Chowfarms
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Great job! What strain is that?
Thanks man! Strain is stardawg. Grew super short, tight, and bushy. Topped them once. They needed a HEAVY defoliantion or else they would have had no airflow whatsoever. First time running her so didn’t know what to expect, very pleased so far though. Also my first time running scrog. Didn’t do nearly enough training/defoliating in veg. That would have made the day 21 strip a lot easier. Cheers bro
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Thank you! I’d say no more than 20-25% TOPS. I usually feed on the higher side. This is my first coco grow and I’ve been keeping it under 1000ppm for the most part(following a buddies advice). I’m gonna check for deficiency symptoms tonight when they wake up! Never even considered that, but it all makes senseLooking good! I'm actually more than convinced defoliation when handled correctly is a great way to go. What percentage of leaves did you pull at day 21?
And have you increased nutrient strength more so than normal (when not defoliating) or do you normally run higher nutrient strengths? One issue I see with defoliation which is supported by several studies is that N availability is drastically reduced by pulling the leaves and root respiration and nutrient uptake is compromised because the plant directs energy away from the roots towards producing more foliage growth (reductions in root respiration and nutrient absorption following plant defoliation are proportional to the level of defoliation). Based on this, dependent on the level of defoliation you need to increase nutrient strength to offset the situation of reduced N and lower levels of uptake in general.
Excited to see!It really depends on the level of defoliation re nutrients. High levels > 30 % would definitely impact the nutrient status --- lower levels of defoliation lesser so. The main issue is N supply because the source leaves supply N. But also other nutrients would also be affected under heavy defoliation. Other than this energy is directed away from the roots and root respiration and nutrient uptake are impacted.
I'm writing on what scientific studies have found and will be sure to post it on this thread when done.
“Defoliations had significant effect on fruit yield per plant. Result revealed that fruit yield increased over control (zero leaves cut) up to 6 leaves defoliated plants and decreased thereafter significantly… The higher fruit yield was recorded in control (zero), 3 and 6 leaves defoliated plants (18 and 36% leaf loss of the total) and the highest fruit weight was recorded in 3 and 6 leaves defoliated plants (1.70 kg per plant).
In contrast, the lowest fruit yield was recorded in 12 leaves defoliated plants (1.19 kg per plant).
The result indicates that tomato plant can tolerant up to 6 leaves loss during flowering. The fruit yield per plant increased under 3 and 6 leaves defoliated plants was due to greater number of fruits per plant and larger fruit size compared to control.”[4]
[End Quote]
What this really tells us is that if defoliation is handled correctly, yield gains occur; however, if handled incorrectly the opposite is true. This really comes down to the percentage of leaf material that is removed from the plant.
It has been concluded that Leaf area distribution is an important determinant of rates of photosynthesis in the canopy. “When the leaf area index (LAI; leaf area per unit ground area) increases, photon flux density (PFD) captured by the canopy increases, leading to higher photosynthetic production in the canopy. However, when leaves at the bottom receive PFD that is lower than the compensation point of photosynthesis, further increase in LAI decreases canopy photosynthesis. There is an optimal LAI that maximizes rates of photosynthesis.”[5]
Therefore, at some point, too much canopy receiving too little light results in lower than optimal photosynthesis.
Iqbal et al (2012) note that: “the photosynthetic potential of lower leaves on a plant axis is less than that of the upper leaves. Thus, one aspect of crop improvement is to maintain a critical leaf number and leaf area for the greatest photosynthetic capacity and most efficient metabolism. The critical leaf number or leaf area may be maintained by the partial removal of leaves. The removal of leaves, partial or complete, has been defined as defoliation... It provides an opportunity for the photosynthetically active younger leaves to grow, efficiently utilize available water and mineral nutrients and influence source-sink relations. Defoliation (removal of leaves) influences growth and photosynthetic capacity of plants, remobilizes carbon and nitrogen reserves and accelerates sink metabolism, leading to improved source-sink relations. The response of plants to defoliation could be used to manipulate source-sink relations by removing lower and senescing leaves to obtain greatest photosynthetic capacity and efficient carbon and nitrogen metabolism under optimal and stressful environments.”[6]
On “source-sink relations”. Sources are plant organs such as leaves that produce sugars for photosynthesis. Sinks are plant organs such as roots, flowers and fruit that consume or store these sugars. In simple terms, sources produce sugars for sinks. Therefore, the source-sink relations relate to the areas of the plant that produce sugars and the areas of the plant that consume or store these sugars. The fact that leaves act as sources (i.e. they manufacture and provide the energy of/for photosynthesis) while fruit and flowers act as sinks (I.e. they consume and store the energy created by sources) is important to understand. Too little in the way of leaves (sources) can compromise the development of sinks (flowers and fruits). Therefore, while some careful defoliation may improve growth, too much defoliation will result in a lack of sources, typically resulting in reduced yields.
