Pruning effects on yield?

[Greensleeves420]

I've heard opposing opinions on this topic so I'm looking for some understanding now.

Is direct light to a deep budsite more important than keeping fan leaves that may be blocking that light.

Some say take ALL the fan leaves off, some say leave as everything on, some say to Only prune fan leaves that cause significant shadow on budsites.

Some say that we feed it plenty of dood and dont need to nutes stored in the fans.

Whats the deal here?

 

[Nunyabiz]

This is one of those issues that you get strong opinions on both sides type things.
And it's like most things probably better somewhere in between.

Myself I always try to let everything go with the flow and do what's natural.
In the long run that's almost always best.

The plant uses leaves for photosynthesis and for storage of mobile nutrients.
The more light reaching as many healthy leaves as possible equals more exudates for the microbes and food for the plant.
The more the leaves transpire the more the roots suck up nutrients.

I do very mild defoliation, I lollipop but not like a Brazilian wax, I just get rid of most everything beneath the SCROG because it's of no real use and is just an energy sink.
After that, usually starting around flower I will move budsites, tuck leaves, and then after careful consideration if a leaf is just plain blocking too much light from a lower bud then I will remove it.
I remove just a few down low if I can open up airflow.
But I try to leave as many as possible.
There is some evidence that if done correctly at exactly the right time you can possibly get slightly better yield.
But the probability of over stressing the plant to hermaphrodite is greater than the possibility of increased yield.

So i skirt the boundry, I strip only energy sinks that recieve little or no light and gives nothing to the plant, only takes energy.
Then only snip just enough for airflow and light to reach lower buds.

That probably ever so slightly increases yields without the added stress and problems that could arise from over doing it.
And I assume by prune you mean defoliate, pruning is more like topping.

 

[LiberalThinker]

Take your pick and find out yourself OR research science papers OR Eenie-Menie-Minie any of the forthcoming opinions here. Strictly, removing fan leaves is not pruning. Pruning is cutting a stem

 

[MochaBud]

I defoliate about 20 days into flower but only upper most fans and only about 15 - 20 at a time this keeps the plant from stressing and opens bud sites to more light then about 40-50 days in (depending on strain) I defoliate again to open more bud sites ...Just my 2 cents

 

[Metal Halide]

I'd only defoliate if everything else is maxed out and you want another 10-15% yields or put in under lighting for similar results and without the stress. Defoliating is def for more experienced growers. I do it heaps, like every few days at around 2-5% with one big chop just before transition. but i have no other stressors going when I do it and i don't do it much during the stretch phase cause i light stress instead.

 

[Jackalope]

Way too much involved to say one way or the other. Some strains will do fine with little defoliating. Others really need to be opened up.

I usually try and super crop and bend my sativas. Hybrids and indicas are a toss up. Indicas and single stalk type strains I usually top.

Still pheno to pheno it is hard to guess. I have topped a lot of plants that took weeks to form 2 good branches. These plants would have been better left untopped. Lower branching will give you a hint as of what to do.

 

[Weaselcracker]

It is possible for buds to develop with less light. It’s not as simple as x amount of light causes x amount of ripening- just because a bud is partially shaded doesn’t mean it won’t do well.
I usually always strip everything lower on the plant. Under a scrog screen I strip everything below the screen. The plants usually grow back some small buds at the nodes all up the stem. If I leave the plant to ripen fully, at harvest these little buds way down in the dark will be very much ripe.

 

[Jackalope]

Now there are also low light strains. I only use 1000 HPS so I never get to notice it much but it is out there. I do have a strain that does better in the back row than it does right under the light.

It is only a guess but I think it is more prevalent in Autoflower strains.

 

[LiberalThinker]

Now there are also low light strains. I only use 1000 HPS so I never get to notice it much but it is out there. I do have a strain that does better in the back row than it does right under the light.

It is only a guess but I think it is more prevalent in Autoflower strains.

That will be the Ruderalis genetics that confers that property as well as the lack of photoperiod,.

 

[safeman]

bottom line: light to bud sites is the task - in veg like to do a"heavy" defoliation week 4 - one day before 12/12 switch (remove fans that cover buds sites) then in week 4 of flower remove fan leaves - the plant has time to recover (grow new leaves) form this if done in week 4 - then 3 days before harvest remove ALL fan leaves ( the plant doesn't need them anymore + it will help the plant dry out)

 

[bobrown14]

This is one of those issues that you get strong opinions on both sides type things.

Only with regard to cannabis.

