Environmental control of the flowering process of Phalaenopsis orchids

E.S. Runkle
Phalaenopsis orchids are the most economically valuable potted orchids produced and sold worldwide owing to their dramatic and showy inflorescences, long flower life, large variety of flower colors, and reliable propagation, as well as the ability to precisely control the flowering process. Assuming sufficient management of the root zone (healthy root system with adequate water and nutrients) and non-limiting environmental conditions, temperature controls flower initiation and flower development. Depending on the cultivar, and to a small extent plant maturity, temperatures >26°C suppress flowering. During the young plant stage, these relatively high temperatures simultaneously promote leaf development and inhibit flowering. Once plants are mature and of sufficient size for their container and desired flowering characteristics (such as inflorescence and flower number), temperatures <25°C initiate the flowering process. Interestingly, the day temperature primarily regulates flowering; the night temperature has little or no impact on inflorescence initiation. As few as 8 h of high temperature each day can prevent flowering in some Phalaenopsis hybrids, whereas others require >12 h of high daytime temperature exposure. Once flower development has been initiated, the minimum temperature for flower development is 11°C and the rate of development increases with temperature until some maximum is reached, above which development is delayed or arrested. Commercial growers utilize this research-based information to reliably and predictably produce uniform populations of potted flowering Phalaenopsis orchids throughout the year.
Runkle, E.S. (2019). Environmental control of the flowering process of Phalaenopsis orchids. Acta Hortic. 1262, 7-12
DOI: 10.17660/ActaHortic.2019.1262.2
https://doi.org/10.17660/ActaHortic.2019.1262.2
floriculture, flower initiation, flower development, plant lighting, potted orchids, temperature
English

Acta Horticulturae