颱風後縮短葉菜類蔬菜供應市場時間之品種研究

Abstract

以90年的桃芝與納莉兩次颱風為例，研究莧菜與小白菜交易量與每公斤平均價格變化，可分為搬漲期、合理利潤期、遲滯期與價格崩盤期四個時期。小白菜之飄漲期兩次颱風分別有18與20天，莧菜則有11與20天，災後立即復耕並無法趕上此時期，唯有在設施栽培或露天栽培耐雨品種可以在此期問內收穫。小白菜之合理利潤期兩次颱風分別有3與8天，莧菜則有5與13天屬此一時期，災後立即復耕再選用生育快速品種，不一定可達此一階段，但期間並不長，在小白菜之遲滯期交易量暴增，價格並未立即下跌，但期問非常短，約只有1-3天。而於價格崩盤期，則非常接近災後復耕收獲的時間。小白菜新品系01-17在桃芝颱風、屏東豪雨與納莉颱風三次區域試驗，平均較對照品種增產92.8%，而且是在綱漲期收獲，可增加農民收益。金豐莧菜新品種平均較對照品種增產42.7%，而且由株高平均高出98.7%，推測約可提早2-4天採收，以莧菜在桃芝颱風飄漲期只有11天，能縮短2-4天收穫即非常重要。根據本研究結果，顯示藉由選育更耐雨品種或適合塑膠布溫室栽培的耐熱品種，提供農民使用，可以增加颱風豪雨後的葉菜類供應量，因而增進採用此項做法農民的經濟收益。 Changes of market yield and average price per kilogram of non-heading chinese cabbage and vegetable amaranth, during typhoon periods of Toraji and Nan in 1991, may be divided into four stages, namely, high-price stage, profitable stage, lag stage and breakdown stage. High-price stages for non-heading chinese cabbage were 18 and 20 days, while they were 11 and 20 days for amaranth, after the periods of Toraji and Nan. By using seed-broadcasted method immediately after typhoon, production of non-heading chinese cabbage and amaranth could not timely reach the high-price stage. When cultivated in plastic house or using rain-tolerant cultivar in net house, there was chance to harvest in this stage. Profitable stages for non-heading chinese cabbage were 3 and 8 days, while they were 5 and 13 days for amaranth, after the periods of Toraji and Nan. It was found that when farmers broadcasted seeds immediately after typhoons, it could reach this stage. Lag stage lasted only 1 to 3 days, in which market yield increased significantly and price was as good as in profitable stage. Breakdown stage was near harvest time if seeds were broadcasted right after typhoon. Regional experiments results showed that non-heading chinese cabbage line ‘01-17’ reached high-price stage with the average yield increased 92.8% relative to those from the local cultivars after Toraji and Narin and heavy rainy in Ping-Tung in 1991. Amaranth cultivar ‘Golden Rich’ had averaged yield 42.7% higher than local cultivars in Shiluo, Tainan and Pingtung with averaged height 92.8% higher and harvest date 2-4 days earlier than the local cultivars. Since high-price stage of amaranth after Toraji had only 11 days, the early harvest was very important to farmers. It suggests that selection and breeding of rain-tolerant or heat-tolerant cultivar is a good strategy for farmers to produce leafy vegetable after typhoon and to maintain a reasonable income after disasters.