LILIUM LONGIFLORUM THUNB., A CLASSIC MODEL TO STUDY TEMPERATURE AND PHOTOPERIOD INTERACTIONS ON DORMANCY, FLOWER INDUCTION, LEAF UNFOLDING AND FLOWER DEVELOPMENT

Bulbs for commercial production require a ±2,000 hr of 5°C for most rapid flowering with ±80 leaves.
However, at 21°C, freshly harvested bulbs will slowly emerge, shoots will elongate under long days and eventually form an apical “pseudo bulbs”. When these plants are shifted to 18°C, anthesis occurs in 60 days.
Plants will have 200+ leaves.
Thus, “vernalization” occurs at temperatures below 20°C. There is also a “casual” substitution for cold by long day, at 16°C for rapid flowering.
Both leaf unfolding and flower elongation rates can be controlled by temperature.
Both growth responses are most rapid at 21°C. It is interesting to note that in the native Japanese habitat sites of Okinawa, Amami and Erabu Islands the average temperature is 21°C.

IX International Symposium on Flower Bulbs

H.F. Wilkins

temperature, photoperiod, flowering, dormancy

https://doi.org/10.17660/ActaHortic.2005.673.36