Although most people plant fruit trees for the purpose of picking the fruit when it ripens, there are some instances when fruit becomes undesirable. For example, pear trees can bear fruit in such abundance that the fruit can create strain and even break the limbs of a pear tree if it is not picked. Fruit that goes unharvested from many trees can fall to the ground, rot and create a mess. There are several methods to prevent fruit trees from bearing fruit.
Prune your fruit trees with branch loppers after the tree has set buds. Many fruit trees set buds on old growth. By pruning back this old growth, you destroy the buds and force the tree to put energy into developing branches and new leaves rather than producing buds and fruit.
Fertilize with a nitrogen rich fertilizer. Nitrogen fertilizers encourage growth of foliage. Trees that put their energy into foliage have little energy leftover for the reproductive process, and will produce few if any buds.
Hand pick any buds that your tree forms. This will prevent the tree from producing fruit. For a faster method, use a high pressure sprayer, such as the kind used to clean the exteriors of homes to knock the buds from the tree.
Chemically treat your tree with a growth regulating hormone designed to prevent the tree from producing fruit. This type of hormone must be mixed with water and sprayed over the tree using a pesticide spray applicator after the tree has flowered.