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the importance of leaves and why not to remove them

importance of leaves defoliation fan leaf removal

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#1 duke

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Posted 13 October 2015 - 12:02 PM

hi all i lifted this thread from elsewhere written by our good friend and comrade grub and thought after reading a few diaries some guidance was helpful so i hope it makes clear the importance of leaves,

icon1.png The Importance Of Leaves.

There seems to be a lot of confusion when it comes to the leaves on your plants, hopefully this brief guide will show how important leavesare and the job that they do...

Like most plants, Cannabis grows leaves from the moment it appears from the soil, the leaves have a vital job...

Photosynthesis - Simply explained, photosynthesis is the process by which plants and few other organisms use to transform light energy into chemical energy.
Plants get their green color from the chlorophyll found inside the leaf cells, plants use this chlorophyll to collect the energy from the sun rays to create the food they need.

Photosynthesis.jpg



The Leaf - If you were to examine a leaf from your plant under a microscope you will see many tiny cells and holes (see below), these allow for light and (CO2) to be absorbed from the environment. Through the process of photosynthesis this light is then converted into sugars and various other compounds which then travels down the leaf stem and feeds the plant. 

stomata.jpg

So in summary...
Leaves are essential for the well-being of your plant. It's the leaves that take in the light, NOT the buds.... If you remove the leaves you are restricting the photosynthesis process and basically slowing down the growth and affecting the health of the plant also science has proven that plants use light not visible to the human eye so that bud shaded by a fan leaf is getting plenty of light because it passes through the fan leaf,its just not visible to a human eye,so DO NOT think removing fan leafs will boost  On the defol thing. Like many here i imagine , i have done them every which way , My own opinion now is that they do NEED the fans attached to the budsites to avoid the sugar leaves wasting energy doing a job they were not designed to do. They can convert but not at anywhere near the rate that a fan leaf does it at. By removing them , the plant then wastes time and energy re-jigging her larder. In my experience , if you strip them right back in veg , the leaves get replaced by identicle ones anyway if still in veg. it does seem pointless with this being the case and time spent increasing her size and potential bud sites is used to put the same leaf sets back on her stems again. I think airflow is paramount among the whole plants structure , particularly as they are wind reliant plant. Direct light on the buds is not the key at all , they have very little ability to convert light there and take their "food " from the stem directly so the tiny sugar leaves are boosters within the bud not the workhorses as fans are. It is also about energy benefits and sinks too and gets very technical at this point and i had to force myself to re read the info a fair bit to conceed that my hopes on defoliation were a little unrealistic. Tucking when needed is a better option if airflow is active. Have a search for "shwazzing" ( i think i spelt it correct) for another mind set on using defol too. very interesting concept but spot the foolish book price it comes from .

They need the fans.l


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#2 duke

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Posted 14 October 2015 - 11:14 AM

this is interesting particularly the last bit about late fertilisation being used to hasten finish,i realise they are talking outdoor but i see no reason it shouldnt work indoors see what you reckon http://www.theweedbl...wering-process/


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#3 duke

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Posted 14 November 2015 - 02:05 PM

hi all i found this article informative and even more reason to cherish every leaf and not pointleslly remove a valuable asset from our grows,peace One of the most important aspects of plant growth is photosynthesis. It’s something that all plants do and it effectively involves taking the available light and transforming it into energy. That’s really the basic definition of photosynthesis, but it goes a lot further than that. The plants receive light through various pigments on their exterior. Chlorophyll is the most abundant pigment in cannabis and most other green plants and so it is largely responsible for bringing in light energy.

In that way, cannabis leaves almost work like solar panels by extending the area that the plant can take in light. More leaves essentially represent more power producers because you have more energy entering into the plant. When the energy is taken into the plant, it is stored in chemical compounds like adenosine-triphosphate (ATP) and nicotinamide-adenine-dinucleotide-phosphate (NADPH2). These are compounds that are built to transfer energy throughout the plant. ATP is integral in the creation of carbohydrates and NADPH2 is integral in the synthesis of carbohydrates.

Of course, the plants need to work with something in order to create these carbohydrates. The name alone lets you know that carbohydrates have some mixture of carbon and hydrogen. In marijuana plants, they get those both of those elements from carbon dioxide (CO2) and water (H2O). Obviously, CO2 is found in the atmosphere and water is generally provided by the grower (or other means in a natural environment). Want to know more about growing marijuana? Get a free guide about growing marijuana at this link here.

