growth regulator

Plant hormones, also known as growth regulators, are substances that control plant growth and development. The primary plant hormones include auxins, gibberellins, cytokinins, abscisic acid, and ethylene.1234

Auxins, such as indoleacetic acid (IAA), promote lengthwise growth by affecting cell walls and enabling cells to elongate. They also influence phototropism (growth toward light) and geotropism (growth against gravity).25

Gibberellins stimulate growth, particularly in compact or dwarf plants, and are used in grape production to increase berry size. Cytokinins are crucial for cell division, with their ratio to auxins influencing root or shoot development. Ethylene acts as a ripening hormone for fruits and also stimulates rooting and flowering in some plants. Abscisic acid, a growth inhibitor, promotes dormancy and leaf fall. These hormones are transported throughout the plant to exert their effects.6435