Cattleya lenght of day and night, to grow and flower

[Dogman]

I hope some of the more experienced people here can help me with these questions.

I have wide range of varieties in Cattleya, most of them start blooming in winter as the days get shorter. I strongly believe that for a lot of those varieties it should be possible to control when they start to flower by controling the lenght of the day and night. So far i found that keeping the plants from flowering can be done with tubelight or small bulbs. It can be done by adding extra hours to the natural lenght of the day, but also to give light in the middle of the night. My question is what type and intensity of the light would be needed to do so?

regards, Joost

[Ray B]

Joost,

If I'm not mistaken, the plants bloom in response to shortened day length, not to light intensity directly - although I suppose there is a minimum intensity the plants need to recognize it as "day".

Most of the time catts are forced early by covering them with black cloth to shorten the daylength, so I'd guess that the flowering could be delayed by keeping the day long via any sufficiently-intense light source. I suspect that the closer the light intensity is to that of natural sunlight, the better.