Why go 24 hours lights on??

[bobman]

but if a plant if classified as not needing a dark period by science. Then is should grow best with 24/7 light because if it did not how would it be classified as a plant that did not need a dark period.

 

[VerdantGreen]

there is a difference between not needing a dark period and what makes it grow best.

a plant doesnt need a big pot but it will grow much bigger and yield better if grown in one.

a mj plant doesnt need temps between around 70 and 80 but it will grow much better if you provide those temps

etc etc.

you go with your 'educated guess' if you like but i dont see how you get the conclusion that plants veg best under 24/0 just because they dont NEED a dark period

 

[bobman]

no no no that is flawed logic my friend. Photosynthesis is a process internal to plant driven by light. if a plant does not need a break from photosynthesis then it will grow better under 24/7. In fact using your examples if you give a plant the best environment including pot size and optimal temperatures than with this species of plant 24/7 should grow it the best. since it is classified as a plant that does not need a break from that process.

 

[TruthOrLie]

roots seem to grow at an explosive rate during lights off.

did i miss that somewhere posted here already?

 

[spurr]

@ bobman,

I want to clarify a few points you are getting confused. When you write "class III" plant, I assume you mean "C3" plant, i.e. vs. C4 and CAM plants, no? If so, they are called C3, and yes, cannabis is a C3 plant. Also, the papers and other resources I posted, and more I can post, are of C3 plants, just like cannabis. That is what I mean by your misunderstanding, until you learn the basics and stop writing false claims about those of us who are providing correct info, I feel little need to help you.

Cannabis isn't a special plant, it's like other C3 plants that use dark cycle (light-independent reactions) for calvin cycle and circadian rhythm (i.e. the plants' biological clock). Plants can even tell when it's 'midnight'! Arabidopsis thaliana is a perfect example, it's a C3 plant that is the most wildly used "model organism" for other C3 plants, such as cannabis. Plants, such as C3 like cannabis, grow most at night and very early morning, that is proven many times over. This is a basic proven scientific theory you must understand to learn about plant physiology.

"Plants Can Sense Midnight"
Howard Hugues Medical Institute, February 01, 2008
A story about the newish paper by renown plant physiologist Joanne Chory, also discusses plant growth and cellular repair at night, etc.
http://www.hhmi.org/news/chory20080213.html​

Also proven many times over is that plants (such as C3) use dark cycle for "light independent reactions". Yes, C3 plants can grow without a dark cycle, but they grow better with a dark cycle (e.g. higher "net rate of photosynthesis", greater growth rates, better carbohydrate assimilate & partitioning, etc.).

Please, prove you points, don't just shout them without any proof. I am responding to you because people who don't know about these topics might think you're correct due to your correct sounding (yet wholly incorrect) claims. See my refs below for what I mean by proof, ideally you would provide peer-reviewed and published papers from respected journals. No one is comparing applies to oranges in terms of C3 plants such as cannabis doing better with a dark cycle, we are comparing apples to apples.

In my point about leaf/plant reaction to too much light (re: leaf curl, aka leaf roll), it's not about a dark cycle. A plant would have similar reactions from too much light, i.e. too many photons during X hours, if X was 6 or 16 or 24. Other factors that can make leafs curl (called 'canoeing" by cannabis growers) is Ca deficiency, high "Air-to-Leaf Vapor Pressure Deficit", low "soil-water status", excessive temperature (i.e. leaf temp), etc...those factors are all interrelated. Leaf heat (temp) and PPFD are closely related, because when a leaf/plant reaches the point of "light saturation" (e.g. the amount of light energy encountered by plants in excess of that which they need for photosynthetic productivity, termed "Excess Excitation Energy", aka "EEE") from too high PPFD, or DLI, the leaf gets hot. Thus the leaf can curl (aka "roll") to reduce its absorption of photons and thus reduce the heat.

