My aunt who is 96 and lives in Manoa Valley on the island of Oahu, cuts the tops of her papaya trees and puts a clean tin can over the top of the tree to prevent bugs or infection til the tree heals from the cut. The tree then grows thicker and sprouts alternat limbs to grow fruit. She has had her trees for a few years and they grow large fruit. My parents have recently cut the tops off of thier papaya trees but they have not fruited. They cut the tops off of 12 trees 3 of the trees died but the others are growing and thickening, growing alternat limbs but no fruit as yet. It has been about 6 months since the cut. Hope this helps.