Influence of different plant growth regulators on flower suppression, herb yield and stevioside content of Stevia (Stevia rebaudiana Bertoni.)

Stevia rebaudiana Bertoni, an emerging perennial herb contains stevioside as a therapeutic principle and thus, is having diversified uses in diabetes, hypertension, tooth ache and variety of beverages. A field experiment was conducted during year 2016-18 to find out the influence of plant growth regulators on flower suppression, herb yield and stevioside content of stevia. In order to determine the effect of different plant growth regulators on flower suppression four different growth regulators each at two levels along with manual deflowering at 15 days interval and control were assessed. The design followed was Complete Randomized Block design with 10 treatments and 3 replications. T9 (GA3-500 ppm) significantly affected and found superior on plant height (53.68 cm), number of branches (38.78), dry herb yield/plant (31.96 g) and dry herb yield/ha (2.37t) whereas it was observed lowest 17.48 cm, 21.04, 17.46 g, and 1.29 t, respectively. The significantly minimum number of inflorescence (6.44) was recorded in T9 as compared to maximum (11.06) in control (T1). T8 (GA3-250 ppm) was found on par with T9 with respect to all above parameters. The highest stevioside content (0.99%) was recorded in T9 and lowest content (0.32%) was in T4 (ABA -250ppm).