The relation between sweet potato growth stages and thermal units

甘藷為台灣重要的雜糧作物之一，適合生長於高溫，潮濕且日照充足的環境，在台灣一年四季皆可栽培。但台灣屬於季風氣候且地形豐富，每年都會面臨許多天然的環境災害，且不同季節與地區環境差異甚大，甘藷所需的栽培時間不一致，因此若利用環境因子建置一個作物生長曆，更有效的規劃甘藷栽培時間。本試驗利用不同月份種植甘藷，使其生長期間經歷不同的溫度，並選出一次分枝、二次分枝、90%覆蓋率以及地下部塊根形成作為時期劃分的特徵，制定甘藷生育時期的積溫。結果發現，地上部氣溫基礎溫度約為10°C，最適溫度約為32°C，而台農57號一次分枝生育度數約為136~ 182 GDD、二次分枝生育度數約為418~541 GDD、90%覆蓋率生育度數約為988~1136 GDD；台農66號則一次分枝生育度數約為172~322 GDD、二次分枝生育度數約為476~572 GDD、90%覆蓋率生育度數約為757~988 GDD，地下部方面，土溫基礎溫度約為10°C，最適溫度約為24°C，而台農57號塊根形成始期約為443~494 GDD，到了約900 GDD時為塊根膨大期，台農66號則塊根形成始期約為411~504 GDD，到了約900 GDD時為塊根膨大期，而塊根成熟期時，兩者生育度數分別約為1620~2125 GDD與1609~2153 GDD，在這之後塊根乾物累積效率可能較差，為適合採收時間，但最後採收適期的時間仍須依生產者目的與市場需求，選擇適合大小採收。Sweet potato (Ipomoea batatas L.) is one of most important crop in Taiwan. It favors in growing with the high temperature, high moisture and high sunshine condition, and can cultivate all of the year in Taiwan. However Taiwan often encounters the tropical monsoon climate with rich terrain and much natural disaster every year. Plant in the different seasons and area, the best harvest day will be different. If there is a growing calendar made up of environment factors can be more easy to plan for the planting days. In this thesis, two sweet potato, Tainong 57 and Tainong 66 are planted in different month through the different temperature and other environment factors. Primary branch, secondary branch, 90% coverage, and the storage root formation were chosen to be the feature of growth stage. Found that the base ambient temperature and optimum ambient temperature of shoot were 10°C and 32°C. The growing degree days of Tainong 57 first branch was about 136 to 182 GDD, secondary branch was about 418 to 541 GDD, 90%coverage was 988 to 1136 GDD. The growing degree days of Tainong 66 for first branch was about 172 to 322 GDD, secondary branch was about 476 to 572 GDD, and 90%coverage was 757 to 988 GDD. On the other hand, the base soil temperature and optimum soil temperature of root were 10°C and 24°C. The growing degree days of Tainong 57 storage root formation phase started at 443~494 GDD, and Tainong 66 started at 411~504 GDD. When growing degree days was reached 900 GDD, the storage root started to thicken. And the storage root mature phase of Tainong 57 and Tainong 66 were 1620 to 2125 GDD and 1609 to 2153 GDD. After then the efficient of dry matter accumulation of storage root may became lower. It was the time to harvest. But the best harvest time would still depend on the purpose of producer and the marketability by choosing the suitable size of storage root.摘要 i Abstract ii 目錄 iii 圖目錄 v 表目錄 vii 縮寫字對照表 ix 中文縮寫 ix 英文縮寫 ix 第一章 、前言 1 第二章 、前人研究 3 一、台灣甘藷生產現況 3 二、甘藷的形態與生長特性 4 三、作物生育時期的劃分 7 四、甘藷生長發育時期的劃分 10 第三章 、材料方法 12 一、試驗材料 12 二、生產栽培方法 12 三、資料調查方法 13 四、積溫計算 14 五、統計分析 14 第四章 、結果 15 一、不同種植時期的氣象因子變化 15 二、甘藷的發育進展 18 三、甘藷的發育進展與積溫的關係 25 四、甘藷生育時期與乾物質的分配 67 第五章 、討論 76 一、甘藷基礎溫度與最適溫度 76 二、甘藷各部位生長與積溫關係 76 三、甘藷生育時期的劃分 77 第六章 、參考文獻 80 附錄 8