Also, someone wrote if plants get more than 6 hours of light the rate of photosynthesis goes down, and that simply isn't true, unless the PPFD (amount of photons within PAR range in a meter^2 per second) is too high. For cananbis too much PPFD is ~>1,600. An example of this is "midday depression of photosynthesis", which is caused by photoinhibition (too much PPFD and/or DLI), too much heat, too high VPD, etc. Usually rate of photosynthesis is decreased after 16-18 hours of non-stop light, this has to due with factors such as "Rubisco" and "Rubisco activase", carbohydrate assimilate, etc.



Please, stop being rude and swearing and calling people names. The simple fact is you are wrong...



Here are papers about leaf rolling from too much light/heat, and yes, they are of C3 plants

1. "Signal transduction in response to excess light: getting out of the chloroplast"
Philip Mullineaux and Stanislaw Karpinski
Current Opinion in Plant Biology, Volume 5, Issue 1, 1 February 2002, Pages 43-48
(full text) http://www.aloj.us.es/bioqplantas/tema4-5/biblio cloroplasto/chlro-nucleo3.pdf

Acclimation to conditions that promote EEE not only includes an increase in the number and activity of dissipatory processes, but also may involve protective strategies that avoid the absorption of excitation energy. These include the movement of chloroplasts away from high light sources [14••], a decrease in the number of photosynthetic reaction centres per unit leaf area [15], leaf curling [16], an increase in the thickness of cuticular wax or other EEE-protective screens [17] and changes in leaf and whole-plant morphology [2].

2. "Photosynthesis performance of non-rolling and flag leaf rolling wheat genotypes during temperature stress"
G. Sariyeva, S. Kenjebaeva, H. K. Lichtenthaler
Acta Botanica Hungarica, Volume 51, Numbers 1-2/March 2009, pp. 185-194


3. "Response of chlorophyll fluorescence to dynamic light in three alpine species differing in plant architecture"
Xiaoyong Cui, Haishan Niu, Jing Wu, Song Gu, Yanfen Wang, Shiping Wang, Xinquan Zhao and Yanhong Tan
Environmental and Experimental Botany, Volume 58, Issues 1-3, December 2006, Pages 149-157
(full text) http://www.geocities.jp/plant_environ/ENG/ProjectPDF/2006/06-Cui-EEB.pdf


4. "Action Spectrum of Photoinhibition in Leaves of Wild Type and npq1-2 and npq4-1 Mutants of Arabidopsis thaliana"
Sarvikas P, Hakala M, Pätsikkä E, Tyystjärvi T, Tyystjärvi E
Plant Cell Physiol (March 2006) 47 (3): 391-400


5. "Development of photosystem-II activity during irradiance of etiolated Helianthus (Asteraceae) seedlings"
Jefferson G Lebkuecher, Kurt A Haldeman, Christine E Harris, Sonia L Holz, Sary A Joudah and Darcy A Minton
American Journal of Botany. 1999;86:1087-1092
(full text) http://www.amjbot.org/cgi/content/full/86/8/1087


6. "Thermal dissipation, leaf rolling and inactivation of PSII reaction centres in Amomum villosum"
Yu-Long Feng, Kun-Fang Cao and Zhi-Li Feng
Journal of Tropical Ecology (2002), 18:6:865-876


7. "CHAPTER 9-3 LIGHT: EFFECTS OF HIGH INTENSITY"
Glime, Janice M.
Bryophyte Ecology. 2007. Volume 1. Physiological Ecology



Info about C3 vs. C4 vs. CAM plant and light/dark cycles, etc.


