The idea is that the impacts (not too hard) convince the tree it is
threatened. When a tree feels its survival is threatened it typically
produces fruits/seeds.

Hey - finally a way to tell if all the people talking to their plants are nuts
or not - scream at your tree "Bloom, you sonofabitch, or you're coming down!",
while revving up your running chainsaw near it.

Only problem I can see is that to be properly scientific, you need a control
nearby that you DON'T make threatening noises at, which means you are going to
need a heck of a big pair of earmuffs for the control tree.........