uses of plant hormones in the commercial production of some crops

Plant hormones can be utilized in the commercial agriculture of important crops such as grapes, pineapple, watermelons and strawberries. In the production of grapes the plant hormone gibberellin is used. Gibberellins are derivatives of gibberellic acid. They are natural plant hormones and promote flowering, stem elongation and break dormancy of seeds. The hormone is used to thin the flowers so as to minimize the competitive effect of early fruiting on vegetation growth. The hormone is also used to increase the berry size by 60%. Gibberellin has also been used to produce seed less berries.
Abscisic acid can also be added as it increases the abscission of mature fruits and seeds but only at high concentration. In the production of pineapple the hormone auxin is mainly used. Auxin is the active ingredient in most rooting mixtures. These products help the vegetative propagation of plants. On a cellular level auxins influence cell elongation, cell division and the formation of adventitious roots. Some auxins are active at extremely low concentrations. Typical auxin concentration ranges from 0.01 to 10 mg/L. in pineapple production exogenous application of auxin can alter fruit size and period of maturity. It increases the size of fruit and rate of maturity.
Ethylene can also be used for controlled ripening of pineapples. In the production of watermelons the hormone ethylene can be used to control the flowering. It is used to stimulate the early production of female flower because melons usually produce male flowers before female flowers. Often male flower production is inhibited following the application of ethylene.
This increases the number of fruits produced per plant. In the production of strawberries the hormone auxin is used to stimulate the growth of strawberries.