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Brooks Whitton and Will Healy

Aeschynanthus `Koral' plants were grown in photoperiods of 8 to 14 hr (8 hr natural daylight plus 0-6 hr incandescent light of 3 μmolm-2s-1) beginning January, March, or June. The number of weeks to anthesis and number of leaves on shoots reaching anthesis were not affected by photoperiod, but differed when treatments began. Number of shoots reaching anthesis per plant was greatest in photoperiods of 13 hr for treatments beginning January or June. Time of year influenced flowering more than photoperiod, suggesting a temperature interaction. A. `Koral' plants were given photoperiods of 12 or 24 hr (daylight fluorescent lamps at 100 or 50 μmolm-2s-1 respectively) at temperatures of 18 or 24 C. After 8 weeks, 18 C plants had fewer nodes before the first flower bud than 24 C plants. Number of nodes to the first flower bud was decreased under the 24 hr treatments at 24 C, while no difference to photoperiod was observed at 18 C. Flowering of A. `Koral' appears to be promoted by 18 C temperature where the plant behaves as a day neutral plant. At 24 C, A. `Koral' responds as a long day plant.

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Brooks Whitton, Will Healy, and Mark Roh

Aeschynanthus `Koral' plants were grown in photoperiods of 8 to 14 hours (8 hours of natural daylight plus 0 to 6 hours of incandescent light of 3 μmol·m-2s-1) beginning January, March, or June. The number of weeks to anthesis and the number of leaves on flowering shoots were not affected by photoperiod but differed based on when treatments commenced. Flowering was inhibited, regardless of photoperiod, when the daily temperature differential was larger than 10C. To study the interaction of photoperiod and temperature, Aeschynanthus `Koral' plants were grown under photoperiods of 12 or 24 hours (daylight fluorescent lamps at 4.3 mol·m-2·day-1) at 18 or 24C. After 8 weeks, plants grown at 18C had fewer nodes before the first flower bud than plants grown at 24C. Aeschynanthus `Koral' was day-neutral at 18C, but responded as a long-day plant at 24C.

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Brooks Whitton, Will Healy, and Mark Roh

Stock plants of Aeschynanthus `Koral' were grown with irradiances of 120 or 240 μmol·s-1·m-2 at 18/17, 24/17, or 30/17C (day/night) under 12-hour thermo- and photoperiods. Tip cuttings from stock plants grown at 18/17C flowered earlier than those from stock plants grown at 24/17 or 30/17C when cuttings were forced in a glasshouse under natural days (23/18 C). No cuttings from stock plants grown at 30/17C reached the visible bud stage after 86 days, while 93% of the cuttings forced at 18/17C did reach the visible bud stage. A. `Koral' plants were grown at 18, 24, or 30C in a factorial combination of temperatures at 12-hour thermo- and photoperiods (100 μmol·s-1·m-2). After 8 weeks, only plants grown at 18/18C had visible buds. After 18 weeks, plants grown at 24/24 or 24/18C had visible buds after having unfolded =2.5 times as many leaves as plants grown at 18/18C. Rapid flowering of A. `Koral' is promoted by constant 18C under a 12-hour photoperiod.