Effect of Gibberellin on Growth of Spring Shoots and Flower Bud Differentiation in Camellia osmantha

The effects of gibberellin on flower bud differentiation and spring shoot growth at the critical stage of flower bud differentiation in Camellia osmantha were analyzed. Plants at fruiting stage was treated by leaf removal and gibberellin application at the 12-day interval. The results showed that the key period of flower bud differentiation was from March 14 to April 19, and during which spraying 800-1 600 mg/L gibberellin could significantly promote flower bud formation of C. osmantha. Application of 200-6 400 mg/L gibberellin at the early stage of flower bud differentiation promoted the elongation of spring shoots, especially the diameter and internode spacing of spring shoots, and the earlier spraying the better. But gibberellin application had no significant effect on the total axillary buds of spring shoots.