1. "Photosynthesis"
UC – Clermont
http://biology.clc.uc.edu/Courses/bio104/photosyn.htm


2. "The Calvin Cycle"
http://hyperphysics.phy-astr.gsu.edu/hbase/biology/calvin.html


3. "TYPES OF PHOTOSYNTHESIS"
http://wc.pima.edu/Bfiero/tucsonecology/plants/plants_photosynthesis.htm


4. "C3, C4 and CAM. Regulation of The Activity of Photosynthesis"
Botany online - The Internet Hypertextbook
http://www.biologie.uni-hamburg.de/b-online/e24/24b.htm


5. "Photosynthesis Problem Set 2"
The Biology Project, University of Arizona
http://www.biology.arizona.edu/biochemistry/problem_sets/photosynthesis_2/photosynthesis_2.html


6. "A Comparison of Dark Respiration between C3 and C4 Plants'"
George T. Byrd, Rowan F. Sage, and R. Harold Brown
Plant Physiol. (1992) 100, 191-198
(full text) http://www.plantphysiol.org/cgi/reprint/100/1/191.pdf

 

[bobman]

I am not going to read all your cut and paste bs. Buddy your science is bogus. Thats been proven by me. Lets pm chimera and see what he says. The guy is going for his doctorate in plant biology. Agreed what he says goes on the subject? Are you brave enough to do your little cut and paste with him? What do you say lets lay some ground rules and make a bet of it. If not shove it.

 

[spurr]

My problem with what he is saying is that he is backing up his argument with no facts.


The only thing i know for sure is marijuana is classified as a type of plant that does not need a dark period. That is fact. That being proven and factual I can only make an educated guess and say 24 hrs of light will grow the plant faster and will have no adverse affects on the plant.

Pot...kettle...black; as the old saying goes. You have provided zero refs, yet I have provided many, and they are ALL on C3 plants, and cannabis is a C3 plant. Read my post above

Please, post your refs, hopefully they are from peer-reviewed and published papers showing that cannabis (and other C3 plants) do not benefit from a dark cycle, i.e. for "light independent reactions" such as calvin cycle, starch conversions, cellular growth and repair, respiration, circadian rhythm (and other phytochrome responses), etc., etc.

No one has claimed cannabis will not grow without a dark cycle, just like many other plants will grow without a dark cycle. However, cannabis (and other C3 plants) grow better and are healthier with a dark cycle. Please, prove me wrong, just don't make empty claims.

 

[spurr]

but if a plant if classified as not needing a dark period by science. Then is should grow best with 24/7 light because if it did not how would it be classified as a plant that did not need a dark period.

Please read what VG has been kind enough to try and teach you. I have little patience for you...you are using logical fallacies to make a incorrect argument.

 

[opt1c]

so it looks like it's time for another side by side... 24/0 v 18/6 or 20/4??

Thinking veg only... dr80 tents... same setup in each tent... 2ft 4bulb t5 in each tent... same strain... fed on the same day etc.

Enough with the talk

 

[spurr]

I am not going to read all your cut and paste bs. Buddy your science is bogus. Thats been proven by me.

Firstly, I do not 'cut and paste' as a rule, to claim I do is simply ignorant and false. I understand my refs, thus I put it into my own words.

If you have proof from sound refs, then post them. Stop making empty claims.

Lets pm chimera and see what he says. The guy is going for his doctorate in plant biology.

Do so, but don't be upset when you're told you're wrong, again . Also, he doesn't have a doctorate in plant biology, I think it's in genetics, lets get your facts straight, ok?

To that point, why would Chimera be your resource? Why don't you cite properly, i.e. peer-reviewed and published papers, or at least resources from well thought of Universities and Governmental bodies?

You made me giggle when you wanted to bet seeds that breeders would take your side. Even if they did, you and they would not be anymore correct. If they claim plants like cannabis don't do better (see what I mean by "better" from my post above) with a night cycle then they are as ignorant as you are

Also, what do you think the authors of the papers I cite are educated in? Auto-mechanics!?! I am (pretty much) a self-taught plant physiologist, I have as much understanding as anyone in the cannabis world, and more than anyone I have ever come across. That isn't me bragging, it's just the way it is.

Agreed what he [chimera] says goes on the subject?

Not if he makes the same wrong claims you are making. I have meet many less than highly intelligent PhD's and Doc's, a title doesn't mean someone is correct, it just means they spent the time/effort to get a title.

