Abstract
Effects of winter night temperature (5, 10, 15 or 20°C) on the flowering, yield and quality of spray-type carnation (Dianthus caryophyllus L.) ‘Light Pink Barbara’ and ‘Cherry Tessino’ were investigated. In both cultivars, secondary lateral shoots sprouted after the second decapitation (second pinch lateral shoots) grew more rapidly at higher night temperature, whereas the length of second pinch lateral shoots at anthesis was the longest at the lowest night temperature (5°C). In both cultivars, the number of days from pinching to flowering decreased, and the yield of cut flowers increased with increasing night temperature. The lowest (5°C) night temperature adversely affected flower quality, resulting in increased second florets. In ‘Cherry Tessino’, the red color pigmentation of white marginal variegation of flowers increased up to completely red petals with increasing night temperature. The chromatic component L* value showed a tendency to decrease with increasing night temperature, and a* value showed a tendency to decrease at 5°C. In conclusion, from the perspective of achieving a good balance between productivity and the quality of cut flowers, suitable night temperatures in winter for cut flower production of spray-type carnation ‘Light Pink Barbara’ and ‘Cherry Tessino’ are suggested to be 10 to 15°C.
