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The Truth About Photoperiods!

Verdant Whisperer

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12/12 is just an arbitrary compromised number. It’s like wearing one size fits all hat. I’d rather have a fitted hat and I like to fit the light schedule to get the most of the best.
100% This is especially true for growing landraces indoors to their optimal potential it makes sense for me to try and mimic their natural photoperiods and temperature shifts and metabollic intake, nutrients and water a strain in equator that finishes in dry season with less water and nutrient availability wont finish the right way if you water up until a few days before harvest regularly, theres a balance, in containers it is harder to find depending on the strain because they dry out quicker between watering in general than the natural earth but by letting them dryout completely then watering just enough to keep them healthy this will help simulate their natural transition, just an example. you have the right idea 100% its best to try and get the full potential of the strain.
 
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Mate Dave

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The paper with the larger plants being 'fuller' with 70+ hours extra energy it provides before photorespiration.

I've done the 13/11, "Gene finding" it used to be termed. You can either flip from 24/0-12/12 inducing a radicle shift and it's cost effective, or you can 18/6 and do the same. The other way is to 24/0 and reduce the light gradually each day. Flowers run longer in length this way, days of flower are still the same, terpenes noticeably elevated. Not elevated as much as when introducing blue into red light, but tighter internodes from the light adjustments and photoperiod seemed evident.

I've a mixed spectrum in my room to play with red, blue, far red etc and temperature, plants that sit in the 'optimal zone' are more pronounced than in other areas.

Theory needs testing here. Doing the math of the lumens or Umols the 70+ hours of whatever. This PPFD could be supplemented in the 12 hour period and potentially garner the same qualities, to test/prove if it is indeed photoperiod or if it is the amount of useable light before plants get saturated or triggered, providing plants are not already pushing the limitations set by the genetics.

The parts of my grow where individual plants get 3 bulbs and some LED are weeks ahead of those that do not get the same treatment. Such intensity makes them form tighter flowers upon flowers..
 
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Verdant Whisperer

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@Verdant Whisperer do you employ a drought stress technique?
when flowering plants last year in rising daylight hours i did to help them finish faster and plan on doing the same this year, outdoors. i made sure to let them dry out really well between watering when they are in flowring, but not enough to where it kills my soil life and plant, just slows down the metabolism of plant and soil. i think most varieties finish flowering in lower amount of rainfall, so i try to reduce the amount of watering in flowering but still keeping my soil active when growing plants in dry season, i noticed in the past the plants i watered alot during dry season, attracted more pest because it had more water and energetic sap to feed on, and the caggage moths are also attracted to them more for this reason, so it is beneficial to mimic nature for fullest maturity in the flowers as well as not make your plant a target for pest in dry season. imagine being a bug and having all this plants with less active and less water content in their sap, when there is this juicy plant that is being watered in dry sesaon, its like the bugs finding a pool of water in the desert.
 

Old Piney

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. the old model says that the phytochromes are responsible for tracking light hours, i am saying they confused this measurements. they dont track the light hours, they track the change in total amount of light energy
First let me thank you for posting this thread and I apologize if I seem a bit gruff at times but I do enjoy a good debate. There is alot of good discussion going on here. Like you I'm not a big fan of how "science"has presented it's self recently. I beleave that science should always be able to change its position and follow new hypothesis. I beleave I do I understand your argument here. I'm not nessarly going with the "old model" but I'm not going with your theory either . Light energy is collected and stored in green plants through photosnithisis in the form of sugar. I beleave its safe to assume that more light intensity equals more photosnithisis that equals more sugar or "energy". With your theory in mind,why wouldn't a plant grown with less direct sunlight mature later than one grown in full sun? I've done this before and they will flower at the same time regardless of how much direct sun they receive. I'm certain that growth regulators and such play a roll, but there is something else involved for the timing to be so percise I do admit that there is some evidence that your theory is correct or perhaps partially correct. Some of the results from the study posted by @RingtailCanyon comes to mind. Edit - I'll go with initiate flowering rather than mature
 
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Verdant Whisperer

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I dont want to get too philosophical but in nature there are generally balancing forces, yin/yang positive/negative, masculine femineine, and they exrpress themselves in many ways, its about finding those cues and looking for the energetic profile you desire, one example i was just thinking about is green versus purple/red phnotypes, green is ussualy more extroverted expansive more of a masculine energy, where high anthrocyanin phenotypes have more of a introspective centered high with more feminine energies.
 

kro-magnon

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So you have no real scientific knowledge, refuse to plan an experiment to prove you hypotesis but we should your word for granted, that's a very good start.
Plants don't count hours to know when to flower but light reduce the amount of the hormone responsible for flowering, with more dark time the level of flowering hormone rise triggering the flowering. This can happen with increasing day time as long as the dark period is long enough to reach the triggering level of flowering hormone. I have flowered plants outdoor during winter while daylenght was rising but the dark was long enough to rise the flowering hormone level.
You will never be able to flower photoperiod plants if the dark period is not long enough to trigger flowering. If you pretend otherwise show us how you do with a serious grow log.
 

