Fan leafs- WTF is their purpose?

[TurboDog]

I know fan leafs store water and nutrients. But dose the plant use those nutrients right away from the leafs?

I was thinking maybe the leafs are storage tanks for nutrients and as it uptakes them to the leafs(storage tanks) the plant uses them as needed.

Or dose the plant grow and get its nutrients directly from the soil to form new growth, bringing the new nutrients to the storage tanks, and then to new growth, which would mean it dosent need the storage tanks of huge fan leafs?

Im trying to figure out if their need as much as we think their needed in indoor growing. I know they store food, but dose the plant not use food from good soil? or is the fan leaf the only area on the plant where it can get energy to form new growth?

FIgureing this out will greatly answer peoples statment of yes you need them because they store food....my question is, why dose it matter if they store it their if the plants getting the nutrients from the ground all the time in good soil, OR is the fan leafs the only source of food and energy for growth of new leafs/bud sites.

knowing microorganisms break down fallen leafs and matter in the forest into usable nutrients for plants, maybe the fan leafs by nature are "storage tanks" for the plant that may have to wait for microorganisms to break down nutrients for it, since it may be in lees that rich organic full of nutrient soil. Therefore needing to pull "energy and food" out of its "storage tanks" in between nutrient break down by microorganisms in the forst soil to supply the matter they consume into usable nutrients for the plant. which my question erlier about how the plant actuely uses nutrients for new growth because if its not directly from fan leafs, then it might render them obsolite for people growing cannabis in controlled conditions such as soil with all the nutrients the plant needs, along with water with good fertilizers. Im trying to figure out if these factors would render the fan leafs in effective in these situations.

 

[TurboDog]

so, my question remains tho, it can use its stored energy to make new roots and growth from a cutting, but talking about a established plant, if in good nutrient rich soil, dose new growth come from the nutrients in the soil, or is it pulled from the fan leafs. as in dose the soil nutreints make new growth or only the "food" in the fan leafs.....? if the fan leafs only purpose is storing food for later, then wouldent they be rendered usless if the roots were able to pull constant nutrients from the soil to form new growth and height....

 

[Madrus Rose]

hope some one has some good input by the morning....

Want to explore the world of trimming up plants , removing fan leaves & defoliating in general?

Try these guys over here on the Defoliation thread...Really, over 150 pages of "scholarly"
discussion on this very subject, lol
https://www.icmag.com/ic/showthread.php?t=174163

No rock or crevice left unstoned or unexplurred
on IC mag
lol



*hey Lola , u forgot to add that Fans can be used as pasties,
& fig leaves can be used for ....well u get the pic girl !

 

[vonforne]

This might help a little.

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.

 

[LoKey]

This might help a little.

well quoted was a good read for me, looking at the citations i presume it was originally from OG ?

 

[TurboDog]

great write up vonforne. heres a few thoughts

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.Fan leaves store mobile nutrients, these stored nutrients are essential in the later stages of flowering.

so I can assume, don't remove all fan leaves, remove teh bottom ones tho because they aid in root development. Im assuming you could remove them from bottom up till mid point of plant, starting this trend maybe 4 weeks into flowering, or 5-6 weeks so they can concentrate last bit of energy on floral development. i wish we could get a side by side comparison with half crop of allmost all fan leafs removed,and another half un touched.....just to see for sure.

 

[Mrpiston38]

hey bud, fan leafs start storing energy right off the bat. even if you use nutes while growing to help ur plant. the plant needs those leafs to help feed plant during photosynth. the only time that u should remove them is if ur doing a SOG OR SCROG type growning and even then its the lower leafs/branches that will not get light and casue potental pest issues. while in flowering the plant will pull all the nutes it can from leafs that chemical ferts do not offer. leaf them alone and ull do fine. (remember that the only time to remove leafs is either once there completly yellow or sick) have fun and i hope that this little bit of info helps.

NEVER REMEMOVE LEAFS DURING FLOWERING....... UR YEILD WILL BE AFFECTED.

 

[VerdantGreen]

OP you seem to be forgetting that fan leaves also manufacture energy from the sun/light and this is what allows our plants to grow. the plant tends to drop them when it doesnt need them anymore and it also then uses the energy/food stored in them for further growth. by removing them you not only reduce the plants ability to photosynthesis but also take away the stored food that can act as a buffer against deficiency.

when flowering they do sometimes get in the way of budsites and then its cool to remove the odd one. remove older ones first as they lose their photosynthetic efficiency - but if they are not causing a problem then i leave them be. why would be know better than the plant?

of course some people believe in removing vast amounts of leaves but i really fail to see how the possible gains from this could possibly outweigh the losses - but thats just me.

VG

 

[+Vibes]

we have a crazy relationship to the plant world... when we question the purpose of leaves...

 

[Greenstar420]

Fan leaves= solar panels

 

[homebrew420]

Leaf them alone! haha. They are the food pruduction sites of the plant. The only time I remove any leafs is when I see them crowding out flowers that will grow to a decent size.

