Effect of Chemicals and Photoperiod on the Growth and Flowering of Thanksgiving Cactus

Abstract

Abstract Schlumbergera truncata (Haw.) Moran ‘Christmas Charm’, ‘Lavender Doll’, and ‘White Christmas’ were grown under an 8 hr natural photoperiod or an 8 hr natural photoperiod plus 4 hr of incandescent light from 10:00 pm to 2:00 am and treated with single sprays of BA at 100 and 200 ppm, GA at 25, 50, and 100 ppm, BA at 100 and 200 ppm plus GA at 25 or 100 ppm, calcium carbide at 2910 ppm, ethephon at 100 and 1000 ppm, daminozide at 5000 ppm, ancymidol at 132 ppm, and chlormequat at 1000 ppm in 2 experiments. No flower buds were initiated from any plants grown under the 8 + 4 hr photoperiod. BA applied at 100 and 200 ppm increased the number of phylloclades on ‘Christmas Charm’ plants grown under the 8 + 4 hr. BA at 200 ppm applied to plants grown under the 8 hr photoperiod caused an increase in flower bud number and earlier flowering in all cultivars tested. BA + 100 or 200 ppm 100 ppm GA applied to plants grown under the 8 hr + 4 hr photoperiod stimulated the growth and elongation of phylloclades. Applied to plants grown under the 8 hr photoperiod, BA plus GA caused the growth and elongation of phylloclades, initiation of lower buds, and induced the development of lateral phylloclades and flower buds. Ancymidol at 132 ppm and 1000 ppm chlormequat sprays produced earlier flower bud initiation and increased flower number to flower bud ratios on ‘Christmas Charm’ plants. Chemical names used: N-(phenylmethyl)-H-purin-6-amine (BA); gibberellic acid (GA); (2-chloroethyl)phosphonic acid (ethephon); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); α-cycloproply-α-4-methoxyphenyl)-5-pyrimidinemethanol) (ancymidol).