Do cannabis plants really 'cannibalize' their own leaves?

[BII]

Much discussion has cited leaf "energy" levels and related light exposure/use. I presume "energy" is actually leaf glucose (and other sugars metabolizable to glucose) levels. [Or should we be talking about ATP?] And I presume, "energy" levels are a minor part of what's involved with leaf "cannibalizing."

To me, the added energy/glucose from upper or healthy leaves "cannibalizing" lower or lesser healthy leaves is not all that important, with healthy and top-most leaves likely already maxing out on glucose/energy levels. Rather the totality of all nutrients in the leaves, particularly mobile/soluble ones (which the plant put in time and energy to uptake and accumulate in the leaves), is more important. In this context, I am biased to keeping yellowing and lower leaves until they clearly turn yellow and lose a visible amount of fluid volume (start to dry up, shrivel).

I presume defoliation, removal of leaves, is different vs. the routine removal of small, wimpy stems/buds near ground level or otherwise low and heavily shaded.

 

[Delps8]

Much discussion has cited leaf "energy" levels and related light exposure/use. I presume "energy" is actually leaf glucose (and other sugars metabolizable to glucose) levels. [Or should we be talking about ATP?] And I presume, "energy" levels are a minor part of what's involved with leaf "cannibalizing."

To me, the added energy/glucose from upper or healthy leaves "cannibalizing" lower or lesser healthy leaves is not all that important, with healthy and top-most leaves likely already maxing out on glucose/energy levels. Rather the totality of all nutrients in the leaves, particularly mobile/soluble ones (which the plant put in time and energy to uptake and accumulate in the leaves), is more important. In this context, I am biased to keeping yellowing and lower leaves until they clearly turn yellow and lose a visible amount of fluid volume (start to dry up, shrivel).

I presume defoliation, removal of leaves, is different vs. the routine removal of small, wimpy stems/buds near ground level or otherwise low and heavily shaded.

Terms are applied loosely. The word "pistol" is often used instead of "stigma", for example. My last bio class was decades ago so, like everyone else who's a home grower, I need to refresh my knowledge regularly.

Per your opening para, "energy" is an analog for glucose being available and "the dark cycle" is taken to be when the grow light is off. I know ATP from distance running but I've never seen it on a cannabis site — that's pretty…in the weeds.

My approach to removing abscissing leaves is similar to yours. I leave it to the plant to make it very clear that leaves are no longer of value before I remove it.

 

[Delps8]

schwazzing/defoiling will be beneficial in the one or other way, So why not do it.

Can you point out any research to back up an assertion that schwazzing improves crop yield and/or crop quality?

The only research I've come across on the topic of which, if any, defoliation technique results in improved outcomes is here.

 

[kfigerm]

"

that schwazzing improves crop yield and/or crop quality?

" wasnt what I said...I said

schwazzing/defoiling will be beneficial in the one or other way, So why not do it.

bringing light (perhaps desinfecting uv) and air down/in is good to prevent mold etc.
I am sure i have seen some side by side videos linked here in the net and some papers somewhere...
Not in research mood atm. Perhaps go though the forums..i think there were some discussions already going on in the last months.

 

[Delps8]

" " wasnt what I said...I said

Understood and that's why I didn't reference your statement when I asked my question.

I'm trying to find hard evidence about schwazzing. It's completely counterintuitive to me which is one of the reasons why I find it interesting. I haven't come across any research about it in the two years that I've been at this so I'm thinking that if schwazzing is the cats meow, someone would have looked into it on a formal basis.

bringing light (perhaps desinfecting uv) and air down/in is good to prevent mold etc.
I am sure i have seen some side by side videos linked here in the net and some papers somewhere...
Not in research mood atm. Perhaps go though the forums..i think there were some discussions already going on in the last months.

If only…

I've been on four cannabis sites for >= two years now and haven't run into anything other than anecdotal evidence. :-(

If something "crops up", it would be great if you could post a link.

 

[kfigerm]

perhaps dig on @Born slippy , he has a thread all starting with the claim "we found out" and he tries out hard...perhaps he knows where to dig for science. I really know I have seen some side by side grow and some paper somewhere...

it's becoma a business man.
As a european it was funny to see what is going on in america...interesting jobs and courses...stumbled on that ...

Cannabis Education

Education can help you get the job you are looking for in the Cannabis Industry.

dol.ny.gov

still baffled ... thats serious...what courses would you chose?

Cheers!

 

[BII]

Have schwazzing proponents explained how it actually works? What plant mechanisms, physiology, etc. are involved? It seems we can consensually agree it yet lacks scientific proof of working as claimed, but are there any rational (established plant physiology-based) reasons proposed to support it? [Note, I admit not putting in time/effort myself to research schwazzing or its online promotion. I'm only asking questions here].