There's some science about what fan leaves function is. It's a lot more than Chlorophyll and sugars. A lot more.

All you have to do is ask yourself, how does my plant get nutrients from the soil?
That big fan leaf is far away from the soil, how could it have an effect?

Water climbs up the plants vascular system, it has to transpire. The more leaf surface the more transpiration and the more nutrients with water climbing up the vascular system to the flowers. Plants grow.

Easy - run 2 clones side by side same everything, trim fan leaves off one, leave the other untouched.

Now that wood be a real science experiment if there where say 50 or 100 pairs and data being kept.

Trim your fans, then when you're ready;

flush those dang roots.

Should improve something. You might feel better for a few hours.

 

[Nunyabiz]

Only with regard to cannabis.

There's some science about what fan leaves function is. It's a lot more than Chlorophyll and sugars. A lot more.

All you have to do is ask yourself, how does my plant get nutrients from the soil?
That big fan leaf is far away from the soil, how could it have an effect?

Water climbs up the plants vascular system, it has to transpire. The more leaf surface the more transpiration and the more nutrients with water climbing up the vascular system to the flowers. Plants grow.

Easy - run 2 clones side by side same everything, trim fan leaves off one, leave the other untouched.

Now that wood be a real science experiment if there where say 50 or 100 pairs and data being kept.

Trim your fans, then when you're ready;

flush those dang roots.

Should improve something. You might feel better for a few hours.

Which is exactly why I keep as many leaves as possible.

 

[Weaselcracker]

They’re actually called ‘leaves’
not ‘removes’
or prunes...

like... duh

 

[No Pain]

I've heard opposing opinions on this topic so I'm looking for some understanding now.

Is direct light to a deep budsite more important than keeping fan leaves that may be blocking that light.

Some say take ALL the fan leaves off, some say leave as everything on, some say to Only prune fan leaves that cause significant shadow on budsites.

Some say that we feed it plenty of dood and dont need to nutes stored in the fans.

Whats the deal here?

The deal here is that everyone has an opinion and method they feel comfortable with and have developed. Its a lot like when to harvest, its a preference .

Now the name of the game is flowers. We all want them and plenty of them . not only that but we want them fat and heavy!
Direct light to a budsite will provide for a more developed ,tighter , firmer (you get the idea) flower.

I have done all the above , left them alone , partial removal and complete strip of fan leaves @day 20 of 12/12 and then again much later ( there are also differing opinions of time frames for people that do this). As mentioned previous there are other factors at play here . Strain, lighting , grow medium and environment all must be considered in my opinion .
Now I will state before I begin that I have only used the full strip method once with all other factor accept strain being equal and so far the results are impressive I have far more denser top shelf flowers (grade A) throughout the lower 2 feet of my canopy than I ever have ( I do a scrog style grow in rdwc) . I will also tell you that I felt the same as others that have posted here in regards to stripping fan leaves( strip as little as possible) prior to trying it and when I did it I still had concern as it was aggressive and the plants looked naked. But I did it to see the results , as the only way to see if something is going to work is to try it. Yes I felt like I was risking my yield but I was willing to put that on the line for the knowledge I would gain . The way I look at things is "I will find success through my failures.").

Now Prior to doing anything like this you must have your feed and environment dialed in , I say that simply because if you are not providing your plants with the very best environment to grow in you cannot expect good results removing items that are there to protect plants in a not so pristine environment.

Other factors that would influence the outcome are your lights and grow medium of choice as well as type of grow trained versus untrained. soil versus hydro ..one of the things that hydro is known for is its faster growth rates when compared to soil and with faster growth rates comes quicker recovery times from any stressor. So I cannot state that someone growing the same strain with the same environmental conditions and using the same training style would see the same results as me .

Lighting ..now that's a whole sperate topic as there are so many different ones being used . But the short end of lighting in this scenario is if you are using lighting that only gives you good penetration for solid flower formation for the first foot of the plant/canopy stripping leaf's is not going to change that and you would see more benefit from running a scrog as penetration and flower formation was a reason that someone came up with it . Now if you are using a light source that gives you good flower formation up to two feet I would say this method would be beneficial regardless of growing the plant in its natural form or training it .

Training verses untrained .. As stated prior its all about the light penetration ..facts a scrog style grow with give you a greater about of fully formed denser flowers than letting it grow naturally as you are increasing the surface area of the plant .