Mate Dave

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A commercial growing technique called 'moonlighting' is often implemented. Used for supplementation. Natural cycle commences and you use the lighting to provide heat to wake the plants up and to push them on in the evenings. You wouldn't need 12 hours of lighting it might be 3 in the am and a few more in the evening. The lighting is used for 1 hour during the night phase at 6 hours into darkness to prevent flowering.

Plants only need one short day and that is they're off. This blue light triggers plants in short days to continue vegging.

This only backs up what I am saying where the amount of Power and useable light is critical to biomass, the reduced cycle is what allows the plant to get as big as can be before genetics limit further production. It also proves that photoperiod isn't determinate of flowering and mass, it triggers hormones/photychromes.

The longer something was in 12/6/1/6 it would get bigger and bigger with less running expences but I've not seen a study on this.
 
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Verdant Whisperer

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Plants don't count hours to know when to flower but light reduce the amount of the hormone responsible for flowering, with more dark time the level of flowering hormone rise triggering the flowering. This can happen with increasing day time as long as the dark period is long enough to reach the triggering level of flowering hormone. I have flowered plants outdoor during winter while daylenght was rising but the dark was long enough to rise the flowering hormone level.
What your saying agrees with my proposed model. the fact your plants can flower while the photoperiod is increasing.
You will never be able to flower photoperiod plants if the dark period is not long enough to trigger flowering. If you pretend otherwise show us how you do with a serious grow log.
If the plant gathers enough energy to initiate flowering, and the auxin levels decrease enough it will initate flowering in light hours its not acclimated to or its genetic blueprint. any strain can flower in 24 hours of light with enough time, some mothers last 20+ years others flower in 7 months in 24 hours of light as ive seen in other post. its a combination of factors. if the plant is being attacked by bugs and super stressed and has all the right factors it will find a way to flower, even if it takes 50 years in 24/0. where some strains can already flower in 24 hours light because of their hormonal profile easier with the right stress and environment and low nitrogen flowering nutrients. and one thing i only grow outdoors now, indoor is a different ball game there are less forces at play but its would be actually easier to manipulate the environment indoor to induce flowering under more light hours by using other factors such as temperature decline over a period gradual decline, reduced light intensity to decreasure auxins. as well as drought dress and nitrogen straving the plant.

have you noticed alot of the times in a veg plant indoors the flowers start in the area that is more shaded lower on the plant but outdoor the first pistols are on the top of the plant where there is the most gibberalins, but in the veg plant sense itll show preflower in veg first where it recieves the least auxins generally in the shaded lower parts of the plant from my experience not the top part closest to the light.
 
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kro-magnon

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You misunderstand the mechanisms of flowering, it is the level of flowering hormone who trigger it, nothing else. Plants can flower in winter with increasing daylenght because the dark period is long enough, no bs energy. A plant will push some pistils if kept rootbound as mother because it creates a hormonal imbalance but it won't flower to maturity, never.

No the flowering don't start in the shaded area of the plant indoor in fact those area are usually less mature than the rest of plant, same with pre-flowers they appear in the top part of the plant.
Learn how the plants really function before saying crazy thing about flowering or if you can flower a photoperiod plant with 20 hours of light a day or more show us how you do it.
 

Mate Dave

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I've got the data from a study done for a Phd in 2014 that tested the 11 and 12 hour day length with various cultivars landraces and hemp. Energy consumption goes up 8%, it would be higher in today's costs to warrant the extra energy costs for the negligible increase of total biomass weight as your not getting anymore cannabinoids 94% still being THc. With some cuttings showing a decrease in overall cannabinoid content. Significant drops in cannabinoid content was observed at 10 weeks of short days. Halliday & Fankhauser 2003 talk about phytochromes and their role, however the effects of short day development are less studied. However there is evidence of a second critical day length observed that female flower production ceases..
 

Mate Dave

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There are some interesting concepts in the thread but the DLI the critical cutoff for flowering. Discovering when the plants either become saturated/ produce white tops and photo respire needs balancing.

