of course,you can partially harvest any plant.harvest top half,leave the rest for a week or so and harvest it then.the left part will keep living.that's what I recently did and do whenever I think it is needed.no worries,your plant won't die when you cut the top buds first.and yes,lower parts will continue to develop.I harvested the bottom half 2 weeks later than first cut.effect was even better.you can even keep feeding it but use half the amount of what youve been giving.