Another thing to be aware of is that studies have shown that root elongation essentially ceases within 24 hours after removal of approximately 50% or more of the shoot system and root mortality and decomposition may begin within 36-48 hours. Root respiration and nutrient acquisition are also reduced following defoliation, but to a lesser extent than root growth. Root respiration begins to decline within hours of defoliation and it may decrease substantially within 24 hours. In line with the reduction in root respiration following defoliation is a rapid reduction in nutrient absorption. Experiments conducted with perennial ryegrass growing in nutrient solution demonstrated that the rate of nitrate (NO3-) absorption began to decline within 30 minutes following removal of 70% of shoot biomass. NO3- absorption decreased to less than 40% of the pre-defoliation rate within 2 hours following defoliation. In these experiments, NO3- absorption continued to decline over the next 4-12 hours until it became negligible for 2 or 7 days before recovery began under high and low light intensities, respectively… Rapid reductions in root respiration and nutrient absorption following plant defoliation are proportional to the level of defoliation. [7]
Basically, following defoliation a plant focuses its energy towards regrowth in the canopy, while sacrificing what is occurring in the below ground parts of the plant (I.e. root growth, root respiration and nutrient absorption/uptake is compromised).
Other studies have concluded that defoliation alters biomass allocation and chemical defence through the carbon–nutrient balance at the plant and at the leaf level. Plant nitrogen concentration, a measure of the carbon–nutrient balance in the plant, significantly decreases immediately after defoliation because leaves have higher nitrogen concentrations than stems and roots.
This means that nutrient considerations need to be made when practicing aggressive defoliation techniques.
You’re perhaps starting to see how complex all of this is, which is why defoliation is a high-risk practice. Handled correctly it can improve yields; however, if handled incorrectly, yield losses can result.
[1] Mabry. C.M. and Wayne. P. W. Defoliation of the annual herb Abutilon theophrasti: mechanisms underlying reproductive compensation. Oecologia July 1997, Volume 111, Issue 2, pp 225-232
[2] Briske, David D., and James H. Richards. "Plant responses to defoliation: a physiological, morphological and demographic evaluation." Wildland plants: physiological ecology and developmental morphology. Society for Range Management, Denver, CO (1995): 635-710.
[3] Politud ER (2016) Effects of artificial defoliations on the growth and yield of okra (Abelmoschus esculentus (L.) Moench.) cv ‘Smooth Cayene’ under mid-elevation condition
[4] A.F.M. Saiful Islamet al (2016) Effect of Defoliation on Growth and Yield Response in Two Tomato (Solanum lycopersicum Mill.) Varieties
[5] Hikosaka. K. Leaf Canopy as a Dynamic System: Ecophysiology and Optimality in Leaf Turnover. Ann Bot 2005 Feb; 95(3): 521–533.
[6] Iqbal. N. Massod. A, and Khan. N. A. Analyzing the significance of defoliation in growth, photosynthetic compensation and source-sink relations. PHOTOSYNTHETICA 50 (2): 161-170, 2012
[7] Briske, D. and Richards, J. (1995) Plant responses to defoliation A physiological, morphological and demographic evaluation
Great info, thank you for sharing!Here's what I have written on the science side of things re defoliation and nutrients...
Many Growers believe leaves shouldn’t be pulled off plants based on the fact that leaves are the energy/light receptors and sugar production factories of photosynthesis and that by removing leaves growers could limit photosynthesis – the end result being less than optimum yields.
In truth, however, things are more complex than this and where plants are defoliated, compensatory photosynthesis, increased carbon availability for new leaf and shoot growth and increased reproductive efficiency (possibly as a result of increased canopy light penetration) have been observed in a number of species.[1] [2] For example, it has been shown that defoliation of the lower leaves of Okra (a herbaceous annual dicot) enables the upper leaves to maximize their photosynthetic activity, thus, optimizing yield.[3] However, studies have also shown that while some defoliation can benefit growth, higher levels of defoliation can result in lower yields. For example, a study with tomato found that:
Shes a beauty..what light was she under bud..Thanks man! Strain is stardawg. Grew super short, tight, and bushy. Topped them once. They needed a HEAVY defoliantion or else they would have had no airflow whatsoever. First time running her so didn’t know what to expect, very pleased so far though. Also my first time running scrog. Didn’t do nearly enough training/defoliating in veg. That would have made the day 21 strip a lot easier. Cheers bro
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Тhe tops(vegetative growth on the pic) are turning into bud sides,not these calyxes.There is always single calyxes on the main stem.Also if you water them the same way with the same amount of water/ferts the pruned side could just leave wet for longer and these signs of def can be just retained moisture in the pot(it also hardens the root breathing).It looks like def and it doesn't improove when you add more fertz….Because the other one with more leaves can drink and eat more:)Could be just that.....During this experiment, I made an observation that might actually support why schwazzing might work.
