Effect of day and night temperatures during short photoperiods on growth and flowering of Chrysanthemum morifolium Ramat
Lepage, I.; Jong, J. de; Smeets, L.
Scientia Horticulturae 22(4): 373-381
ISSN/ISBN: 0304-4238 DOI: 10.1016/s0304-4238(84)80009-6
The effect of day and night temperatures of 10, 14 and 18.degree. C on growth and flowering under short days was studied with 6 cultivars of chrysanthemum. A high day temperature resulted in earlier flowering and taller stems, but did not influence flower number and final total fresh weight, and only slightly influenced the distribution of fresh matter over stem, leaves and flowers. A high night temperature resulted in earlier flowering, more flowers and reduced stem and leaf weight. It did not affect leaf number and it influenced height and total fresh weight only slightly. Except for height, the day temperature acted independently from the night temperature. The cultivars responded similarly, except for 2 cultivars which generally did not flower at 10/10, 10/14 and 14/10.degree. C D/N [day/night]. One cultivar produced more flowers at 14 than at 18.degree. C.