Please explain the phrase "Penetration" in reference to lights.

[Dub_j]

light penetrates the canopy area, onto the stem and places where new growth is, doesn't it? a canopy of a plant is not one or many leaves, but the general area, so if light bounces around and ends up through the canopy didn't it penetrate something?

 

[TheEnhancementSmoker]

It might be a good idea to go ahead and change the name of this forum to "Cannabis Sativa, Indica, and Ruderalis Passion," to help eliminate any confusion from the vague "marijuana" nomenclature.

 

[Aurora_Indicas_Dad]

lol

 

[POTUS]

It might be a good idea to go ahead and change the name of this forum to "Cannabis Sativa, Indica, and Ruderalis Passion," to help eliminate any confusion from the vague "marijuana" nomenclature.

The best part of it is that the thread has nothing to do with the meaning of the word penetration.

Pretty funny that you thought so.

 

[TheEnhancementSmoker]

The best part of it is that the thread has nothing to do with the meaning of the word penetration.

Pretty funny that you thought so.

Well, then what did this mean in your first post?
1. What is "Penetration"?


I have no idea what your point is.

 

[POTUS]

Well, then what did this mean in your first post?
1. What is "Penetration"?

It was used in context with the rest of the post. That context made it clear that I wasn't looking for a definition of the word, but an explanation of how it applies to increasing the value of a grow.

After more than 40 years of growing weed, I'm sure I know what I'm talking about.

 

[Aurora_Indicas_Dad]

i'd hope so,but no need to nag on people for usin the word,right?

 

[Dub_j]

who cares get lifted!

 

[POTUS]

i'd hope so,but no need to nag on people for usin the word,right?

If you think that's what I was doing, then you didn't understand what I said.

You need to go back and try to understand what it is that I said.

 

[Rogue]

I keep running into the phrase "Penetration" in reference to the use of lights on an indoor grow. Statements like "Provides better penetration" and "Not enough penetration".

Scenario: A grow room that is covered wall to wall with plants. The leaf canopy of plants is in excellent health and has no openings in it as viewed from the top.

I'd like to hear everyone's take on exactly what this means to them if applied to the above scenario.

1. What is "Penetration"?

2. Why is penetration needed?

3. What happens if penetration is not present?

Please answer these questions specifically in reference to the scenario as stated above.

To be fair, I have to make it clear that I believe "Penetration" to be another fallacy in the minds of over-enthusiastic growers that have picked up a trade phrase that is inappropriately used and has no real merit.

Anyone who can provide me with ANY professional reference to Light Penetration that specifically means beneficial light reaching through a plants leaf canopy to the lower leaves of the same plant and providing something NOT gained by the upper leaf canopy, please do so. I'm betting that no one can. Please don't swamp me with anecdotal stories.

I would be especially interested in any comments on the benefit of actually *removing* leaves to allow "penetration" to the lower areas of the same plant.

Please keep in mind that I am NOT trying to start an argument. I'm trying to bring a misconception to light and explain to everyone how this fiction of "Light Penetration" is a well spread myth that holds no true scientific basis or benefit.

In actuality, I would love it if someone proved me wrong with quotes from anyone who is a plant biologist or other professional in the field. Please link to any articles or studies that show me being incorrect.

Thanks,

Stoney

Well in your above example penetration is moot except for how deeply the light is penetrating the leaves from above. The light from a 23 watt CFL probably will not go very deep into the leaves to dim, not maximum usuage of the plant area able to receive light. A 400 watt HPS would have light go through the entire leaf and shine slightly on others below, maximum usuage of plant area able to receive light.

 

[The New Girl]

Ref: 2. For satisfaction usually
Call me: 1-555-444-1212 HAHAHAAHA

The light that contacts any leaves on the plant benefits the entire plant, not just the part that the light hits. Having it hit somewhere else on the plant is pointless. The plant will create additional leaves to gather sunlight until it's maxed out or as close as possible. Removing leaves to let sunlight through to other leaves is crazy.

Wow. Thanks POTUS. I did read the other couple of pages but referenced this one as it taught me a lot. Thanks for all the info thru all of your posts on this. This clarifies so much!
PS: Oh, and can we all be nice guys.

