Ok here is some reading for you from another grower if you must insist on arguing the point
Defoliation in this thread is: The removal of leaf, by hand, to be rid of shading of any other buds, nodes, or growth in crowded situations.
This could be called a substitute to the removal of lower branches, another popular technique sometimes called lollipopping.
As described by k33ftr elsewhere: Defoliation encourages branching in vegging plants in the same way as nipping the leader. The benefit of this technique is that the leader is retained to continue to create branches. It also shortens nodal length creating a more compact specimen.
Of importance is: It also shortens nodal length creating a more compact specimen. More on that later.
Some growers have been enjoying yields in very compact plants at only 32" cubed above and beyond 12oz per plant using this technique. Again, over 12oz dry per plant on girls that are no taller than 32 inches and just as wide around.
Again from k33ftr: 3 decades of experience with this technique reveal that bud growth benefits more from light exposure than whether the corresponding fan leaf is present.
Yes he has 3 decades of experience using this technique. It's pretty hard to argue against that much experience. And it makes sense! Bud growth benefits more from light exposure than having a corresponding leaf present.
The idea is to allow any and all bud sites to fully produce. Unlike removing lower branches, we keep them and get plenty of light to them. We grow real buds not popcorn off these lower branches. This method allows light to penetrate to any and all of the bud sites for full benefit throughout the entire plant.
Some people may be shocked at just how few leaves are on these plants and how robust they actually are.
As one can see, there is an abundance of bud. It's a pretty even canopy. And clearly there are still leaves on the plants. We dont have any main colas sticking 6-8 inches or more above the rest of the bud sites either. That would mean much of the plant is getting less light while one small section (the main cola) is getting most of the light. Why not get most of the light to all of the plant?
Once we understand that we're trying to get the maximum amount of a limited light source in a limited area, we can begin to understand how and when to apply this technique and what other techniques are used in conjunction to make the whole process come through.
Prior to trying out this technique, please have your methods and strains down pat! This is important! This technique tends to work much better on indicas or indica dominants. Know your methods well. Have your ppm, ph, and atmosphere dialed in already. above all, don't over crowd your grow with plants! There are some that do use this in high count, fast flip to flower, small plant grows, but I'm talking about plants that get a real veg period. Say 4-6 weeks on avg.
The last thing you want to do is not have all your other peripheral methods down pat, have an issue, and blame a poor result on using this method when say, root rot due to high water temps was the real issue.
So we start this all out in veg. We begin our plant training to defoliation in veg. Once our girls are about 8" tall with about 6-8 pairs of true leaves we begin. We remove the fan leaves! You can top them also if you wish. If it's a natural shrubster type strain you may not want to. Grower choice. To be bit more specific, I remove all the leaves except the little cluster at the top.
In less than a week they will re-leaf. And boy will they ever! They will come back with a vengeance! More leaf, more nodes, more compact, in just one week. It's important to note, we only do this on good healthy plants. As an experienced grower you know if your plants are healthy and strong. With experience, you soon find you can tell by feel when you grab a branch or leaf if it's healthy and robust. Thus ready for the stripper pole and some leaf removal.