Scribsanswered grow question 5 years ago Hey dude - I grow a Sativa and although she's way less bushy than yours, I still defoliate/prune to ensure all leaves get equal exposure to light. As said in another answer, leaves are like solar panels, and those getting minimal lighting or living under the shade of other leaves are basically draining more energy than they produce, whereas fully exposed leaves can produce energy at optimal levels thus offsetting the energy cost. A solar panel in the shade is useless. Also, more leaves = more energy consumed, energy that's not going into growing buds.
For example, when you clone, the reason you cut half of each leaf's fingers is to reduce the cost in energy consumption from the leaves, slow down the pace at which the plant processes the remaining nutrients in the stem, and focus the remaining energy instead on root growth vs upward growth.
When I prune & defoliate, I basically reduce the plant's maintenance cost from leaves, so that the saved energy goes into buds, and I only get rid of buds or leaves that receive minimal light. In flowering, I've pruned dwarf budsites that would never grow more because completely underexposed.
Hope this helps.