Is it's use for some, many or most users more of a cult thing, a belief, wishful/magical thinking, etc.? And/or is it more of a modern online social or viral conspiracy movement? Do more active proponents claim they know hidden secrets/truths, what's best, cite the "establishment" or conspiracies as working against their beliefs, etc.? Any of this involved?

 

[blue]

Have schwazzing proponents explained how it actually works? What plant mechanisms, physiology, etc. are involved? It seems we can consensually agree it yet lacks scientific proof of working as claimed, but are there any rational (established plant physiology-based) reasons proposed to support it? [Note, I admit not putting in time/effort myself to research schwazzing or its online promotion. I'm only asking questions here].

Is it's use for some, many or most users more of a cult thing, a belief, wishful/magical thinking, etc.? And/or is it more of a modern online social or viral conspiracy movement? Do more active proponents claim they know hidden secrets/truths, what's best, cite the "establishment" or conspiracies as working against their beliefs, etc.? Any of this involved?

I don't know ... I've seen it's been done for years - I first saw it on a strain hunnter video years and years ago.
It's been gaining popularity for the last 2 years (about the time i first heard of the word Schwazz ... which sounds a bit rude really lol)

No science yet, but the pudding looks tasty enough and could save one hell of an end trimming job (and a mold risk)

10 years ago, people would go crazy if you said you topped or defoliated your autoflower ... but not now!

I've got my eye on it, but since using an autopot (and having a few heavy foliage plants that ultimately caused a mold fest), i've been quite happy to strip leave where necessary (although i've never tried a schwazz either!)

Food for thought ^_^

 

[Waira]

For years I and others have referenced that when a cannabis plant is lacking nutrients in the soil, they will take nutrients from their existing leaves. I realized I have no idea where I got that information, and that while it seems on the surface to 'make sense', I have no idea if it's true. From a botanical standpoint, is this accurate? Or just Bro Science? I tried to do google searches on this and I can't find any information to back that up.

An alternative paradigm would be that the the fan leaves that change color and eventually die when a plant is lacking available soil based nutrients, are simply being abandoned by the plant. This would imply that the plant is able to prioritize where limited resources are distributed, and it focuses on it's reproductive imperative.

This is relevant in terms of defoliation techniques, because either (A) removing leaves removes a resource for the plant in terms of accessible stored nutrients, or (B) we are enabling the plant to direct its limited resources away from the leaves, which take a lot of energy to support, and 'helping' it focus its energy on the buds. Of course, it's entirely possible that neither of those scenarios represent how plants actually work, I really have no idea.

late, but the thread wandered off the topic a bit.... it's 100% fact, leaves (and other parts of the plant) can store certain nutrients (in various forms, some functional, like proteins/Nitrogen), but not like there are inert "deposits" of them laying around in cells. They are in a way cannibalized...
The caveat comes down to whether they are mobile (within the plant) or immobile (nearly so, like Ca or totally, like Fe)... This means immobile nutrients, once taken in initially and metabolized, cannot be translocated from "storage" to higher demand areas (growth tips mainly) where they are needed.
*(the now banned Stressed is wrong, he can do his own fucking research on something that's basically flat-Earth proven! gezzus, really??)

When diagnosing a troubled plant with suspect deficiencies, one tell-tale about what's lacking (why is a whole other ball of tangle string!) is where the symptoms are showing. Lowers--> mid level is usually a mobile nute; upper/tops are immobile nute defc.'s because that high demand zone can't be supplied by routing established nute elements from elsewhere to where it's needed more.
Ca can be a bitch to figure by this method; it often shows at mids as well as uppers, but not as strongly on tops as most of the micronutes do, the metal family mainly (Fe, Zn, Mn, Cu) but S shows on tops too, very similar to Fe symptoms.
I think in the case of Ca, it may be why I see some sources calling it "poorly mobile" while others call it fully immobile -

If you haven't visited the Infirmary section yet, have a look around in the Sticky section on top, and References too!
The Defc./toxicity Pic Depot, pg. 2 will have a lot of charts and graphs to help show the complexity behind finding out the WHY behind a defc.(s),... seldom is it a simple lack-of IME, and I ran that gig for 7 years before "retiring" (too much work/time anymore).... very often it's either a pH issue and/or what's called an antagonistic uptake issue, where too much of one nute ion screws with the uptake of another; even if enough if around, pH (changes chemistry and form of nute ion, rendering it unavailable) and antagonism can "lock" some nutes out....

 

[Cannaficionado]

They will if they are available and there is nothing for the roots to grab and move up. You'll see it a lot after flower especially if you only water the last couple weeks