I ran across this article and did not know where to post it so I put it here--

http://edis.ifas.ufl.edu/CH146

It has been discussed previously in one of the early post. GA3 will revert back the terminal nodes into vegetative mode at proper timing and concentration. This will help young grafted plants to grow faster and bigger to save on labor of snipping flower buds or low-quality fruits anyway.

GA3 will also help fruit set at certain concentration if applied during peak bloom and post bloom.

I used to have a table of concentrations and timing depending on cultivar. Can't remember where it is, I no longer use GA as most of my trees are mature.