What is the optimal wavelength of light for growing plants (cacti indoors in a n

kirther at ix.netcom.com kirther at ix.netcom.com
Tue Oct 14 15:53:24 EST 1997

On 1997-10-14 lederman at eisner.decus.DISABLE-JUNK-EMAIL.org said:
   >I used to grow plants under lights, and have read many reference
   >books (and even own a few), and all of them indicate that the above
   >statement is wrong.  Plants are sensitive to red and near infrared.
   >The balance between shorter and longer wavelengths (plants are
   >relatively insensitive to green) will have an effect on how the
   >plant grows.  Too much of one or the other will cause the plant
   >either to be very short and 'stocky' or very long and 'gangly'.  At
   >the moment, however, I don't remember which excess causes which

My wife did an experiment a few years ago with different color 
lamps and the lamps under the longer wavelength (red) lights were 
short and stocky while the plants grown under the shorter 
wavelength (blue) were long and thin. My explanation for this is 
that plants use the wavelength of the light they "see" to regulate 
their growth in relation to their neighbors. If a plant sees lots 
of red light, it is seeing the setting and rising sun so it is too 
tall and should grow slower. If it sees only blue light, it is 
viewing the sky only, so it is too short an needs to grow taller. 
I have no idea if this theory has any merit <g>.

Vic Roberts
70413.1423 at compuserve.com
kirther at ix.netcom.com

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