Pantnagar Journal of Research

Abstract

A field experiment was conducted to evaluate the effects of four plant growth regulators (PGRs)-Gibberellic Acid (GA₃), Naphthalene Acetic Acid (NAA), Triacontanol (TRIA), and Catechol on the vegetative growth and flowering parameters of African marigold (Tagetes erecta L. cv. Pusa Narangi Gainda). Foliar application of different concentrations of these PGRs significantly influenced plant height, spread, number of branches, leaf count, and floral characteristics. The results revealed that treatments with Catechol at 500 ppm and GA₃ at 200 ppm consistently promoted superior vegetative growth, including increased plant height, spread, branch number, and leaf count. In contrast, treatment with NAA at 30 ppm and NAA at 20 ppm suppressed vegetative growth. Recording the lowest plant height (48.00-51.12 cm and leaf count. Flowering parameters, such as fresh and dry flower weight, flower diameter, and the number of flowers per plant, were also significantly enhanced by Catechol and GA₃ treatments, indicating that Catechol at 1500 ppm and GA₃ at 200 ppm are effective promoters of growth and yield in African marigold.