How hard should i defoliate? (pics inside)

I tried defoliating (fan leaf removing) from week 3 on some setups (vertical and horizontal) and sometimes week 5 and week 7-8.
Tried max defoliation (all fan leafs) on week 3 and got 30% average yield in that system (vertical system) and in the same time tried full defoliation on horizontal system and harvest is in 2 days but it looks promising (about 100% average yield)

So i tried few tings on different system with same genetics. In my experience and from now on I defoliate but only if its a overcrowded bush - I mean if 2 fan leafs overlap I remove one, and have a major defoliation(50-60%) in harvest time -2 weeks.

The_Enthusiast said:

I tried defoliating (fan leaf removing) from week 3 on some setups (vertical and horizontal) and sometimes week 5 and week 7-8.
Tried max defoliation (all fan leafs) on week 3 and got 30% average yield in that system (vertical system) and in the same time tried full defoliation on horizontal system and harvest is in 2 days but it looks promising (about 100% average yield)

So i tried few tings on different system with same genetics. In my experience and from now on I defoliate but only if its a overcrowded bush - I mean if 2 fan leafs overlap I remove one, and have a major defoliation(50-60%) in harvest time -2 weeks.

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I'll venture that you feel your getting a benefit at the last 2 weeks of bloom. Because it's the last two weeks of bloom - the bulking phase! The last 2 weeks is when the buds can put on as much as 40 to even 50% of their finished weight!

During that last two weeks, the plant is focusing on the buds and just about all nutrition is going to those bulking buds. The plant is still working all the way through but, it's working so hard that it's even taking "stored" nutrients from leaves to increase the efforts to build those buds and reproduce!

Your removing a nutrient source for bud expansion.....To lose 50-60% of the actual tools the plant use's to not only take from but, to create/convert nutrition,,,,,,sounds awful counter productive.

Don't you think?

In my experience, with hydroponics, nutrients are easily available for uptake so no need for that uptake from fan leafs. As far as sugar production in fan leafs, I'm still not sure if fan leafs produce sugars for whole plant or just stem, roots... etc.

It's my impression (nothing more) that buds, at the end at least, have better usage of new found light on them than from stored elements or sugars in fan leafs.

I'm familiar with outside (field) agronomics, olives, citrus trees and so on, and pruning of all of them. Some prefer 50% pruning each year, some only overlapping branches, some none.

I believe people defoliate backwards. Firstly let me say that removal of all the leaves is nonsense (at least that is my take), and even though a plant will grow back provided its roots were healthy, it would have done better with less defoliation.
New leaves don't produce the sugars that older healthy fan leaves do. IMO- The trick is to remove the top fans that are collecting most of the light and leave the larger ones underneath because they can produce more sugars.

Fan leaves also show deficiencies from mobile nutrients so why would you want to remove them? It is much harder to figure out a deficiency when all you have is new growth to go by.

The_Enthusiast said:

In my experience, with hydroponics, nutrients are easily available for uptake so no need for that uptake from fan leafs. As far as sugar production in fan leafs, I'm still not sure if fan leafs produce sugars for whole plant or just stem, roots... etc.

It's my impression (nothing more) that buds, at the end at least, have better usage of new found light on them than from stored elements or sugars in fan leafs.

I'm familiar with outside (field) agronomics, olives, citrus trees and so on, and pruning of all of them. Some prefer 50% pruning each year, some only overlapping branches, some none.

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Perennials - That's the tree's your talking about. You need to prune back to produce quality and quantity, every year after plant is established! This is true for grapes and most other perennial producers of "fruit"...

MJ is an annual! - The plant starts and ends in a single season.
Topping produces more "mains"....
Careful pruning opens airflow and removing "suckers" that would otherwise make final bud sizes smaller, helps!
Defoliation simple reduces the ability of the plant to manufacture/deliver necessary nutrition to get near plant potentials.

@NaturalFarmer Very interesting point of view!

I agree with you that single season vs "multi-year" crop isn't the same in therms of pruning and everything.

I never found good research on defoliation (nor the time nor percent made). In first few years I didn't defoliate, and I tried few timings and percentages of defoliation.
From that I learned as i said before defoliation only if its crowded (I am a SOG grower).
Buds are bigger if I defoliate for last two weeks (but again only those leafs that produce a lot of shade so 20-30%)

The_Enthusiast said:

I agree with you that single season vs "multi-year" crop isn't the same in therms of pruning and everything.

I never found good research on defoliation (nor the time nor percent made). In first few years I didn't defoliate, and I tried few timings and percentages of defoliation.
From that I learned as i said before defoliation only if its crowded (I am a SOG grower).
Buds are bigger if I defoliate for last two weeks (but again only those leafs that produce a lot of shade so 20-30%)

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So you aren't talking about full on defoliation, right? Just thinning or removing some leaves that you think might not be helping out?

The reason that the word defoliation causes such a stir around here is because when most people read "defoliate" we all automatic assume you mean taking all the leaves off. This is not beneficial to the plant at all and is why we(most) frown on it.

Again, I don't have any issues with light pruning/thinning or trimming and training.

I'm not a native speaker but verb "to defoliate" doesn't mean defoliate 100%?
I always thought that to defoliate is to remove fan leafs but in a percent that has to be specified.

I'm sorry If I misused the word defoliate

Gary Goodson said:

So you aren't talking about full on defoliation, right? Just thinning or removing some leaves that you think might not be helping out?

The reason that the word defoliation causes such a stir around here is because when most people read "defoliate" we all automatic assume you mean taking all the leaves off. This is not beneficial to the plant at all and is why we(most) frown on it.

Again, I don't have any issues with light pruning/thinning or trimming and training.

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LOL,

defoliated, defoliating. 1. to strip (a tree, bush, etc.) of leaves. 2. to destroy or cause widespread loss of leaves in (an area of jungle, forest, etc.), as by using chemical sprays or incendiary bombs, in order to deprive enemy troops or guerrilla forces of concealment.

The_Enthusiast said:

I agree with you that single season vs "multi-year" crop isn't the same in therms of pruning and everything.

I never found good research on defoliation (nor the time nor percent made). In first few years I didn't defoliate, and I tried few timings and percentages of defoliation.
From that I learned as i said before defoliation only if its crowded (I am a SOG grower).
Buds are bigger if I defoliate for last two weeks (but again only those leafs that produce a lot of shade so 20-30%)

Click to expand...

But then your right back to the last 2 weeks being WHEN the plant bulks up naturally!

I do remove some shading leaves.....Usually to allow light to covered bud sites. Not for the buds to gain any increase in size or yield but, to simply allow them to "ripen" evenly with the others. This is usually on rather "pure" or "classic" indica formation plants...