Effect of Growth Regulators on Plant Growth and Flowering in Dahlia (Dahlia variabilis) cv. Charmit

An experiment entitled “Effect of growth regulators on plant growth and flowering in dahlia (Dahlia variabilis) cv. Charmit” was conducted to evaluate the response of dahlia to different growth regulators (Ethephon @ 500, 750 and 1000 ppm, Alar @ 1000, 2000 and 3000 ppm and Maleic hydrazide @ 500, 750, and 1000 ppm). Ten different treatment combinations were replicated thrice in a Randomized Completely Block Design. The investigation revealed that MH 1000 ppm was very effective and recorded minimum plant height, maximum leaf number, stem diameter, primary and secondary branch number. Significant influence of growth regulators was observed on various floral parameters. Flower bud appearance and colour break was delayed while flowering duration shortened. However, flower bud size, flower number, diameter and fresh weight increased. Maximum days to flower bud appearance and colour break, maximum flower diameter, flower fresh weight and minimum peduncle length was observed with ethephon 1000 ppm. Highest flower number was recorded with MH 500 ppm while maximum flower bud diameter with MH 1000 ppm. Among all growth regulators Maleic hydrazide was found more effective followed by Ethephon and Alar in modifying the plant architecture of dahlia.