THE FORCING OF FRITILLARIA IMPERIALIS L.

Fritillaria imperialis L. can be forced as a cut flower or as a potted plant.
This bulbous plant, native to the region between Turkey and India, needs storage at 25°C from lifting of the bulbs in June until mid September for flower initiation.
Flower formation takes place from mid September to mid October.
To obtain a good flowering plant with sufficient stem length a cold period is required.
The aim of this study was to determine the effects of cooling temperature and duration on flowering and stem length in relation to flower formation.
Preliminary studies indicated that cooling at 9°C for 13-17 weeks resulted in very short, flowering plants whereas cooling at 2°C resulted in tall plants with aborted flowers.
After storage at 25°C bulbs were planted and cooling was started at mid September or mid October at 9°C (12-3 weeks), followed by 3 weeks of 5°C, and a period of 2°C (3-12 weeks). The total cold-treatment amounted to 15 or 18 weeks.
When cooling was started mid September (beginning of flower formation) a period of at least 6 weeks at 9°C was necessary to obtain good flowering quality.
These cooling temperatures had no influence on flowering when cooling was started mid October (flower formation finished). It is concluded that a cold regime starting mid October of 12 weeks at 9°C + 3 weeks at 5°C + 3 weeks at 2°C results in good flowering short plants, whereas a cold regime of 3 weeks at 9°C + 3 weeks at 5°C + 12 weeks at 2°C results in good flowering tall plants.

VIII International Symposium on Flowerbulbs

P.J. van Leeuwen, J.P.T. Trompert, J.A. van der Weijden

Fritillaria imperialis, forcing, flower formation, potted plant, cut flower

https://doi.org/10.17660/ActaHortic.2002.570.19