>> I have always wondered what's the story behind the the GRO−LUX Standard
>> because, when I started growing plants in my apartment in the 70's,
>> that lamp often seemed to be the only available fluorescent plant light
>> in many department stores. There were plant lights from GE available
Re: Gro−Lux Standard Phosphor Identification
>> Do you know why Sylvania created what they did, (Gro-Lights) and why the other
>> manufacturers didn't bother to match the spectral output. That seems
>> to be the rule of thumb for about every other lamp type. Why did
>> Sylvania ALONE make so unique and truer match to plant needs?
>> I often visit and help people with lighting information in a gardening
>> forum, and this is a common question. Sylvania has pamphlets. but not
>> any deep technical history.
>> Ron Seadler
"Jeff Waymouth" <jfwaymouth3@xxxxxxxxxxx> wrote in message
> I'm afraid I can't answer that question. The only thing that I can say is
> that, for years and years, we had a photobiologist as a part of our staff.
> His name was Christos Mpelkas (Greek, Ionnis!) and knew more about all
> horticultural lighting applications than any person I have ever met.
> He retired about 10 or 15 years ago and died a few years ago.
> If you look deeply into the old engineering bulletins that GTE SYLVANIA put
> out, you will find his name associated with every single one.
> The only thing I can think of is that he knew this was the best
> formulation and insisted upon it.
> By the way, one thing I learned (long ago) from sitting inon one of his
> presentations is that the absolute best blend of light for sprouting and
> growing plants is NOT simply the GRO−LUX. It is a one for one mix of
> GRO_LUX and GRO−LUX Wide Spectrum. That provides the best red to blue and
> red to far red ratios for general plant illumination.
> A personal thought here, I have never understood how people can talk about
> light for plant growth in terms using foot candles for an intensity curve.
> Photosynthetically Active Radiation (PAR) is a much better measure, since
> foot candles are based on lumens which are based on the human eye's
> sensitivity curve, which is heavily green weighted (peaking at 555nm)
> which is a color are amost plants do not use at all (or how do we see
> their leaves as green?)
> Jeff Waymouth
> Zink wrote: