General question about light
 

Looking for opinions, science, and/or anecdotal evidence:

(Disregarding the obvious situation in which the light intensity is so great
that pant tissues are burned)

Is it possible to give a plant too much light?

It is well established that too little light will lead to slower growth,
more "leggy" growth, and less blooming, and I have frequently heard that
plants should be grown as bright as possible without damaging them, but is
that really good advice? Are there cases where plants grow better in more
subdued lighting? If so, which, and why is that?

--

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

General question about light
 

I've seen some that have better flower color when grown a little shadier --
Epc. Frances Dyer, for one. Kenni

"Ray" wrote in message
. ..
Looking for opinions, science, and/or anecdotal evidence:

(Disregarding the obvious situation in which the light intensity is so
great that pant tissues are burned)

Is it possible to give a plant too much light?

It is well established that too little light will lead to slower growth,
more "leggy" growth, and less blooming, and I have frequently heard that
plants should be grown as bright as possible without damaging them, but is
that really good advice? Are there cases where plants grow better in more
subdued lighting? If so, which, and why is that?

--

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

General question about light
 

Yes, it is possible to give a plant too much light. Physically, not only
can one burn the leaves (since light is heat) but on a chemical basis the
ring structure of chlorophyll gets damaged when bombarded with too much
light. (all those double bonds get broken, irreparably) Plants then turn
that sickly light green and die.

I have noticed that in too much light the inflorescence doesn't elongate
properly and flowers are crowded on a stem. Which then makes me wonder
about how to detrermine the proper amount of light and my head swims and I
come back to the computer and read my silly murder mystery newsgroup. Or
watch TV.

If you ever really wanted to read up on photosynthesis the University of
Arizona has a marvelous photosynthesis page with great links to follow.
Googling terms lead to some great papers, too. Dr Wang's research on phal
production has a lot of science on proper light levels. To blow my own horn
I'll provide the link to Dr Wang's papers via OrchidSafari, *G*
http://www.geocities.com/brassia.geo/OSTA.html

K Barrett


"Ray" wrote in message
. ..
Looking for opinions, science, and/or anecdotal evidence:

(Disregarding the obvious situation in which the light intensity is so
great that pant tissues are burned)

Is it possible to give a plant too much light?

It is well established that too little light will lead to slower growth,
more "leggy" growth, and less blooming, and I have frequently heard that
plants should be grown as bright as possible without damaging them, but is
that really good advice? Are there cases where plants grow better in more
subdued lighting? If so, which, and why is that?

--

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

General question about light
 

Ok. my head hurts
On the stupid side, If it blooms and doen't die will that work?

Jack

General question about light
 

Do you think you could actually tell us WHERE Dr. Wang's papers are on that
long list?

--

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


"K Barrett" wrote in message
. ..
Yes, it is possible to give a plant too much light. Physically, not only
can one burn the leaves (since light is heat) but on a chemical basis the
ring structure of chlorophyll gets damaged when bombarded with too much
light. (all those double bonds get broken, irreparably) Plants then turn
that sickly light green and die.

I have noticed that in too much light the inflorescence doesn't elongate
properly and flowers are crowded on a stem. Which then makes me wonder
about how to detrermine the proper amount of light and my head swims and I
come back to the computer and read my silly murder mystery newsgroup. Or
watch TV.

If you ever really wanted to read up on photosynthesis the University of
Arizona has a marvelous photosynthesis page with great links to follow.
Googling terms lead to some great papers, too. Dr Wang's research on phal
production has a lot of science on proper light levels. To blow my own
horn I'll provide the link to Dr Wang's papers via OrchidSafari, *G*
http://www.geocities.com/brassia.geo/OSTA.html

K Barrett


"Ray" wrote in message
. ..
Looking for opinions, science, and/or anecdotal evidence:

(Disregarding the obvious situation in which the light intensity is so
great that pant tissues are burned)

Is it possible to give a plant too much light?

