| The genetically dwarf Asiatic hybrid (GDAH) lilies have the potential to become one of the most important greenhouse pot plants. This study solved some problems that growers are now facing. It also provided some basic information concerning the requirements and timing of flower initiation and development in these lilies.; The GDAH lilies can be produced year-round, but proper storage and forcing temperatures are essential to produce quality plants. The commercially used storage temperature, {dollar}-{dollar}2{dollar}spcirc{dollar}C, obviously is not the best because most bulbs sprouted after 4-6 months, which affected plant quality adversely. Non-cooled bulbs were killed when stored at {dollar}-{dollar}3{dollar}spcirc{dollar}C; however, the bulbs of the same cultivars tolerated {dollar}-{dollar}3{dollar}spcirc{dollar}C after being acclimated at 4{dollar}spcirc{dollar}C for 2 weeks. This opened a door to providing quality bulbs year-round.; Quality plants were produced at 10-15{dollar}spcirc{dollar}C. They do not seem to be photoperiodic as L. longiflorum with regard to flower initiation, time of flowering and the number of flowers.; Unlike Easter Lilies, these Asiatic hybrids did not need the commercially practiced cooling to initiate flower buds. However, they do need a period of cooling to break dormancy, i.e. to promote fast and uniform growth. The theoretical separation of vernalization and breaking dormancy could potentially benefit the lily industry when an alternative method of breaking bulb dormancy can be found, such as a growth regulator treatment.; In some cultivars, time of cooling significantly increased plant height, which means that cooling in these cultivars may very well be an alternative in plant height control.; Initiated meristems had higher levels of GA-like substances than non-initiated ones. However, it was not clear whether the higher level of GA-like substances in initiated meristems was the result of flower initiation or if it resulted in flower initiation. The possibility of applying GAs or other growth regulators to promote earlier flower initiation should be explored.; These lilies cannot be kept for much longer than a week at temperatures above 4{dollar}spcirc{dollar}C without flower buds opening. Therefore, more precise production programs are needed for them, to match production schedules with holidays and special events, than for Easter lilies. |
