The stalks? What part, I mean it will surely die if you chop it at the bottom. If the tops buds are finished, you can chop that part of the stalk so the lower buds are receiving all the light so that they can finish
ya its called lollipopping. you clear the bottom 12" or so of vegetation off of the plant. This will make larger buds due to there being extra energy now that those practically worthless buds are gone