The Sunlight Project.Sun as the Ultimate Guide for Led Growing.

Hosebomber · Nov 8, 2012

There are a few things I would like to point out. First, your statement of:

What ? Through BL harvesting, Deep RL is irradiated from Ch ?
Interesting...Irradiated where exactly ?
To nearby chlorophyll molecules ?
Plants are glowing deep red light when exposed to BL ?
...
Aha! That's why they appear brown ,
at color-pass unfiltered Infra-red photographs...
Taking about autotrophic organisms...
They glow the reds they are missing...

Is incorrect. Read http://www.springerlink.com/content/lw2n69rx22g821k6/ for more information on florescence of plants. That is also confirmed by the statement a few lines up where you state " there is no photon emission".

Next is the green light absorption that you highlighted "that are absorbed". You should have continued that underlining to include the portion about it having a much flatter quantum yield from all other wavelengths. Green light has very poor quantum yield and has only shown to be effective when the plant is over saturated in usable light (see http://www.plantphysiol.org/content/157/3/1528.full?sid=ff680d71-27f2-4166-8cd3-c17d03c265b4 http://jxb.oxfordjournals.org/content/58/12/3099.full and http://pcp.oxfordjournals.org/content/50/4/684.full for more information).

The last thing I would mention is that you comment of:

Turns some PFr back to Pr...But not the HIR one...That one needs darkness only....
-So duration / power effects of 650-680 nm light are not photoreversible if light was provided in high irradiances or for prolonged periods...
12 hours under plenty of 650-680 photons , is enough for plant to "sense " that a lot of light is out there...
Photomorphogenesis begins. Plant needs to "Sun Adapt " ....It's the only way to survive...(and/or thrive...)

This is in contrast to the article you linked and the source they used in writing that article. They concluded that it requires continuous prolonged exposure. In the PhyA system all HIR is degraded in less than 15 minutes. "Although the reason why a minimum of 24 h of irradiation is still required to elicit the response is obscure, we speculate that a 24-h irradiation period leads to an irreversible change in hypocotyl growth rate that persists for several days in the absence of any further light stimulus." You can read that full article here: http://www.plantphysiol.org/content/122/1/147.full

stardustsailor · Nov 8, 2012

Is incorrect. Read http://www.springerlink.com/content/lw2n69rx22g821k6/ for more information on florescence of plants. That is also confirmed by the statement a few lines up where you state " there is no photon emission".

From link you suggested...(Much thanx for the link..)

In what way is incorrect ?
.....

• Heat loss from the higher excited state to the lowest excited state (with no photon emission)
•Fluorescence from the lowest excited state to ground level
(radiates a 673 nm photon, in the red region)
...Heat loss and fluorescence are not the same thing ,neither they counteract each other...

Blue light=> chlorophylls =>heat loss=> Fluorescence in mesophyll cells => re-absorption at red ....
and/or
Blue light=> water +ogygen =>ionising=> peroxides=>anti-oxidant biosynthesis..
And/or
Blue light=> Energy transfer to another molecule. i.e water =>mechanical molecular vibration=> heat..

(Just only couple of BL's properties ,amongst many....)

....

Next is the green light absorption that you highlighted "that are absorbed". You should have continued that underlining to include the portion about it having a much flatter quantum yield from all other wavelengths. Green light has very poor quantum yield and has only shown to be effective when the plant is over saturated in usable light (see http://www.plantphysiol.org/content/...3-c17d03c265b4 http://jxb.oxfordjournals.org/content/58/12/3099.full and http://pcp.oxfordjournals.org/content/50/4/684.full for more information).

I do not disaggree.There's plenty of green light in sunlight....
No need for great absorption peaks or quantum yields ,there...

-Yes,shown to be effective when the plant is over saturated in usable light ,acting
as "Photosynthesis inhibitor "... http://jxb.oxfordjournals.org/content/58/12/3099.short

-Plays a substantial role in Shade Adaptance and Neighbor Detection .
http://www.plantphysiol.org/content/157/3/1528.abstract
http://5e.plantphys.net/article.php?ch=e&id=236

-Counteracts Blue-mediated responces ..(when needed as part of a sun adaptance scheme...)
http://5e.plantphys.net/article.php?ch=e&id=267

Some ...Not "only"...

