Cyclamen Flower Development in Response to Temperature

Abstract

Commercially plug-produced Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots 15 weeks from seeding and placed at 16 °C. The irradiance was 10 mol/day per m2 during a 16-h day length throughout the study. Three weeks from transplant, the plants were placed at 8, 12, 16, 20, or 24 °C. At the time of temperature change, flower buds were first visible. Time to first open flower decreased with increasing temperature to 20 °C. On average, the cyclamens grown at 20 °C required 60 ± 4.5 days from transplant (165 days from seeding) to first open flower. There was no difference in rate of flowering for the plants grown at 16 or 24 °C (74 ± 9.5 days from transplant). Cyclamens grown at 12 °C required on average 28 more days and cyclamens grown at 8 °C, 45 more days to first open flower compared to plants grown at 20 °C. There was no difference in number of leaves per plant (55 ± 14.4). However, the plants grown at 24 °C had significantly larger leaves and total leaf area per plant (1060 ± 235 cm2) than plants in the other temperature treatments (585 ± 104 cm2). The number of flowers and buds per plant was 45 ± 10.6 for plants grown at 16, 20 or 24 °C. Significantly less flowers and buds were produced by plants grown at 12 °C (34 ± 7.9) or 8 °C (17 ± 3.7).