Defoliation Trial - 4 Clones
- Thread starter Hobbes
- Start date
cindysid
Well-Known Member
I'm planning my first scrog, first LED flower grow for this Spring. I know that defoliation will be absolutely necessary for airflow. I hope it also improves my yield.
Nizza
Well-Known Member
Frontiers | The Influence of Apical and Basal Defoliation on the Canopy Structure and Biochemical Composition of Vitis vinifera cv. Shiraz Grapes and Wine
Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit ...
www.frontiersin.org
cindysid
Well-Known Member
Very interesting article! How interesting that removing apical growth reduced alcohol concentration in the end product! Basal defoliation seems much more effective at least for grapes.Frontiers | The Influence of Apical and Basal Defoliation on the Canopy Structure and Biochemical Composition of Vitis vinifera cv. Shiraz Grapes and Wine
Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit ...
Rurumo
Well-Known Member
Here is an interesting paper that talks about how soil microbes can induce systemic resistance and help regrow plant tissue in response to herbivorous insects. https://www.frontiersin.org/articles/10.3389/fpls.2017.01816/full
And this one gets into some good detail about ISR/SAR https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233886/
I've always noticed strong growth following some defoliation, so it makes sense to me that we're seeing the result of induced systemic resistance. The question is how much defoliation is optimal, and when should it be done? I have no idea, so I'm pretty conservative with it. It's a really interesting topic and I'm looking forward to your grow Hobbes.
Hobbes
Well-Known Member
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Thanks for the links Rurumo, I'll dive into them.
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I've still got 4 weeks of flower so the smell will probably grow even more, right now it's a floral-berry smell. The only strain that I had just a strong smell was Blue Dream, and that was all blueberry and no floral.
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"Her aroma and taste are sweet and fruity, sometimes a bit spicy, with a sugary aftertaste when smoked." - Serious Seeds.
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Thanks for the links Rurumo, I'll dive into them.
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I've still got 4 weeks of flower so the smell will probably grow even more, right now it's a floral-berry smell. The only strain that I had just a strong smell was Blue Dream, and that was all blueberry and no floral.
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"Her aroma and taste are sweet and fruity, sometimes a bit spicy, with a sugary aftertaste when smoked." - Serious Seeds.
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Serious Happiness Strain ® Originally Bred by Serious Seeds
Two legends were crossed to produce the Serious Happiness strain. We combined our famous Warlock-father with our legendary AK-47-mother and the result gave us
www.seriousseeds.com
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Samwell Seed Well
Well-Known Member
Nice!
Samwell Seed Well
Well-Known Member
lots of benefits to removing leaves and eliciting a atypical hormone response as well as , a boost of growth from internal production of auxins.
most people are lazy, or they defoliate too often, has to be timed to arrest growth only right after to promote another
Hobbes
Well-Known Member
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I found this through a google search, the author makes a good point that I haven't considered.
It takes energy to keep a leaf alive.
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"That's where defoliation comes in; by removing some of this excess foliage, not only do you free up some of your plant's energy (by reducing the amount of foliage it needs to keep alive), but you help your plant make better use of its limited light source. "
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"Does defoliation increase yields?
Pruning, or defoliation, is a technique that keeps your cannabis plants healthy and growing properly. By removing small amounts of foliage during various phases of the life cycle, growers can increase a crop's yield and potency by allowing light to hit bud-producing nodes more directly."
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"How can this be? Why would the plant make leaves if it doesn’t need them?
Outdoors, cannabis plants need extra leaves to store nutrients and create an extra wall of defense in case the plant gets attacked by pests or otherwise loses all its leaves. But indoors there should be no pests, and you are there to give your plants the exact nutrients it wants at the exact right time. This makes holding onto leaves a lot less useful for the plant, especially some plants which get extremely bushy without defoliation."
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"Cannabis isn’t the only plant that benefits from defoliation
To those naysayers who claim defoliation can NEVER work, I think it’s important to point out that cannabis isn’t the only plant that rewards growers with bigger yields and higher quality from defoliation. Some commercial crops, such as cotton, need to be defoliated during their grow to produce the best yields and quality of cotton. In fact, even after 40 years of intense study on cotton defoliation, there is still controversy and ongoing research by commercial crop producers to further pinpoint the exact time and way to defoliate cotton plants in the field to produce the best results."
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"Proponents of defoliation generally cite higher yields as a benefit of defoliation, and it is this particular claim that is most in contention.
Opponents often invoke reduced photosynthetic activity as their reason against defoliation. The argument goes: more light, more leaves, more energy, more nutrient reserves, more yield.
