phytochrome manipulation

[Desertboy]

I quoted this before but I believe it to be very important!

Photoperiodism in a Short-Day Plant

Experiments with the cocklebur have shown that the term short-day is something of a misnomer; what the cocklebur needs is a sufficiently long night.

• Cockleburs (adapted to the latitude of Michigan) will flower only if they have been kept in the dark for at least 8.5 hours — the critical period. (A and B).
• Interruption of an otherwise long night by light — red (660 nm) rays are particularly effective — prevents flowering. (C) unless
• it is followed by irradiation with far red (730 nm) light (D). See spectrum of electromagnetic radiation.
• An intense exposure to far red light at the start of the night reduces the dark requirement by 2 hours (E).

These response are mediated by phytochrome.

Phytochrome

• Phytochrome is a homodimer: two identical protein molecules each conjugated to a light-absorbing molecule (compare rhodopsin).
• Plants make 5 phytochromes: PhyA, PhyB, as well as C, D, and E.
• There is some redundancy in function of the different phytochromes, but there also seem to be functions that are unique to one or another. The phytochromes also differ in their absorption spectrum; that is, which wavelengths (e.g., red vs. far-red) they absorb best.
  
• Phytochromes exist in two interconvertible forms
  • PR because it absorbs red (R; 660 nm) light;
  • PFR because it absorbs far red (FR; 730 nm) light.
• These are the relationships:
  • Absorption of red light by PR converts it into PFR.
  • Absorption of far red light by PFR converts it into PR.
  • In the dark, PFR spontaneously converts back to PR.

http://users.rcn.com/jkimball.me a.ultranet/BiologyPages/P/Photoperiodism.html


This contradicts the 660nm not causing Pr-Prf they effectively kept a plant in veg using a pulsing light mid point through of 660nm.

They also forced flower plants under less dark hours using pulsing FR and pretty much proved for me at least that pulsing FR during the dark hours will eliminate hermies and mean you can visit during lights off with any nm light without interrupting the flower cycle as long as the pulses are close enough together (Every 15mins for 1-5 seconds sounds good to me).

This study to me is the validation of the theory and proof that it does work even if the plant in question wasn't cannabis.

 

[midnightrider]

interesting topic , experimenting with creating the perfect zone of light , controling the photoperiodic response ultimatly increasing trichome production will take a while , i put this experiment on hold a while back ,,,,, used reptisun uvb floro lamps and compacts during the last 2 hours of 12/12 cycle starting week 5 of a 9 wk flower and got visable amber , watching it get darker and darker on ak48 in which i had never gotten visable amber on the 3 previous grows prior to chop ,,,,, i changed strains and never set it back up ---- thread might inspire me too ----- mho , one needs to be extremely familar with a certain strain , nutes , envirornment all have to be the same to get a scientifical and accurate result and most important BE CAREFUL WITH UVB LIGHTING , do not be in the room with them on ,id go in there for a short period of time but never look directly at it , uvb light will burn your retinea over a not so long period of time and it wont hurt , youll just wonder why your eyes are getting bad all of a sudden and they wont heal ... thanks for reading , i know in new to forum but i felt i had something to offer on this topic ,,,,, peace

 

[Dunge]

Was there any evidence that the product was improved by UV light additions?

 

[midnightrider]

hello dunge , i would like to say yes but i cant , see the enviornment changed (lower temps) from the 3 previous so i couldnt be sure plus i switched to a different product which was a big improvement so i put the experiment on hold .

 

[primeform]

finally getting my 4 far red bulbs ordered tomorrow. since they come from europe they use e27 fixtures. Does anyone know if I need to wire them to 220 or if i can simply use american e26 at 110? How did you wire yours desertboy?

 

[Desertboy]

I think you will need to run them at 220v, I struggled to get E27 fitting's in the UK I thought they were US fittings.

I bet they'd fit in e26 fittings fine just wire the fitting to 220v circuit, am I right in think you all have 220 & 110 in your houses in the states?


