Tipping the new growth flushes has been demonstrated to help initiate flowering. There was a research article written about this here in Hawaii by Dr. Francis Zee. What you are doing is trying to stop the tree from going into growth flush stage and instead get it into panicle forming stage. When there are growth flushes you will not get flowering. This is a reason that fertilizer timing is also very important. If you apply fertilizer during what you want to be dormant winter stage, then you will get undesired new flush growth.