum morifolium Ramat. as affected by time of application of gibberellic acid
Cathey, H.M.; Stuart, N.W.
Proceedings American Society Hort Science 547-554
Effects of time of gibberellic acid application on growth and flowering of chrysanthemums were studied. The stem of the plant was responsive to application of aqueous sprays of gibberellic acid at any time during growth. For the 10-week variety tested, the period of greatest sensitivity for stem elongation occurred in the 3d week after the start of short photoperiods. Previous to this stage in the development of the flower, higher concentrations were required to bring about elongation of the stem. Peak sensitivity for elongation of the peduncles occurred in the 4th week after the start of short photoperiods. Applications of concentrated solutions of gibberellic acid in the 7th week of short photoperiods hastened the development of florets.