dh321 at PGSTUMAIL.PG.CC.MD.US ("David R. Hershey") wrote:
>they generate. A low tech solution to the heat problem is to remove the
>heat by shining the light through a clear plastic or glass container
>containing 3 or so inches of water. I once used a rectangular glass
>chromatography tank. If you are doing single leaf measurements and need to
>light only a small area, an incandescent spotlight might work if you use a
>water filter. I used one once but do not remember if the PAR was above
This will work.....and you can get over 1000 umol m-2 s-1. Now, you can choose the
type of lamp depending on wether your plants require blue light or not. HPS lamps (high
pressure sodium) lamps have no blue light, while MH (metal halide) lamps have plenty.
Blue light is important for stem elongation......Fluorescents are cool (in terms of heat) but
they age with time.....you might get 500 umol m-2 s-1 tops!