Used as a synthetic auxin in agriculture and horticulture to promote root development in plant cuttings, especially in vegetative propagation of ornamental and fruit plants. Commonly applied in rooting powders and solutions to enhance uniform and faster root formation. Also used to prevent premature fruit drop, improve fruit set, and control fruit thinning in apple and pear orchards. In tissue culture, it supports callus induction and cell division. Its stability and effectiveness make it preferred over natural auxins like IAA in many commercial plant growth regulators.