We use 230v in the UK (I think) used to be 240v when I was a kid and europe was 220v I think it's stabilised now at 230v for us all but I might well be wrong.


Contact Philips if in doubt give us a shout I have the proper email address to get the right answers.

I think the FR light is making my plant flower faster even though this time (Since I had timer failure) I've ran 12/12.

Going to do another run this time 12/12 with a proper flashing FR in the dark period and a control flowering out the same clone without FR and comparing the flower times.

This was taken Day 24, AK47 Serious seeds looks more like Day 31 from my previous AK grows.

If you're really stuck getting E27's PM me and I'll order some in the UK and post them out to you but I have to get them internet order only no one stocks them.

B&Q our largest DIY place didn't even know what they were even though they sell E27 lamps, no one sells the bloody fittings.

 

[primeform]

got my 4 lamps today and went down to the hardware store to try and wire it. i did get the e27 fittings with them but going to try the e26 with 220 breaker like you said. I even picked up a 220 water heater timer to put inline. the greenhouse is still flowering nicely even tho these bulbs are 3 weeks late and we are well into 14 hours of light each day. going to throw these bulbs over them and hope to finish up strong the last few weeks.

 

[primeform]

installed them in my greenhouse no problem. looks like i need 4 more to complete the coverage. ill add a few to my indoor round next time as well and move up to 14/10

 

[squiggly]

As a matter of chemistry--often times species are selective as to the wavelength of light they can absorb. Infared light causes most covalent bonds to vibrate--but there are some caveats.

The absorption in different bands of light has peaks and valleys--this is also true for UV and vis spec light. In vis spec, we perceive this as color, wavelengths which aren't readily absorbed are reflected back to us. So something absorbing heavily in the red spectrum will appear green (opposite on the color wheel from red). Hence chlorophyll.

In the UV/IR spec we can perceive this through instrumentation.

An IR spectrophotometer measures the vibration/disruption in energy caused by a sample, allowing us to classify chemicals based on functional group. Different wavelengths will produce different results.

In UV detectors (such as in HPLC) analytes will absorb light and the light not transmitted through the sample comes across as a reading. Different analytes have peak absorption in different wavelengths and it is important to consider this when calibrating the detector--sometimes this requires special tricks. The same is true for the IR application, different compounds will absorb IR light of different wavelengths better or worse based on their properties.

For most of these reactions what is happening is a photon is either knocking an electron out of its orbital--or it is promoting it to a higher energy orbital on an atom. Both of these require specific energy levels/wavelengths to achieve.

What I'm trying to say is that pushing higher into the IR band might not necessarily be better. In fact it may do nothing. (Edit: Turns out going much past the optimum level ~710-740nm would be negative according to the below document.)

Hope this helps.

Edit:

Did some digging and found a document that I think will be quite useful in explaining all of this--Near page bottom is a wealth of info on controlling stem length with pr/pfr ratio.

About halfway down the page you will see graphs depicting absorptions in different wavelengths--these are showing different responses in the plants, but if you plot an absorption spectrum for a single molecule it looks almost identical. There is a large amount of biochemistry info on the page such as the mechanism of the protein, it different domains, its regulator pathways, etc. Alot of that is probably redundant for this application but pretty cool anyway if the language isn't a barrier for you.

http://plantphys.info/plant_physiology/phytochrome.shtml

 

[click80]

As a matter of chemistry--often times species are selective as to the wavelength of light they can absorb. Infared light causes most covalent bonds to vibrate--but there are some caveats.

The absorption in different bands of light has peaks and valleys--this is also true for UV and vis spec light. In vis spec, we perceive this as color, wavelengths which aren't readily absorbed are reflected back to us. So something absorbing heavily in the red spectrum will appear green (opposite on the color wheel from red). Hence chlorophyll.

In the UV/IR spec we can perceive this through instrumentation.