Opponents are correct in their belief that photosynthetic activity is generally reduced by medium to heavy defoliation. Experiments involving defoliation and its effect on yield in many diverse plants have shown a consistent, causal link between defoliation and reduced yield in field-grown plants (outdoors.) This decrease is attributed to plant stress and decreased photosynthetic activity.
An exception in which yields increase is when the leaves removed have begun to senesce and have become sinks on the plant, rather than sources.
Typically, these older, larger fan leaves have lost efficiency with age. Opponents of defoliation often use the solar panel analogy. More and bigger solar panels mean more food for the plant. However, just as solar panels from 10 years ago are less efficient than those produced more recently, leaves also lose efficiency as they age. Leaves can begin to require more energy to stay alive than they produce. At this point, they are energy sinks, just as buds are. Unfortunately, buds as sinks produce a desired product; leaves do not. So at this point for the leaf, it is ALWAYS beneficial to remove them."
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Beyond Yield : Release of Volatiles as a Defense against Herbivory
"Terpenes are present in varying degrees in many healthy plants. However, when plants are damaged or defoliated through herbivory, particularly from insects and mites, the levels of terpenes and other volatiles are substantially increased in response to the damage.
This increase in volatile production, including terpenes, is most often used as a signal to repel pest insects, or more commonly, to attract the enemies of pest insects.
This effect appears to be systemic, meaning; infestation on an individual branch will elicit terpene production in distal, undamaged branches. "
.
.
.
I found this through a google search, the author makes a good point that I haven't considered.
It takes energy to keep a leaf alive.
.
"That's where defoliation comes in; by removing some of this excess foliage, not only do you free up some of your plant's energy (by reducing the amount of foliage it needs to keep alive), but you help your plant make better use of its limited light source. "
.
.
.
"Does defoliation increase yields?
Pruning, or defoliation, is a technique that keeps your cannabis plants healthy and growing properly. By removing small amounts of foliage during various phases of the life cycle, growers can increase a crop's yield and potency by allowing light to hit bud-producing nodes more directly."
.
.
.
"How can this be? Why would the plant make leaves if it doesn’t need them?
Outdoors, cannabis plants need extra leaves to store nutrients and create an extra wall of defense in case the plant gets attacked by pests or otherwise loses all its leaves. But indoors there should be no pests, and you are there to give your plants the exact nutrients it wants at the exact right time. This makes holding onto leaves a lot less useful for the plant, especially some plants which get extremely bushy without defoliation."
.
.
.
"Cannabis isn’t the only plant that benefits from defoliation
To those naysayers who claim defoliation can NEVER work, I think it’s important to point out that cannabis isn’t the only plant that rewards growers with bigger yields and higher quality from defoliation. Some commercial crops, such as cotton, need to be defoliated during their grow to produce the best yields and quality of cotton. In fact, even after 40 years of intense study on cotton defoliation, there is still controversy and ongoing research by commercial crop producers to further pinpoint the exact time and way to defoliate cotton plants in the field to produce the best results."
.
.
.
"Proponents of defoliation generally cite higher yields as a benefit of defoliation, and it is this particular claim that is most in contention.
Opponents often invoke reduced photosynthetic activity as their reason against defoliation. The argument goes: more light, more leaves, more energy, more nutrient reserves, more yield.
Opponents are correct in their belief that photosynthetic activity is generally reduced by medium to heavy defoliation. Experiments involving defoliation and its effect on yield in many diverse plants have shown a consistent, causal link between defoliation and reduced yield in field-grown plants (outdoors.) This decrease is attributed to plant stress and decreased photosynthetic activity.
An exception in which yields increase is when the leaves removed have begun to senesce and have become sinks on the plant, rather than sources.
Typically, these older, larger fan leaves have lost efficiency with age. Opponents of defoliation often use the solar panel analogy. More and bigger solar panels mean more food for the plant. However, just as solar panels from 10 years ago are less efficient than those produced more recently, leaves also lose efficiency as they age. Leaves can begin to require more energy to stay alive than they produce. At this point, they are energy sinks, just as buds are. Unfortunately, buds as sinks produce a desired product; leaves do not. So at this point for the leaf, it is ALWAYS beneficial to remove them."
.
.
.
Beyond Yield : Release of Volatiles as a Defense against Herbivory
"Terpenes are present in varying degrees in many healthy plants. However, when plants are damaged or defoliated through herbivory, particularly from insects and mites, the levels of terpenes and other volatiles are substantially increased in response to the damage.
This increase in volatile production, including terpenes, is most often used as a signal to repel pest insects, or more commonly, to attract the enemies of pest insects.
This effect appears to be systemic, meaning; infestation on an individual branch will elicit terpene production in distal, undamaged branches. "
.
.
.