It is well established that too little light will lead to slower growth,
more "leggy" growth, and less blooming, and I have frequently heard that
plants should be grown as bright as possible without damaging them, but
is that really good advice? Are there cases where plants grow better in
more subdued lighting? If so, which, and why is that?

--

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

General question about light
 

It's about half way down
here is the paper

http://primera.tamu.edu/orchids/paper2pg1.htm

If you grow Phals it would be very helpful on bloom stagering from the
same crop

Jack

General question about light
 

LOL! Where it says
"Articles by Dr. Yin-Tung Wang of Texas A&M click here "

K



"Ray" wrote in message
. ..
Do you think you could actually tell us WHERE Dr. Wang's papers are on
that long list?

--

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


"K Barrett" wrote in message
. ..
Yes, it is possible to give a plant too much light. Physically, not only
can one burn the leaves (since light is heat) but on a chemical basis the
ring structure of chlorophyll gets damaged when bombarded with too much
light. (all those double bonds get broken, irreparably) Plants then turn
that sickly light green and die.

I have noticed that in too much light the inflorescence doesn't elongate
properly and flowers are crowded on a stem. Which then makes me wonder
about how to detrermine the proper amount of light and my head swims and
I come back to the computer and read my silly murder mystery newsgroup.
Or watch TV.

If you ever really wanted to read up on photosynthesis the University of
Arizona has a marvelous photosynthesis page with great links to follow.
Googling terms lead to some great papers, too. Dr Wang's research on
phal production has a lot of science on proper light levels. To blow my
own horn I'll provide the link to Dr Wang's papers via OrchidSafari, *G*
http://www.geocities.com/brassia.geo/OSTA.html

K Barrett


"Ray" wrote in message
. ..
Looking for opinions, science, and/or anecdotal evidence:

(Disregarding the obvious situation in which the light intensity is so
great that pant tissues are burned)

Is it possible to give a plant too much light?

It is well established that too little light will lead to slower growth,
more "leggy" growth, and less blooming, and I have frequently heard that
plants should be grown as bright as possible without damaging them, but
is that really good advice? Are there cases where plants grow better in
more subdued lighting? If so, which, and why is that?

--

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

General question about light
 

On Sun, 26 Mar 2006 08:45:09 -0500 in Ray wrote:
Looking for opinions, science, and/or anecdotal evidence:

(Disregarding the obvious situation in which the light intensity is so great
that pant tissues are burned)

Is it possible to give a plant too much light?

It is well established that too little light will lead to slower growth,
more "leggy" growth, and less blooming, and I have frequently heard that
plants should be grown as bright as possible without damaging them, but is
that really good advice? Are there cases where plants grow better in more
subdued lighting? If so, which, and why is that?

I can offer one counter example.
Ludisia grown as bright as possible without damage turns an ugly (to me)
orange color.


--
Chris Dukes
Suspicion breeds confidence -- Brazil

General question about light
 

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?
Joe T

General question about light
 

Of course they can be, but if you consider the inverse-square rule, at any
appreciable distance, the light intensity is next to nothing, so I really
have my doubts that it would be an issue.

--

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


"jtill" wrote in message
ups.com...
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?
Joe T

General question about light
 

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

General question about light
 

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

General question about light
 

I suspect that the human eye is far more capable of detecting light than is
a plant.

If the two were close in sensitivity, stars would prevent plants from
blooming!

--

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


"?" 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

General question about light
 

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?

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

General question about light
 

I have only slowly got my act somewhat together on this orchid thing.
Probably will ask other question as time goes along. Because it is easy
here in the Houston/Galveston to use my yard for orchids only small
problems crop up. The street light worried me so thanks for discussing
that.To much light? I will let you know since mine get a lot of it. I
burned a Cattleya pretty bad last summer in what I thought was mottled
shade under a Pecan tree. Well. I was blocking the morning sun and not
the afternoon! Small problem right? HA! It is a little tricky to find
that spot in my yard that has the right lighting, in winter for sure
without the leaves. First I am working on growth, later blooming will
be cultivated. That Cattleya I sunburned did bloom this winter, burn
and all!
Ray, all the plants I buy seem to have rotten roots. Your SemiHydro
sure is looking better all the time. In a clay pot and saucer even the
pot gets into the act providing a wall of dampness around the root
system.

