Trimming leaves to allow light ?

mccumcumber said:

I don't trim any of my leaves. Why? Because if you can keep them green and healthy they are more productive than not having them. It's bio 101, I didn't know that was disputable.
http://en.wikipedia.org/wiki/Photosynthesis

Click to expand...

Technically the buds themselves serve as leaves and you want as much light as possible to be hitting them. I agree with keeping as many on as possible but when you have a plant that has been lst'd well or scrog'd, then you will inevitably have to clear SOME of the riffraff. To each their own though....live, grow, be happy.

be interesting to see a side by side of this one under say a 400 watt and then under 1000 ,i'm betting trimming helps on the smaller watt light ?i could donate 2 clones for the cause and run them under my 400 anyone with a grand wanna see?

Well I'm not gonna pay you a grand but I'd love to see the side by side

Defoliation's effect on sunflower yield. Interesting read. Different amounts of defoliation done at different times.
https://www.soils.org/publications/aj/abstracts/93/3/634
"Crop yield loss increased with increasing level of defoliation. Preflowering stage R3 was the most sensitive. At this stage a 100% defoliation of the leaf surface resulted in 92% yield loss, reducing both the number of seeds per head and 1000-seed weight. A 100% defoliation at stage R7 (back of head a pale yellow) caused a 50% yield loss, while at stage R9 (physiological maturity) defoliation had no effect on yield."

Couple other good ones:

http://jxb.oxfordjournals.org/content/47/Special_Issue/1239.short

http://www.ingentaconnect.com/content/esa/jee/1980/00000073/00000001/art00034

grand as in 1000 watt light i don't have mine hooked up so need someone to do the 1000 watt test,i can start this in about a week got to get my big gurl finished out first,but i do have 2 shark attack clones just waiting in the wings to do this with.

mike91sr said:

Defoliation's effect on sunflower yield. Interesting read. Different amounts of defoliation done at different times.
https://www.soils.org/publications/aj/abstracts/93/3/634
"Crop yield loss increased with increasing level of defoliation. Preflowering stage R3 was the most sensitive. At this stage a 100% defoliation of the leaf surface resulted in 92% yield loss, reducing both the number of seeds per head and 1000-seed weight. A 100% defoliation at stage R7 (back of head a pale yellow) caused a 50% yield loss, while at stage R9 (physiological maturity) defoliation had no effect on yield."

Couple other good ones:

http://jxb.oxfordjournals.org/content/47/Special_Issue/1239.short

http://www.ingentaconnect.com/content/esa/jee/1980/00000073/00000001/art00034

Click to expand...

comparing an outdoor crop to an indoor one is not quite the same,your using a light source that can not be duplicated indoors and as i mentioned earlier the only time i see it as beneficial is in a low light situation where light penetration is an issue.

Just because a plant is moved from the outside to inside doesnt mean the physiology changes. The environment does, and of course with it so would the results of the study. But it would change proportionately, and assuming the ability to determine optimal light strength (resulting in more/less penetration in a dense indoor grow), the results can pretty easily be applied to our situation. It's not the exact measurements that should matter, it's the concept and proportionality behind it. Also, the last study has relatively nothing to do with the amount or type of light.

Besides, the next best thing I find relating to indoor growing is on cannabis forums. Some guy saying he yielded 2x as much by defoliating this grow compared to last grow is far from as consistent and accurate as a lab having controls and multiple test subjects under the same environment except for one small change, making it possible to attain quantitative results.

well i read that 3 times still don't really see a point? question is will defoiling help on an indoor grow,where light penetration is an issue unless you got your plant surrounded by thousand watters.And i disagree with your indoor cannabis forums who do you think come up with hydroponics?well it wasn't pot growers it was nasa.and i think if you would read other forums such as sustainable farming where they can run these experiments without fear from prosecution with their lettuce plants and tomatoes.And almost all your store produce is grown hydroponically so i think sticking to weed forums is cutting yourself out of a lot of information.But i don't have a lab nor i doubt you do so what we have is hearsay and the only way to clear that shit is with experiments.which i am willing to provide in the best controlled exp. i can produce if thats not good enough well can always do it yourself or go on believing everything you read .you can have a study on something by 5 different places and you will get 5 different results just the way it is.

