Effect of supplemental light, benzyl adenine (BA) on the growth and flowering of two cultivar of Chrysanthemum plant (Dendranthema grandiflora Tzvelev)

   This study was conducted during the period from 23rd September 2021 to 1st May 2022 in Horticulture stations / Akre / Iraqi Kurdistan region, amid to scheduled the flower production of Chrysanthemum (Dendrathema grandiflora Tzvelev), by use the supplemental light with (Natural day, 1.5-month, 3-month) treatment, and BA with 0, 200 and 400 mg.l-1 and two cultivars Avalon (pink) and Flirt (red). The best results include, use 3-month of supplemental light significantly increased the day to flower bud, days to anthesis to 143.36, 201.10 day respectively compared with 1.5 month which need 119.61 , 175.02 day and control which need 49.28, 78.31day for the two characteristics respectively this mean that 3-month delay the flower production by 122.79 day than control, Plant high, the flower grade and Plant growth index also increased significantly with increased the supplemental light to 1.5 and 3-month compared with control. spray Chrysanthemum with BA increased significantly the day to flower bud emergence, vase life and flower grade compared with control. the Flirt (red) cultivar significantly superior than Avalon (pink) in day flower bud emergence, day flowering anthesis, plant high and flower grade. Key Words: supplemental light, benzyl adenine, cultivars, chrysanthemum