This is in contrast to the article you linked and the source they used in writing that article. They concluded that it requires continuous prolonged exposure. In the PhyA system all HIR is degraded in less than 15 minutes. "Although the reason why a minimum of 24 h of irradiation is still required to elicit the response is obscure, we speculate that a 24-h irradiation period leads to an irreversible change in hypocotyl growth rate that persists for several days in the absence of any further light stimulus." You can read that full article here: http://www.plantphysiol.org/content/122/1/147.full

There are some HIR -mediated responces ,that are not FRL photoreversible...
Like overall "Sun Adaptance "...
FRL can affect,though, the HIR mediated Circadian oscillator
of " +35 sec/per day =>check !=> grow " or the one " -38 sec per day =>check ! => flower "...
Which also can act as " from - 38" to -3 hours of light in one day's cycle ? = check ! => cloudy day /neighbor plant / obstacle "
But it's a point worth of analysing (very helpful for led growing research...) ...
Nice link ,much thanx once more.Have to find some time to study it better...

P.S.:
-Research refers mainly to young seedling where PHY it comprises about 0.2% of total extractable protein,
about 50 times more concentrated than in mature green tissues.
50 times more different ....
-They irradiated separately with FRL & RL ,using leds...
Thus,saturating phytochromes..
At natural sunlight RL : FRL ratio is 1.2 approx.
Both wls are irradiated during daytime ...
But still more Pfr than Pr ,there ...
(Also lower wls of red ,excite Pr to Pfr...i.e 620-640 nm...
But not that much-saturating level ,excitation there...)
So,even more Pfr...

There are plenty of HIR responses,that are not photo-labile (photoreversible )

The high irradiance reaction (HIR) requires continuous or prolonged irradiation with high-intensity light. The response in this case is proportional to the irradiance received by the plant; again, photoreversibility is absent. Typical HIR responses are anthocyanin synthesis or inhibition of hypocotyl elongation. Although phytochromes clearly are involved in these responses, evidence indicates that other photoreceptors that absorb UV or blue light contribute to this control.

http://www.photobiology.info/Shinkle.html

Studies with phytochrome-deficient mutants grown in defined VLFR, LFR and HIR light environments have revealed that specific phytochromes can be ascribed to individual responses (Figure 1B), although significant redundancy exists (Møller et al., 2002; Nagy and Schäfer, 2002). FR-HIR responses are, however, specifically mediated by phyA due to the unusual spectral properties of this phytochrome. It has been proposed that a novel form of PrA (denoted Pr[SUP]+[/SUP]A), which has photocycled through Pfr, is responsible

http://www.nature.com/embor/journal/v3/n11/full/embor036.html

Nicely done for general idea of PHY:
http://plantphys.info/plant_physiology/phytochrome.shtml

stardustsailor · Nov 8, 2012

- In tropical rainforests, large plants' canopies reach to a height of 80-100 meters .. ( 240 -300 feet ) ..
Underneath their dense canopies ,in shade ,thrive Earth's most productive plants (regarding flowers & fruits ) ....

High light power= large sized individual / unit ?
Low light levels =increased population ? (more flowers=>more fruits =>more seeds..)

Sun Adapted
(through RL-rL * HighIrradiationResponse PHY responses =Lots of Power/duration Above Directed 650-680 nm )
(* rL= 620-640 nm red , RL = 650-680 nm red ...)
A tall plant,with deep main radicle root ,in search of water..
Away from topsoil nutrient zone..
(Because this kinda of power level of light ,causes that dry soil....Heh...)
With Sun adaptated sparse& small leaves ..Same as brancing...
Neither vegging or flowering are heavy because of the almost constant 12/12..
Grows and flowers ,at same time,from a point ...

The above plant has vegged ,protecting it's shelf from excess light
(Notice : Chronic photoinhibitionirreversible reduction of maximum PS rate (O2 evolved per quantum mol)
from excess light.Cumulative effects of recurring photoinhibition over a growing season can reduce crop yield. )
stretching during prolonged darkness -almost constant 12/12*-,

*but not flowering because of excess (from Deep RL ),Pfr PHY state & no " twilight " effects
http://www.plantphysiol.org/content/67/6/1230

Click to expand...