How light can be manipulated with photoperiod angle spectrum heat etc and the role played on the plants photosynthetic pathway. Those specialised cells sensing Blue Red whatever comes with it, shade, intensity the duration and the angle of it have a way to be simulated.

I think that Autoflowering plants may flower in a number of ways and responses, unlike regular seeds when put into 12/12 they don't grow on like auto's..

You can plant them in 12/12 and they will flower but grow a bit first then differentiate. If you plant them on 24/0 same thing really they grow a bit and the flower.

Individuals lacking a critical day length makes testing how a spectrum and the duration received directly influences the resulting architecture difficult. Out of these clonal populations the phytochemical will differ from the adaptions in the environment.

There's methodologies implementing container size and other 'stress reduction' methods with potential to let auto genotype grow longer but ultimately the limit for what you get from the phenotypes is set by it's genotype..

These differences could be seen with regular genetics by switching the photoperiods.
Unless you make a photoperiod flower with long day hours all this thread is just nonsense.

Says unless you can swap out the trigger for critical day length find it and turn it off then what we know is current and how it is.

I don't think you have to breed it you just need to find it.. You can look forever and you won't find a plant that will veg in short days without moonlighting and you won't find one that will veg in short days and flower in long ones without changing the Cam pathway.

That's trying to find a Cam2 plant in Cam3 populations. How do we and is it even possible to segregate and see that 🤔

The methodologies to manipulate a "Niche" clonal environment pushing more useable light in a 12/12 or more DLI in the 13/11 will get you more flower but not necessarily anymore cannabinoids chemo-type/phenotype dependent.

You can probably push more bio-flavonoids / flavourants to your hearts content manipulating spectrum within the DLI more than day length itself.. If in 18 hours the plant gets abc of xyz then can a 'Niche' spectrum provide that requirement in 12 or 13.

Running 12/6/1/6 instead of 18/6 you might find that flipping to 13/11 then pushes what's currently known.
12/6/1/6 and flowering 13/11 is the same sort of hours of DLI that Colombian gets. It's a 5 hour reduction in power if that PAR Umols PPFD can be put into the crop in the 13 hours the day length hasn't changed.. The running costs have.. You could push the UV/ 'Niche' on and off over the whole day, or concentrate it and reduce power consumption. It's finding that balance of responses from the chloroplast.

Going 18/6 to 12/12 or 13/11 is more radicle shift in DLI and the amount of photons a plant gonna get limiting time and causing a sense of urgency and the "stretch" people talk of. Rather than gradually reducing it to determine critical daylength.

If you was to reduce the light from 18/6 till you hit flowers every time you grow a seed crop you could just give it a hour or even half a hour more and theoretically that should be enough to prevent flowering.

How the lineage and hormonal balance is inherited and its roles on plant processes and function needs more investigation.

Looking at Lebanon or Morocco compared to compared Afghanistan with Jamaica to Colombia the photoperiods are very different..

A quick flowering long blooming genotype with a DLI of 14.5 hours could be pushed to the very limits of size and ability reducing energy costs finding the 'Critical' - Sweet Spot and the real questions...

How much light and what it really needs and what's it costing me..

This process to find the DLI combined with the 'Niche' spectrum should deliver everything the Chemotype has to offer.. Pushing flower size to limits, maybe breaking total cannabinoid concentrations for greenhouse grown crops, maxing out terpenes into the 5%+ range under the correct environmental tweaks.

 
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kro-magnon

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There are some interesting concepts in the thread but the DLI the critical cutoff for flowering and when the plants either become saturated or produce white tops needs balancing.

How the lineage and hormonal balance is inherited and its roles of plant processes and function needs more investigation. Looking at Lebanon or Morocco compared to compared Afghanistan with Jamaica to Colombia the photoperiods are very different..

How light can be manipulated with photoperiod angle spectrum heat etc and the role heat spectrum plays on the plant photosynthetic pathways.

I think that autos may flower in a number of ways and responses. You can plant them in 12/12 and they will flower but grow and then differentiate. If you plant them on 24/0 same thing really they grow and the flower. Slight differences in chemo-type/ variance in phenotype and the critical day length make testing with identical clonal phenotypes tricky.

The Spectrum and the duration plants receive directly influences the resulting structure of them and out of clonal populations the phytochemical will differ. There's methodologies implementing container size 'stress reduction' methods with potential to let them grow for longer but the genotype ultimately sets the limit for what you get from the phenotypes.



