Defoliation side by side - discussion welcome

I have done A LOT of searching, and as we all know we still haven't got a conclusive answer on whether defoliation is beneficial or not.

Most of the side by side's I've seen have been quite lacking on this subject. People have defoliated tall plants that don't even fill out the entire canopy, pretty much negating the point of defoliation in the first place; to improve light penetration to the lower parts of the plant. I mean, if there is plenty of space for the light to bounce down from the sides to the lower parts of the plant, what is the point of defoliating in the 1st place?

From my studies I've come to the conclusion, that defoliation should help in getting higher yields, if there is enough foliage at the bottom of the plant, so that those leaves and bud sites can absorb the light that passes through the top. There should always be enough foliage throughout the plant so that no light is wasted by passing down to the bottom of the grow space and bouncing back up.

Now I plan to test this theory, and find out whether defoliation can increase yields on an extremely bushy plant.

Plants:
- Critical Bilbo, all from clones on a mother plant, age 6 months.
(The person I got these clones from has yielded over 1g/w under a 600w HPS using SCROG method, so the genetics should be pretty good for this test)

Grow setup:
4x Zeus 308 "quantum boards" running at 480w, spectrum 3000K
1x 50 watt, hyper red & far red booster
Total of watts 528, measured from the wall.
Big oscillating fan
1000cfm exhaust (running @700)

Climate:
Day temp: 25-27 celsius
Night temp: 18-19 celsius
Humidity: 40-45%
I will do my best to keep the climate in this range throughout the entire grow

Nutrient schedule & soil:
Guanokalong Complete mix with added perlite of 30% total
Biocanna nutrient line
Canna Boost (not bio)
Soil Balance Pro
Epsom Salts
Worm Castings tea

Vegetative phase & training:
4 weeks
Topped once
Supercropped 5 times
Foliar fed with silicon & Epsom salts in the first 2 weeks

My plan is to defoliate at day 21 of flower, I will be defoliating 3 plants in total, the plants on the right side in the attached pictures.

Right now I just passed the first week of flowering (day 9), so we are gonna have to wait a couple of weeks before the chop. Meanwhile enjoy the pictures

Okay, week two flower (day 14) update time!
Buds are starting to form up, just 7 days to go til' my planned defoliation date.

I lent an EC meter and recorded some values, so I thought I might as well share them with you as well.

Tap water:
EC: 0.2
PH: 6.8

Feeding solution:
EC: 1.35-1.70*
PH: 5.50-5.75*
*some nutrients are used every other watering

Run-off:
EC: 1.7
PH: 7.0

Looking at the data it seems like I'm getting some nutrient buildup in the soil, so I might have to increase the amount of runoff water, still really far away from any troubles though.

I've also done some measurements with a LUX meter, and converted the data into PAR using a multiplying factor I got from my lamp retailer. Approximately, I have a 2x2 area that is lit at 1000PPF, the sides and edges of the tent range between 550-700PPF. Drop from the 2x2 area to the sides is linear. Fixture distance from canopy is 19 inches. I stopped using my red booster light after day 10, right now only running the Zeus boards.

Since the end of some of my leaf tips have been a bit yellow, I'm not sure if it's tip burn or genetics, but it hasn't progressed during flowering. I've added some close-up shots of the leaves so you can judge for yourself. Overall plants are in perfect health though.

Happy holidays, I'll be back right before new years to give you an update on the defoliation!

Cool man nice garden I hope your test goes well.

I've tried all kinds of stuff over the years to decide how I feel about trimming leaves, but it's always good to see what others come up with too.

Thundercat said:

Cool man nice garden I hope your test goes well.

I've tried all kinds of stuff over the years to decide how I feel about trimming leaves, but it's always good to see what others come up with too.

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Do you defoliate or not?

I do under the canopy a few leaves and branches at a time they don’t seem to mind

Your experiment is really nicely put together. Well done.

Without sounding like I'm trying to derail your efforts I would like to add that when I do a leaf strip defoliation it is usually already done by the time the flowers are established as shown here. Sometime between days 14-21 as soon as I notice the stretch stop and pistils start puffing out.

It will be fun observing how your experiment goes and bless up for putting in the effort and work to share with us.

Fat Manatee said:

Do you defoliate or not?

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I don't "defoliate". When I first saw this term used, it described stripping nearly all the leaves off the plant to let more light in. Now a days people seem to have differing opinions on it.

I do selective pruning . I like to trim a few certain leaves and a few lower branches through out veg, and early in flower. I do this to allow light to some tops, and to control the places the plant spends its energy working. I don't want it putting energy into repairing damage I do, or into growing small larfy buds. So I choose specific leaves and shoots that look like they could serve to be pruned.

