24 to 72 hours of dark? Take 48 hours of light instead

[PlanetJ]

So, ever from the first time I heard about the dark periodm, I remained sceptical. I tried it once now, and saw absolutely no improvement. Thats not science, but still.

I just stumbled on a YT vid. I know direct links are not appreciated here, but I see no other way to properly start this conversation, tho I did my best to provide a text version of the argument. Hoping to get some feedback from people on this.

The TL;DR: 24h - 72h dark period is bro science according to Dr. Bruce Bugbee, 48h lights before harvest is where its at. According to science.

Dark period: doesnt make sense; there is no evidence, and the theory, that trichomes and terpenes s are formed at night, as not true. They are formed during photo synthesis from sugars, using energy.

Instead of 24h to 72h of dark, work on perhaps 48h of light, but prevent the tent becoming hot so the terpenes dont evaporate as much. Too cold isnt good either, as that would prevent creating new ones, while just preserving whats there. People are experimenting with 48h of light right now instead of dark while keeping temps on low end.

What are your thoughts on this? I think this makes sense personally, wondering what this community thinks about it. Not sure yet if I'm about to try it yet. It's probably all marginal.

 

[Bounce3d]

stubbing in to see where the discussion leads. an interesting one!

 

[PlanetJ]

It should be .. sadly the video link got removed.

You should be able to find the last vid of Mr. Grow It on youtube about 48h light. I'd love to hear what peoples first reaction is.

 

[PlanetJ]

Lot of views, 0 opinions .. right .. /sad panda

I've tried to find a bit more, but as this is a highly cannabis specific practice, I cant find a lot of science on it. I saw some lab results of someone that suggested a 2% increase in THC and some terpene profile changes after 24h dark I believe, and not a lot of other changes afterwards.

Dr. Bruce Bugbee comments on that in the video, and mentions this is more likely due to a lower temperature in the environment than anything else and the role was more preservation than creation, given the creation process requiring photosynthesis, and the plant has no batteries. It's much like a solar panel .. no light, no photosynthesis.

To me, it kinda makes sense. Im not too sure about his 48h light tho. Not that I think they would hermie, but more that I cant see how that affects other factors in the room, that might end up it being a net negative.

It's hard to control for everything in these tests we do, but if we are to believe Dr. Bugsbee, it seems we can retire the practise of putting our plants in the dark.

 

[Phytoplankton]

Couldn't find the vid, but there is plenty of science that says terpenes are most prevelant after darkness, just at dawn. So calling the darkness period "broscience" isn't really accurate. Maybe Bugbee has some actual scientific studies disputing this, I looked, I can't find it

 

[Rexer]

Lot of views, 0 opinions .. right .. /sad panda

I've tried to find a bit more, but as this is a highly cannabis specific practice, I cant find a lot of science on it. I saw some lab results of someone that suggested a 2% increase in THC and some terpene profile changes after 24h dark I believe, and not a lot of other changes afterwards.

Dr. Bruce Bugbee comments on that in the video, and mentions this is more likely due to a lower temperature in the environment than anything else and the role was more preservation than creation, given the creation process requiring photosynthesis, and the plant has no batteries. It's much like a solar panel .. no light, no photosynthesis.

To me, it kinda makes sense. Im not too sure about his 48h light tho. Not that I think they would hermie, but more that I cant see how that affects other factors in the room, that might end up it being a net negative.

It's hard to control for everything in these tests we do, but if we are to believe Dr. Bugsbee, it seems we can retire the practise of putting our plants in the dark.

Apologies Planetj

I watched the video last night, meant to get back to you, got side tracked and forgot


It is interesting, though I don't do the darkness - strictly out of necessity.

I lower my temperature towards end of flower and try to drop RH as much as possible. I've noticed a very nice increase in both density, and trichomes since doing so.

 

[PlanetJ]

Couldn't find the vid, but there is plenty of science that says terpenes are most prevelant after darkness, just at dawn. So calling the darkness period "broscience" isn't really accurate. Maybe Bugbee has some actual scientific studies disputing this, I looked, I can't find it

He seems to be working on that.

Hemp Research Underway at Utah State University

Exploring collaborations with University of Utah College of Pharmacy.

www.usu.edu

The main argument he uses to tackle the graph you posted, is that this is more likely due to temperature than the dark period in itself. I'm not qualified to judge that statement on how valid it is, but wel all know terps evaporate at higher temps so there seems to be at least a plausible explanation there, maybe.

As I tried it just once, on a bad plant, I really like to hear from the people who basically have experience with this after they learned to grow without issues, unlike me.

 

[PlanetJ]

Apologies Planetj

I watched the video last night, meant to get back to you, got side tracked and forgot


It is interesting, though I don't do the darkness - strictly out of necessity.

I lower my temperature towards end of flower and try to drop RH as much as possible. I've noticed a very nice increase in both density, and trichomes since doing so.

