Treatment of plant growth regulating substance and modification of growing media to stimulate flowering of bougainvillea in air polluted streetscape

Abstract

Abstract Bougainvillea is a flowering shrub that has a robust and attractive character to use as road greenery. This plant can be used in a median and roadside for beautification, comfort, and safety of the road. However, it was unclear if the bougainvillea adapts to growth and produces enough flowers under the influence of air pollution in the road environment. This study aimed to determine the paclobutrazol concentration and the gravel thickness, which can stimulate the flowering of bougainvillea on the roadside. The experiment used a factorial randomized block design that consisted of two factors with three replications. The thickness of gravel media consisted of 0 cm, 5 cm, and 10 cm, and plant growth regulating substance of paclobutrazol concentration consisted of 0 ppm, 50 ppm, 100 ppm, and 200 ppm. The study showed that the fastest and most generated flowers were found in the treatment of gravel media as thick as 10 cm and paclobutrazol with a concentration of 200 ppm