General question about light
 

"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

General question about light
 

That's true, but the clay pot - because it will allow more evaporation -
will be cooler, which may not be a good thing for really warm growing
plants.

--

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


"jtill" wrote in message
oups.com...
I have only slowly got my act somewhat together on this orchid thing.
Probably will ask other question as time goes along. Because it is easy
here in the Houston/Galveston to use my yard for orchids only small
problems crop up. The street light worried me so thanks for discussing
that.To much light? I will let you know since mine get a lot of it. I
burned a Cattleya pretty bad last summer in what I thought was mottled
shade under a Pecan tree. Well. I was blocking the morning sun and not
the afternoon! Small problem right? HA! It is a little tricky to find
that spot in my yard that has the right lighting, in winter for sure
without the leaves. First I am working on growth, later blooming will
be cultivated. That Cattleya I sunburned did bloom this winter, burn
and all!
Ray, all the plants I buy seem to have rotten roots. Your SemiHydro
sure is looking better all the time. In a clay pot and saucer even the
pot gets into the act providing a wall of dampness around the root
system.

General question about light
 

Interesting point as I have made sure to buy warm growing orchids as
the temp. in Houston area often is in the mid 90s for extended periods.
I often use a misting device to cool my plants as they are outside and
a fan would look crazy in my yard! There are so many little points to
this hobby it is a wonder we succed at all. Will try my hand at glueing
plastic containers to clay saucers.
10 footcandles, that is micro light indeed! Will have to give up
smoking in my yard! ;-)) I will also look up the light pattern of a HPS
1000 watt streetlight. Will let you know.
Joe T

General question about light
 

Well, 10 footcandles is not "micro light indeed" ! A quick check shows
that street lighting is recommended and designed to provide 0.4
footcandles at street level. Doorway entrance lighting is recommended
at 5.0 footcandles. I now remember engineering an outside work area
and spec'ed one foot candle at the work level, the lighting scheme
looked like a ball stadium! Anyway, I am relaxing about my back yard
orchids sleeping OK.
Joe T

General question about light
 

Joe, it's the saucers you need to get rid of -- a plastic pot will hold
water much longer than will a clay pot, all else being equal. Saucers
should not be used with either one, outdoors [indoors, they can be a
necessary evil]. Kenni

"jtill" wrote in message
ups.com...
Interesting point as I have made sure to buy warm growing orchids as
the temp. in Houston area often is in the mid 90s for extended periods.
I often use a misting device to cool my plants as they are outside and
a fan would look crazy in my yard! There are so many little points to
this hobby it is a wonder we succed at all. Will try my hand at glueing
plastic containers to clay saucers.
10 footcandles, that is micro light indeed! Will have to give up
smoking in my yard! ;-)) I will also look up the light pattern of a HPS
1000 watt streetlight. Will let you know.
Joe T

General question about light
 

On Fri, 31 Mar 2006 12:54:10 -0500 in Kenni Judd wrote:
Joe, it's the saucers you need to get rid of -- a plastic pot will hold
water much longer than will a clay pot, all else being equal. Saucers
should not be used with either one, outdoors [indoors, they can be a
necessary evil]. Kenni

As memory serves, he's glueing on saucers to prevent tipping
of top heavy pots.

Probably more eco friendly than putting a depleted uranium round in the bottom
of the pot.

