Control red to far-red light ratio to limit stretching

VerdantGreen · Nov 20, 2010

weezard - hi and thanks - interesting findings - was it the same cutting?. were you also using 640 in the ratio too or did 660 make up all the red?? just wondering that because the 660 peak may include more far red than 640, depending on the full range. guessing really

perhaps more blue has some influence too that changed your outcome...

dave - thanks for that - im pretty sure i read somewhere that most MH's actually have more red (as proportion of total output) than HPS. is that true??

VG

Weezard · Nov 20, 2010

Da skinny and a query.

Da skinny and a query.

Aloha V.G, et al

VerdantGreen said:
weezard - hi and thanks - interesting findings - was it the same cutting?.

Sistah clones.
Started out as close to identical as I could get.

were you also using 640 in the ratio too or did 660 make up all the red?? just wondering that because the 660 peak may include more far red than 640, depending on the full range. guessing really

Just 660nm.
And a narrow bandwidth as well, so, no 740nm.

Also I like to over-cool and I suck the heat out of the back of the heatsink, then out of the room, so there's very little IR to cloud the issue.

perhaps more blue has some influence too that changed your outcome...

VG

That's exactly what I surmise.

I run 30W. of blue and ~150W. of Deep Red so the R:B is 5:1 with the red at turned all the way up.
I took it to ~2:1 for the test.

It seems consistant with earlier, and later, results.

A higher blue to red ratio has produced shorter internodes over several grows.
And made for fatter leaves also.
Both in width and thickness!

Given the energy of shorter wavelengths, I expected thicker leaf, but wider leaf has me puzzled.
Thylakoids will cause thickening when the light is too energetic.
But I would think that wider leaves would negate that protection with more exposure.

Best that I come up with so far, is a guess that the plant is "looking for" more red while it's dodging too much blue?

Why else get thick, and fat?
Ah dunno.

Whuddaya think, guys?

Mahalo fo' info,

Da wondering 'zard

VerdantGreen · Nov 23, 2010

i see spurr got banned so hopefully if/when he comes back he can let us know what he thinks about this.
ive requested a new forum, the link is in my sig if anyone is interested in supporting.

VG

zenoonez · Nov 23, 2010

VerdantGreen said:
i see spurr got banned so hopefully if/when he comes back he can let us know what he thinks about this.
ive requested a new forum, the link is in my sig if anyone is interested in supporting.

VG

Posted in your thread in support. I think it would be nice to have somewhere that is encouraging of science based discussion. Oh and spurr, if you get unbanned or come back under another nic, hit me up I have some further questions for you.

VerdantGreen · Nov 24, 2010

i found a couple of references about blue light
"Phototropins Promote Plant Growth in Response to Blue Light in Low Light Environments"
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1087990/
"Quantitative contributions of blue light and PAR to the photocontrol of plant morphogenesis in Trifolium repens"
http://jxb.oxfordjournals.org/content/57/10/2379.full

This demonstrates that the quantitative aspects of Blue Light and PAR sensitivity have to be considered to understand the control of the shade-avoidance responses, in addition to phytochrome-mediated responses to the Red:Far Red ratio.

Weezard · Nov 24, 2010

Sorry, no habla ubergeek.

Sorry, no habla ubergeek.

VerdantGreen said:
i found a couple of references about blue light
"Phototropins Promote Plant Growth in Response to Blue Light in Low Light Environments"
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1087990/
"Quantitative contributions of blue light and PAR to the photocontrol of plant morphogenesis in Trifolium repens"
http://jxb.oxfordjournals.org/content/57/10/2379.full

Mahalo VG.

I do appreciate the favor of the links.

But, for a Guy with my edumacation, that's like big boots in deep mud.

I'm forced to admit that I get very little from these kine citations.
Read them 3 times.
All I got, was older.
To me, they appear as a jumble of $40 words with very little discernable/useable, information.
It's seems to me that they are purposly obtuse.
Even going out of their way to obfuscate any practical application of the "research".

I desperately need an educated digester for dis kine sing.

Perhap you could recommend a "horticulture for dummies" tutorial?

Aloha and mahalo

Weezard

3rdEye · Nov 25, 2010

Excellent thread and wonderful to hear of some of the practical experiments that have been carried out here. I'm following this thread.

In particular the R:FR ratios are of interest as i would like to work with some sativas and sativa dominant plants inside and keeping that stretch do a minimum would be very nice.

Working my way backwards through the reference material. That Trifolium paper is interesting so far.

Dave Coulier · Nov 25, 2010

Thanks for the links verdant. Ive started to read them now.

VerdantGreen · Nov 25, 2010

weezard, i have to confess that i also find it quite hard to plough through these papers

. but from what i understood it seems that blue light, amongst other things, influences the frequency at which leaves occur on the stem - so if cannabis is the same, that would also influence the frequency of sidebranches (given that they occur at the leaf axils)

3rd eye, i will be using the red tubes in a few weeks when i put a new round of plants in the cab. i also have blue ones so i will also give those ago at some point.

dave - cool, thanks, let us know what you can glean from them, if anything....

