臺灣根莖薯類作物線蟲病害之發生

Abstract

本省根莖菜類及薯類作物主要病原線蟲為南方根瘤線蟲(Meloidogyne thcognita)、爪哇根瘤線蟲(M. javanica )、根腐線蟲(Pratylenchus coffeac)、腎形線蟲(Rotylenchulus rerniformis)、穿根線蟲(Hirechinanniella spp.)及葉芽線蟲(Apbe1enchoides besseyi)，而以前二者最重要。蘿蔔、胡蘿蔔、牛蒡、綠竹、麻竹、蘆筍及山葵只有根部感染根瘤線蟲，塊根、塊莖或筍部位並未被其寄生。豆薯、黑皮波羅門參、甘藷、山藥、樹薯、馬鈴薯、芋及薑等作物則連塊根、塊莖及薯塊上都受侵害。除竹類外，遭線蟲為害植株地上部出現黃化、矮化、缺水及缺微量元素病徵，地下部則有結瘤、根腐及儲藏器官表皮突起、凹洞及腐爛等徵狀。與水稻輪作方式有助於降低砂質壤土及黏質壤土馬鈴薯田中根瘤線蟲族群密度；反之，於山坡旱田輪作薑或山藥，根瘤線蟲於作物植後8個月每百公克土壤高達1200隻以上。防治試驗顯示以80 ％滅線蟲、幾丁質有機添加物、塑膠布覆蓋、尿素及氨氮化鈣處理皆能有效防治薑田根瘤線蟲病害。 Nematodes as major parasites of root and tuber crops in Taiwan are Meloidogyne incognila, M. javanica, Pralylenchus coffeae, Roiylenchulus reniformis, Hirschmanniella app., and Aphelenchiodes besseyi. And the two species of root-knot nematode are the most important among them. Meloidogyne spp. only cause typical knotting or galling of roots on Chinese radish, carrot, edibe burdock, bamboo, asparagus and wasabi. In addition, this nematodes parasitizing the tubers, stems, rhizomes and other storage organs produce galls in the outer tissues giving rise to abnormal, warty or knobbly and rot occasionally. Symptom above ground of this nematode infected plants often show early yellowing, falling, wilting at high temperature and stunting. The prolonged flooding employed in the rotating with rice culture obtaining a reduction in the population of root-knot nematode both at the sandy loam and clay loam potato yields. Otherhands, populations of root-knot nematode would soon reach to the high peak of above 1200 per 100 g soil at 8th month after the ginger and yam were grown. The results of the control show that soil treatments of 80 % Nemamort EC., chitinous amendment, plastic mulching, urea and Ca (CN)2 were all beneficial to reduce the populations of root-knot nematodes and root-knot index compared to the check.