 

[Tater]

The canopy of your pot plants will work the same way as the canopy in a forest or the rain forest or wherever. Basically each plant is trying to maximize its available light, if its the only plant growing then no problem. If you have many plants growing then you could have a problem. This is pretty simply biology. If you have a more vigorous plant that grows above and effectively covers the lower plants then those lower plants are going to respond by stretching whether it is sideways or up doesn't matter. Light penetration is a real phenomenon. Go watch a documentary about the rain forest or any forest. The reason you find sparse vegetation on the forest floors is because the light cannot penetrate the canopy. Its the same with pot.

So to answer your question.

1. What is "Penetration"?

The distance that light can travel past the canopy before losing the concentration required by plants to photosynthesize.

2. Why is penetration needed?

It is a fundamental requirement if you want to have growth below the canopy.

3. What happens if penetration is not present?

All growth below the canopy will slow and eventually stop. Any leaves below the canopy that are no longer photosynthesizing light will stop growing and eventually be cannibalized by the plant.

Please answer these questions specifically in reference to the scenario as stated above.

The above senario has nothing (NOTHING) to do with the questions you asked. The setup you have described is either a SOG or SCROG grow where the goal is to light the canopy as evenly as you can ignoring the lower bud sites.

To be fair, I have to make it clear that I believe "Penetration" to be another fallacy in the minds of over-enthusiastic growers that have picked up a trade phrase that is inappropriately used and has no real merit.

Penetration is anything but a fallacy. I'm glad you stated this was nothing more than your belief though because it is definitely not based in fact.

Anyone who can provide me with ANY professional reference to Light Penetration that specifically means beneficial light reaching through a plants leaf canopy to the lower leaves of the same plant and providing something NOT gained by the upper leaf canopy, please do so. I'm betting that no one can. Please don't swamp me with anecdotal stories.

I wish I could. I could point you to lots of studies involving other plants, or ecosystems of the forest floor etc none based on the study of Cannabis. This is simply because these studies do not exist mainly because of the illegal narcotic label that has been attached to the plant. It makes it very difficult for legitimate scientist to obtain funding for these projects. So this leaves us with personal experience, the experiences of others, and scientific data on other plants. This should give us enough to create a hypothesis on what would happen if light penetration beyond the canopy was increased.

I would be especially interested in any comments on the benefit of actually *removing* leaves to allow "penetration" to the lower areas of the same plant.

This should be another topic all together as it doesn't apply to the question you asked. Removing leaves from your plant is probably the dumbest thing you can do. (Again I'm pulling my knowledge from outside of the Cannabis plant) Leaves are responsible for pretty much all the basic functions of the plant. If they receive sunlight they photosynthesis and provide sugars to the plant to be used as energy and if they are no longer receiving light are dying and yellow (barring disease) then the plant will cannibalize the plant using the leaf for energy. Discussing the leaves actual job and life stages is also outside of the scope of this post and if anyone really wants to know about it there are plenty of botany textbooks available for free online.

Please keep in mind that I am NOT trying to start an argument. I'm trying to bring a misconception to light and explain to everyone how this fiction of "Light Penetration" is a well spread myth that holds no true scientific basis or benefit.

I appreciate your goal you are just simply misinformed. Light penetration through the canopy and its resulting effects on plant life below the canopy is well researched and documented. Once again this phenomenon can be observed by taking a stroll through any forest. While you are there look at the cut lines and roads that travel through the forest notice how dense the vegetation is on the edges of these. This is because the forest was cleared allowing more light to hit the floor which in turn increased vegetative growth.

In actuality, I would love it if someone proved me wrong with quotes from anyone who is a plant biologist or other professional in the field. Please link to any articles or studies that show me being incorrect.

No problem, here you go. This is just a google search but it does a great job of demonstrating the vast amount of studies done on the topic. Granted these are all based on other plants besides marijuana. But as stated above there are reasons for this.
hxxp://www.google.ca/search?q=canopy+light+penetration&ie=utf-8&oe=utf-8&aq=t&rls=com.ubuntu:en-US:unofficial&client=firefox-a

Oh and to clear up a misconception (not directed at you Potus) when the topic of canopy penetration is discussed we are not talking about light penetrating through a leaf to the one's below, more of light reflection through to the lower parts of the canopy.

