The uses of various synthetic plant hormones in agriculture are many—one of the most generally known of these uses being their action in reducing pre-harvest drop of fruit. Naphthalene acetic acid, commonly known as N.A.A. is widely used for this purpose with apples, but 2,4-DichIorophenoxyacetic acid, commonly known as 2,4-D, is much more effective with citrus fruit