Sending its main root deep ,in search of water (650-680 nm RL from leds , by the way ,causes exactly that ! ),
but away from nutrient-rich topsoil...No much leaves there...
Much energy was spent in protection from light, deep root system ,stalk (tall plant ),
long branches...
Not much stored at (small ,sparse )leaves as carbonhydrate.Neither,plenty of mobile elements,stored there..
After summer solstice from 12 hours daylight dropped to 11 hours ...Still under strong light...
Growing and flowering ,together ,all the time until maturation ( ? longgggg flowering...)
Flower buds due to " Growing and flowering ,together" ,form rather long ,but not "thick "..
Not heavy flowering there...Not much stored mineral assimilates & energy resources,to support heavy flowering ....

vs

Shade adapted (through FRL LF (Low Fluence) PHY responses ,along with others).
A plant with plenty of lateral superficial roots ,scattered to nutrient-rich topsoil ,
,with lots of large (storage capable ) -leaves ...

Relative low rates per leaf ,Nitrates assimilation due to relatively low
-but long and trouble-free-PS rates ,but more storage room (more leafs)there also,and more lateral roots .
So Absolute Nitrate Assim. is rather great......

Click to expand...

...Lots of short noded brances...

The above plant has vegged ,under angled and low power light,with pretty dispersed blue wls and not much deep RL /FRL...
From 12 at vernal equinox up to 15 hours in Summ.Solstice...Always under low to moderate power levels of angled / dispersed light...
Mostly with lower wls rL (600-640 nm ) ..
Not much Energy was spent in protection from light.
On the contrary..
Strong efforts were made ,for best light harvesting...
Short stature (short nights -more BL ) ,many nodes close together ,dense branching ,dense foliage..
Big sized, thin leaves,which serve as a large mineral assimilates' & energy resources' ,storage..
Lateral mostly roots ,scattered superficially at topsoil ,collect as many nutrients possible...
Low PS rates there you see,but for prolonged periods of daylight...
Not heat or water issues ,there also...(moderate climate Not arid (dry) from excess sunlight's evaporation..
Also ,soil rich in water from winter's ice/snow/rainfalls)..

After summer solstice from 12 hours daylight dropped to 10 hours at harvest date ...
Light power decreases also......
Now there's the twilight effect,setting in....
Flowering rates increase*[SUP]1[/SUP] in from middle of August (approx )...
To become more "intense " every day...
Lasting for 2 and a half months ,from the 7 month cycle....
Flower buds due to "intense" flowering "mode" ,grow on tops ..
Short and thick..Squatty ..(no new nodes made...Vegging rates*[SUP]1[/SUP] decrease rapidly..)
Really heavy flowering there...
Plenty of ,stored mineral assimilates & energy resources
(due to long vegging period , & Shade Adaptance),to support heavy flowering ...
Leaves wither and die...But flower buds get crazy in size...
In a very short period of time ,with low power levels of light....
...
Both of the above plants,excist (and look like -yield like ),in REAL natural environment ...
Maybe,just maybe now, mistaken also as different kinds of species..
....
Anyway...
Production ?
Meaning what ?

For one of them regards unit's own mass/size ,
for the other regards it's reproductive organs .....

If you know what I mean...

*[SUP]1 ...[/SUP]One ,relatively, good indicator for that,(vegetative state decreasing,reproductive increasing ) is change of phyllotaxy.
From opposite ,new nodes (branch /leaf/flower sites),thus new leaves become alternate (= spiral shape of early buds,forming...).
https://en.wikipedia.org/wiki/Phyllotaxis

Providing deep reds ,plant gets more efficient in low reds absorbance & PS utiisation....
And vice -versa...
Plant search for what's missing..Not for what's there..
Specially if that what's there "means effective but destructive-not for long ... ".....
So providing 640 nm rL enhances the mechanisms* for more efficient 660 nm RL harvesting.
* Chloroplast spacing and orientation ,higher PSI SII rates ,more ChA
and some other "light adaptance" reactions.
What's left is the supply of 660 nm ,now..
Has to be ..In balance"...
Not to reverse "shade adaptance " (which is reversible due to mostly FRL /RL-rL FL PHY responses)
or mess-up circadian oscillator(easily reversible...),
but to bring the plant to its best efficiency point...
...
Caution now, there...
For each given quality of light ,there are more three properties left to consider.
Quantity,Duration,Direction.

