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Lets discuss purposeful defoliation


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Lets discuss  defoliation

Sure we all trim off the odd leaf here and there however some folks trim much more and earlier than others.

 

I was discussing this exact topic with a newbie med grower of mine who seems to be fairly averse to doing so especially in the canopy of the garden.  I however take a more hands on approach with most of my vegetable and flowering crops both indoor and out. Personally I  remove many leaves that I feel interfere with fruit or bud sites in the way of shading. In fact I am much more likely to cut (or simply pinch) off leaves that basically get in the way.

 

(please be aware that I have been growing vegetables and flowers for literally as long as I can remember (one of my first jobs ever was selling seed packs door to door for like 1 or 2 cents each at like 7 or 8 years old.) And though admittedly not any sort of "horticultural expert" I do seems to possess the proverbial "green thumb"

 

IN an effort to increase the learning curve of all of us med growers, rec growers or simply gardeners in general  I would like to open the forum by fist asking a general question.

 

That is: how many , in what way, in what area, and for what purpose do you trim otherwise health leaves off your plantings and more pointedly during the mid to late flowering phase?

 

Thanks in advance

 

GS

 

 

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Yop,

 

Well to start off if you'd like to see some passed insight we had one little topic on Def once, http://forums.strainhunters.com/topic/3682-defoliation-a-new-supercropping-technique/?hl=defoliation

Always worth haveing a look ;)

 

And as far as personal experience, i didnt go as far as making a total defoliation like shown in some photos, but i do like you trim many leaves that i consider are blocking the light or flowers, or whatever if they are in the way. I usually wait for at least 4th week of flower to do this, when the flower sites are all formed and developped and starting to pump up on the width, then i look where it could need a cleaning, and i clean.

 

Cheers

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it has been tested all around the globe, look and you shall find.   there is huge amount of evidence you are getting much slower growth, spend more time and get smaller buds in the end with defoliation

 

i have yet to find any side by side grow that  did not show slow retarded plants,   that defoliating field study link is also not showing anything only slow vegging plants in dwc, it doesnt even have the flowering period or side by side control plants

 

its not some hypothesis its bases on thousands of years of experience and scientific research,   the laws of thermodynamics

 

leaf collects light the light energy that allows the plant to make lots of buds    you take leafs away you take bud building energy away  its the laws of physics and thermodynamics not magic

 

leaf cannot block light from plant its there to to take the light for use doh,  i understand that big monster plant might need some trimming on the center parts to get airflow in but never canopy leaf to expose budsite... that is ridiculous faith/religious based thinking and does not make any kind of sense

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all you need to do is grab any book ever written on plants on the last century and look up photosynthesis to see explanation, tho you might need to have some basic scientific terms in your vocabulary to understand but its fairly simple concept and easy to test too with control plants..

 

you know when people make claims that are totally against the way it has been known to work for centuries its your responsibility to provide the evidence of the hypothesis you claim, you are claiming the fiction so you need to give proof not me.

 

you prob have side by side control plant test aswell?  right

e83cyb.png

 

can you find any that show opposite result:) i cant

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I've never been all that keen on stripping leaves for the pure and simple fact that the leaves are what gathers the suns energy. Ive grown indoors for a number ofyears and only strip aaway the bottom of the plant for a bit better air circulation. 

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First off no need for this to get combative so lets sit back smoke a nice bowl maybe have some granola . I understand how we people are when discussing something we are passionate about.

 

secondly I was simply asking for opinions and clarification. you offered a plausible one and I simply asked for critical scientific evidence which of course is de rigueur for this sort of query. and I agree photo evidence although not scientific in nature but more anecdotal does provide some means for comparison. And for that I thank you

 

case in point in the bottom left picture below the fellows hand on the branch at say 4 o-clock there appears to be several small stumps.

  To Me they look remarkably similar to what remains after leaves are taken off.

 

 why are the flowers near the stem at bottom of the plant smaller ? it couldn't be that these guys get less light .... could it?

wouldn't the fan leaves produce enough energy to produce huge buds down there as well? obviously they have access to huge amounts of nutrients being right on the main stem? So Why, if not for lack of light, do these flower sites go underdeveloped?

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PS I dont mean to be a Dick (as we say in the US) but this is kinda of what I expected to see from other than opinion posts, which by the way are totally appreciated as well and I feel are very valid given the villification of MJ over the last 6 or so decades and the experiential nature of most development in the crop type.

 

here is a paper (Abstract included below)  describing natural and manual defoliation and its effects ...

 

http://www.academia.edu/5755478/Effect_of_defoliation_on_growth_reproductive_characters_and_yield_in_mungbean_Vigna_radiata_L._Wilczek_

 

Abstract

"Loss of foliage in mungbean [Vigna radiata (L.) Wilczek] crop through leaf eating insects and diseases is common in tropical and sub-tropical countries where farmers do not protect their crops adequately. Experiments were carried out with eight levels of defoliation (0, 25, 50 and 75% either from top or from base of the canopy, and 100%) to investigate the growth, reproductive characters, and yield attributes in two high and two low yielding mungbean genotypes. Results revealed that degrees of defoliation  parallely decreased leaf area and total dry matter (TDM) production irrespective of seasons and genotypes. Defoliation not only reduced source sizes but also decreased total sink (flower) production resulting in lower pod and seed yields. However, basal 25% defoliation did not significantly decrease TDM and seed yield plant -1 indicating the fact that the mungbean plant, in general, can tolerate 25% basal leaf loss of the canopy. Furthermore, the high yielding genotypes showed higher compensatory mechanism of source loss than the low yielders. Exceeding this threshold limit (> 25%) either from the base or from the top of the canopy defoliation significantly reduced TDM and seed yield. Reduction in yield was higher with top defoliation than basal defoliation. Implication of the results in relation to pest management is also discussed."