I liked what you posted about selectively removing some leaves to allow light to the lower growth. Removing ALL the fan leaves like some guys do is laughable in my book. I've tried it , the plants definitely didn't produce more bud or anything special. They grew back about half as many leaves as they had and just kept flowering.

Plants have leaves for a reason so I don't like to remove any that don't seem to be problems. The plant will spend energy trying to grow back more leaves since it needs them. In my book that is energy that isn't getting put into the buds .

CannaBruh said:

Your experiment is really nicely put together. Well done.

Without sounding like I'm trying to derail your efforts I would like to add that when I do a leaf strip defoliation it is usually already done by the time the flowers are established as shown here. Sometime between days 14-21 as soon as I notice the stretch stop and pistils start puffing out.

It will be fun observing how your experiment goes and bless up for putting in the effort and work to share with us.

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I'm thinking the same, as the lower bud sites could already use the light. The dude I got these clones from has been doing bilbo for a few years now, and he always lollipops his scrog setup at week 3 with good results, so that's how I ended up choosing day 21 as defol day. They do seem to keep stretching still too (at least the biggest cola's).

I'm definitely gonna be experimenting more in the future, so might be trying what you suggest in a growth later on.

I do a lot of leaf tucking in veg after my first topping seems to helps flatten the canopy .

Fat Manatee said:

I'm thinking the same, as the lower bud sites could already use the light. The dude I got these clones from has been doing bilbo for a few years now, and he always lollipops his scrog setup at week 3 with good results, so that's how I ended up choosing day 21 as defol day. They do seem to keep stretching still too (at least the biggest cola's).

I'm definitely gonna be experimenting more in the future, so might be trying what you suggest in a growth later on.

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I think in a scrog lollipopping is great, and then tucking upper leaves under to let budsites to the canopy. It lets you get great air flow under your canopy. I've also seen guys underlight the canopy .

I ended up pruning three days earlier then expected (day 18 flower), as the stretch ended earlier then I expected, and the plants had shifted to full bud production.

In the attached pictures it may seem that I did not chop a lot of leaves, as there's so many to begin with! However I chopped a total of 82,9 grams, so nearly 30 grams per plant. Once the plants start maturing, I'm expecting the foliage to open up a little more as the weight of the buds will bend the stems. By the end, the plants should look much different from the control group.

The plants that were pruned are the three on the right side of the tent.
I'll keep you posted!

Day 2 after defoliation. The leaves have re-arranged themselves so that it's easier to see how much defoliation was done, and a lot more bud sites are now exposed to light.

1st, defoliation side
2nd, not defoliated
3rd, both sides

subbed!

good work man, hopefully this will help clear this for once

eyderbuddy said:

subbed!

good work man, hopefully this will help clear this for once

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Further experiments should be done to dial in the timing of the strip. This is a good start for these kinds of side by sides.

eyderbuddy said:

subbed!

good work man, hopefully this will help clear this for once

Click to expand...

Further experimentation will definitely be needed.
I'm planning on doing a lollipop in the next run after this. Depending if this defoliation run is a success, I will be combining both pruning methods together, for the next test.

Okay! End of week 4 flowering (day 2, update time!
It's been pretty quiet since my last update, and not much has changed. Now I'm finally starting to see the bud sites swelling up. The up coming weeks should be really exciting.

There's not much difference between the two groups, apart from the trimmed side showing a bit of magnesium deficiency, especially one plant at the top right of the corner shows visible mag def, which you should be able to see in the images too. I've increased the amount of Epsom Salts in the feed. However it's quite puzzling why one of the plants is showing more of a deficiency then others, as they have all received identical treatment, and are clones.

Images, galore!

Next time try it the grandmasterlevel way? When I first saw what he did I almost shit my pants lol.. anyway he does it at day 12 or 14 and strips every single fan leaf it’s crazy but he swears by it.. I’ll post a link to the video.. make sure your sitting down lol

Going to be a great thread......

Fat Manatee said:

Okay! End of week 4 flowering (day 2, update time!
It's been pretty quiet since my last update, and not much has changed. Now I'm finally starting to see the bud sites swelling up. The up coming weeks should be really exciting.

There's not much difference between the two groups, apart from the trimmed side showing a bit of magnesium deficiency, especially one plant at the top right of the corner shows visible mag def, which you should be able to see in the images too. I've increased the amount of Epsom Salts in the feed. However it's quite puzzling why one of the plants is showing more of a deficiency then others, as they have all received identical treatment, and are clones.

Images, galore!

Click to expand...

Defoliation definition from Dictionary.com:

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.

Prune definition from Dictionary.com:

I would argue that you are running pruning research, not defoliation research. I like the way you set up your experiment and look forward to seeing your results. My hypothesis is that your pruned plants will produce the same or better than your controls.

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.