Studies on the impact of growth regulators on morphological and flowering attributes of globe amaranth (Gomphrena globosa L.)

The present investigation on gomphrena was laid out in a Randomized Block Design (RBD) carried out at Floriculture block in Dr. YSRHU- College of Horticulture, Anantharajupeta, Annamayya district, Andhra Pradesh in 2024. This experiment was focused on the influence of growth regulators viz., GA3 (100, 200 and 300 ppm) NAA (50,100 and 150 ppm), BA (100, 150 and 200 ppm), Paclobutrazol (40, 60 and 80 ppm), Cycocel (1000, 2000 and 3000 ppm) and control sprayed at 30 days after transplanting (DAT). The results revealed that, among different growth regulators, spraying of gibberellic acid at 200 ppm registered significantly maximum plant height (47.02 and 53.53 cm) and internodal length (9.13 and 10.46 cm) at 60 and 90 DAT. The plant spread, number of primary branches and number of secondary branches were found to be maximum at 60 and 90 DAT in Paclobutrazol @ 80 ppm. In flowering attributes, GA3 @ 200 ppm took a minimum number of days for the first flowering (38.00 days), maximum stalk length (18.39 cm) and flower diameter (2.06 cm). The highest number of flowers plant-1 (95.22) was recorded in Paclobutrazol @ 80 ppm. Hence based on results obtained from the present investigation it can be concluded that plants sprayed with GA3 @ 200 ppm were effective concerning plant height, internodal length, early flowering, stalk length and flower diameter, whereas paclobutrazol was effective in flower production.