An IR spectrophotometer measures the vibration/disruption in energy caused by a sample, allowing us to classify chemicals based on functional group. Different wavelengths will produce different results.

In UV detectors (such as in HPLC) analytes will absorb light and the light not transmitted through the sample comes across as a reading. Different analytes have peak absorption in different wavelengths and it is important to consider this when calibrating the detector--sometimes this requires special tricks. The same is true for the IR application, different compounds will absorb IR light of different wavelengths better or worse based on their properties.

For most of these reactions what is happening is a photon is either knocking an electron out of its orbital--or it is promoting it to a higher energy orbital on an atom. Both of these require specific energy levels/wavelengths to achieve.

What I'm trying to say is that pushing higher into the IR band might not necessarily be better. In fact it may do nothing. (Edit: Turns out going much past the optimum level ~710-740nm would be negative according to the below document.)

Hope this helps.

Edit:

Did some digging and found a document that I think will be quite useful in explaining all of this--Near page bottom is a wealth of info on controlling stem length with pr/pfr ratio.

About halfway down the page you will see graphs depicting absorptions in different wavelengths--these are showing different responses in the plants, but if you plot an absorption spectrum for a single molecule it looks almost identical. There is a large amount of biochemistry info on the page such as the mechanism of the protein, it different domains, its regulator pathways, etc. Alot of that is probably redundant for this application but pretty cool anyway if the language isn't a barrier for you.

http://plantphys.info/plant_physiology/phytochrome.shtml

very concise understandable post...wish i would have had you for chem 1a...might have passed...lol

 

[click80]

that is a great link...if you go to bottom of page and click the course schedule...that page has a lot of info links...just read at the one on mineral diffusion...explains why toxicities exhibit certain identifiable symptoms...good stuff

 

[squiggly]

very concise understandable post...wish i would have had you for chem 1a...might have passed...lol

Thanks :)

I'm actually working on getting a cannabis chemistry compendium together for posting here at the farm. Hopefully it will be sticky worthy and can answer alot of people's questions before they're asked.

Chemistry is my passion, and I'd like nothing more than to interest others in it--or help them solve problems with it.

 

[click80]

Thanks :)

I'm actually working on getting a cannabis chemistry compendium together for posting here at the farm. Hopefully it will be sticky worthy and can answer alot of people's questions before they're asked.

Chemistry is my passion, and I'd like nothing more than to interest others in it--or help them solve problems with it.

That would be really nice...i would like to see a lot more stickies on here. Especially nice would be a thread/sticky on plant chemistry and the biological processes...especially rooting. I could go on and on...lol

I would love a thread/sticky on Beneficial Organism Chemistry/Biology, structure of the same and reproduction processes....like I said on and on...

 

[growlights]

I have been developing discrete spectrum grow lights to trigger Phytochrome state changes and all the lights one needs for a PAD systems as well.

 

[Dr.Trichome]

very way cool thread.
but it kind of dropped off before we heard how well it works.
Prime, dex, desert. . . .
Love to hear some results, as this Is really interesting

 

[Desertboy]

My experiences with FR were swayed by timer failures I will be trying this again later this year with a much better setup.

Things I learnt about Far Red 720-740nm

1. FR makes plants stretch if used all through dark period it makes plants leggy and prone to snapping. It needs to be pulsed 15 seconds on 15mins off is a good zone for shortening the day length and 1 min on/10 off for stretching the plants any more and the plants become leggy and thin

2. FR makes no difference lights on HPS contains a considerable chunk already.

3. Digital timers do not like being on the same circuit as HPS and they reset (Inductive load I'm sure) this is probably not an issue with digital ballasts only magnetics and maybe limited to sparking multiple lights on the same circuit those with 1.2kw or less will probably not experience an issue. The best way to solve is computer controlled relays and some simple programming.

4. It does shorten daylength I flashed it at some plants I had outdoors (July 15th onwards) and the set that it was flashed at went into flower within a few days the control set at the top of the garden were a good month later and suffered bud rot and yield was just poor in comparison to the FR plants.

