Summary: | 碩士 === 國立臺灣大學 === 園藝學研究所 === 91 === This study was conducted to determine the effects of different season, temperature and weeks of lighting on the growth and flowering of six chosen cultivars.The purpose is to improve the flower quality of selected cultivars and increase the potential of their competitiveness.
In fall the natural high temperature and long day condition delayed the flowering of autumn flowering cultivars. This problem could be solved and the quality of flowering could be improved by growing them under 20/15℃ and 15/13℃ in phytotron. The continuously rainy weather in the northern Taiwan caused low light intensity in winter, and only ‘Redock Improved’ could flower to expectably and still performed good. ‘Silver Jubilee’ was affected largely by the low light during growth period, resulted in delaying days to visible buds and developing of flowers. Measuring the net photosynthetic rate of new and local summer flowering cultivars grown under 20/15℃ and 25/20℃, the results shown that the net photosynthesis curve of ‘Puma Sunny’, ‘Redock Improved’, and ‘白銅錢’ were similar under low light conditions, while the fresh weight of the three cultivars did not decrease under high temperature during winter. ‘鑽石白’, the local autumn flowering cultivar, performed nice even during fall and winter, and the days to flower of summer flowering cultivar, ‘小紅娘’, did not be delayed by high temperature.
As the weeks of lighting increased, the plant height and leaf number of ‘Lineker Salmon’, ‘Silver Jubilee’, and ‘Vyking’ increased. The plant height of ‘Lineker Salmon’ attained 90 cm, the standard height of cut chrysanthemum, only expose to 3 weeks of lighting in winter experiment, and 4 weeks in autumn and spring. ‘Silver Jubilee’ needed 2 weeks in the winter, and 4 weeks in autumn and spring. The temperature of 15~20℃ is optimal for to leaf growing uduring winter in Taipei, furthermore the plant height and node number were increased with the lighting weeks in winter. High temperature in autumn lowered fresh weight per flower and diameter of flower in comparison to other seasons. Lighting for 4, 5, and 6 weeks caused the decreases in fresh weight per flower and diameter of flowers for the high temperature during flower development.
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