本研究探討除草劑平速爛(penoxsulam)2.7%水分散性油懸劑，在臺灣地區不同氣候環境下施用，對一、二期作移植水稻田雜草之防除效果及稻株藥害之評估，以提供安全有效之使用方法，作為農民在田間應用之參考。試驗分別在桃園區農業改良場、台中區農業改良場及高雄區農業改良場三場附近農田內進行。桃園場一期作田面雜草主要為稗草及球花蒿草，其他包括木虱草、鴨舌草、紅骨草、鳢腸及母草；台中場以稗草、螢藺、鴨舌草及鱧腸為主，少部分為畔茅及球花蒿草；高雄場以稗草、鴨舌草及碎米莎草等為主，其中稗草密度較高。桃園場二期作主要為尖瓣花及母草，其他尚包括稗草、螢藺、球花蒿草、木虱草、鴨舌草及紅骨草等；台中場之稗草、鴨舌草、母草及尖瓣花均零星分布於田面；高雄場以稗草、鴨舌草及球花蒿草為主，其中鴨舌草之密度較高。調查雜草發生株數所估算之藥效試驗結果顯示；每公頃施用1.0公升或1.5公升平速爛2.7%水分散性油懸劑，對稗草、螢藺、球花蒿草、鴨舌草、尖瓣花及母草均有明顯之防治效果；但期作間之比較，桃園場在兩期作之殺草效果均與對照藥劑無顯著差異；台中場以二期作之防治率較佳；高雄場二期作之效果普遍較一期作為差。以雜草總生物量估算之藥效試驗結果顯示；桃園場測試藥劑對植株鮮重之影響較株數之抑制明顯。台中場調查結果鮮重與株數之變化趨勢相近。高雄場一、二期作之鮮重與株數之反應不一致。藥害試驗結果顯示；測試藥劑平速爛對稻株株高及分蘗之影響，與人工除草區之稻株無明顯差異。此外三試驗場各處理之稻株產量，亦均與人工除草區無顯著差異。綜合本研究所得之藥效及藥害試驗結果，測試藥劑平速爛2.7%水分散性油懸劑，於雜草2-4葉時，以每公頃1.0公升或1.5公升施用，均可有效防除稗草、螢藺、球花蒿草、鴨舌草、尖瓣花及母草等水田雜草。同時對稻株生育及稻穀產量，亦未引起株形異常、生長抑制及減產等藥害現象的發生。

Chemical weed control with effective and highly active herbicides has been very useful and convenient means. It has contributed to stable crop production and is labor saving. Recent herbicides have had characteristics such as high effectiveness without causing environmental pollution or harmful effects, and appropriate herbicides having high activity, low toxicity, high selectivity and being non-persistent have been developed. Penoxsulam was applied for weed control in transplanted and direct-seeded rice field. The experiments were conducted by Taoyuan, Taichung, and Kaohsiung District Agricultural Research and Extension Stations to evaluate penoxsulam for rice crop tolerance and efficacy of weed control. Echinochloa crus-galli, Cyperus difformis, Schoenoplectus juncoides, Monochoria vaginalis, Lindernia procumbens, and Sphenoclea zeylanica. were controlled with high efficiency by applications of penoxsulam Weed with 1.0 and 1.5 L/ha. Penoxsulam at 1.0 and 1.5 L/ha was safe on tested rice cultivars. They can be applied at 2-4 leaf age of paddy weeds after rice transplanting and have to date proven very effective in the control of a wide range of annual and perennial broad leaf weeds, as well as sedges.