Abstract

Bedding plants with their seemingly infinite variety of flower colour and plant form fit into almost any landscape situation. They provide that necessary touch of colour to an often drab landscape. New species are introduced into urban landscapes more rapidly to break the monotony. In view of this context, an experiment was conducted during 2019 at the Faculty of Agriculture, Annamalai University, Tamil Nadu, India to study the effect of growth retardants on sunflower so as to be grown as bedding plants. This experiment was laid out in a randomized block design and was replicated thrice. Three growth retardants namely paclobutrazol (30, 60 and 90 ppm), cycocel (2000, 4000 and 6000 ppm) and Alar (1500, 3000 and 4500 ppm) were applied to the plants. A control plot was maintained for comparison. Around twenty-five plants were maintained for each plot. Among the various treatments, plants treated with Alar @ 4500 ppm recorded the minimum plant height (71.50 cm), shortest internodal length (3.71 cm), maximum number of primary branches (17.12), highest number of flowers (15.81), maximum carotenoid content (1.42 mg/g) and the highest overall performance rating (6.01), making it evident that it is the most suitable plant growth retardant to be used for ornamental sunflowers grown as bedding plants.