STORAGE TIME AND FORCING TEMPERATURE EFFECTS ON GROWTH AND FLOWERING OF DWARF ASIATIC LILIES

Abstract

Commercially cooled bulbs of five genetically dwarf Asiatic hybrid lilies were stored frozen at -2 C. Every 4 weeks for a total of 40 weeks, they were potted and forced in controlled environment chambers at 10, 15, 20, or 25 C. For each temperature, days from the time of potting to shoot emergence, visible bud appearance, and anthesis generally decreased as storage time increased. The number of flowers per plant and plant height were not significantly affected by storage time. Compared with those at 15, 20, or 25 C, plants at 10 C required significantly more time from potting to shoot emergence, visible bud, and anthesis. However, the temperature effects on forcing time were not linear. There was a 30-50 day decrease from potting to anthesis when temperature was increased from 10 to 15 C, but there was only a decrease of about 10 days when temperature was increased from 15 to 20 C. In contrast, there was no significant difference in forcing time between plants at 20 and 25 C. This indicates there is no need to force these lilies above 20 C. Plants at 25 C had more aborted flower buds than those at 10, 15, or 20 C. Plants at 10 C were taller then those at 15, 20, or 25 C.