How far into flowering would R9 be on a cannabis plant? I'm assuming that's pretty near harvest when the calyxes are swollen, cause the article said physiological maturity. I just don't see why you would bother trimming the leaves at the very end anyway, there doesn't seem to be any benefit and there's a whole lot of room for error.

Also, 1k watt light in a 4x4 area ~18" away from the plant source has damn near the same amount of lumens of the sun. I'm also pretty sure that the penetration of a HID is the same across the board, your plant is just receiving a smaller amount of lumens from the smaller lights.

ThegrowerMOJO said:

well i read that 3 times still don't really see a point? question is will defoiling help on an indoor grow,where light penetration is an issue unless you got your plant surrounded by thousand watters.And i disagree with your indoor cannabis forums who do you think come up with hydroponics?well it wasn't pot growers it was nasa.and i think if you would read other forums such as sustainable farming where they can run these experiments without fear from prosecution with their lettuce plants and tomatoes.And almost all your store produce is grown hydroponically so i think sticking to weed forums is cutting yourself out of a lot of information.But i don't have a lab nor i doubt you do so what we have is hearsay and the only way to clear that shit is with experiments.which i am willing to provide in the best controlled exp. i can produce if thats not good enough well can always do it yourself or go on believing everything you read .you can have a study on something by 5 different places and you will get 5 different results just the way it is.

Click to expand...

Listen I was posting relevant links for people to read, if you disagree with it that's cool. I'm not trying to start shit I was just explaining that while it's different, there were certain physiological affects that were quantitatively measured, and the findings can be applied to our situation even though it's different. Will they be the same results? No, like I said. But there is no reason to assume that they wouldn't at least follow the same pattern, given the guidelines I already mentioned (actually knowing how limited your light source is). So you don't need to start coming at me like I'm some ignorant pothead intent on believing my friend's closet grow results over a fully documented experiment in a legitimate lab. My point about the cannabis forums was the opposite of what I think you understood it as. Aside from what I linked, most of the info I could find on the subject is stuff by pot growers which I generally don't consider conclusive. I meant that in a way that says I couldn't find anything better so take it for what it's worth. If you have better sources than me, please post them. I'm all for legitimate research.

So I don't limit myself to cannabis forums, I thought that would be obvious considering I'm the only one linking outside sources that are credible. I don't believe everything I read either, which is why I find tests and studies done by universities with professionals and link them here, as opposed to regurgitating the shit I read on this forum last week as fact (not saying you are, it's just common around here). So by all means, experiment with this for everyone's benefit including mine, I'll follow and appreciate the work you do and will consider the results in my own future personal decisions about what to do. I won't, however, consider it to be quantitative or trump anything I read from oxford or uc davis even if their test was done on a different plant in a different environment because we're unable to determine the cellular level effects like they are, and that's what IMO is what matters most in understanding WHY we are changing the things we change.

mccumcumber said:

How far into flowering would R9 be on a cannabis plant? I'm assuming that's pretty near harvest when the calyxes are swollen, cause the article said physiological maturity. I just don't see why you would bother trimming the leaves at the very end anyway, there doesn't seem to be any benefit and there's a whole lot of room for error.

Click to expand...

Yes, as far as I understood it's just pre-ripe basically. I'd personally never trim at the end either unless I started getting worried about mold.

mccumcumber said:

How far into flowering would R9 be on a cannabis plant? I'm assuming that's pretty near harvest when the calyxes are swollen, cause the article said physiological maturity. I just don't see why you would bother trimming the leaves at the very end anyway, there doesn't seem to be any benefit and there's a whole lot of room for error.

Also, 1k watt light in a 4x4 area ~18" away from the plant source has damn near the same amount of lumens of the sun. I'm also pretty sure that the penetration of a HID is the same across the board, your plant is just receiving a smaller amount of lumens from the smaller lights.

