Tabernaemontana divaricata (L.) (Crape jasmine) is a commercial important loose flower suitable for year round production in India. Application of growth regulators can increase its ability to produce more flowers. Hence, a field experiment was conducted in a farmer’s field at Manarpalyam village of Selam district, Tamilnadu during 2020-2021 to study the effect of foliar application of regulators on growth and flower yield. Randomized Block Design was adopted with nine treatments in three replications. Treatment comprise of four plant growth regulator (NAA (@ 100 and 150ppm, GA₃ @ 75 and 150ppm, MH @ 500 and 750ppm, CCC (@ 500 and 750ppm) and water spray as control. Data pertaining to growth and yield parameters were recorded at periodical intervals. Among the growth regulators NAA and GA₃ significantly enhanced all the growth parameters however, application of growth retardants MH and CCC reduced certain growth parameters like plant height, internodal length, plant spread, leaf area. All other growth and yield parameters viz., primary branches, secondary branches, number of leaves, stem girth, DMP, weight of hundred flowers, single flower weight, and number of flowers/plant/day were significantly increased due to all the treatments. Application of GA₃ @ 150ppm recorded the maximum values in all growth and yield parameters. The highest flower yield (11.75 g/plant/day, 70.52 g/plot/day, and 39.18kg/ha/day) was recorded in GA₃@150ppm followed by the next best treatment GA₃@75ppm. It could be concluded that foliar application GA₃@150ppm on 60, 120 and 180 days after planting can improve the flower yield up to 11.75t/ha/year.

Key Words     : Tabernaemontana divaricata, Crape jasmine, GA₃, NAA, MH, CCC, Growth papameters, Yield Parameters