Defoliation at beginning of flower?

Different wavelengths of light have different penetration depths. The first 2 to 3 layers of leaf will recieve ample blue and red and green for robust bud growth. Only even begin to think about defoliation once your canopy has a a excess of 2-3 layers deep other wise you are reducing plants ability to perform gas exchange which is a precursor for photosynthesis. The cannabis plant is hardwired as such. Anytime a leaf consumes more energy than it produces the plant will initiate pcd programmed cell death, it will strip all the mobile nutrients from said lead which will turn yellow, this yellow is carotenoid and still capable of photosynthesis. Eventually the plant will detach once it has remobilized everything it can. The only time you want to defoliate is to expedite what you already know plant won't "utilize" later in flower. How do you know? Well thats where experience comes in, you won't know until you watch a plant defoliate itself, then all you do is "defoliate" that which you know won't be used. (wasted energy) There are mechanisms within the plant thay are made to protect from herbivory, pinching leaves as if it was being eaten can trick the plant and trigger responses but this is more during terpene production and the benefits will be a % or two at most. Large Buds don't develop because a lack of energy they lack the ratio of colors to produce proper buds, Green light will penetrate 6, 7 layers, if you supplement side red and blue, you can give th lower parts the 1:2;1 they crave almost removing entirely the need for any defoliation at all. Pruning is another thing.