No need to apologize at all I know how it goes, I've been meaning to update my journal for the past 50 minutes

The lowering of the temperature seems to track what is suggested in the video/by Bugbee as the reason for the phenomenon ascribed to the dark period by many. Thanks for your input, much appreciated!

 

[Regrowth]

What's always bothered me is that we hang in the dark or dry in a fridge.
If there's some gain to be had from the dark period are we not doing it already?
And for way longer periods; we also cure in the dark for months at a time.
Any studies done should have to consider this. Are they testing after a n-hour dark period but without any dry/cure? Both for proper data? Personally it doesn't make much sense to me apart from the note about terpenes... but I've seen some people who swear by it.

 

[Phytoplankton]

There are other reasons for 48-72 hours of darkness before harvest, chiefly, the darkness stops photosynthesis and during that dark period the plant will metabolize carbohydrates (into sugars) and then the sugars in an effort to keep alive. Sugars make for a harsher smoke.

 

[PlanetJ]

There are other reasons for 48-72 hours of darkness before harvest, chiefly, the darkness stops photosynthesis and during that dark period the plant will metabolize carbohydrates (into sugars) and then the sugars in an effort to keep alive. Sugars make for a harsher smoke.

So regarding that, studies show that these reserves that are build are basically depleted at sunrise, as the plant doesnt store a lot of excess.

"In order to cope with night-time darkness, plants during the day allocate part of their photosynthate for storage, often as starch. This stored reserve is then degraded at night to sustain metabolism and growth. However, night-time starch degradation must be tightly controlled, as over-rapid turnover results in premature depletion of starch before dawn, leading to starvation. Recent experiments in Arabidopsis have shown that starch degradation proceeds at a constant rate during the night and is set such that starch reserves are exhausted almost precisely at dawn. Intriguingly, this pattern is robust with the degradation rate being adjusted to compensate for unexpected changes in the time of darkness onset. While a fundamental role for the circadian clock is well-established, the underlying mechanisms controlling starch degradation remain poorly characterized. Here, we discuss recent quantitative models that have been proposed to explain how plants can compute the appropriate starch degradation rate, a process that requires an effective arithmetic division calculation. We review experimental confirmation of the models, and describe aspects that require further investigation. Overall, the process of night-time starch degradation necessitates a fundamental metabolic role for the circadian clock and, more generally, highlights how cells process information in order to optimally manage their resources."

Abstract from: How plants manage food reserves at night: quantitative models and open questions

That article has always been the main reason that I remained sceptical, as given this, there is no known to me process that still has energy to continue after about 12h of darkness. The plant calculates the required starch based on the amount of light it had and how long it took to get light again .. in a sense.

It's all pretty difficult to wade through if I'm honest, as I know people are swearing by it, and logic dictates that where there is smoke, there is fire .. so something positive must be had from it, maybe under certain conditions .. it's so much easier to just accept and try VS having a brain that blocks due to not understanding the causality chain ..

I really dont know an awful lot on the science involved that is cannabis specific, and information out there is really hard to verify without very expensive (to me) equipment and a setup that I would not be able to maintain, controlling all variables.

Do you have any insights as to what process might be going on after the starches are used up?

 

[PlanetJ]

If there's some gain to be had from the dark period are we not doing it already?

Im thinking the same, combined with the abstract from the linked study a post up, if we dry cold and under good conditions, given in a cut plant no process runs that would otherwise use energy, and energy is expended after ~12h dark, perhaps the rest is microbial.

 

[Phytoplankton]

Do you have any insights as to what process might be going on after the starches are used up?

Starches (carbohydrates) are reserve energy (since most plants don't store many fats, except in the seeds). The carbs are metabolized into sugars, once the sugars are depleted and there is no photosynthesis, most biological action will go into a pause, and microbial/chemical action will take over (curing). Bottom line as far as terpenes go I think it's a mute point, since terpenes will volatilize over time regardless.

 

[Regrowth]

There are other reasons for 48-72 hours of darkness before harvest, chiefly, the darkness stops photosynthesis and during that dark period the plant will metabolize carbohydrates (into sugars) and then the sugars in an effort to keep alive. Sugars make for a harsher smoke.

Guess you need the root system in tact for that reason? Interesting, thanks for your answer.
It's great to get explanations that are logical and not based on assumption.
A lot of people attribute the dark period mostly to trichome production it seems. Cheers.

 

[PlanetJ]

He has an AMA section ..

Some interesting questions and answers there, along with an removed question from a removed user, which I believe is asking about increased CBD/THC and/or terpene production at night. The answer suggests that to be not the case:

I hate/love rabbit holes like these .. sigh, there goes my night..

 

[Emilya Green]

but prevent the tent becoming hot so the terpenes dont evaporate as much.

This is a glaring example that there is still plenty out there that we all need to learn and plenty that we still don't quite understand. Bugbee is good, especially with light, but he certainly doesn't know everything, especially some of the new techniques and methods.