Plants can absorb CO2 from the atmosphere or from the soil. Water is, of course, absorbed through the roots and transferred into the plant itself. So, the light energy (in the form of ATP and NADPH2) comes together with CO2 and H2O to create carbohydrates (CH2O). As a result of this transaction, there is a spare O2 molecule that gets released into the air. Marijuana absorbs and utilizes all of the items required for photosynthesis and then releases oxygen into the atmosphere.

Once the carbohydrates have been created, they are utilized as food energy and “building material” for the plant. One of the things that carbohydrates create is a sugar called glucose (CH2O)6, which is essentially a string of 6 carbohydrate molecules. Glucose is then strung together itself to create cellulose which then accounts for about 4/5 of the plant cell structure. Cellulose is one of the most important and prevalent organic compounds on the planet, and its creation in the marijuana plant is due in large part because of photosynthesis.

Carbon dioxide is a naturally-occurring gas, but you can add more CO2 if you’re growing in a grow room. Most air has a concentration of about .03% carbon dioxide which perfectly safe for you to breathe and great for your plants. But, marijuana plants can actually handle about .15% carbon dioxide in the atmosphere. Having a higher concentration of CO2 correlates to more growth in the plant. More light will also produce more growth. This is obviously because of the way photosynthesis works. If you are consistently providing light energy and CO2 to the plant, it will respond by making more carbohydrates and eventually more cellulose (among other compounds).

It should also be noted that the same can’t be said about water. Unless you’re using a hydroponic system, a constant stream of water will act as a deluge that will drown the roots. That is to say, adding extra water won’t produce bigger plants; it will just weaken them (and maybe even kill them). While water is a necessary component to the life of the plant, you should never overuse it. This is largely because the roots also need oxygen to “breathe.” If you drown the plant in water and don’t let the soil create natural holes for oxygen infusion, then you will start to notice a severely enervated plant.

 


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#4 duke

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Posted 14 November 2015 - 02:22 PM

and also this one by ed rosenthal 

HOW DO FAN LEAVES FUNCTION

The large fan leaves have a definite function in the growth and development of cannabis. Large leaves serve as photosynthetic factories for the production of sugars and other necessary growth substances. Most cannabis plants begin to lose their larger leaves when they enter the flowering stage and this trend continues on until senescence (death of the plant).

Fan leaves account for the greatest area for the reception of photons on a plant, thus they account for the majority of photosynthesis which occurs within a plant. Cells in the plant’s leaves, called chloroplasts, contain a green pigment called chlorophyll which interacts with sunlight to split the water in the plant into its basic components. Leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through-- but they reflect all the green light, which means it looks darker below the leaf to a human than it does to the plant because our eyes are most sensitive to the green spectrum (Shipperke, 03.15.2002).

Photosynthesis occurs in all green parts of plants. The process has two stages, the light reactions and the Calvin cycle, that convert water and carbon dioxide into sugar and oxygen. These sugars are later used to power all the processes in the plant, including the synthesis of THC and other cannabinoids (Shipperke, 04.02.2002; Ca, 03.13.2002). Fan leaves possess the greatest number of stomata, which are small pores or valves on the underside of the leaf which water vapor and carbon dioxide diffuse during transpiration and photosynthesis (carbon fixation). Carbon dioxide first enters the leaf through the stomata and combines with the stored energy in the chloroplasts through a chemical reaction (the Calvin cycle) to produce a simple sugar. This sugar is unloaded into the tissues and transported through tubes in the leaf to supply the synthesized food to other plant parts such as growing or respiring tissues like young leaves, roots, and flowers of the plant. meristems (UK Tricky Knome, 03.14.2002).

Removal of fan leaves will not only slow growth, but it will also hinder the plants ability to rid itself of toxic gases, and also hinder the regulation of the plants temperature via stomata. Changes in the plants chemical metabolism caused by fan leave removal causes the plant to work overtime to rid ?toxins? with less leaves, as a result the pant may allocate more growth hormones into growing more leaves to make up for what has been lost(Equator, 03.15.2002). Removing large amounts of fan leaves may also interfere with the metabolic balance of the plant. Leaf removal may also cause sex reversal resulting from a metabolic imbalance.

