As I recall, Diana tells people to whack their fruit trees with a rolled-up newspaper :)
No. I whack Mr. Wonderful with a rolled up newspaper, LOL!
I don’t know where hitting a tree to make it produce comes from. Some Old Wives Tale.
As for me? I pray for a wet spring and no late frosts. I feed my fruit trees with a granular New Lawn Starter that is a 10-18-10 formulation as soon as they start leafing out.
Also, I don’t prune them until they are about 5 years old, so they can TAKE it.
My fruit trees produce quite well! TONS of cherries and peaches this season. My apples, not so much, but I got a TON of apples from friends, so Life Is Still Good. :)