Help with experimental lighting

[David R. Hershey]

Most plant growth chambers use various types of HID (high intensity
discharge) lamps, such as sodium vapor and use fans to remove the heat
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
740. 

Micromoles per square meter per second are units of PAR 
(photosynthetically active radiation) or PPF (Photosynthetic photon 
flux). PAR in full sunlight at noon on a cloudless day is usually about 2000.

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David R. Hershey
					
Snail mail: 6700 Belcrest Road #112, Hyattsville, MD 20782-1340

Adjunct Professor, Biology/Horticulture Department
Prince George's Community College, Largo, MD 20772-2199

Email: dh321 at pgstumail.pg.cc.md.us
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