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Hobbes
Well-Known Member
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And one write up on the other side:
Defoliation: Myth vs Science
It may surprise you to hear, that there is a small but very dedicated group of cannabis farmers who are convinced they can increasing their crops by removing ALL the big leaves in the flower cycle. Believers in this myth call the technique Schwazzing.
If you're a Scientist, the same thing is called "Abscission Stress" and the data produced by this group generally shows that any stress in the flower cycle results in lost profits.
You might think that any technique claimed to make a significant difference in the production of Cannabis flowers would be important enough that it would be tested and proven with some real data. Hopefully this would be a University study with no financial gain from the data, but even a private study could be fine if it were done well and not just to promote some product.
So far.... NOTHING!
Real data on this issue - with cannabis - simply does not exist.
Both sides are absolutely adamant in their conviction about how correct they are, but no matter what either side "thinks" they know... neither one can prove it.
...
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Defoliation: Myth vs Science (linkedin.com)
.
And one write up on the other side:
Defoliation: Myth vs Science
It may surprise you to hear, that there is a small but very dedicated group of cannabis farmers who are convinced they can increasing their crops by removing ALL the big leaves in the flower cycle. Believers in this myth call the technique Schwazzing.
If you're a Scientist, the same thing is called "Abscission Stress" and the data produced by this group generally shows that any stress in the flower cycle results in lost profits.
You might think that any technique claimed to make a significant difference in the production of Cannabis flowers would be important enough that it would be tested and proven with some real data. Hopefully this would be a University study with no financial gain from the data, but even a private study could be fine if it were done well and not just to promote some product.
So far.... NOTHING!
Real data on this issue - with cannabis - simply does not exist.
Both sides are absolutely adamant in their conviction about how correct they are, but no matter what either side "thinks" they know... neither one can prove it.
...
.
Defoliation: Myth vs Science (linkedin.com)
.
Last edited:
Severed Tongue
Well-Known Member
So, I'm nearing 8 weeks of flowering, and majority of my main fans are damaged from spraying and subsequently showering a couple days later to clean off the residue and dead bugs.
Unfortunately I used my bathroom shower and it was too much and damaged all of them. I've left them on as they appear to still be doing their job, but have trimmed anything that might give way to infection.
At any rate, I've beat the bugs, but I'm wondering what would happen if I removed them all at this point?
Anyone have experience doing this at 8 weeks into flower?
Unfortunately I used my bathroom shower and it was too much and damaged all of them. I've left them on as they appear to still be doing their job, but have trimmed anything that might give way to infection.
At any rate, I've beat the bugs, but I'm wondering what would happen if I removed them all at this point?
Anyone have experience doing this at 8 weeks into flower?
keifcake
Well-Known Member
When first making the switch to led, proper light distance is a very important lesson I learned the hard way. I had mine too close at first, and started seeing deficiencies pop up that I was trying to treat, and after several weeks I finally started searching symptoms of too much light, and it appears the same as nutrient Def as it's slowly killing the plant.
Star Dog
Well-Known Member
Both sides are absolutely adamant in their conviction about how correct they are, but no matter what either side "thinks" they know... neither one can prove it.
This is why I like these sort of experiments/tests
I know this is primarily about yeild but I've an interest in the humidity changes, humidity is a expensive problem for me if the reduction in humidity through defoliation was sufficient any potential loss in yeild would be worth it to me for the peace of mind.
I've not seen below 90% this year.
This is why I like these sort of experiments/tests
I know this is primarily about yeild but I've an interest in the humidity changes, humidity is a expensive problem for me if the reduction in humidity through defoliation was sufficient any potential loss in yeild would be worth it to me for the peace of mind.
I've not seen below 90% this year.
Boatguy
Well-Known Member
Where do you find temps with humidity levels like that? Kinda horrifying.
In my area we see that kind of humidity mainly in the summer, like july and august. It sucks
Star Dog
Well-Known Member
That was actually during the night it got up to 8c today and the humidity down to 93% lol.
On the Scottish west coast the winds coming off the sea have soaked up lots of moisture from the gulf stream.
Boatguy
Well-Known Member
Yikes. Im in the northeast us.
After a summer of heat and humidity, we are greeted with cold temps and no humidity. Drying is easy here in the summer but growing is difficult, winter is the opposite.
cindysid
Well-Known Member
Yes, I will definitely need some guidance on that. Been growing with hps for years. Finally decided to try led.
cindysid
Well-Known Member
I'm certainly no expert but I would remove the biggest ones that aren't directly attached to buds. JMO
Star Dog
Well-Known Member
I know that with tomatoes there's a particular type of vigorous growing vegetation that needs removing for the benefit of the crop, I'm not a tomato grower but it's a known practice you can check out.