--
Chris Dukes
Suspicion breeds confidence -- Brazil

General question about light
 

Kenni, that may be true for water holding culture, I am using SemiHydro
clay pellets that drain free water instantly and require a small sump
that holds water to provide for the wicking of water up the pot
internally, and in my case keeping the pot wet. In my use of clay pots,
which is not true SemiHydro, I need a saucer to hold that water. The
beauty of SH is that there is much air space in the culture all the way
down the pot bottom as well as damp clay to allow the roots to breath
and adsorb (or is it absorb) water and food. Someone will calculate the
free air space one day and my guess is about 30% throughtout the pot.
I may very well run into trouble with this approach but it makes sense
to me. I use RO water and very low levels of sea weed solution as a
food. I simply had to much trouble with bark, charcoal and inerts so
have switched to expanded clay. I use clay pots rather than plastic
because the wind blows my plants over in plastic. Is that enough air
circulation! ;-)) Hey, I do listen to you folk, being a newbie I need
the information and am very glad this forum and others are so free with
help and advice.
Thanks!!!
Joe T

General question about light
 

Chris Dukes
Suspicion breeds confidence -- Brazil

My wife is from Ponta Pora, Brazil and she is always saying things like
your "Suspicion breeds Confidence". I seldom understand her either!

Joe T

General question about light
 

Joe,

If you have trays full of water, it certainly IS "true" semi-hydroponics,
you just have an external reservoir, rather than internal.

Your guess on the 30% open air space is probably high, but pretty
reasonable. If the particles were perfect spheres of uniform size, it's
about 40% open - no matter what the diameter. The more irregular the shape
and dissimilar the size of the particles, the less is open. My own
measurements with PrimeAgra many moons ago showed 26%.

--

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


"jtill" wrote in message
oups.com...
Kenni, that may be true for water holding culture, I am using SemiHydro
clay pellets that drain free water instantly and require a small sump
that holds water to provide for the wicking of water up the pot
internally, and in my case keeping the pot wet. In my use of clay pots,
which is not true SemiHydro, I need a saucer to hold that water. The
beauty of SH is that there is much air space in the culture all the way
down the pot bottom as well as damp clay to allow the roots to breath
and adsorb (or is it absorb) water and food. Someone will calculate the
free air space one day and my guess is about 30% throughtout the pot.
I may very well run into trouble with this approach but it makes sense
to me. I use RO water and very low levels of sea weed solution as a
food. I simply had to much trouble with bark, charcoal and inerts so
have switched to expanded clay. I use clay pots rather than plastic
because the wind blows my plants over in plastic. Is that enough air
circulation! ;-)) Hey, I do listen to you folk, being a newbie I need
the information and am very glad this forum and others are so free with
help and advice.
Thanks!!!
Joe T

General question about light
 

Hello Ray
After searching through my old Chem. E. books for cataylist packing
density calculations I finally read your site with all that info
already worked out by you! :-)). Anyway, I am slowly collecting the
methodology of orchid (your site is a great source) growing. If those
darn plants will just hold on for a while longer....
Joe T

General question about light
 

Joe,

I'm a ceramic engineer, so part of the basic course work is particle
packing - with the idea of making a super dense body, like a brick.
Obviously we're looking to go in the opposite direction with orchid media,
but the math's the same.

When I give my talks on Semi-hydro culture, folks are always amazed that a
room full of basketballs and ping-pong balls - or even BB's - gives the
same open volume. One guy - a HS Math teacher - did the calculation while I
spoke just to verify!

--

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


"jtill" wrote in message
ups.com...
Hello Ray
After searching through my old Chem. E. books for cataylist packing
density calculations I finally read your site with all that info
already worked out by you! :-)). Anyway, I am slowly collecting the
methodology of orchid (your site is a great source) growing. If those
darn plants will just hold on for a while longer....
Joe T

I accept noticed that in too abundant ablaze the bloom doesn't elongate properly and flowers are awash on a stem. Which again makes me wonder about how to detrermine the able bulk of ablaze and my arch swims and I come aback to the computer and apprehend my asinine annihilation abstruseness newsgroup.