Effect of plant growth regulators on spike yield and bulb production of tuberose (Polianthes tuberosa Linn.) cv. “Hyderabad Double”

A field experiment was conducted to find out the effect of plant growth regulators on spike yield and bulb production of tuberose (Polianthes tuberosa Linn.) cv. Hyderabad Double at Main Experiment Station, Department of Horticulture, N. D. University of Agriculture & Technology, Faizabad (U.P.), India during the year 2010–11. Treatments including three levels of GA₃ at 100, 200 and 300 ppm, NAA at 100, 200 and 300 ppm and BA at 100, 200 and 300 ppm with one control were tried. Plant growth regulators were applied as pre planting soaking 24 hrs before sowing of tuberose bulb. Application of GA₃ 300 ppm resulted increased length of spike (86.20 cm), number of florets per spike (45.07), number of spike per clump (3.73), number of spike per ha. (3.68 lakh), number of bulb per clump (6.60), weight of bulb per clump (159.00 g) and yield of bulb (156.87q/ha) per ha.