I have tried the 36 hours of darkness and I know it works. I have documented how well it works several times in my journals. No matter how hard you try, you can't convince me that in the right hands and with the right timing, it works quite well. Plants do grow at night, and you can see it with every plant you grow from here on. Do a height measurement of a plant in the 2 weeks of stretch before lights out. You will find that some plants can grow 2 or 3 inches overnight, in the dark.

The point of my quote however is to show you how far off you are with your "opinions" in this matter. Trichomes do not evaporate. Just last night while budwashing my present harvest I mixed up 3 buckets... one had baking soda and lemon in it, and it was very hot water, as hot as my water heater can put out. I dunked and swirled and swished my buds around in that bucket for a good minute. Guess what? The trichomes are still all there. None exploded from the heat and all appear to still be perfectly ok. Sorry, but this alone invalidates your evaporation theory... completely. The truth is that extreme cold will strip the trichomes, not heat. Swishing and swirling in a bucket of ice water could completely strip my trichomes... look up bubble hash for examples.

So, continue on. I will expect that years from now, reading your comments of today will embarrass you as much as some of my early writings have done to me. Keep learning and keep experimenting and every year you will know a little more truth. Save yourself some red face later on though by being absolutely sure about the things you profess to know today, before you publish them.

 

[PlanetJ]

your "opinions" in this matter. Trichomes

they are not mine, and I believe I said terpenes. I 'know' nothing on these subjects, and just aggregate what I can find and pass it through my own logic. I then ask people that know more if it tracks or not what I arrive at.

As for the evaporation of terpenes, I dont think that is controversial, is it?

 

[Rexer]

Save yourself some red face later on though by being absolutely sure about the things you profess to know today, before you publish them.

Oh that's so me! And you don't even have to go back that far . Though I'm not red faced, and only wish some could be taken back. The rest just proves my point in the next paragraph.

This place helps grow both plants and growers, continued conversations with experienced growers (like yourself), helps a lot.

I was actually going to tag you in as I know you have done some extensive research on this. I'm glad you made your way over here to help.

 

[Phytoplankton]

It's great to get explanations that are logical and not based on assumption.

While I am far, far from an expert, I do have a minor in Botany (albeit from a long time ago), but I try to keep up on stuff I'm interested in. A class in basic plant physiology would benefit a lot of people. What I see is that people will take a piece of information, that's part of a bigger biological system, and key in on that one piece, without taking into consideration all the other factors that are involved. It's kinda like some of the claims of "bigger harvest, more terpenes, denser buds", that people use to sell products, while many of them work to some degree (some are just plain snake oil), there is also a point of dimishing return. I liken it to some of the anti cancer foods: This one makes you 20% less likely to get cancer, another claims 30%, another claims 10%, another claims 40%, etc. Does that mean that is I do all these things I have 0 or little chance of getting cancer.... NO it doesn't, they may help lower my chances, but again, there is a point of dimishing return. OK, off my soapbox!

 

[bobrown14]

Lot of views, 0 opinions .. right .. /sad panda

I've tried to find a bit more, but as this is a highly cannabis specific practice, I cant find a lot of science on it. I saw some lab results of someone that suggested a 2% increase in THC and some terpene profile changes after 24h dark I believe, and not a lot of other changes afterwards.

Dr. Bruce Bugbee comments on that in the video, and mentions this is more likely due to a lower temperature in the environment than anything else and the role was more preservation than creation, given the creation process requiring photosynthesis, and the plant has no batteries. It's much like a solar panel .. no light, no photosynthesis.

To me, it kinda makes sense. Im not too sure about his 48h light tho. Not that I think they would hermie, but more that I cant see how that affects other factors in the room, that might end up it being a net negative.

It's hard to control for everything in these tests we do, but if we are to believe Dr. Bugsbee, it seems we can retire the practise of putting our plants in the dark.

I agree on the Bro science on the dark period.

What you mentioned about stored energy is not correct. Plants make sugars/carbs during photosynthesis and store that energy in many places including fan leaves and even roots. Those carbs, up to 50% of them are actually translocated to the root zone and used as root exudate. Again another reason not to defoil (another bro grow technique).

Root exudate made up from the carbs during photosynthesis, goes to the Rhizosphere attracting and feeding growing microbes which in turn feed the plant by using those carbs to break down soil organic matter.

Yeah so that Rhizosphere/microbe process is a storehouse of energy.


Doesn't have anything to do with a dark period tho... still need light to produce those carbs. Shutting that down with no light is just counter productive.

Grow naturally until chop day. Your choice of chop day likely has WAY more influence on your terp and THC level than anything else you can manipulate.

When I read stuff that sounds too good and/or too easy to be true its probably BS.

I've found over the years that our hard work in the garden is rewarded with bountiful fruits. There aint no sub for that. There's no easy way out.

No magic potion no miracles just gotta put in the work and reap what you sow.