can someone help me understand ( phytochrome / 730nm )

[habeeb]

hey guys,

i'm trying to learn about phytochromes, and why we add 730nm , but I am confused as i can't understand scientific wording.. can someoen explain it to me in "stoner talk"

also, I'm trying to fisgure out, why people say if you add 730nm, the plant flowers quicker. we see this on the HGL panel, but I am confused as how adding 730nm during the day helps with flowering quicker.. I thought the whole tests were to use 12 hours and delay flowering in the case of a vegetative state, and then i started to read about the pulse of 660nm and 730nm, and how only the last pulse mattered to the plant..

also I'm not understanding when people say you can put the plant to sleep instantly. why, what do we want that for, what would that do?


can some people help clarify in simple terms whats this all about, why do we want 730nm in panels, whats the whole point of all this.....

 

[DZLHIT]

My stoner logic understanding of it... when the light kicks on after 12 hours of darkness all of the phytochrome is Pr. The Pr absorbs the red light and converts into Pfr, which absorbs IR light. Pfr inhibits flowering for short day plants, when you add IR to the daylight mix, the levels of Pfr go down and the levels of Pr go up. Hormones associated with those phytochrome levels will reflect that ratio. This produces a little bit of the shade response, a long with elevating the levels of flowering hormones in the plant. When the lights go out, there is already a larger amount of Pr, and thus less Pfr had you not used IR lighting. The level of Pfr drops lower at an early time and your plant makes more hormone sooner. I believe using it all day as opposed to pulsing it at night(lights off) gives indoor growers an extra advantage as the hormone levels in the plant fluxuate less during the day... possibly an optimization?

 

[habeeb]

^

thanks..

only thing I can add is far red is not IR yet.. I think I read this earlier back some people mixing up far red and IR.



I'm under the assumption still, there's nothing you can do to speed up the flowering hormone... who knows, I read just in 2005 they discovered the flowering hormone ( florigen )

I think in a bottle it might induce early flower set, but there still learning, and we have no clue i think how complex plant systems are, and how each and every thing plays off one another ( mendels wheel I think its called for nutrient.. )

 

[DZLHIT]

Yes, sorry I was blurring the line. The plant responds to far red, so it still works as I explained.

I didn't mean to imply you can speed up the hormone, only that with lower levels of Pr the hormone builds up to certain threshold level @ lights off sooner...so the plant is producing hormones are a higher level for a longer period of time during the 12 hour dark cycle, as opposed to no IR during daylight.

There is certainly still a balance to be struck, people are having great results with just white leds...

 

[Phaeton]

Total darkness converts the daytime red accumulation in about two hours, then the florigen begins to be produced.
The 730 nm produced by the evening sky accomplishes the conversion in about ten minutes, reducing the amount of total dark needed by two hours.

Outside plants rarely wait until after equinox to flower, the faster conversion from infra-red allows budding with over twelve hours of light.

It will also cancel small light leaks by converting the 660 nm red faster than it can get in.

The night vents leak light into the budroom and hermies were regular until 30 watts of infra-red were added. No more hermies, none.
Thirty minutes per night, down from three hours. More does not hurt, but is not needed.

This is also why a full moon bright enough to read by does not interfere with budding, the infra-red cancels red faster than the moon makes it.

The hormones are produced at the same rate, they just start sooner for a stronger signal.

 

[rrog]

Man what a great thread! So are 660 as well as 730 both needed as supplementation? Not enough produced with all while LEDs I assume.

 

[Crusader Rabbit]

This link to a page on photoperiodism discusses "short day" plants like cannabis.

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


This thread discusses the use of blue light to extend the hours of photosynthesis. Unfortunately we were working in the dark for many pages until more experienced/knowledgeable people showed up around page ten. There might be useful info here.

https://www.icmag.com/ic/showthread.php?t=251557&page=10

 

[Crusader Rabbit]

This image might be a useful reference here.

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[DZLHIT]

This link to a page on photoperiodism discusses "short day" plants like cannabis.

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


This thread discusses the use of blue light to extend the hours of photosynthesis. Unfortunately we were working in the dark for many pages until more experienced/knowledgeable people showed up around page ten. There might be useful info here.

https://www.icmag.com/ic/showthread.php?t=251557&page=10

Thats interesting, trying to play with the circadian rhythm of the plant. Check out 'cryptochrome'

Thanks for the link!

