Effects of different photoperiods on flowering time of facultative long day ornamental annuals

Experiments were carried out to study flowering response under four distinct controlled photoperiod (8, 11, 14 & 17 h d-1). A curvilinear facultative response was observed in almost all cultivars studied. Moss Rose, Pansy, Snapdragon, Petunia and Annual Verbena took minimum time to flower, when grown under 17 h photoperiod however, it was significantly (P less than 0.05) increased, when photoperiod decreased to 8 h. These findings revealed a prospect of plant scheduling of the flowering time of facultative LDPs grown under short day photoperiod to extend their marketing period.