A small branch with a crack can be wrapped with graft tape or electrical tape to hold it together. Whenever there is good contact between the cambium, or inner shell of the bark, of the two pieces, the wood must merge after a few months of growth. It is rarely possible to successfully put broken limbs back together. Attempting to wire or tie them back to the main trunk is almost always a waste of energy.
Unlike people, woody plants cannot heal damaged tissues. Instead, they compartment wounds with layers of cells that prevent damage from spreading further. Therefore, the damaged wood does not grow back and, even if the branch manages to survive, it will be very weak because its vascular system has been severely compromised. In addition, it will never be possible to remove the ties or cables that hold a broken branch in place, which could mean a permanent nuisance in the landscape.
This not only raises the height of the stake, but also provides a softer cushion for the fruit tree branch. One day, a tree stands proudly with a large harvest of fruit, and the next day, a large branch has broken under the weight, altering the shape of the tree and eliminating a large part of the branches that produce premium fruit. In cases where several important branches are damaged or the tree doesn't look like it will survive, be patient and resist the urge to lose the tree. In addition, tree specialists have the best tips and solutions for caring for your tree and treating broken branches.
In general, when a tree or shrub has a broken branch, it's almost always easier to cut losses and remove it. It's not uncommon for trees and shrubs to break their branches during storms, and home gardeners are often curious to know if there's any way to reposition them or remove cuttings from branches. Before starting the repair of the tree, remove the fruit from the broken branch (making the branch considerably lighter) and lift the branch to its original height, which should seal the damaged area so well that you can barely detect the crack. Natural phenomena, such as thunder, lightning, strong winds, storms, or thick ice sheets, can cause trees to lose their branches.
If you're considering using a tree wound dressing to help heal the wound, read this related question of the week. If there are still many branches left along the trunk, they will grow more vigorously as the tree tries to replace what it lost. I still don't have enough long-term experience with this repair method to give advice on how long this could take, but as I write this, I have two apple trees in the yard with stakes that hold up the damaged branches, and one has been in place for a few years without any signs of regression, producing apples abundant each one fall. In theory, if you give your tree enough time, this method of repairing trees will strengthen the damaged area on its own, cultivating new wood until the branch can stand on its own once again.
If it is obvious that the tree cannot be saved probably because the damage is excessive or because the tree is almost dead, then it's time to say goodbye to the tree.