Are you brave enough to do your little cut and paste with him? What do you say lets lay some ground rules and make a bet of it. If not shove it.

Lol. I think Chimera would not like how you are using his name. And I do not cut/paste. Ask him if you like, but don't be upset if he doesn't agree with you, re: that plants do not do better with a night. And if he does agree with you he's as wrong as you are...

Simple fact relevant to this thread: plants grow the most during night and very early morning.

/done

 

[spurr]

so it looks like it's time for another side by side... 24/0 v 18/6 or 20/4??

Thinking veg only... dr80 tents... same setup in each tent... 2ft 4bulb t5 in each tent... same strain... fed on the same day etc.

Enough with the talk

I agree, enough talk. There is no need to run side by sides because the jury is already in: plants like cananbis (C3) do better, and grow faster, with a dark cycle assuming enough DLI is provided in the day.

Also, side by sides without controlling all major factors that affect growth is a waste of time and proves nothing. To do a side by side that shows anything worthwhile you need to control and measure PPFD, PPFD-DLI, soil-water status (i.e. "water tension"), VPD, ADT, C02, etc., etc.

I am working on getting a very large grant this coming year, if I secure said grant I am buying a butt load of analytical plant physiology tools (worth around $50k+) to carry out proper scientifically sound tests/experiments/studies on cannabis to study various hypotheses and to re-prove already proven scientific theories (that isn't the same as a laypersons definition of "theory"). Stay tuned for studies that have never been done before on cannabis, and some that have been done, e.g. ideal PPFD, etc.

 

[bobman]

Coward. you have met less than intelligent phd's and docs. your a joke. I tell you what lets contact 10 breeders and see their answers. or is that not good enough for you. Neville, shanti, dj short, chimera, simon, franco, soma and whoever else you want but be a man and put your money where your mouth is. I tell you I never make a bet without knowing the outcome but on this one I do not know what they are going to say. So just so i have this straight you believe plants grow more in the dark. what exactly are you saying because I am saying 24/7 for fastest most optimum growth. Let me just hear exactly what you are claiming so I get it all correct and nothing magically changes. You are taking the opposite of my line and saying you will achieve the fastest and most optimal growth from a dark period? How long, give me all the variables so we can cite it and reference it for future generations.

 

[The Phoenix]

When you've been growing cannabis for quite a while you will begin to read what your plants are trying to tell you.

When vegging a combination outdoor/indoor, or growing with 1kw lighting indoors, it's fairly easy to read them and see what is needed because you are pushing the plants rather hard.

When I walk into a 1kw veg room and see the plants leaves drooping down slightly on a 24 hr cycle when the plants are well fed, then you know somethings going on. When the same plants and conditions in another room on 18/6 are perky and look impressive, then you have to say they sure are happy with the rest.

Just an observation I have made after many, many years of 24 hr veg cycle watching. I now run nothing but 18/6 in veg and my plants seem much healthier now more consistantly. BTW, I veg a few 1000 plants a year both outdoors and indoors, so I'm actually more interested in the veg cycle than the flower cycle because of the cost.

 

[bobman]

I agree I would love to be wrong for the shear cost alone. But I don't think the big dogs would agree on less light equals healthier plants. Would you like to take the challenge sir.

 

[spurr]

Coward. you have met less than intelligent phd's and docs. your a joke.

Ok, thanks for clearing that up for me

I tell you what lets contact 10 breeders and see their answers. or is that not good enough for you. Neville, shanti, dj short, chimera, simon, franco, soma and whoever else you want but be a man and put your money where your mouth is.

No that is not good enough, what IS good enough is peer-reviewed and published papers and/or other legit academic resources such as Universities resources, etc. You should stop thinking just because someone is well known they are correct, that is one of the many "logical fallacies" you are using, that one is called "appeal to popularity", another one you are using is called "appeal to common practice"; look them up and stop using them!

Look into the rules of APA formatted papers to learn more, other formats of academic papers are also valid, but I like APA.