There is a relationship regarding the amount of carbohydrates a leaf produces and CO2 intake relative to outside forces. When you have a situation whereby the leaf is no longer productive for the plant for whatever reason that may be - low light, old age, disease, insect attack etc, the plant will discard it. (Thunderbunny as citied, by Nietzsche, 03.13.2002.

Plants have two different kinds of vessels in their stems to move stuff around, xylem and phloem. Xylem runs from the roots up the stem carrying water and nutrients. Phloem runs both up and down to move sugars hormones, proteins, etc but mostly sugars. Each part of the plant can be either a sugar source or a sugar sink (Shipperke, 03.15.2002). Phloem moves from sources (areas of supply) to sinks (areas of metabolism or storage). Granted that the flowers can produce some photosynthate, but they are no where near as effective as fan leaves (resin glands significantly reduce light to the tissue they are found on). Flowers are sink tissues, leaves are source tissues. Sinks do not produce enough photosynthate, and are importers. Sources give photosynthate to sinks in closest proximity. Upper leaves bring sucrose to shoot apical meristem and young leaves while lower leaves bring goodies to roots (UK Tricky Knome, 03.17.2002). Remove the source and the sink will be affected (Diels Alder, 03.15.2002).

The leaves at the top of a plant tend to supply the top growing shoots. The leaves at the bottom of the plant tend to supply the roots. The middle leaves can go either way as the demand changes. During flowering and fruiting, only the very bottom leaves supply the roots and the rest of the leaves try to get as much energy as possible to the flowers of fruits. For this reason, the more leaves are unshaded and in good light, the more chance the plant has of creating extra storage of energy that will ultimately go into yield (Leaf, 03.13.2002). However Jeast (03.13.02) believes that the rich green leaves emerging from the bud are a sufficient energy source of solar energy for the plant’s floral development. Therefore the old fan leaves are once again rendered useless and only drain energy from the developing part of the plant (Jeast, 03.13.02).

Fan leaves store mobile nutrients, these stored nutrients are essential in the later stages of flowering. When flushing a plant the fan leaves will lose their color quickly. This is because the nutrients are being mobilized to the atypical meristem (grow tip, bud site). Draining your fan leaves with a flushing period will increase floral development (Ca, 13.03.2002). Fan leaves therefore serve as a nutrient deficiency buffer zone for the plant (Higstar, 03.13.2002).

Nutrient burn usually causes bottom leaves begin to die however DaGnome (03.15.2002) observed that if you do not remove the leaves then they will absorb damage as premature removal generally results in more leaf loss. However if growing hydroponically under ideal conditions it could be argued that fan leaves serve as a nutrient buffer is a moot point.

WHEN AND WHAT TO TRIM IF AT ALL

To trim or not to trim that is the question. Try everything for yourself. Try it all ways. (The Crazy Composer, 13.03.2002). Simply put there is no universal answer it depends on how your are growing when where and what you trim (Cardboardbill, 03.13.2002)

Genetic Variance

Cannabis phenotypes play a large part. A strain with very few leaves and long internodes will need a lot less trimming - if a trimming technique is even adopted. A strain with a surplus of leaves and short internodes would require more thinning to get the same amount of light to the lower buds (The Crazy Composer, 13.03.2002). Cannabis varieties from high sunshine equatorial areas like thai sativa have thin leaves most likely due to more light than say a indicia plant from afghan regions have wider fan leaves due to less light intensity in their natural environment (Lebman, 03.20.2002).

Remove non productive ?dead? leaf material

Here are some signs to look for when removing foliage. Leaves that have reached their final size and are ageing will stop producing chlorophyll and start changing to a lighter color, often yellowing and showing purple petioles (leaf stems). This is when the leaves’ capacity to produce sugars starts to diminish, so they are the ones to take out of the way to allow Sunlight to fall on the younger leaves that are producing at a higher rate. The older leaves, even though larger, are no longer very productive once they are not dark green anymore. By the time they start looking pale or discolored, they are not contributing anything to the plant at all. Obviously, the lower leaves are the oldest and the first to age. Old leaves can be removed at any time they are shading younger ones, but try to never remove a leaf in its expanding stage because it is producing at full power (Leaf, 03.13.2002.

