Here is a abstract from an article about Phals and temperature and flowering. email me and I can send you the entire article....
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Abstract
Phalaenopsis orchids are among the most valuable
potted flowering crops commercially produced throughout
the world because of their long flower life and ease
of crop scheduling to meet specific market dates.
During commercial production, Phalaenopsis are usually
grown at an air temperature >28 C to inhibit flower
initiation, and a cooler night than day temperature
regimen (e.g. 25/20 C day/night) is used to induce
flowering. However, the specific effect of day and night
temperature on flower initiation has not been well
described, and the reported requirement for a diurnal
temperature fluctuation to elicit flowering is unclear.
Two Phalaenopsis clones were grown in glass greenhouse
compartments with constant temperature set
points of 14, 17, 20, 23, 26, or 29 C and fluctuating
day/night (12 h/12 h) temperatures of 20/14, 23/17, 26/14,
26/20, 29/17, or 29/23 C. The photoperiod was 12 h, and
the maximum irradiance was controlled to <150 mmol
m2 s1. After 20 weeks, >80% of plants of both clones
had a visible inflorescence when grown at constant 14,
17, 20, or 23 C and at fluctuating day/night temperatures
of 20/14 C or 23/17 C. None of the plants were
reproductive within 20 weeks when grown at a constant
29 C or at 29/17 C or 29/23 C day/night temperature
regimens. The number of inflorescences per
plant and the number of flower buds on the first inflorescence
were greatest when the average daily temperature
was 14 C or 17 C. These results indicate that
a day/night fluctuation in temperature is not required
for inflorescence initiation in these two Phalaenopsis
clones. Furthermore, the inhibition of flowering when
the day temperature was 29 C and the night temperature
was 17 C or 23 C suggests that a warm day
temperature inhibits flower initiation in Phalaenopsis.
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