Click to expand...

sorry but there is no way a artificial light can reproduce the sun,lumens at the top of the plant ok maybe but as for penetration (which is the whole point of this post)there is no way.it can't be done for the simple fact of the distant the sun is at and the amount of light spread it produces

Mike not trying to come at you like a dumb pothead(sorry if this is how your taking it.)but i have seen study after study done by univ. and other labs not just on cannabis but almost everything in general .Point i am trying to get at is one study will find one thing 2 weeks later another study finds complete different picture.look at asprin hell been studying that shit for 50 years still can't figure out if it kill you or save you.(see what i am getting at?) No one is always going to get the same results as someone else i understand this just a fact of life but the basic premise behind the results is what i am after.i have run large multi 1000 watt rooms and know you can't get the same results on smaller watt lights ,not talking about yield i'm talking about growth pattern and light diffusion.

ThegrowerMOJO said:

Mike not trying to come at you like a dumb pothead(sorry if this is how your taking it.)but i have seen study after study done by univ. and other labs not just on cannabis but almost everything in general .Point i am trying to get at is one study will find one thing 2 weeks later another study finds complete different picture.look at asprin hell been studying that shit for 50 years still can't figure out if it kill you or save you.(see what i am getting at?) No one is always going to get the same results as someone else i understand this just a fact of life but the basic premise behind the results is what i am after.i have run large multi 1000 watt rooms and know you can't get the same results on smaller watt lights ,not talking about yield i'm talking about growth pattern and light diffusion.

Click to expand...

no worries then, I just get tired of catching heat for posting the most legitimate studies I can find from credible sources, from somebody who once heard their uncle's friend talking about how when he was 16 and tried something it worked awesome. You're right though, stuff is constantly being contradicted and re-discovered. And medicine is no different, but it's sure as shit better than pre-aspirin or penicillin days in general. I get your point though. But to ignore the newly-validated info just because it may be contradicted later is to always live in the dark and never have learned anything TO contradict in the first place. Yes results will vary, but I was trying to get at the very thing you said, "the basic premise behind the results". The pattern is there, showing that there is a distinct relationship between the amount of foliage and the amount of possible fruit, ONLY if light is not a limiting factor (which it usually is for indoor growers).

So with that said, the conclusion to make for indoor grows is it depends on your specific environment. If you have 1000w on a single 3'x2' plant, why would you defoliate? But if you have 1000w in a 5x5 room stuffed full, obviously defoliation will help get every bit of light you can into lower areas. The question then becomes when, what parts, and how much. I think if you read and understand the links I posted, you should be able to at least have a bit more of a grasp on when/why/how to go about defoliation, if you choose to. Regardless of total gain/loss and the measured results, the study at least showed what effect timing and amount had in general. Interpretation and decisions based on the info are totally a personal choice, and I would likely do something different than you given the same facts and circumstances, that's what helps us continue improving and learning.

ThegrowerMOJO said:

sorry but there is no way a artificial light can reproduce the sun,lumens at the top of the plant ok maybe but as for penetration (which is the whole point of this post)there is no way.it can't be done for the simple fact of the distant the sun is at and the amount of light spread it produces

Click to expand...

actually a 1000 watt bulb produces more lumens as per the sun only difference is the sun produuces alot of other types of radiation, ultraviolet light X rays etc but it mostly gets dissipated via magnetic poles you ever see northern lights ????
so getting to the point here on most summer days the sun emits 88,000 lumens due to cloud activity 130 watts per Sq foot the sun produces

in order to achieve decent yields one must determine amount of lighting secondly amount of penetration
now yes a plant is like a factory it stores its energy in its leafs and uses them sugars when needed but to simplify things one should trim all smaller buds and lower leafs to allow plant to use up all its energy to upper bud sites

lighting said:

actually a 1000 watt bulb produces more lumens as per the sun only difference is the sun produuces alot of other types of radiation, ultraviolet light X rays etc but it mostly gets dissipated via magnetic poles you ever see northern lights ????
so getting to the point here on most summer days the sun emits 88,000 lumens due to cloud activity 130 watts per Sq foot the sun produces

Click to expand...

OK i suggest you go back and re read what i said! i said lumens maybe! but not coverage

and like always should research before opening one's mouth http://en.wikipedia.org/wiki/Lux

how did this thread get moved from trimming leafs to light / sun power any way lol were not talking about coverage were talking about leaf trimming and yes IMO everyone should trim 1/3 of plants lower leafs and bud sites allowing upper buds to achieve maximum weight who the hell wants fluffy shake for buds anyways when left on plant it only hurts your upper buds as for plants energy being wasted