不同覆蓋材料對茭白幼苗生長影響之研究

Studies on the Effect of Cover Materials on the Growth of Coba (Zizania latifalia Turcz.) Seedlings

青殼品種茭白在臺灣南部地區冬季育苗期間利用隧道棚整根苗法及配合塑膠布覆蓋保溫育苗，可提高苗床溫度及增加可供定植苗與健壯苗之育苗率，利用透明塑膠布與淡藍色塑膠布覆蓋不但可以提高茁床之溫度各8.2°C及6.7°C ，而且可以促進幼苗植株高度與鮮重之增長，但不能促進提早幼苗之萌芽時間及增加根冠之萌芽數，若以一般農民慣用之可供定植苗之植株高度80～100公分及健壯苗高度100公分以上之幼苗而言，利用透明塑膠布及淡藍色塑膠布保溫育茁之育苗率各高達76.9%及69.6%，而一般農民慣用之育苗法僅17.2%。若以一般農民慣用之可供定植茵植株鮮重8.1~12.0公克及健壯苗12公克以上之幼苗而言，以透明塑膠布及淡藍色塑膠布保溫育苗之育苗率亦各高達58.8%及44.2%，而一般農民慣用之育苗法僅13.2%，由此試驗結果可知茭白在臺灣南部地區冬季利用塑膠布保溫育苗效果極佳，此種育苗技術足可提供農民育苗之參考與應用。

Dormancy crown of coba (Zizania lalifalia Turcz. ), cv. Green Shell, were used as experimental material at present study. There were five treatments, included: a) Crown reversed put in a nursery bed covered with a tunnel shaped transparent plastic sheet. b) Crown reversed put in a nursery bed covered with a tunnel shaped pale blue colored plastic sheet.c) Crown reversed put in a nursering bed covered with two layers of a tunel shaped jute bag. d) Crown reversed without any covering (check 1). This is the normal nursery method used by farmers and e) Crown notreversed without any covering (check 2). The experimental results indicate that the nursery bed temperature is increased 8.2°C and 6.7°C as compared with check plots when the bed is covered with a tunnel shaped transparent and pale blue colored plastic sheet respectively. Only a little increase in nursery bed temperature was observed when it was shaded with jute bags. The plant height and fresh weight increased when the nursering bed was covered with either transparent or pale colored plastic sheet, but germination time and rate were not changed. when classified according to seedling plant height, good guality seedlings were between 80~100 cm and the best seedlings were higher than 100 cm. The percent suitable for transplanting in the transparent and pale blue colored plastic sheet treatments were 76.9% and 69.6% respectively. while the method used by farmers had only 17.2%. However, if classified according to fresh weight of young seedlings, seedlings suitable for transplanting weighted between 8.1~12.0 g and the best seedlings were heavier than 12 g. The percentage of suitable seedlings from the treatments covered with treatments covered with transparent and pale blue colored plastic sheet were 58.8% and 44.2% respectively. While the farmers method had only 13.2%. The data show that a nursery of coba seedlings covered with transparent or pale blue colored plastic sheet will be more productive in southern Taiwan during cool winter season and the materials required are available and inexpensive.