Effect of duration of night interruption on growth and flowering of Chrysanthemum cv. Kikiobiory

Abstract

The study was conducted to determine the effect of duration of night interruption using incandescent bulbs on sustained quality flower production of potted standard Chrysanthemum cv. Kikiobiory. The different night interruption (NI) treatments i.e. control, <5 sec. flash, 30-, 60-, 90- and 120- min. significantly (p<0.05) affected allthe vegetative and floral parameters. The plant height, number of leaves and root suckers per plant increased with the increase duration of NI treatments with maximum at 120- min. NI (90.42 cm, 34.75 and 12.10, respectively). The days taken to flower bud appearance, colour break stage and full bloom were delayed, whereas flower quality with respect to duration of flowering and flower diameter were deteriorated with increase in duration of NI treatments. The days taken to flower bud appearance, colour break stage and full bloom were highest at 120- min. NI (136.84, 183.22 and 202.25 days, respectively) which delayed the flowering by 63.94 days, where full bloom flower appeared in March. There was reduction in duration of flowering and flower diameter with increased NI duration with lowest at 120 min. NI (7.83 days and 15.69 cm). It was observed that increase (120 min.) in night interruption increased the vegetative growth and delayed the flowering; however, flower quality was deteriorated. Thus, it was concluded that 60 min. NI improved flower quality with sustained flower production in potted Chrysanthemum cv. Kikiobiory.