Outdoors, fan leaves serve an additional and very important purpose of protecting the buds from the elements and predators. These leaves often become damaged in the course of doing their duty, and will then wither or break off (Jeast, 03.13.02). However depending on the humidity of the growing climate Leaf (03.13.2002) suggests to trim most leaves that show signs of age, are dull in color, yellowing, and obviously any brown or spotted leaves that have bugs or bug damage to prevent mould.

To Increase Lower Bud Development

Light efficiency decreases with distance. The inverse squared light rule states that illuminance is inversely proportionate to the square of the distance from the light source.

Removing the largest area of photosynthesis that is closest to the light source simply to benefit smaller leaves growing out of the but sites that are further away is not logical when growing indoors”(Smokinrav, 03.15.2002). Cultivating outdoors under the sun, the fan leaves don’t create nearly as much shade as they do indoors (~shabang~, 03.13.2002). This is consistent with the inverse squared light rule; the sun is 149,597,890 km away so a few feet has no real effect on intensity. This suggests that a trimming benefit could be achieved outdoors as opposed to indoors however leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through except for green light which is reflected, therefore removal of fan leaves would only provide a 15% increase light transmission outdoors (Shipperke, 03.15.2002).

Jeast (03.12.2002) removes fan leaves that are yellowing or starting to yellow (these are usually on the lower stems) and also mid-stem fan leaves that are shading buds. He always try to retain the upper 2 - 3 sets of fan leaves indoors as he believe they are the ones that are truly “working”. The concept of the upper fan leaves doing all the work is consistent with effect of the inverse square rule on lighting intensity indoors and the flow on effect for photosynthesis. In support for trimming HyGradeChronic (03.25.2002) states selective trimming benefits lower floral development, allowing the buds to fill out and tighten up better. However he does mention that humidity must be kept to a minimum as leftover stems from the leaf can develop mould unless kept at optimum humidity. Another flow on effect to leaf trimming mentioned by HydradeChronic is that it takes seven to ten days longer for floral development to finish, but the resulting florescence is at it?s peak from top to bottom.

An alternative to trimming to increase light to lower floral clusters is to use a light mover on a single plant the results are better thanks to the better penetration of light at different angles. Even simple under lighting and side lighting works well to counter fan leaves by adding extra light where it would not normally get (Vapour, 03/13.2002).

Increase upper bud development

What folks need to focus on is the causes of premature leaf drop as that negatively affects yields. If you’ve read my posts over the years, I try to pound that issue home whenever given a chance. After a good root development, the most important element in floral production is the retention of healthy leaves (Thunderbunny as citied, by Nietzsche, 03.13.2002).

Green Reaper (03.12.2002) suggests that large leaves actually take more energy to maintain than they produce. In contrast Thunderbunny (as citied, by Nietzsche, 03.13.2002) states that when a leaf no longer serves a productive purpose, the plant will remove the leftover metabolites from the leaf, which causes the old spotty, yellowing, necrotic image and then the leaf drops. Once that leaf is gone, a percentage of what would be available carbohydrates for future plant growth is diminished in direct relationship to the loss. The mobility of plants sugars and nutrients suggests that fully developed fan leaves are sources not sinks. Whether developing fan leaves are a sink or a source however is not as clear. An actively growing leaf may be a sink, using energy from the other parts of the plant to fuel their development (George, 03.20.2002). Older developed leaves and that are sources. However there is no evidence to support that during the plants life cycle the development of fan leaves takes more energy then a fully developed fan leave provides, that is to say sink phase is greater than the source phase (Nietzsche). It would also seem illogical from an evolutionary point of view that a plant would evolve to produce leaves that take more energy to sustain then they produce (~shabang~, 03.13.2002).

Trim fan leaves in the last 14 days to help speed up flushing

It helps speed up the flushing process and or makes flushing unnecessary (Homemadepot, 03.13.2002). However the leaves should naturally yellow, too much green in the leaves translates to too much “green” taste in the leaves in my opinion (Bigislandbud, 03.14.2002).

Reducing the Stretch

If trimming fan leaves reduced the stretch it is likely that this occurred because it takes away from the plant’s available energy stores and energy generators (~Shabang~, 03.13.2002). This method of reducing the stretch should only be used if absolutely necessary, other options include chemical treatment may be a more viable option.