Greenstar^^ is on to something there.

Peace

 

[darryl]

fan leaves serve a large purpose they aid in photosynthesis and when the plant is in final stages of flowering the leaves will turn yellow because the plant is using the last of its rescousces! a plants only a stick without leaves! lol

good question though no such thing as a dumb one you learned there for your question wasspot on!
keep growin and keep learning!

 

[VerdantGreen]

great write up vonforne. heres a few thoughts

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.Fan leaves store mobile nutrients, these stored nutrients are essential in the later stages of flowering.

so I can assume, don't remove all fan leaves, remove teh bottom ones tho because they aid in root development. Im assuming you could remove them from bottom up till mid point of plant, starting this trend maybe 4 weeks into flowering, or 5-6 weeks so they can concentrate last bit of energy on floral development. i wish we could get a side by side comparison with half crop of allmost all fan leafs removed,and another half un touched.....just to see for sure.

you seem determined to pull some leaves lol. why would you think the roots are unimportant? remember that a removed leaf will not be able to give it;s stored energy back to the plant. seriously if it's not in the way then leave it be. we dont need to be always intervening, doing something to our plants - its one of the best lessons you can learn.

now if you've run a cut a few times and feel you have maximised it's potential in every way - that may be the time to experiment with defoliation, not before. imo.

VG

 

[Madrus Rose]

you seem determined to pull some leaves lol. why would you think the roots are unimportant? remember that a removed leaf will not be able to give it;s stored energy back to the plant. seriously if it's not in the way then leave it be. we dont need to be always intervening, doing something to our plants - its one of the best lessons you can learn.

now if you've run a cut a few times and feel you have maximised it's potential in every way - that may be the time to experiment with defoliation, not before. imo.

VG

the link posted above to the defoliation thread has over 140 pages of agressive debates on the subject of leaf removal . My 2c over there was this below . Have seen the most consitently high quality growers always employ trimming up plants & deleafing so must ardently disagree. Removing lower leaves is work but well worth the effort , the plants can surely take this judicious pruning & produce more with less bottom flarf etc .
https://www.icmag.com/ic/showthread.php?p=3986140#post3986140

" my two cents is the best grows have seen done online always employed defoliating . There are those more experienced than I but who've consistently banged it out of the park in their rooms deleafing . And in every case taller plants ( og, sd etc) were denuded up the first 1/2 meter forcing growth to the tops while increasing airflow in & around the pot zone. Depending on strain Lst, scrog, sog & plus early initial topping results in a larfless high yielding , completely filled in canopy , within the parameters of the usable light/ lumen penetration.

The proof is in the pudding as u English say ! But for larger rooms this is quite an exercise but well worth the effort in every case , IMO .
""

end quote

 

[VerdantGreen]

the link posted above to the defoliation thread has over 140 pages of agressive debates on the subject of leaf removal . My 2c over there was this below . Have seen the most consitently high quality growers always employ trimming up plants & deleafing so must ardently disagree. Removing lower leaves is work but well worth the effort , the plants can surely take this judicious pruning & produce more with less bottom flarf etc .
https://www.icmag.com/ic/showthread.php?p=3986140#post3986140

" my two cents is the best grows have seen done online always employed defoliating . There are those more experienced than I but who've consistently banged it out of the park in their rooms deleafing . And in every case taller plants ( og, sd etc) were denuded up the first 1/2 meter forcing growth to the tops while increasing airflow in & around the pot zone. Depending on strain Lst, scrog, sog & plus early initial topping results in a larfless high yielding , completely filled in canopy , within the parameters of the usable light/ lumen penetration.

The proof is in the pudding as u English say ! But for larger rooms this is quite an exercise but well worth the effort in every case , IMO .
""

end quote

hi MR, of course you are entitled to your opinion, but i feel that a member who has to ask the question 'what are leafs for' is not ready to try defoliating. the OP neglects to mention that leaves are what allows the plant to make energy from light - a vital process for growing plants and life on earth in general

i would also add that the techniques you mention in your quote are not defoliation as described in the defoliation thread - which advocates removing pretty much all the leaves from a plant numerous times through veg and flower. you say that defoliation is 'well worth the effort in every case' but in the thread are many people that have actually tried it that wouldn't agree with you - even the staunch supporters of the method will say it's success is strain dependent and not for beginners.

if you check out some of my grow threads then you will see that i am no stranger to a 'completely filled in canopy' - and i dont remove leaves unless they are directly shading a budsite. even on the lower parts of the plant under the screen i prefer to leave the leaf as i find that the plant soon sucks the stored nutrients out of them and drops them of it's own accord - that is what the lower leaves are for.

cheers

VG

 

[TurboDog]

hi, thanks all for input. The thread title was stated like this to attract attention. I knew leafs stored nutrients, and i know they needed them to complete photosynthesis. I was wondering EXACTLY how they functioned so I could better understand if defoliating/trimming healthy leaf off would make sense from s scientific stand point. You guys gave good input tho.