山藥之品種特性與生產促進研究

Abstract

山藥為薯蕷科（Dioscoreaceae）薯蕷屬（Dioscorea）多年生蔓性作物，係世界十大根莖類作物之一，具高產及富含營養之特色，可供食用、藥用與保健利用。山藥之塊莖又稱擔根體，有滋養、強壯及止瀉功效，能滋陰又能補氣，為常用保健生藥材料；傳統醫藥最早之本草藥典「神農本草經」即將山藥列為上品藥材之一。山藥塊莖之營養價值很高，粘度大，富含植物性蛋白質、必需氨基酸、黏液質、多糖體，具礦物元素P、K、Ca、S、Mg，及微量元素Fe、Cu及Zn等，為消化不良、食慾不振及脾胃虛弱者之補虛聖品，極適合生食或烹調成各式精美之菜餚。 山藥為農業試驗所正發展之重點特用作物，多年以來，本所即不斷進行山藥種原之引進、繁殖、評估與篩選工作，同時進行優良品系之觀察、比較、特性調查、品質分析、病虫害防治、區域試驗、栽培技術提升與多元化產品之開發等研究。本所目前正推出試作之十多種山藥新品種系，即分別具備高產、優質及獨特塊莖特色，這些山藥品種系正在名間、埔里、竹山、二水、左鎮、苗栗、花蓮、基隆等鄉鎮地區推廣。由於適合各個地方之品種有別，所以慎選優良抗病蟲之合適品種，為山藥生產促進之首要措施。山藥之種植方式可分為一般高畦及塑膠穴管兩種，以塑膠穴管誘導種植法最值得推介。塑膠穴管及添加有機栽培介質（管內裝填或田區混施）之種植法，除了可以促進產量之外，另可改良塊莖之形狀，使薯形肥大整齊、薯皮光滑，增進不少商品價值，另就採收之省工，以及採收時塊莖幾無破損率而言，穴管栽培之山藥都較一般栽培者佔盡優勢，深具參考利用價值。台灣之氣候土質很適宜山藥生長，栽培管理簡單，且病蟲害不多，若能選擇適當高產優質品種，且田間管理得宜，並多方開發新鮮利用及加工產品，則塊莖收量與品質將不至太差，可因此提高農民不少收益。 Yam (Dioscoreaceae, Dioscorea spp.) is one of the most important root crops in the world due to its high yield potential and nutritional value and can be recommended for table use, processing, and medicinal purposes. Its tubers have been usually used as food or particularly used as a crude drug by people suffered from indigestion, anorexia, and diarrhea for thousand years as recorded in Shennung’s Herbal, the first pharmacology testament of Chinese herbs. Because of many superior characteristics in the flesh of yam tubers like high quality of nutrition, high viscosity, and high contents of protein, amino acids and many mineral elements etc., the tubers possesses many medicinal effects such as healthful for general tonic and nourishing, stomachic, and antidiarrhea etc. Studies on the development and utilization of yam are currently emphasized by Taiwan Agricultural Research Institute (TART). For many years, the germplasm of different types of yam have been collected, propagated, evaluated and selected in this institute. A total of 10 superior varieties and lines has been selected and extended to many county areas in Taiwan after a series of testing on tuber yield, flesh quality and disease resistance and after a series of comparisons including acclimatization, observation, and preliminary, advanced, and regional yield trials. In order to increase the production potential of yam, the cultivating method using half plastic pipes is strongly recommended because the tubers produced from this method were so easily harvested and were uniform in shape with high appearance quality and no mechanical damage was found after harvest so that a higher price of the tubers could be expected. Experimental results showed that a higher mean tuber yield of yam could be obtained from the plastic-pipe cultivating method when organic mixed media were filled not only in the pipes but also were additionally mixed in the plot soil. Yam is particularly suitable to the climate of Taiwan. It can be easily grown in all areas having an altitude lower than 1,000 meter, with vigorous growth and without serious diseases. In order to increase significantly the income of yam farmer, it is necessary to continue to introduce more yam germplasm, to select more superior varieties, to develop more efficient cultivating techniques, to improve tuber quality, and to produce more products obtained from fresh utilization or from processed methods.