With all that said I think the question is misconstrued and poorly formed. A better question would have been, does lighting below a canopy increase yield to the point of making it worth the effort. Then you would also need to address if you are talking about single plants, large plants (say a ebb and flow bucket system with 10 plants) or small plants (say in a sog with 50 plants utilizing a screen). The questions you have asked are all basic science and have been researched and well observed.

I also am not attempting to instigate an argument and find your goal to be an admirable. The problem is that you are incorrect and furthering the spread of misinformation. It would be an interesting topic for study though to find out if overall harvest of a single plant is increased by lighting below the canopy. Controls and parameters would need to be set out as well as clear and defined goals to the experiment.

In my opinion I do agree with you that worrying about light reaching the lower branches is a futile effort in most grow situations and most likely will not increase yields enough to be worth it.

Tater

Edited for spelling and grammar.

 

[massproducer]

Dang tater you took a lot of the words right out of my mouth. Very well said. Light "Penetration" deal with the law of diminishing light, which states that light will diminish by the square of the distace away from the source. So meaning at 1 foot you recieve around 100% of the availible light, but at 2 feet you only recieve 1/4 of the light, at 3 feet 1/9 and at 4 feet you would only revice 1/16 of the availible light. It is all about intensity.

I agree that using a 400 and growing trees, you will always have very small popcorn buds on your lower branches, but that is because a 400, doesn't have much penetrating power. while 3-400's will give more light and better distribution then a 1000, the 3-400's will never be able to match the 1000 in its penetrating power.

 

[Runbyhemp]

I would hold the same beliefs as Tater.

 

[Tater]

Massproducer: I can't really comment on light intensity except that I know that it diminishes the further from the source it is. Its probably close to what you wrote though as that seems to be the general consensus. And your second paragraph has more to do with your first paragraph than it does with light penetration of the canopy. Like you said its all about intensity.

Runbyhemp: I didn't post my belief's just facts.

 

[massproducer]

Light penetration and intensity are basically the same thing, just a different way of looking at the same coin. The only thing i am speaking about is light penetration.

 

[Tater]

Intensity describes the amount of lumens at a certain distance and can measured with or without a barrier. Penetration describes the intensity of light after passing a barrier, in this case an canopy of leaves. The topics although similar are still quite different.

haha man I've been watching to much startrek that last part was all vulcan like. lol sorry I'm high and a dork.

 

[POTUS]

In my opinion I do agree with you that worrying about light reaching the lower branches is a futile effort in most grow situations and most likely will not increase yields enough to be worth it.

I must not have made myself clear about what I'm talking about. You're obviously educated and speak intelligently on the subject.

Let me be more clear; I'm speaking strictly about indoor grows in a confined space with the proper amount of plants or LST and topping done to maximize the space and light. To apply it to a grow that has embedded problems due to improper spacing or growing techniques would be pointless. That would be like telling someone with their shoes on backward, the proper way to run. (First, turn your shoes around and do this correctly). It's the same with growing. My statements were not only my opinion, but also exactly the way it works in real life. Nothing I said was incorrect if taken in the manner I was intending.

I'm speaking of light penetration onto the lower parts of the same plant, not others as in your rain forest example. So, each argument you presented in regards to other plants being slowed would be oranges and apples. As to what you did point out about plant growth in a rain forest is correct, of course.

*IF* a plant is shading no other plant, then removing leaves from the top of the plant for no other reason than to provide light to the lower portions of the same plant would be a really crazy thing to do. It would, in fact, slow the growth of the entire plant and *lessen* the weight of the final harvested bud. That's a fact. Their is no argument that can hold water to what I just said.

Redirecting the leaves using LST would be effective IF one were trying to have side growth become top growth. If the top leaves are redirected to provide more light to the lower branches for no other reason than to make the lower buds grow larger, than I have seen in real life grows that that won't make the final harvest any better. I base this not on what some person in a biology book says, (even though it's correct there as well), I'm speaking from personal experience after growing many thousands of MJ plants indoors and trying every conceivable method of growing that I've ever heard of.

That's 25 years of indoor, dirt and hydroponic MJ and more than 40 years of growing outside.

Bottom growth of buds have never and will never be equal to the growth on the upper parts of the plant if maximum energy is provided and proportioned in any manner possible on the plant. I mean this to include interior lighting or exterior lighting of any kind and of any amount.

