It is very satisfying to grow fruit in your own backyard. The availability and freshness are unparalleled. After the trees get large enough and start producing large quantities of fruit, whether it be plums, peaches, apples, nectarines or lemons, one of your main concerns might be how to make sure the branch is not overloaded and will not crack under the weight of the fruit. You can do a few things to address this problem.
Prune your trees before they are even budding in the early spring. This is the most effective way to support the heavy fruit-laden branches. Generally, trees are pruned to keep the centers open and the fruit-bearing branches short. A good measurement for the angle of branches for structure is 40 to 60 degrees. After a few years of this heavy pruning, the branches become thick and strong and no support is needed.
Thin out the fruit before it gets large. A tree covered in blossoms is beautiful, but if all the blossoms are pollinated, the resulting fruit will be stunted and small. Give the small fruit a simple twist between your thumb and finger to remove it. Leave only one fruit for every six inches of branch.
Support the branch by installing a tension wire across the top of the trees for smaller trees, like dwarfed root stocks. You can run supports down to young branches that look like they cannot hold the weight of the fruit. Another simple support is used from the ground by propping two 2-by-4s with a hook or nail on each that you rest under the branches. This can be used temporarily until the tree is trained to be strong enough to hold its fruit.