Response of night interruption regimes on vegetative and reproductive growth of Kalanchoe blossfeldiana poelln

Kalanchoe (Kalanchoe blossfeldiana) isa qualitative short-day plant belonging to Crassulaceae family. As photoperiod regulates the growth and flowering of this crop, understanding photoperiodic response is a prerequisite for getting economical produce year-round. The influence of a combination of days and time of night interruption (NI)was examined on the growth and flowering of Kalanchoe. Different combinations of artificial long days were provided by exposure to NI (30 minutes and 60 minutes) and duration (20, 30, and 40 days). The vegetative and floral parameters varied among plants exposed to different duration of night interruption. A decrease in plant height, the number of branches per plant, and the number of flowers per plant were observed as compared with the control i.e. devoid of night interruption. The night interruption had no effect on stem girth and petiole thickness. It also exhibits a certain beneficial effect on plant growth in connection with the number of branches per plant and plant height which are desirable characteristics for commercial potted plants for sale. These results suggested that the duration of night interruption affects the morphogenesis and flowering of kalanchoe, and that response is photoperiod dependent.