Strains ..they also could play a factor as I have only done this with one strain but I feel that there may be some that would not preform as well using this method just as some strains do not respond well to training and are better left alone . I can tell you that I will be utilizing this method in my next grow which will be a different strain .

so the reason that you see opinions as well as results all over the map are due to the amount of variables . I would suggest if you have the space as I am fortunate to have . Is to think a grow out . meaning what strain you want to run next ( if you run a single type each grow) and do a test run with it while you are growing out your current grow . If you grow in Hydro you could grow that plant in coco and test it as coco will provide you with close to if not identical results as long as the other environmental factors are equal .

here are a couple of pictures before,after and resulting flowers of my test child in coco that is about three weeks ahead on my main room . The strip picture looks like I was trying to kill it and to be honest it scared me . But for the knowledge the risk needed to be taken .
hope all of this aids you in one way or another , On with the pictures!!

 

[bobrown14]

The deal here is that everyone has an opinion and method they feel comfortable with and have developed. Its a lot like when to harvest, its a preference .

Now the name of the game is flowers. We all want them and plenty of them . not only that but we want them fat and heavy!
Direct light to a budsite will provide for a more developed ,tighter , firmer (you get the idea) flower.

My post was not opinion.

There is VERY LITTLE chlorophyll in a cannabis flower so what do you think direct sunlight is doing to the flower to make danky'er nugs?

Sunlight makes chlorophyll make sugars for the plant use as energy. Flowers function is sexual and for the production of seed. Sugars are needed for the seed production.

Leaves ftw!

"Plants make food in their leaves. The leaves contain a pigment called chlorophyll, which colors the leaves green. Chlorophyll can make food the plant can use from carbon dioxide, water, nutrients, and energy from sunlight. This process is called photosynthesis.

During the process of photosynthesis, plants release oxygen into the air. People and animals need oxygen to breathe."





Its actually been tested that the 2nd bud down from the top bud has the most and highest tested THC content. This is actually a little trick the breeders found out about when they get their flowers tested.

The lower down nugs are more potent.

It's has something to do with the trichomes and senescence.

You scrog for yields.

"The name of the game" for me is quality. One path to quality is genetics.


Here's a macro pic of the top with the lower nugs - you can see there are more trichomes down LOWER and not as many on the top.

Here's a few examples what I'm talking about.

DSC_0008 (2).JPG

• bobrown14
• Jun 24, 2019
• 1

Jellium #4

DSC_0009 (4).JPG

• bobrown14
• Jun 24, 2019

Jellium #4 - close up

DSC_0006.JPG

• bobrown14
• May 28, 2019

Jellium

DSC_0006 (3).JPG

• bobrown14
• May 28, 2019

Jellium

 

[Rucifer999]

I recently trimmed during flower to see how that affected my girls. Again it all comes down to the strain(s). Some will react positive some will not. I try not to trim fan leaves my belief is if she doesn't want certain leaves alive after awhile they will fall off easily when I tug on them slightly.

Been doing this for years now now problems my girls are always happy. When you tuck the leaves also after awhile they will die off.

 

[No Pain]

My post was not opinion.

There is VERY LITTLE chlorophyll in a cannabis flower so what do you think direct sunlight is doing to the flower to make danky'er nugs?

Sunlight makes chlorophyll make sugars for the plant use as energy. Flowers function is sexual and for the production of seed. Sugars are needed for the seed production.

Leaves ftw!

"Plants make food in their leaves. The leaves contain a pigment called chlorophyll, which colors the leaves green. Chlorophyll can make food the plant can use from carbon dioxide, water, nutrients, and energy from sunlight. This process is called photosynthesis.

During the process of photosynthesis, plants release oxygen into the air. People and animals need oxygen to breathe."





Its actually been tested that the 2nd bud down from the top bud has the most and highest tested THC content. This is actually a little trick the breeders found out about when they get their flowers tested.

The lower down nugs are more potent.

It's has something to do with the trichomes and senescence.

You scrog for yields.

"The name of the game" for me is quality. One path to quality is genetics.


Here's a macro pic of the top with the lower nugs - you can see there are more trichomes down LOWER and not as many on the top.

Here's a few examples what I'm talking about.

DSC_0008 (2).JPG

• bobrown14
• Jun 24, 2019
• 1

Jellium #4

DSC_0009 (4).JPG

• bobrown14
• Jun 24, 2019

Jellium #4 - close up

DSC_0006.JPG

• bobrown14
• May 28, 2019

Jellium

DSC_0006 (3).JPG

• bobrown14
• May 28, 2019

Jellium

You never heard (read) me state that leafs didn't have a function and that's what your prior post talks about .

