Flowering of Cyclamen is strongly influenced by glasshouse air temperature. In the research described here, one objective was to lower the temperature to save energy in winter and yet maintain normal production by manipulating other factors.
Young Cyclamen plants were placed in controlled environment chambers at either 16 degsC or 20 degsC, where they were then given light for eight, 12 or 16 hours each day.
The plants in the 16-hour day obviously received more hours of light each day and, as the light intensity was constant, they received twice the quantity of light of those in the eight-hour day.
Flowering of the plants grown at 16 degsC in the controlled eight-hour days was delayed relative to those grown at 20 degsC and many failed to flower.
If the duration of lighting in the environment at 16 degsC was increased to 12 hours each day, the Cyclamen flowered at the same time as those in eight-hour days at 20 degsC.
Flowering with a night-interruption treatment of four hours of light at 16 degsC was also equivalent to that in eight-hour days at 20 degsC.
When lit for 16 hours a day, all of the plants flowered at 16 degsC and with little delay. Cyclamen can be produced at 16 degsC in winter, if either a night interruption treatment is used or if more light is given each day.
Flowering of Cyclamen is Accelerated by an Increase in Temperature, Photoperiod and Daily Light Integral by Oh, Rhie, Park, Runkle and Kim (2008). Journal of Horticultural Science & Biotechnology 83 (5): 559-562. The authors' abstract of their manuscript can be seen in full at www.jhortscib.com.