Horticultural Science and Technology 원예과학기술지 ISSN:1226-8763(Print) 2465-8588(Online)

Having a variety of flower colors makes Schlumbergera truncata more valuable as an ornamental. S. truncata quality is mainly determined based on the number of phylloclades and flowering at the apical phylloclades. Cytokinins have been shown to promote branching and flowering in Cactaceae. This study was carried out to investigate the effects of growth regulators on the plant growth and flowering of four cultivars of S. truncata: ‘Orange Candle’, ‘Pink Dew’, ‘Red Roman’, and ‘Snow Queen’. Foliar treatments of benzylamino purine (BA) or both a mixture of BA and gibberellic acid (GA₃) were applied (100-200 mg·L^-1) when plants reached the three-phylloclade stage under a long-day photoperiod. All plants treated with BA alone or the mixture of BA and GA₃ produced more phylloclades and branches than the control. Application of BA significantly produced more phylloclades and branches than BA in combination with GA₃. However, BA application shortened the length of phylloclades, while adding GA₃ to BA promoted the elongation of phylloclades but delayed flowering. During the second trial, only BA was applied at 0 to 100 mg·L^-1 to the plants at the two-phylloclade stage under a long-day photoperiod. The number of phylloclades increased by 19.8-33.0% without shortening the length of phylloclades when BA was applied at 50 or 75 mg·L^-1 concentration. The number of flower buds increased by 100 to 190% under short days when BA at 100 mg·L^-1 was applied on ‘Orange Candle’ and ‘Red Roman’, while BA application at 150 -200 mg·L^-1 increased only from 33.0 to 41.7% in ‘Pink Dew’ and ‘Snow Queen’. The number of flower buds increased with the higher concentration of BA, but the number of days to flower decreased and the length of the flowers shortened. In conclusion, Only BA application appears to be more effective for increasing the number of phylloclades and flower buds in S. truncata.