 

You may wish to pay strict attention to figure 3 with shows a slight increase in raceme - (aceme (/reɪˈsiːm/ or /rəˈsiːm/) is an unbranched, indeterminate type of inflorescence bearing pedicellate flowers — flowers having short floral stalks called pedicels — along its axis. In botany, axis means a shoot, in this case one bearing the flowers.)

Furthermore "In the current investigation basal 25% defoliation showed superiority in seed yield compared to the other treatments  Because of TDM, greater number of opened Flowers and increased pod and seed sites. This could be argued in a way that basal leaves are aged, photosynthetically weaker and may act as a burden and compete for assimilate with growing pods (sink) while most of the assimilate transport to the pods when absence of lower leaves (basal defoliation). "
Here is a copy of one of the studies cited in the above paper http://www.idosi.org/wjas/wjas6%284%29/17.pdf
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''In the current investigation basal 25% defoliation showed superiority in seed yield compared to the other treatments'' other treatments meaning other % defoliated plants not the control plant that was untreated    notice treated and untreated

 

the figure 4 clearly shows it, they dont talk about control when saying that 25% was superior to other treated plants, gotta be sharp with the words or it can mislead

gallery_24245_1541_11849.jpg

 

''You may wish to pay strict attention to figure 3 with shows a slight increase in raceme''   

 

yes but notice how all of the plants that are showing the increased raceme in fig 3 are showing great negative impact in figure 4&5 that has pod count and seed counts(more important than flower count) the ones that show increased raceme great number of flowers failed to make pod  and ended up having huge yield loss, you didnt post conclusion either

 

gallery_24245_1541_15678.jpg

also it is good to post parameters and conclusion so we know how it was done so there wont be no misleading information

gallery_24245_1541_57255.jpg

 

yeah lower shady part defoliation may or may not be beneficial in some mungbean varietys but there is no clear conclusion on the test with control and -25% foliage test the change is small as you can see, and at higher % very very negative and im seeing people do much more here than 25% from lower nodes, they take all fan leafs...

 

we must also remember that plant size, its normal foliage ''tightness'', light power, indoor vs outdoor, fast or slow crop, veg time and many many other things can and will effect the end result

 

when we look at the results with cannabis they seem to be stunned every time in my opinion from what i have seen, slower veg if done at veg so you spend more time growing it(im rarely vegging over month and get huge plants look at them), and less bud in flower if done during flower as it seem to start to replace lost leafs with new ones on top and you seem to end up with leafier buds and less bud overall than without defol,  or that is my perceived experience how the leaf/bud structure goes to worse

 

the test shows pretty clear that its just extra work for mungbean workers

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Thank you so much for your input.

 

Yes !!

Sso My conclusion given this information would be no more than 25% defoliation and limited to the lower 1/2 of the plant. which seems natural and common sense that we wouldn't want to cut more than 25% of the foliage out (which is a lot in my opinion)

 

the pending question would have to do with leaves shading bud sites near the canopy or upper 1/2 of of the plant. (or otherwize non diseased and not pertaining to training or cropping)

 

hopefully with the beginning of decriminalization and the end of vilification in the US and other parts of the world we will have the opportunity to see (if not participate in) critical studies done in unbiased environments that will definitively answer these questions on a per specie and strain basis.

 

And Thank goodness mungbean trimmers simply love their labor and the fruits thereof. :crazy:

 

what I would also like to see is more on the other side of the coin. ( you know answer the questions and then question the answers.)

 

now obviously the fellow who's post Dust provided to us is convinced his methodology works wonders.

 

In as much I feel it would be beneficial to hear for these folks as well.

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''so My conclusion given this information would be no more than 25% defoliation and limited to the lower 1/2 of the plant''

 

well if you look at it proper its more like no more than 0% because the 25% didnt have any positive impact so there would be no reason to do it infact the 25% seems to be buffer protection for it, a back up 25% if you will. best would be to not veg too big or tall plant for indoor in first place so there is no need for extreme trimming measures.  like the study said you can loose upto 25% to insects without having major impact in yield so its like a safety buffer for the plant

 

what if you take the 25% and end up loosing another 10% to nute def or something else, than you are immidietly over limit with mungbean, yes  still mungbean not cannabis:)

 

in another scenario you keep all leafs and loose lets say 25% during flowering/fruiting but still end up only with minor loss if any in yield becouse it had those extra leafs to save the day!

 

that being said i end up having to trim some lower nodes and leafs aswell with some strains just becouse they grow so bushy or if i dont have room to put in flower soon enough to avoid most popcorn buds but its usually no where near the 25%, and i always feel bad doing it:/ i try to flower them so small there is no extra growth or leaf and they always get big during the first half of flower

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  • 4 months later...

Ok we went with about a 20-25% defoliation limited to the lower branches and sparse defoliation of giant leaves among the upper and we have been producing nicely. there has been some dried up leaves and premature branches among the lower which were also taken off and our bud production seems more than satisfactory. our subjects are by no means compact with the sativa hybrids topping over 60 inches from soil to top of plant and indica's running about 32-36"

 

this is by no means a critical study but this level of defoliation seems to be by no  means overly detrimental to the plant.

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