Effects of Cooling Temperature and Duration on Flowering of the Nobile Dendrobium Orchid

Abstract

<jats:p>The effects of cooling temperature [constant (10, 13, 15, or 18 °C, or 15, 18, or 21 °C)] and duration (2, 3, 4, 5, or 6 weeks, or 3, 4, 5, 6, or 7 weeks) at two separate locations (College Station and Weslaco, TX) on growth and flowering of <jats:italic>Dendrobium</jats:italic> Sea Mary ‘Snow King’, a <jats:italic>Dendrobium nobile</jats:italic> Lindl. hybrid, were investigated and the cooling requirement for flowering was quantified. Interactions between temperature and cooling duration were significant on time required to reach anthesis from either the beginning or completion of cooling, average flower number per flowering node, and percentage of nodes with aborted buds. Increasing cooling duration from 2 to 6 or 3 to 7 weeks resulted in less time to reach anthesis after the completion of cooling. However, the increased cooling durations extended the time needed for producing a flowering crop. Plants cooled at a relatively higher temperature among 10, 13, and 15 °C required less time to reach anthesis after the completion of cooling. Plants had more flowering nodes and total flowers when cooled at 10, 13, or 15 °C than at 18 °C in College Station or at 15 or 18 °C than at 21 °C in Weslaco. The results suggest that 3 weeks at 13 °C has saturated the cooling requirement, and 3 weeks at 13 or 15 °C is a recommended cooling treatment that saves production cost without retarding flower development.</jats:p>

The Dendrobium Orchid: Botany, horticulture, and utilization

“…A cooling treatment induced flowering in Dendrobium Sea Mary “Snow King,” Dendrobium Hinode “Toutenkou” and Dendrobium Snowflake “Red Star,” a hybrid of D. nobile . Once the cooling requirement for flower initiation had been met and floral primordia had been differentiated, removing plants from cooling back to a warm (24°C) environment accelerated the development of flower buds (Yen et al., 2008). Interactions between cooling temperature and cooling duration were significant with regard to the time required to reach anthesis from either the beginning or the completion of cooling (Yen et al., 2008).…”

“…Once the cooling requirement for flower initiation had been met and floral primordia had been differentiated, removing plants from cooling back to a warm (24˚C) environment accelerated the development of flower buds (Yen et al, 2008). Interactions between cooling temperature and cooling duration were significant with regard to the time required to reach anthesis from either the beginning or the completion of cooling (Yen et al, 2008). D. nobile "Lindley" plants exposed to 13˚C produced flowers regardless of the photoperiod, whereas plants held at 18˚C remained vegetative (Goh & Arditti, 1985).…”

Transcriptomic and Metabolomic Analyses Reveal Differences in Flavonoid Pathway Gene Expression Profiles between Two Dendrobium Varieties during Vernalization

“…The accumulation of flavonoids also has an age-dependent effect, but there are remarkable differences between different tissues [8]. Dendrobium flower bud differentiation, which can be divided into seven phases [10], can be completed in 56 days at 22/17 • C, or in 35 days at 18/13 • C [10][11][12][13][14].…”

Floral Initiation, Organogenesis, and Flowering of Mature Paphiopedilum Clair de Lune ‘Edgard Van Belle’ Award of Merit/American Orchid Society Plants Derived from Divisions

“…Flowering of Phalaenopsis amabilis was induced because the plants were grown at cool temperatures (25/20 C day/night) compared with high temperatures (30/23 C day/night) (Chen et al 1994). Similarly, relatively high temperatures may be disadvantageous to floral induction in Dendrobium nobile and potted Miltoniopsis (Lopez and Runkle 2006;Yen et al 2008). To the best of our knowledge, there few studies on the growth and flower development of Paphiopedilum orchids (Feng et al 2021;Pi et al 2009;Yin et al 2022).…”