I already proved beyond reproach that C3 plants (not "class III" ) do better with a dark cycle. If you won't want to take the time to read my refs, or find your own refs, then that's your problem, not mine.

Of the breeders you listed, Chimera would probably be the better source, but that doesn't mean he's right. Also, like I wrote, I doubt he would like how you are calling him out, before you know what he would write. it's not only rude, but also uncouth to call them out as you have done, claiming they will agree with you before you find out their positions. Please, use properly cited refs, don't use logical fallacies like you have been doing this whole time.

I tell you I never make a bet without knowing the outcome but on this one I do not know what they are going to say.

Then stop assuming you do, and claiming your assumptions are correct.

So just so i have this straight you believe plants grow more in the dark.

It's not what I believe, it's a fact assuming enough DLI is provided in the day, to provide enough "net rate of photosynthesis" and Co2 fixation and carbohydrate assimilate. This goes back to what I wrote about low light levels of DLI, etc. Me thinks you need to re-read this thread...

what exactly are you saying because I am saying 24/7 for fastest most optimum growth.

I am saying you are ignorant, and worse yet, you won't accept you are ignorant. Being ignorant isn't a bad thing, I'm ignorant of lots of things, like rocket science. But I know I'm ignorant and I don't make ridiculous claims about rocket science to actual rocket scientists.

Let me just hear exactly what you are claiming so I get it all correct and nothing magically changes.

Like I wrote, you need to re-read this thread. But this time, really read it, don't just skim over it with your preconceived notions blocking out what I, and others, have written and the refs we have cited.

You are taking the opposite of my line and saying you will achieve the fastest and most optimal growth from a dark period?

Yes, of course.

How long, give me all the variables so we can cite it and reference it for future generations.

<sigh> re-read the thread.

 

[spurr]

I agree I would love to be wrong for the shear cost alone. But I don't think the big dogs would agree on less light equals healthier plants. Would you like to take the challenge sir.

You don't measure amount of light (photons) over a day by hours of light per day! I covered this with JapanFreaker already. You use DLI ("Daily Light Integral" using PPFD and hours of daylight) to measure amount of light over a day.

For outdoor/greenhouse growers who grow under the sun it's best to use "3-day DLI" because using DLI isn't accurate due to flux of PPFD from the sun each day, ex. from cloud cover, bell-shaped PPFD over the day, etc. For indoor growers under and artificial lighting using DLI is fine because we can provide the same PPFD over the whole day, each day.

You can have a day that is 18 hours of light (in a 24 hour period) and provide more light (i.e. higher DLI) than a day that is 24 hours (in a 24 hour period). With that hypothetical 18 hour day, you not only provide more photons, but you also provide a dark period, that is the key to best and most growth.

Please, please, please, get the basics understood before you try to make claims like you're claiming.

 

[spurr]

@ MODS:

can you please lock this never-ending and repetitive thread? TIA!

 

[The Phoenix]

I agree I would love to be wrong for the shear cost alone. But I don't think the big dogs would agree on less light equals healthier plants. Would you like to take the challenge sir.

I've been growing cannabis for around 30 years in California, and own a collective with more experienced growers than me. We all agree that 24hr cycles are OK to use, but when we are pushing plants to the limit with the sun outdoors, and 1kw lighting indoors, we all agree that 18/6 gives us plants that look healthier in veg during the duration of the grow.

I cant be challanged more than I already am, because it's my business. I've vegged nearly 7000 plants in the last 3 years alone from seed and clone, so what kind of challange can you throw at me that I've not already seen????

 

[bobman]

just so we get this cleared up what is your degree in? And what papers have you published on the topic? buddy if those peoples opinion do not mater to you then you are a jackass. Most of them have biology degrees. man up bitch put your money where your mouth is. if not go slink off some where and let the men talk.

 

[The Phoenix]

@ MODS:

can you please lock this never-ending and repetitive thread? TIA!

spurr, you've made your point already, so now it's up to the viewers to agree or disaggree. Why are you so bent that some dont see things your way?