(31(1):59-70)亞熱帶地區之甘藍種子生產

Low temperatures are essential for cabbage flower induction. Most cabbage varieties cannot bloom and produce seeds in the tropics because of insufficiently low temperatures. Some shallow bolting types may flower completely in the highlands but fail to produce seed during the subsequent rainy season. According to the phasic development of cruciferous crops, plants were instead planted in the highlands for first phase (Thermo-phase) development, and then transplanted to the lowlands for second phase development. The materials used were tropical Yehscu cabbage which requires only shallow low temperatures, and the northern K-Y cross Chu -Chiou cabbage which requires a deeper degree of low temperatures. The results show that flowering and seed ripening were accelerated by warmer and dryer (or longer day) conditions after complete vernalization. Seed production is thus possible by using different altitudes in the tropics corresponding to the phasic requirements of cabbage.甘藍之開花需有足夠的低溫，在熱帶地區大部份甘藍品種因低溫不足而不能開花採種。一些低溫要求較淺的品種雖可在高海拔地區開花，但花期逢雨季，致結種子困難。依十字花科蔬菜開花之相的發育（phasic development），可在較高海拔地使其完成第一相（感溫相）之發育，然後移植於平地行第二相（感光相）之發育。 以低溫要求較淺之熱帶型葉深甘藍和低溫要求較深之北方型初秋甘藍為材料。於高冷地春化後再移植於平地，利用其溫暖乾燥的條件促進開花和種子的成熟。因此，依甘藍開花相的發育需要，在熱帶地區可利用不同之海拔行採種