That said, I probably missed some of your points, but after reading your post, I see that you and I really do agree on what I was intending to say. I'm sorry I didn't make it more clear. (Ok, I was high)hehe

Peace man. Let's discuss in a peaceful manner. Antagonism isn't necessary and negative insinuations won't ever be cool.

Also, I should point out that many, many studies have been done and are currently being done by hundreds of test groups, planet wide.

The medical research being done on our favorite weed is astronomical. Look at the bibliography in any of several hundred books about MJ and you'll find 20+ more books on the subject in their bibliographies that in turn will direct you to hundreds more.

Light studies on thousands of plants of every kind on the planet has been done and as well, are being done at this moment. Lighting studies on MJ specifically? I haven't seen any by anyone at the Universities, but I'm sure there must be someone doing them. In a University setting, the professors can pretty much do anything they can think of as a study. With all the professors being of a much younger age than when I was younger, (I'm 75 on my next birthday), and much more familiar with MJ than those in the mid 1950's, I can only imagine that MJ is being studied like crazy. A search on .edu studies and MJ or it's components would probably turn up many.

Any group of medical researchers that are in a field of study that encompasses *anything* that is known to be possibly beneficial to humans or animals as a result of incorporating MJ into their bodies would have ongoing studies right now. You and I will probably never know that those studies ever existed, but we may someday benefit from them if they indeed do prove that MJ can be used medically for any number of things.

Peace! I'm glad that we agree. Perhaps not totally, but you've shown that you and I do agree on many things.

First and foremost, you like to get high. So do I !

What a small world. hehe

 

[POTUS]

Dang tater you took a lot of the words right out of my mouth. Very well said. Light "Penetration" deal with the law of diminishing light, which states that light will diminish by the square of the distance away from the source. So meaning at 1 foot you receive around 100% of the available light, but at 2 feet you only receive 1/4 of the light, at 3 feet 1/9 and at 4 feet you would only receive 1/16 of the available light. It is all about intensity.

I understand exactly what you're saying and I agree to this point.

I agree that using a 400 and growing trees, you will always have very small popcorn buds on your lower branches, but that is because a 400, doesn't have much penetrating power. while 3-400's will give more light and better distribution then a 1000, the 3-400's will never be able to match the 1000 in its penetrating power.

This is where you and I think differently. We may think the same, but perhaps we're just saying it differently.

Plant growth in regards to light is dependant on the spectrum and the amount of lumens that come in contact with the surface of the plants light receptors. Regardless of the wattage of a light, if the same amount of lumens as described above, come in contact with the plant, then the growth will be exactly the same of that where you alter the wattage, but stay with the same lumen contact. That's simple math.

Explain something to me please; If the canopy of a plant is dense enough to present a solid wall of green leaf toward the light, what exactly is going to penetrate that wall of green? Are you talking about light passing through the leaves themselves? We have to have an understanding of exactly what it is you mean in regards to penetration in this example.

As for light distribution, it's already well known that many smaller lights will grow a much better canopy of leaf. The light intensity is simply more constant at any given point.

So, if you'll explain more to me about exactly how light penetration works and give me a growing example of what you mean, then I'll no doubt understand you better.

Thanks!

Stoney

 

[POTUS]

Intensity describes the amount of lumens at a certain distance and can measured with or without a barrier. Penetration describes the intensity of light after passing a barrier, in this case an canopy of leaves. The topics although similar are still quite different.

haha man I've been watching to much startrek that last part was all vulcan like. lol sorry I'm high and a dork.

I don't think you sound "dorky" at all. You sound pretty well educated to me. You're well spoken and articulate.

I am wondering about the exact meaning of something you've said however. If penetration describes the intensity of light after passing a barrier, then please describe that barrier very specifically. The barrier penetration is the part I don't understand in what you're saying.

In your previous post, you said something about not meaning light passing through a leaf. I would agree. The intensity of light that has passed through a mature leaf would be so diminished that it really wouldn't count for much.

You also mentioned reflection. Given that a full canopy is presented that allows no direct light to pass through it, (unless a strong enough wind is provided to actually *move* the leaves), then reflection wouldn't take place, again, unless I'm misunderstanding what you're saying.

If you could give me a very specific example of light penetration, it would help me understand.

Thanks again!

Stoney