The growth of plants is regulated by plant hormones. Some of the major hormones include; auxins, gibberellins, ethylene, abscisic acid, and cytokinin. Abscisic acid is a stress hormone that inhibits the growth of seeds during the scarcity of water such as during winter. Ethylene hormone promotes ripening of fruits. The hormone can exist in gaseous form and therefore if exposed to unripe fruits can induce ripening. Auxins promote apical growth while gibberellins promote internodal growth in stems