On the defoliation side I have more bud sites lower in the plants, and I suspect that this is because the bottom of the plant received more light and airflow. However I pruned quite late, so there is not a major difference with the amount of bud sites. In both groups, there is still quite many sites with a single calyx, that could've developed into a budsite.
Image ripped off google images:
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With schwazzing, you would open up all the bud sites to light and airflow at the beginning of flowering, which would lead to more calyxes turning into bud sites.
Maybe this truly is worth of an experiment in a future..
Thank you sir. She’s under a 1kw hps. That row pictures is actually 4 plants. They were significantly shorter than the rest of the room so I put them under 1k’s to make up for the lack of height. Rest of the room is under 600’s, needless to say I don’t want to run 6’s anymore but once Summer hits I won’t have a choiceShes a beauty..what light was she under bud..
Cheers max
Looks great . I have a star dawg @ week 5 flower, hope mine turn out as nice as yoursThanks man! Strain is stardawg. Grew super short, tight, and bushy. Topped them once. They needed a HEAVY defoliantion or else they would have had no airflow whatsoever. First time running her so didn’t know what to expect, very pleased so far though. Also my first time running scrog. Didn’t do nearly enough training/defoliating in veg. That would have made the day 21 strip a lot easier. Cheers bro
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right behind me bro!! Mine took right off as soon as I flipped. Thinking it’s because they were nice and root bound maybe? Started developing noticeabley before everything else.Looks great . I have a star dawg @ week 5 flower, hope mine turn out as nice as yours
As long as don’t go too mad all is good .View attachment 851607
right behind me bro!! Mine took right off as soon as I flipped. Thinking it’s because they were nice and root bound maybe? Started developing noticeabley before everything else.
Here is a pic of a leaf off of each strain post defoliation (2 weeks since heavy, 2-3 days since last light one). I don’t see any signs of deficiencies. Guess I lucked out and didn’t take too much! I’m sold on defoliation. Every time from here on out
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right behind me bro!! Mine took right off as soon as I flipped. Thinking it’s because they were nice and root bound maybe? Started developing noticeabley before everything else.
Here is a pic of a leaf off of each strain post defoliation (2 weeks since heavy, 2-3 days since last light one). I don’t see any signs of deficiencies. Guess I lucked out and didn’t take too much! I’m sold on defoliation. Every time from here on out
Looks good. I’m at day 47 I think now on my scrog. You still got a lit of white pistils. Mine aren’t trying to go the 70 days I want to push em. I got some pistils turning now.but still feeding. I’m starting flush soon too. Definately post weights. I can’t remember how many you got in there. I think you can push em a bit still n bump the carbsMini-update, week 6 (day 45)
Flushing was started on day 42 with molasses and canna boost, which I will be running for a full week, starting with plain water on week 7.
Buds are starting to ripen, as pistils have been turning brown for the past couple of days.
Deficiencies are getting worse in the two plants on the rear of the tent. This is a great mystery, as the other 4 plants are just fine. I have measured the EC and PH of runoff, measured the amount of light throughout the canopy, temperatures, humidity etc. Apart from the two plants in the middle getting a little extra light, all conditions are identical. The problem is affecting 1 defoliated plant, and 1 control group plant. So the defoliation is not the reason for the deficiency either (albeit, the symptoms started 10 days earlier). I just don't understand? How on earth is this possible?
My goal is to have the plants yellow at the end of flower, but this is definitely a week too soon. However, it has not affected the size of the buds so far, which to my eye seem to be quite identical with the other plants... It will be interesting to measure the weights at the end for each plant, to see if it has affected yield.
Anyways, here are the pictures.
Mini-update, week 6 (day 45)
Flushing was started on day 42 with molasses and canna boost, which I will be running for a full week, starting with plain water on week 7.
Buds are starting to ripen, as pistils have been turning brown for the past couple of days.
Deficiencies are getting worse in the two plants on the rear of the tent. This is a great mystery, as the other 4 plants are just fine. I have measured the EC and PH of runoff, measured the amount of light throughout the canopy, temperatures, humidity etc. Apart from the two plants in the middle getting a little extra light, all conditions are identical. The problem is affecting 1 defoliated plant, and 1 control group plant. So the defoliation is not the reason for the deficiency either (albeit, the symptoms started 10 days earlier). I just don't understand? How on earth is this possible?
My goal is to have the plants yellow at the end of flower, but this is definitely a week too soon. However, it has not affected the size of the buds so far, which to my eye seem to be quite identical with the other plants... It will be interesting to measure the weights at the end for each plant, to see if it has affected yield.
Anyways, here are the pictures.
Yeah I think so too. But the deficiency means the flush is starting to work. I would have fed a week from now probably then started flush.The deficiency is because you stopped feeding weeks early. Even if you are foing to “flush” wait until the bud stops growing and begins to ripen. Those are in peak bloom.
Yeah I think so too. But the deficiency means the flush is starting to work. I would have fed a week from now probably then started flush.
In general.Started to work on what? The plant is starting to go hungry. Yield and quality will suffer.
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