非農藥資材對三種白粉病之田間防治試驗

Abstract

白粉病為許多經濟作物包括瓜類、蘋果、葡萄及玫瑰等之重要病害，每年均會造成巨大的經濟損失。白粉病以化學防治為主，但農藥長期地施用也產生了對施藥者安全危害、殘毒及環境生態衝擊等問題，故以非農藥資材防治白粉病是一個理想的對策。在本研究中以散油劑、沙拉脫、泡舒及Tween 20乳化之葵花油和窄域油進行田間白粉病防治試驗。結果發現以1% Tween 20乳化之葵花油對月橘、大波斯菊和紫薇白粉病均有良好的防治效果，其防治效果可分別達79.9%、76.3%，61.4%、61.0%及53.6%。窄域油以水稀釋300倍亦能使三種白粉病降低50.4%以上，而各種油類處理均較傳統化學藥劑對照組免賴得稀釋3000倍液 (對月橘、大波斯菊和紫薇白粉病防治率依序為42.5%、50.3%，32.2%、36.3%及31.9%) 具有較高的防治效果。在孢子發芽試驗中，各種油類處理和對照組相比，均具有顯著抑制孢子發芽的效果，推測此為油類防治白粉病的作用機制之一。未來可將葵花油和窄域油推廣至重要經濟作物白粉病防治上，以減少農藥之使用。

Powdery mildew is a serious disease of many important economic crops including cucurbits, apple, grape and rose. It causes great economic loses every year. Many fungicides had been developed for the control of powdery mildews. However, frequent use of fungicides has raised public concern regarding worker safety, consumer healths, and the environment pollution in recent year. Controlling the powdery mildews with non-pesticide method is an ideal strategy. In this study, sunflower oils emulsified with oil dispersant, Salatt, PAOS, or Tween 20, and narrow-range oil were tested to control the powdery mildews in the field. Results indicated that 1% sunflower oil emudified with Tween 20 has the greastest control efficacy against the powder mildews of common jasmin orange, common cosmos, and common crape myrtle with control rate of 78%, 61%, and 54%, respectively. The narrow-range oil at 300 fold dilution also decreased the desease severity for more than 50.4%. All oil treatments were more effect than benomyl on control of powdery mildews. In the conidial germination tests, all sunflower oil treatments decreased the conidial germination rate, significantly. The inhibitions of conidial germination were observed and may be the control mechanism of sunflower oil. Our data indicate that sunflower oil and narrow-range oil can be applied to the control the powdery mildews.