 

[Crusader Rabbit]

Check out 'cryptochrome'

Yes, the effort to use blue light to extend photosynthesis into the "dark" period failed because we didn't know about cryptochromes. Blue light drives the plant's circadian rythm.

 

[rrog]

All very, very cool.

 

[babelfish]

Man what a great thread! So are 660 as well as 730 both needed as supplementation? Not enough produced with all while LEDs I assume.

heh exactly what i was thinking.. the whites are giving something the other spectrums don't provide..

Total darkness converts the daytime red accumulation in about two hours, then the florigen begins to be produced.
The 730 nm produced by the evening sky accomplishes the conversion in about ten minutes, reducing the amount of total dark needed by two hours.

Outside plants rarely wait until after equinox to flower, the faster conversion from infra-red allows budding with over twelve hours of light.

It will also cancel small light leaks by converting the 660 nm red faster than it can get in.

The night vents leak light into the budroom and hermies were regular until 30 watts of infra-red were added. No more hermies, none.
Thirty minutes per night, down from three hours. More does not hurt, but is not needed.

This is also why a full moon bright enough to read by does not interfere with budding, the infra-red cancels red faster than the moon makes it.

The hormones are produced at the same rate, they just start sooner for a stronger signal.

I wondered about just that - the 'moon effect' shall we say.
this is during the daytime cycle? What about IR during the night cycle?

Thats interesting, trying to play with the circadian rhythm of the plant. Check out 'cryptochrome'

Thanks for the link!

Yes, the effort to use blue light to extend photosynthesis into the "dark" period failed because we didn't know about cryptochromes. Blue light drives the plant's circadian rythm.

VERY interesting.. 'cryptochrome' eh.. even wikipedia's info is pretty confusing.. have to do some more reading on this..

Gr8 thread!

 

[TwilighTavern]

Heey, it's my first post here and i'm sorry to answer such an old Thread.
I think this topic represent THE actual challenge for Indoor and outdoor Grow lights.And i got a lot to say about.

It's mostly about flowering. At the beggining of the story, there are led panels and their monochromatic dual spectrums (blue and red). This huge error has allowed growers to learn 2 very important things
- Never trust what is written on a led panel, most of the time that's bullshit.
- Flowering is a big deal and involve a lot of widely unknown biological steps.

Nowadays, most led panels provide a little amount of 730nm in their spectrums, and obviously the growers have noticed the impact on flowering time. But at the same time they also have heard about the effects of 730nm supplémentation at nightfall, and its effect on night duration and flowering induction.

This duality is confusing and i'm gonna try to clarify the phytochromes effects on flowering.

-The flowering induction is driven by a gene called Flowering Locus.
Basically, the night duration (Circadian clock associated genes) is a key factor in flowering locus expression and flowering induction.
The phytochrome is acting as a daylenght detector and play a major role in photoperiodism (signaling to Circadian clock genes).
Using 730nm to desactivate phytochromes at nightfall is a way to "make plants sleep faster". The same treatment exist under natural conditions as the solar spectrum is shifting to infra-red zone at nightfall.

-Regardless to night duration and cyrcadian clock, the pytochrome's activated form directly repress the Flowering Locus expression. The more the pytochromes are activated and the more the flowering will be late. The 730nm radiation, by desactivating a part of the phytochromes, and lowering the average Pfr/Pr (activated form / desactivated form), lead to an higher amount of Flowering Locus expression and an enhanced flowering induction.

Concerning the later part of flowering stage, i know phytochromes are also involved in senescence through Ethylene associated genes, and i think that a high 730nm amount in spectrum can lead to an early senescence. But that's a topic i should study more cuz i'm still confused on some points.

Anyway if u are looking for a flowering spectrum u can't ignore phytochromes interactions. And concerning this points, i think led grow lights makers are far from a decent knowledge.

 

[lightnerdtoo]

The length of the night determines when a short day plant flowers, the Flower Initiator causes the phytochrome state to change in moments, rather than 2 hours. applying the 730nm light (far red) allows one to have a longer lit period. The best way is to start at 12/12 for a week, then switch to 13/11 until it's time to flush, then go back to 12/12 for a very dank finish. The 20 watt units are now the same price as the 10 watt units used to be.
https://growlightsource.com/the-flo...e-flower-initiator-accelerator-far-red-730nm/