Says unless you can swap out the trigger for critical day length find it and turn it off then what we know is current and how it is.

I don't think you have to breed it you just need to find it.. You can look forever and you won't find it.

That's trying to find a Cam2 plant in Cam3 populations. How do we segregate that 🤔

The methodologies to manipulate a "Niche" clonal environment pushing more useable light in a 12/12 or more DLI in the 13/11 will get you more flower but not necessarily anymore cannabinoids/ Again that's Chemotype/phenotype. You can probably push more bio'flavonoids / flavourants with manipulating spectrum more than day length.

Daylength and light intensity genetics will be the things you can push breeding..

Running 12/6/1/6 or 18/6 to determine critical daylength you might find that flipping to 13/11 then pushes what's currently known about and with the 'Niche' spectrum you could push the watts and UV over the whole day or concentrate it and reduce power consumption. It's finding that balance of responses from the chloroplast.

A quick flowering long blooming genotype with a DLI of and a CPP could be pushed to the very limits of size and ability reducing energy costs finding the 'Critical' - Sweet Spot. This process combined with the 'Niche' spectrum to deliver everything the Chemotype has to offer.. Pushing Flower size to limits, maybe breaking total cannabinoid concentrations for greenhouse grown crops, maxing out terpenes into the 5% range under the correct environmental tweeks. Thiols esters and what not.


I have a pretty good understanding of english but I don't get what you mean in this post, to me it sounds like a world salad
 

Mate Dave

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The more you say the more there is to say. There's a lot to be said..

Geographical cannabis has either near equal photoperiods such as Colombian or Afghans which have more of a challenging Environmental swing. This suggests to me the critical day length in Colombian is perhaps more sensitive but no less important that that of Afghan where they get longer days and possibly 2 more months.. I don't know I've not grown there..

I'll see if I can edit up the alphabet salad I posted make it read better.. I know what I'm trying to say it's finding the words
 

kro-magnon

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The more you say the more there is to say. There's a lot to be said..

Geographical cannabis has either near equal photoperiods such as Colombian or Afghans which have more of a challenging Environmental swing. This suggests to me the critical day length in Colombian is perhaps more sensitive but no less important that that of Afghan where they get longer days and possibly 2 more months.. I don't know I've not grown there..

I'll see if I can edit up the alphabet salad I posted make it read better.. I know what I'm trying to say it's finding the words
Thanks for trying to make it makes sense for me. The fact equatorial cannabis has a much longer flowering period is related to their proximity to the equator where day and night have pretty much the same lenght.
 

H e d g e

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Auxin distribution could be a factor. I’m experimenting with polycot thai plants to adapt them for indoors, shorter node distance, shorter root length, larger floral clusters..
88F31963-228D-43A7-BDC8-4BEF35DC05FB.jpeg


Some interesting info in the following link including observations on cotyledon shape and size..
 
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Verdant Whisperer

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Auxin distribution could be a factor, I’m experimenting with polycot thai plants to adapt them for indoors, shorter node distance, shorter root length, larger floral clusters..
View attachment 19133030

Some interesting info in the following link including observations on cotyledon shape and size..
Thats excellent by selecting for the lower auxin levels this should do two things, decrease height, and increase side branching which is good for indoors. one cue to look for is less auxins there leaves are less symmetrical as well. you see the small seedling its leaves growing on top. so one thing in terms of effects, other than terpenes ect cannabinoids looking through a simple concept that can be connected, Auxins= are like related to the energy the strain delivers the amount of life it has to it whether it is a warm or a cold high.
Amplitude= is how hard the high hits, a strain with a lot of amplitude will hit fast and hard and be like a roller coaster, one with lower amplitude and more symmetry in the cotyledons and leaves and stable growth will be more consistent in effect.
Gibberellins are in charge of reproductions the strains with more sexual organs, Hairs* and more elongation . Gibberellins are expansive and generally have a lighter more cerebral type of function in the high, the reason tropical strains are higher in gibberellins is they have more reproductive potential and are faster growing so they need less resources into cytokinin's as lower auxin strains require.
Cytokinin's are basically the defense functions of the plant the more cytokinin's the more resin, but these generally end up in more division than expansion instead of reproduction or growth or regulation cytokinins role as master of defense, they are in charge of that. In nature generally the lower auxin plants have lower cytokinin's, but i think in unnatural environment strains could be bred to high cytokinin's and high auxins but need increased energy output to match the cost of production higher PAR and more Nutrients adjusted to their metabolism.
 
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