...

Which is less stressful ,I wonder...
From shade to light ?
Or from light to shade ?
To be or not to be ?

More about all those ,later on...

tenthirty · Nov 8, 2012

Not to reverse "shade adaptance " (which is reversible due to mostly FRL / RL FL PHY responses)

We're about to find out. I just put my shade adapted plants under the HPS. I'm hoping it will make them really bulk up and hammer the flowering response.
From previous experience, I'd say it take 3 weeks or so to fully reverse shade adaptance, based on what you have said and my observations on the previous run.
Too bad that the quality of the HPS light is so shitty.

Which is less stressful ,I wonder...
From shade to light ?
Or from light to shade ?
To be or not to be ?

My guess is from light to shade.
Does it take more effort to focus on something or close your eyes.
I would suspect that the antenna pigment has to be pretty much aligned with the light source to be able to catch a photon.
This would mean that the antenna pigment would have to move in some way, either reorient itself or act like a lens in your eye.
From shade to light, the machine is starting up and aligning itself.
Remember to change your oil regularly for those cold startups. :lol:

What I want to know is, what is the best amplitude and modulation of the visible spectrum for a given stage of our favorite plants life?

But I digress.....please continue

stardustsailor · Nov 9, 2012

We're about to find out. I just put my shade adapted plants under the HPS. I'm hoping it will make them really bulk up and hammer the flowering response.From previous experience, I'd say it take 3 weeks or so to fully reverse shade adaptance, based on what you have said and my observations on the previous run.Too bad that the quality of the HPS light is so shitty.

Well,my brother Ten-thirty...Actually HPS provide ( light quality -wise ),a "Shade Adapt" light
quality ....
(Lots of Greens -yellows -orange-FRL .
Not so much Blues(almost none compared to other emitted wls).
Neither so much deep/reds...(not in a "balanced" ,at least power level,with the other wls....)

Now...
HPS is an artificial Light source...Possessing also ,some extra properties ..
Like distance from canopy...
That's why they work quite well..
They adapt plants ,to "shade",while providing lots of that "shade adaptive light" ....

Temperature effects ,must be taken into account also,
as elevated temps from HPS ,slow down PS rates ( at C3 plants,at least...)

Effects from translocating HPS-grown plants ,outdoors to sun to flower ,may be a proof for :
" My guess is from light to shade. " (i.e . Sun => HPS ) is less stressful than from shade to light ..(i.e. HPS=> Sun )

"From light to shade " actually happens ,in natural environments during flowering...
After summer solstice, sunlight power levels drop (a bit at 15° N ,lots at 45° N)

...best amplitude and modulation ...

Click to expand...

Hmmm,that's a tough one...
I want to know it,also...

P.S. ; Read this :
Photomorphogenesis is an organismal response to information present in the light environment. There is information concerning: simple presence of light, light direction, light intensity, light duration, spectral quality and polarization.
Studies have demonstrated photomorphogenic effects of all of these parameters of the light environment in diverse organisms. However, it must be acknowledged that the responses to polarization were observed in laboratory conditions that may not have any parallel in the natural light environment. It should also be noted that the earliest responses to light exhibited by germinating seedlings are initiated by the mere presence (or absence) of light, information of the simplest sort possible.

http://5e.plantphys.net/article.php?ch=t&id=56

Leaf thickness and chloroplast orientation & repositioning.

As for cell chloroplasts of higher plants ,two main (known ) Sun/shade adaptances they do exhibit,
regarding their macroscopic physiology as cell organelles .
( not their biochemistry..That's another story,to tell... )

-Orientation :
...

