Abstract

The aim of the present study was to determine the effect of Plant Growth Regulators (PGRs) viz. Indole-3-acetic acid (IAA), Gibberellic acid (GA₃) and Kinetin in their physiological ranges from 10^-7 to 10^-5 M on tuberous roots of Coleus barbatus(patharchur) with their respective control. The certified seed material was procured from Forest Research Institute (FRI), Dehradun, Uttarakhand (India). Significant variation was reported in growth of tuberous roots of Coleus due to hormonal treatments and out of these three hormones IAA at 10^-5 M was observed highly effective as compared to control, GA₃ and Kinetin. Application of IAA at 10^-5 M, resulted in maximum promotory effect on number of tubers, fresh weight and dry weight, followed by GA₃ at 10^-5 M, Kinetin at 10^-7 M as compared to control. Application of IAA, GA₃ and Kinetin resulted in more number of tubers, which was found increased by c.a. 52, 28 and 16%, respectively as compared to control.

Key words: Coleus barbatus, indole-3- acetic acid, gibberellin, kinetin.