Should i start defoliation?

Definitely don't do it. As GrowingGrannie said there should be a reason and there are mainly two of them to defoliate 1. To create airflows in bushy, mainly indica, strains to prevent mold (see my opium diary where leaves literally overlap into each other or stack layers because of tight spacing) 2. To provide light to buds shadowed by leaves It seems that you can just tie these branches down to create an even canopy (LST) and this would be the best option. However you should also be careful because into flowering plant's stems become harder (they need to carry all these forming buds), so be gentle not to break it

I like to wait until thellant is done stretching, for sure, to defoliate. So, it's usually week 4-5, for me. When I defoliate, I only remove leaves that cover buds. AND! This part is very important: lollipop BEFORE you defoliate leaves. Like someone else mentioned, taking off the tiny branches and buds that don't get much light will help the plant focus on buds that DO get plenty of light. This makes for bigger buds and less scurfy buds. If you lollipop right, you won't get any scurf at all! Once you lollipop, then you defoliate. If you want to talk more on this topic, feel free to message me on here by clicking the little airplane button in the bottom-right corner of the screen.

There has to be a REASON for defoliation - it's not something that is ever done "just because." Your plant actually doesn't look like it needs anything done to it - there's plenty of air flow through her and unless some of the larger fan leaves are blocking other bud sites, she's got pretty good lighting all the way through. It would be good to see a pic of the entire plant from the side rather than just from above... If you'd like a fairly decent article on defoliation to reference, this is one I find particularly good... read it and YOU make the decision as to whether you're needing to remove any leaves (they ARE the things most important to the growth and well-being of the plant!)... https://www.growweedeasy.com/nebulas-super-simple-3-step-defoliation-tutorial Good luck! She's looking really good!

Yes. Perfect in the third week. Try to remove the lower branches that get no light or almost no light at all (Hold your hand inside to see if enough light comes through) .This way your plants don't waste unnecessary energy and produce bigger buds. Happy growing!