You will get two completely opposite answers to this often asked question. I am firmly in the "do not remove" camp. The only time I will prune anything is when the bottom suckers are making contact with soil. Soil borne disease can travel up to the plant and cause trouble. This situation can be remedied by removing leaves contacting soil or with a good mulching program.
Others will advise pruning suckers. Your choice...I made mine many years ago.