My entire post was about my experience with not defoliating , defoliating and extreme defoliation as well as training and my opinion on why some peoples experiences may vary and gave my opinion as to why .

In regards to scrogging or any training for that matter is all about maximizing the quantity of quality top shelf flowers .You make an assumption and imply that I'm not after quality and well you are wrong.

Those are some beautiful flowers you posted . How deep are they into the canopy/plant . A picture of them plus a picture of the entire plant would have been most helpful for the question that was asked in this thread. They do not seem to be buried under fan leaves as the background shows a very open plant structure. In my opinion it would have also been helpful to the original poster if you stated what kind of lighting you are using .

Lastly I ask you , Have you ever done timed extreme defoliation ? If you fully absorbed what I stated it was that I was very hesitant to do so and it had to do with certain beliefs . If in fact you yourself have never tried it then you cannot argue that it doesn't function nor that it doesn't produce quality flowers .

In regards to flower formation I explained what I have witnessed in regards to flower formation and the density of those flowers by defoliation and at no time did I make any reference to potency.

So in the end if you are going to specifically direct something to me as if I singled you out . Please make sure that you have read my entire post and absorbed what I was stating and if you feel that somewhere in there that I am calling you out or specifically talking to or about you . By all means pull me to the mat as I do not mind and do not have to be right . But know that when I type a page on questions of this nature that I am speaking from my experience and not literature or theory . If its theory /opinion or literature I am man enough to state/imply that if you reread my prior post you will understand that.

If you made it this far I would like to thank you for your time and look forward to your feedback .

 

[Barney86]

I think wether defol makes a difference or not depends largely on wether or not you train them.
Christmas tree growers don't need to do a lot because the plant is growing naturally so things should be in the right place.
If you're training them things aren't in the right place so you need to defol in order to properly develop the plant.

I trim my plants all the way through veg and bloom, even autos.
I'm little and often as apposed to all at once though. Clean things up a bit once or twice a week. Tie things down or supercrop them as and when required to try and keep things even.
Raise the lights or lower them to stretch or fill out after a training session depending on what needs done.
I just go with it and do what looks best.
If I do wee 1-2oz autos on the sidelines I barely touch them. Centre stage plants get hit harder.

 

[bobrown14]

You never heard (read) me state that leafs didn't have a function and that's what your prior post talks about .


In regards to scrogging or any training for that matter is all about maximizing the quantity of quality top shelf flowers .You make an assumption and imply that I'm not after quality and well you are wrong.

Those are some beautiful flowers you posted . How deep are they into the canopy/plant . A picture of them plus a picture of the entire plant would have been most helpful for the question that was asked in this thread. They do not seem to be buried under fan leaves as the background shows a very open plant structure. In my opinion it would have also been helpful to the original poster if you stated what kind of lighting you are using .

Lastly I ask you , Have you ever done timed extreme defoliation?

Thanks for the complement on the flowers. I just grow them naturally. So it's the genetics that make them grow like that. I like a longer inter-node spacing because I'm not a huge fan of trimming.

I didn't make any assumption of your growing practice. I Just stated that you "scrog for yields". That's all I said. If thats not true so be it. All good.

Those plants VVV are taller than me so +6'. They yield about 5-7 zips dried in the can per plant. They are cookies variants so they are bred for the inter-nodal spacing. Maybe that wasn't intentional but I like it.

You wont find me doing any defoliation.

I haven't flown around the world either, doesn't mean I don't know its round.

There are many functions that leaves perform. Including growth triggering based on lighting, transpiration, food production, defense of pests, sinks and sources of sugars for flower and seed production.

The important functions are Photosynthesis and also Transpiration along with floral induction.

These 3 are huge.

Floral induction is the leaves synthesize and translocate the flower-inducing hormone called florigen to trigger flower formation.

Also if plants are getting far-red lighting (shade lighting), they have the ability to trigger the plant to grow larger. Think about a plant in the shade, why does it grow taller to get to the light? That's the leaves communicating with the apical meristem (main shoot) to release growth hormones to grow taller plants to get more light.

The OP asked about pruning affecting yields and I'm going with a scientific answer and say it will negatively affect yields.

There's a fact that there are very small amounts of chlorophyll in flowers so taking away the leaves that produce the food for the plants to make flowers is counter productive.

I'm not telling you to not do it, I'm just saying that it's not productive. The cannabis growing paradigm is the only area of botany that I've seen this "phenomena" argued.

Lots of folks like to touch there plants. The plants look to you as a pest and defoliation and general touching is stressful.