You can now source FR LED's for peanuts for those with a soldering iron the parts are available to wire this up properly for $50 or so but you would need to solder and wire relays to make it all work without a computer.

None of it is difficult just fiddly when I get round to it I shall do a quick how to with a breakdown of costs.

 

[Desertboy]

I have been developing discrete spectrum grow lights to trigger Phytochrome state changes and all the lights one needs for a PAD systems as well.

on your site you say
"Wavelength: FAR RED 660nm and 690nm Super LEDs" which is wrong

Where as wiki says
"Far-red light is light at the extreme red end of the visible spectrum, between red and infra-red light. Usually regarded as the region between 710 and 850 nm wavelength, it is dimly visible to some eyes. It is largely reflected or transmitted by plants because of the absorbance spectrum of chlorophyll, and it is perceived by the plant photoreceptor phytochrome. However, some organisms can use it as a source of energy in photosynthesis.[1][2] Far-red light also is used for vision by certain organisms such as some species of deep-sea fishes." from
http://en.wikipedia.org/wiki/Far-red

"In the case of phytochrome the ground state is Pr, the r indicating that it absorbs red light particularly strongly. The absorbance maximum is a sharp peak 650–670 nm, so concentrated phytochrome solutions look turquoise-blue to the human eye. But once a red photon has been absorbed, the pigment undergoes a rapid conformational change to form the Pfr state. Here fr indicates that now not red but far-red (also called "near infra-red"; 705–740 nm) is preferentially absorbed. This shift in absorbance is apparent to the human eye as a slightly more greenish colour. When Pfr absorbs far-red light it is converted back to Pr. Hence, red light makes Pfr, far-red light makes Pr. In plants at least Pfr is the physiologically active or "signalling" state."

http://en.wikipedia.org/wiki/Phytochrome

650-670 is peak nm for waking the plant up

705-740 peak nm for putting plant to sleep

 

[growlights]

You must have found a typo, my DEEP Red Boosters are 660/680-690nm. The FAR RED lamps are 730nm, The Flower Initiator. I am trying to find the typo right now.

 

[growlights]

very way cool thread.
but it kind of dropped off before we heard how well it works.
Prime, dex, desert. . . .
Love to hear some results, as this Is really interesting

I can aim you at some YouTube videos, is that OK here?

 

[growlights]

Ca

on your site you say
"Wavelength: FAR RED 660nm and 690nm Super LEDs" which is wrong

Where as wiki says
"Far-red light is light at the extreme red end of the visible spectrum, between red and infra-red light. Usually regarded as the region between 710 and 850 nm wavelength, it is dimly visible to some eyes. It is largely reflected or transmitted by plants because of the absorbance spectrum of chlorophyll, and it is perceived by the plant photoreceptor phytochrome. However, some organisms can use it as a source of energy in photosynthesis.[1][2] Far-red light also is used for vision by certain organismsou read that, I cannot find the ty such as some species of deep-sea fishes." from
http://en.wikipedia.org/wiki/Far-red

"In the case of phytochrome the ground state is Pr, the r indicating that it absorbs red light particularly strongly. The absorbance maximum is a sharp peak 650–670 nm, so concentrated phytochrome solutions look turquoise-blue to the human eye. But once a red photon has been absorbed, the pigment undergoes a rapid conformational change to form the Pfr state. Here fr indicates that now not red but far-red (also called "near infra-red"; 705–740 nm) is preferentially absorbed. This shift in absorbance is apparent to the human eye as a slightly more greenish colour. When Pfr absorbs far-red light it is converted back to Pr. Hence, red light makes Pfr, far-red light makes Pr. In plants at least Pfr is the physiologically active or "signalling" state."

http://en.wikipedia.org/wiki/Phytochrome

650-670 is peak nm for waking the plant up

705-740 peak nm for putting plant to sleep

Can you recall where you read that, I cannot find the typo?