外加亞磷酸可溶性矽及吲哚乙酸誘導香蕉對黃葉病抗性之研究

Studies on the Induced Resistance to Fusarium Wilt of Banana by Exogeneous Applications of Phosphorous Acid, Silicate and Indoleacetic Acid

香蕉黃葉病為當今全球香蕉產業所面臨最嚴重的問題之一。許多資材具有可誘導作物提升對病原菌入侵的防禦及抑制能力。本試驗探討以亞磷酸、可溶性矽、吲哚乙酸及其組合溶液噴施北蕉蕉株及進行根圈土壤灌注後，香蕉黃葉病的發生情形。試區係選用曾連續種植香蕉二年，原擬轉作水稻的罹病蕉園，第一年種植組織培養苗作為測試植株，第二年則以其吸芽苗及宿根苗蕉株進行，其中以未處理蕉株作為對照。組織培養蕉株自三月定植後約2個月即出現香蕉黃葉病外部病徵，罹病蕉株數量逐月增加，各處理至十一月之累積罹病率已達到94.3%~100%，處理間無明顯差異，顯示在本試驗設計下，施用三種資材之個別溶液及其混合溶液對香蕉黃葉病無抑制效果，各處理罹病蕉株之內、外部徵狀均屬嚴重程度。第二年採取土壤灌注方式將個別資材施用於吸芽苗及宿根苗蕉株四週，六至十月計進行5次。在生長期間，各種資材處理之蕉株陸續感病，其結果和組織培養苗蕉株相同。本試驗結果顯示，亞磷酸、可溶性矽及吲哚乙酸等三種物質在田間對香蕉組織培養苗、吸芽苗及宿根苗蕉株均未能表現提升香蕉黃葉病抑制效果。

Fusarium wilt of banana (Musa spp), caused by Fusarium oxysporum f. sp. Cubense, has been identified in Taiwan for nearly fifty years, is the most devastating soil-borne disease in the world’s banana producing countries. Many substances were found to have the capability in promoting the induced defending and inhibiting ability against the invasion of soil–borne pathogens. Phosphorus acid, soluble silicon and indoleacetic acid were tested on Pei-Chiao (Cavendish Subgroup, AAA) to control the disease incidence of Fusarium wilt. Results from the two-year experiment indicated that none of the three substances could suppress the occurrence and the severity of the disease in both the plant cropping and the ratoon cropping. Due to the vast root system of banana plant and the spatial variability in the pathogen of Fusarium wilt, the strategy of applying soil mixtures which were effective to the control of soil-borne diseases in the short term crops might not work similarly and efficiently in the control of Fusarium wilt of banana. To overcome this disease problem, it is recommended that the concept of soil health (or soil quality) and organic farming be involved in the cultivation managements, with the witness of the eighteen years of achievement in the organic banana farming from the Taiwan Banana Research Institute.