Effect of Different Treatments on Flowering of Bougainvillea glabra‘Sao Paulo’

During February 24th and June 18th of 2021, experiments were conducted on effect of different pruning intensities, different pruning time, different fertilization concentration and growth regulators on flowering of Bougainvillea glabra‘Sao Paulo’in greenhouse in Shenzhen, Guangdong province. The results showed that pruning intensity, pruning time, fertilization concentration and growth regulators had significant effects on regulating the flowering phase of B. glabra‘Sao Paulo’. Pruning has great influence on flowering phase, compared with no pruning, especially heavy pruning and prunin 60 days before flowering. Treatment by different fertilization concentration and the control (no fertilization) had earlier budding and flowering phase, but the treatments had longer duration of the flowering phase. Compared with the control, the flowering period of 0.3% concentration treated B. glabra‘Sao Paulo’ended 10 days later. B. glabra‘Sao Paulo’treated by chlormethalin and paclobutrazol had 20 days and 19 days earlier and longer flowering phase of 49 days and 40 days, respectively. Pruning intensity, pruning time and growth regulators had significant effects on single-branch flower formation and branching number (P<0.05), while fertilization concentration only had significant effect on flower number of single-branch.