Hello, nice and healthy looking plants. Yes you can prune (defoliate?) but that wont fatten your buds, and it might stress your plants if you don't do it right, If i'm right your plant just entered flowering stage, in first 2 or 3 weeks plant will mostly strech towards light. I personaly like to do light selective defoliation (only big fan leafs that cover bud sites) in beggining of week 1 of flower, and after 2 weeks i like to heavly lollipop all lower bud sites to get most of my top buds that are exposed to light.