Where they turn either perpendicular to Sun Rays (Shade adaptance ),
where they let 430-440 nm & 650-680 nm photons ,partially pass through (...for the rest of chloroplasts to harvest..),
(lamella thylakoids protruding in Stroma (liquid ) with PSI & ChA being their dominate photosystem / PS pigment ,respectively
While gathering most of 440-460 nm & 620-640 nm photons with "dense packed " antenna/light harvesting proteins,
at stacked grana thylakoids ,(with PSII & ChB being their dominate photosystem / PS pigment ,respectively) .

-Thylakoid stacking permits energy partitioning between the photosystems, allowing the most efficient use
of the available energy...(Meaning maybe,low available energy ? )

.....
Or parallel / angled to strong sun rays ( Sun adaptance ) ..
They decrease their thylakoids' efficient active surface ,against powerful sunlight levels....
Protecting their PS systems....

And ....
-Repositioning :

-Chloroplasts can reposition themselves along the side walls of cells, so that the more superficial ones provide shade to deeper chloroplasts along the same wall, in response to excessively intense light.

thick or thin leaves ....
One can ask...
If Sun Adapted leaves get thicker..?
How they do let light pass to the leaves underneath them ?

-By small overall number of leaves ...
(thus no need for many lateral roots either. )

-By erected lamina (leaf blade )

-By overall small sized leaf blades

-Or form new leaf shape,i.e. digitate : narrow & elongated leaf blade 'digits'.
(mj can form palmate,lobed or digitate leaf shapes,also as Shade/Sun Adaptance response.... )
https://upload.wikimedia.org/wikipedia/commons/e/e8/Leaf_morphology.svg

-By sparse long branching.(stretched -long internodal distances)

-By overall large plant size/stature

To name a few more ,Sun Adaptations....

If sunlight does not pass ,underneath top layer of canopy...
(As in rainforests...)
Plant ,do not have green leaves underneath...
(i.e dense population of sugar cane or corn...
Being green/productive only on tops...)

stardustsailor · Nov 9, 2012

..

From bottom to top ...
.....
Reproductive effort is defined as that proportion of the total energy budget of an organism that is devoted to reproductive processes. Reproductive effort at a given age within a species will be selected to maximize reproductive value at that age.
Reproductive effort is not directly affected by changes in juvenile survivorship, nor necessarily reduced by an increase in adult survivorship.
Selection for high levels of reproductive effort should occur when extrinsic adult mortality is high, in environments with constant juvenile survivorship, and in good years for juvenile survivorship in a variable environment, provided that the quality of the year is predictable by adults.
Data necessary to measure reproductive effort and to understand how selection results in different levels of effort between individuals and species are discussed. We make several predictions about the effect of increased resource availability on reproductive effort. The empirical bases for testing these predictions are presently inadequate, and we consider data on energy budgets of organisms in nature to be essential for such test. We also conclude that variance in life table parameters must be known in detail to understand the selective bases of levels of reproductive effort.

http://www.pnas.org/content/72/6/2227.short
....
reproductive effort :The proportion of its resources that an organism expends on reproduction.
http://www.jstor.org/discover/10.2307/2460502?uid=2&uid=4&sid=21101268726173
If resources are low .... (Sun adapted plant.)
(decreased storage of assimilates/ chemical energy -Carbonhydrates-
and deep roots in ground ,away from topsoil,for efficient assimilation of new...
High photosynthetic rates,but with less " Photosynthetic overall mechanisms ",
under constant defence against light....)
Then ,yes,probably reproductive effort -The proportion of its resources that an organism expends on reproduction.-has to be high....

the efficiency of the synthetic process itself.
Since K1 and K2 are measures of that fraction of the
total energy intake which is diverted into somatic
growth, they are analagous to RE and by an identical
series of arguments to those used above it can be
shown that, all other things being equal, ecological
growth efficiencies should be greater at lower temperatures
(that is, at higher latitudes: Fig. 3 & 4).

http://www.int-res.com/articles/meps/38/m038p089.pdf

...

The Sunlight Project.Sun as the Ultimate Guide for Led Growing.

Hosebomber

Active Member

stardustsailor

Well-Known Member

stardustsailor

Well-Known Member

tenthirty

Well-Known Member

stardustsailor

Well-Known Member

stardustsailor

Well-Known Member