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can anyone exsplain why/how defoling increases yeilds?

I think the general idea is that by defoliating you expose more bud sites to light, which in turn induces them to grow. More buds that grow = higher yields.

The trick is not to go crazy on the defoliation; too much defoliation can stress out a plant, increasing chances for problems as a result.
 
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How I see it


There's a couple of principles at work with Defol. and it matters if it's the main training scheme or an added one.

Defol in a way simulates nature where non-lethal damage invigorates the plant making it stronger and growing.

As I see it, the real purpose of Defol is to make a 3d canopy rather than a flat one. The idea being that with the air and light that the lower bud sites get exposed to will become grade A/B buds rather than larf. With the plant open like that you also reduce the chance for mold.

I would expect that it also acts as a semi-pest prevention measure as in an aggressive Defol program leaves aren't left long enough to become colonized. That's just a guess, but seems reasonable to me.

It seems like a good way to manage vertical grow space since you can add the room below the canopy normally lollipoped or barren because of light not penetrating.
 
I have looked into the physiology of it, read all the studys and any other information on the subject. It appears the only process to have any involvement is nutrient translocation. The stress induced by the removal of leaves could induce the movement of nutrients from one location to another. However controlled studys show such manipulation to barely make a difference and most plant species show a negative impact with more than 30 percent removal. Also i have seen no controlled side by side showing an improvement. In fact i can recall one person who attempted a comparison only to find that neither plant was any different.

Theres also the possibility for the removal of older leaves to have an impact, however this would be specific defoliation and not the traditional method.

I am very interested in finding more information on this but currently its an unproven method for me and holds no scientific structure.
 
I think a comparison is actually going on now on the forums, between light and heavy Defol, and IIRC that seems the consensus, little difference
 
Could you provide that for me ?. I guess the heavy defoliation to give negative yeilds and light would give practically zero difference.
 
There are 3 things that buds need to gain weight;

Light

Wind

Nutrients


By removing the leaves the block either light or a breeze the bud recognizes the conditions needed to get a pollen particle, thus will grow larger in attempting to make a seed. There is also less plant matter to soak up nutrients as well, leaves are nutrient tanks to protect the plant through drought and to provide for the buds when nutrients are scant.

Thus enters the gardener who recognized this ingenious way to ensure the nutes you put in go straight to the buds and the buds know to use them to try to make seeds for the next generation.

Although we all know an unpollenated plant just makes buds!
 
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Thanks for that, its a shame he didnt have a control. He also appears to mix up the pictures ?. He refers to light and heavy defol but i swear what he calls the heavy defol, has more leaves lol.

Anycase thanks.
 
I have a hard time telling the 2 apart myself, but it's a good one to watch :)

Defol is an accepted and tested ag. technique. There's little to suggest it wouldn't work for cannabis. If one applies it correctly it makes for awesome full lawns, lol. Research suggests that defoliation increases below-ground mycorrhiza, not just in activity but that seedlings next to adults that get defoliated have better establishment than those not near defoliated adults. Again not cannabis, but there is a lot of studies that show it is beneficial, at least to some plants.
 
Also, defoliation is usually in conjuction with breaking the apical dominance and creating many main colas of equal size- rather than one large cola-
You get many colas, with greater overall weight/denisty as they tend to be the same distance to the light
Not all strains defoliate well.
It's still a controversial subject, but once you get good results- it's very hard to not defoliate plants( in some form or another)
 
What you are suggesting i have seen before but does not correlate to produce and yeild but reproduction and germination. As far as among horticulture studies, i have read many on defoliation effect on many species of plants. Tomatoes, maize, corn, tammarillos, flowers etc. They all show similar key traits and show no evidence of substantial increase in yeild. Although a select few show increase yeilds with <30% defoliation, the gain is sub 2% and within a margin of error.
Theres also the study on cotton which is often referred to with such topics, but none actually read the study which talks about the timing of defoliation and its application with mechanical harvesting and how it improves the efficiency. The increase in yeild is not from biological yeild but from improved harvesting efficiency.

I still would like some controlled comparisons in our own species but people insist on trying it on its own and using highly subjective opinions to conclude their results. Of the very few comparisons i have seen (only one i could ever find) it showed no improvement but instead a decreased response.
 
Although environmental stimuli influences behavior characteristics, these are mostly minimal. Sexual expression is brought on by photoperiodism and genetics, without these the initiation process cannot start. As the development of sexual expression continues, it depends on basic principles of growth from generic materials provided by the plants photosynthesis process. As the flower acts like a true "sink" it will initially use most nutrients provided to develop its flowers.
Light, carbon dioxide and minerals are the requirements for plant development processes. Exposing the flower has very little impact as the leaves have very little photosynthetic capacity compared to the more mature leaves.
 
I personaly havnt seen much of a difference with defoling so thats why I ask the only difference iv seen is maybe 0.5-1 more of a gram per bud if bud sites are clear of leaves and with some strains I havnt noticed anything so I wounder how it actualy works
 
The only variable i see is the sun, i cannot work out why this would be different however. I will think on it.
 
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