|Authors: ||L.A. Newton, E.S. Runkle|
|Keywords: ||cytokinin, pansy orchid, plant growth regulator|
Exogenous application of the synthetic cytokinin benzyladenine (BA) can promote vegetative growth or stimulate flowering of some potted orchids, but studies have been published on only a limited number of orchid genera.
We performed experiments to determine if BA promoted growth of axillary vegetative shoots or flowering inflorescences of potted Miltoniopsis. A foliar spray (0.2 L/m2) of 6-BA was applied to three sizes of plants.
In Expt. 1, BA was applied five times every six weeks at 0, 200, 400, or 800 mg/L; in Expt. 2, BA was applied to young plants five times every two weeks at 0 or 4,000 mg/L, and to large plants once at 0, 1,000, 2,000, or 4,000 mg/L at the beginning of, or 4 weeks into, an 8-week flower-inducing treatment at 14°C. All plants were otherwise grown at 20°C under a 16-h photoperiod.
There were no effects of BA on flowering of Miltoniopsis, but spray applications at 4,000 mg/L increased the number of new vegetative shoots on young plants of two cultivars, from essentially no new shoots to 2.0 new shoots per plant.
These results suggest that BA can be used to increase axillary shoot development of young Miltoniopsis, which could be particularly useful for asexual propagation and to increase shoot number before plants are induced to flower.
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