"Ray" wrote in message
. ..
I really don't think the photoperiodicity plays a role in my original
query. Sure, we interpret "x" hours of light and "y" hours of dark, but to
the plant, do we really know when that break occurs?

Yes we do. The Arizona university photsyntesis pages have a lot on
information about breaking the dark period, and the dimophic chemistry that
regulates the photoperiod. Additionally, did you see Rotor's comment that as
little as 10 ft candles of light will break the period? Read it again.

K

In any case where the plants are exposed to a gradual decrease in light
intensity, it seems likely that there is some point at which the plant -
for all practical purposes - "thinks" it's dark, while to us it may be a
long way off. If we put the opaque covering of Dr. Rotor's article on
before that point, yes we have shortened the day length, but if it's
afterwards, the true day length - to the plant - is actually shorter.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Artwork, Books and Lots of Free Info!


"K Barrett" wrote in message
...
Try http://www.orchidtrek.com/rotor/photperiod.html
and the rest of Rotor's articles.
http://www.geocities.com/brassia.geo/OSTA.html

K Barrett

"?" wrote in message
rg...
On 28 Mar 2006 10:58:45 -0800 in
. com jtill
wrote:
Ray, my plants are outside so I try to place them so that they get
morning sun and mottled shade in the afternoon. I am to new at this to
have any information you could use. But, this seemed to be a chance to
ask about street lights. Are stray lights a problem for day length
controlled plants?

I've only seen literature on street lights having an effect on
zygo-cacti.
Ray makes a good point about inverse square law quickly bringing the
effective light level to nill.
However, on nights with scattered low clouds , the bank of street lights
2 miles north of me produces entirely too much light in my yard for
stargazing to the south. And then there was the apartment I was in
where
the bedroom window was about 10 feet away from the bulb from the street
light.
What I'm trying to say, is you need to indicate if you have a
pathological
case with the street light illumination.


--
Chris Dukes
Suspicion breeds confidence -- Brazil