Much like a ruminant (deer) animal chewing on its leaves. There's a stress reaction from the plant. The plants have the ability to make themselves taste bad, that's just one reaction. They also have the ability thru the use Pheromones that communicate to other plants that there are pests
(hoo-mans or deer or bugs) close by and then all the plants taste bad. Might even have the ability to make people sick or allergic, no studies yet in on that one but I've seen sneezing start along with watery eyes be a thing when tugging on fan leaves on many occasions (not me).

If a cannabis plant is left to grow naturally, the fan leaves will eventually fall off on their own accord. We won't need to help that happen. This is not an opinion.

Full sized plant pic - finish times are 40-45 days of 12/12 lighting:

DSC_0014 (2).JPG

• bobrown14
• May 22, 2019
• family picture

Family Picture

 

[No Pain]

Thanks for the complement on the flowers. I just grow them naturally. So it's the genetics that make them grow like that. I like a longer inter-node spacing because I'm not a huge fan of trimming.

I didn't make any assumption of your growing practice. I Just stated that you "scrog for yields". That's all I said. If thats not true so be it. All good.

Those plants VVV are taller than me so +6'. They yield about 5-7 zips dried in the can per plant. They are cookies variants so they are bred for the inter-nodal spacing. Maybe that wasn't intentional but I like it.

You wont find me doing any defoliation.

I haven't flown around the world either, doesn't mean I don't know its round.

There are many functions that leaves perform. Including growth triggering based on lighting, transpiration, food production, defense of pests, sinks and sources of sugars for flower and seed production.

The important functions are Photosynthesis and also Transpiration along with floral induction.

These 3 are huge.

Floral induction is the leaves synthesize and translocate the flower-inducing hormone called florigen to trigger flower formation.

Also if plants are getting far-red lighting (shade lighting), they have the ability to trigger the plant to grow larger. Think about a plant in the shade, why does it grow taller to get to the light? That's the leaves communicating with the apical meristem (main shoot) to release growth hormones to grow taller plants to get more light.

The OP asked about pruning affecting yields and I'm going with a scientific answer and say it will negatively affect yields.

There's a fact that there are very small amounts of chlorophyll in flowers so taking away the leaves that produce the food for the plants to make flowers is counter productive.

I'm not telling you to not do it, I'm just saying that it's not productive. The cannabis growing paradigm is the only area of botany that I've seen this "phenomena" argued.

Lots of folks like to touch there plants. The plants look to you as a pest and defoliation and general touching is stressful.

Much like a ruminant (deer) animal chewing on its leaves. There's a stress reaction from the plant. The plants have the ability to make themselves taste bad, that's just one reaction. They also have the ability thru the use Pheromones that communicate to other plants that there are pests
(hoo-mans or deer or bugs) close by and then all the plants taste bad. Might even have the ability to make people sick or allergic, no studies yet in on that one but I've seen sneezing start along with watery eyes be a thing when tugging on fan leaves on many occasions (not me).

If a cannabis plant is left to grow naturally, the fan leaves will eventually fall off on their own accord. We won't need to help that happen. This is not an opinion.

Full sized plant pic - finish times are 40-45 days of 12/12 lighting:

DSC_0014 (2).JPG

• bobrown14
• May 22, 2019
• family picture

Family Picture

You are welcome for the compliment . The plants look nice and have a very open structure and they really aren't leafy at all .

In regards to science and the cannabis plant and its defensive mechanism . Its actually why timed defoliation works , now I can't say and I wont speculate on whether it would work on your strain as it already looks defoliated and that's natural growth and why I also stated that I felt it was strain dependent .

with my strain and in my situation I can personaly and honestly say that the science is wrong in defoliation having a negative outcome . Now im not saying that the science is wrong in every situation as looking at your plants structure I would lean to it being dead on as even with the extreme defoliation mine are still more leafy and closed as compared to yours and that's genetics .

to me defoliation has its place and its up to the grower to understand how it could affect them in a positive manner as well as a negative . In the end the grower is the judge and the jury as to whether it is preformed and its best to make an informed decision than not to . Unfortunately there has been no scientific studies using pure sativas, pure indicas as well as their crosses that lean to a sativa dominant and indica dominant and comparing the data of defoliation and natural growth that I am aware of .

Until then we are the study and the comparison, you bring information and knowledge from one side of the spectrum and I bring it from another . The biggest difference between us both is that I now use defoliation when I never used to because of science. Simply because I had super dense plants , if I where to have always had open structured plants such as yours I probably wouldn't have even looked into defoliation .

so in ending . Nice Grow and Happy Growing .