My daughter called me asking about her pear tree since it has never produced any fruit. I looked around for some solutions. I even got out some books looking for what to do. This is how to help a fruit tree that doesn't produce fruit.
Lots of wood chips, I mean lots of them. These chips will hold the water in the soil and also they will keep the ground shaded and cool.
Try planting some nitrogen fixers. A good solution would be to surround the tree with comfrey which will get chopped and dropped on a regular basis. Adding some perennial flowers, including mint. No fertilizer is needed, just wood chips and chop and drop.
Using a timer when watering helps a lot because even one missed watering or if the soil gets to dry this can cause enough stress for blossoms to drop at any stage during the flowering stage.
Plants also take in minerals thru their leaves, not just from their roots. So it helps to make a foliar spray and spray the leaves.
Some other things that help are Epsom salts and
compost tea.
After the first year of adding wood chips, chop and drop, and tea spraying the fruit trees will most likely show signs of improvement.