HOW TO TRIM IF YOU CHOOSE TO DO SO

If you decide to trim your fan leaves, one should always do it by clipping the petiole about halfway between the base of the fan leaf and the stem/branch. Allow the remainder of the petiole to dry up and fall off on its own. This will help protect the plant from risks of infections. They should never be stripped or broken off at the base of the petiole as that would be expose more chance of infecting the plant. Petiole is the he foot stalk of a leaf (10k, 03.16.2002)

Leaf (03.13.2002) believes that excessive leaf trimming and branch pruning will cause the plant to use extra energy to repair itself. However, trimming must be done from time to time, for the longer a plant is left untrimmed, the more material must be removed at one time, therefore the greater the damage that the plant will need to repair. Do not trim fan leaves during veg either, unless they turn yellow. The first real pruning starts when going into 12/12 (Jeast, 03.13.2002). When trimming and pruning, I try to ensure that I do not cause the plant to ‘bleed’. Leaf tries to pinch off shoots and leaves with my fingernails as opposed to leaving a clean cut. One thing to remember is every time you cut into any part of a plant, you are exposing the inside of the plant to fungus and bacteria (Leaf, 03.13.2002).

Tuck instead of trimming

Another method is to tuck your fans leaves under to expose the buds, don’t forget that even though they wont be getting as much light they are still photosynthesizing and more importantly exchanging gases storing nutrients, and building sugars which the bud then converts into THC and other cannibinoids (Ca, 13.03.2002)

This Synopsis paper, is a consensus of opinions compiled in the Overgrow Growing Consensus forum. Compiled and written by Nietzsche, originally posted 4/20/2002. thanks to the author for sharing this knowledge,peace

 

Picture%20016.jpgshelf%20plant%20(1%20of%201).jpgRachaelIMG_3772.jpg

 


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#5 Nappa

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Posted 09 December 2015 - 11:48 PM

My mate done 4 defoliate do vs 4 normal and he said he'll never do it again.. My 2p


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#6 Mrs Willy

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Posted 10 December 2015 - 12:38 AM

I have defoliated and tbh yield is better with leaves on. Its the plants decision. Some strains loads of leaves fall off, others leaves stay on.

The only thing i have seen that still makes me think it is worth defoliating  is training/supercropping a plant and then defoliating in the middle under the light. The same principal as trimming the undersides of a scrog, supercropping, topping really. But the defoliation is to reduce the risk of budrot, and to encourage growth of upper budsites in veg/early flower. That works imho.

 

But if growing a naturalish plant (which is what i do these days) then let the plant decide when it sheds its leaves, especially once flower is in full swing. I pull em off when they are discoloured and not doing much. For me that is the signal to acknowledge that the plant will shed them itself soon enough.

 

They way i see it is that colas can grow in the shade.. most long colas have to. The bigger the leaves the more reluctant you should be of ripping them off as they feed the shaded colas.  Re arranging the plants regularly  to ensure the big leaves have the most light is an underrated approach imho. Thats where the underside cola bulk comes from.  All about leaf surface area exposure to the light.

 

I have never defoliated post week 3-4 flower as then it is pointless imho. I have often pulled off the crabby leaves post week 3-4 , but thats because the plant shows signs of not needing the leaves anymore.. by yellowing crisping up etc. Post week 3-4 flower, if the leaves are green in any scenario (scrog, natural etc) then leave em on until they reach a stage where they yellow and begin to look useless. That is the plant telling you "i dont need this anymore".. so yank em off..:) Otherwise leave em on until the plants shows you that they are not required.

 

:)


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#7 duke

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Posted 10 December 2015 - 12:23 PM

@Mrs Willy i been preaching leaf preservation all my growing life just about but i to went through the experimental defoil and probably every other madass idea a stoner can read/think of and all led me back to the same conclusion,leaves are good and we should treat them better and let them do there job without thinking that we no better than nature an affliction we be better without imo,peace


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#8 duke

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Posted 20 December 2015 - 09:44 PM

hi all if you happen to notice your post in this thread has gone i was trying to tidy it up and move some comments down to bottom and they vanished,somewere i no not where!but its tidier and all relevant bits at the top,peace


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#9 duke

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Posted 15 October 2016 - 10:56 AM

hi all after reading a few diarys around here lately i felt a bump for this thread was a good idea,love your leaves!!!!!!!!!!!!


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#10 DreDdYBoY

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Posted 15 October 2016 - 11:01 AM

hi all after reading a few diarys around here lately i felt a bump for this thread was a good idea,love your leaves!!!!!!!!!!!!


Hmmm you sure :D
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