Hmm... Keeping Poinsettias in total darkness is probably only because
places where humans grow poinsettias are usually subject to human
intervention with the light - street lights, house lights, etc. I know
that one street light will keep them from blooming, but total darkness
does not exist in their native habitats - they are not under snow for
months. In Florida they bloom, and the moon shines there. It is
reasonable to assume that the red light of our artificial light is the
source of the problem, but that moonlight is not.
Does anyone know the actual spectrum of moonlight? Is the lack of color
simply its inability to stimulate our cones due to low intensity, or is
there really an altered spectrum?
Janice
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Janice M. Glime, Professor
Department of Biological Sciences
Michigan Technological University
Houghton, MI 49931-1295
jmglime at mtu.edu
906-487-2546
FAX 906-487-3167
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