VG

MrFista · Nov 25, 2010

"Perhap you could recommend a "horticulture for dummies" tutorial?

Aloha and mahalo

Weezard "

No hort for dummies tutorial and you are obviously no dummy but... Working on a small tutorial for biology basics - why the big words is part of that. What is the worst part of reading science documents for you, the most painful?

The stats? The language?

Every industry has its own jargon but biology has a whole couple extra languages of words to plow through. I get a meaning on wiki, then I got to look up the words that describe the words, sometimes need the meaning of the words describing the words that describe the words... Sometimes it's plain hard study! Hard work, learning about plants can be hard work, prepare for it it doesn't come so easy as you wish but the understanding will come. The intricacies of the language are to try and describe the intricacies of the living world and believe me the details are mind boggling.

There is no quick educational fix plant biology is as challenging as medicine when you get down to the details. I think it is even harder as most of it has been ignored until recently so we don't have the huge databases of previous research to draw from.

You can grow a garden without the need for it all. So it's a choice really, do you want to know WTF the scientists are talking about, or not. If you do, well, they worked damned hard to do what they do, the understanding requires hard work as well. Some of it probably is deliberately obtuse, but a lot of it, is plain hard to grasp. My chemistry professors, when I said I felt dumb trying to grasp some basic kinetics said - "but it's actually very hard." Same when I struggled with neuronal circuitry and other bodily systems.

So - you are not dumb, it is hard. One word at a time, that's how I do it.

Spurr, I did a bunch of reading and thought I'd posted you a reasonably astute reply but it is not here?... lol - stoner! Busy turning my section into a permaculture paradise but this conversation is not finished! :bump:

VerdantGreen · Nov 25, 2010

welcome back spurr

superpedro · Nov 27, 2010

Hey.

Did you know switching shutting off the f-red spectrum the last two hours, and having a peak in intensity around the middle of the light period is the optimal cycle for minimal stretch.?

Weezard · Nov 27, 2010

You don't say?

You don't say?

superpedro said:
Hey.

Did you know switching shutting off the f-red spectrum the last two hours, and having a peak in intensity around the middle of the light period is the optimal cycle for minimal stretch.?

Is this first hand experience?
Theory?
Cited reference?
Please expand.

Aloha,
Weezard

superpedro · Nov 27, 2010

Much of the info I have got is from Fiona lightings test runs of LED setups at the PKM plant nursery in Denmark.
It has been known for a while, some studies by DTU photonics showed it a few years back.
We have been getting advice about using special curtains to block out f-red for the last two hours to minimize stretch, since it reduces our use of chemical retardants.

I don't have any first hand LED knowledge yet. But i guess you know what I do..

Just want to tell you all what I am told.

superpedro · Nov 27, 2010

lol.. On the crazy side. They did some experiments on some SDP's giving them two extra hours of only blue in the flowering period(1h blue, 12 hours normal light, one hour blue), and it made the plant veg and flower at the same time. Got very stretchy too.
Probably didn't end up usable, haven't heard about it since.

Exiting future for plants

hades · Nov 27, 2010

Hi everyone,

Just found this forum and am pretty interested, I've always wanted a sub-forum like this.

Have you all ever read of using red plastic mulch to increase the red:f-red ratio? There are companies that sell it for this purpose, as well as to keep soil temperature constant/hotter and to reduce erosion and water evaporation.

This was something that I really researched back in the Overgrow days. This thread totally took me back. No one knew about it back then, but the science was there.

See you all around more!

spurr · Nov 27, 2010

VerdantGreen said:
welcome back spurr

Thanks for bringing me back! And for being the catalyst for this sub-forum. I owe ya, and Gypsy and OldPink too! :tiphat:

Dave Coulier · Nov 27, 2010

hades said:
Hi everyone,

Just found this forum and am pretty interested, I've always wanted a sub-forum like this.

Have you all ever read of using red plastic mulch to increase the red:f-red ratio? There are companies that sell it for this purpose, as well as to keep soil temperature constant/hotter and to reduce erosion and water evaporation.

This was something that I really researched back in the Overgrow days. This thread totally took me back. No one knew about it back then, but the science was there.

See you all around more!

Using red plastic mulch actually increases the far red:red ratio over the incoming light sources fr:red ratio from what I have read. White mulch will have the same reflected far-red:red ratio, and will provide the same benefits with regards to soil temp, water loss.

Check out this PDF to learn more.

imadoofus · Nov 28, 2010

it has been speculated on other forums ambient temperature fluctuations during the day/night cycles contributes significantly to stretching during the onset of flowering.

several mods on serious seeds forums relate similar validations regarding this.

researching different light studies for my upcoming mh/hps comparison has revealed a reoccuring theme on how regardless of using a mh/hps for flowering, the stretch was the same given for each strain used.

spurr · Nov 28, 2010

imadoofus said:
it has been speculated on other forums ambient temperature fluctuations during the day/night cycles contributes significantly to stretching during the onset of flowering.

Yes, see what I wrote about "DIF".

Control red to far-red light ratio to limit stretching

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