本研究主要針對丁拉免速隆(butachlor+bensulfuron-methyl)、百速隆(pyrazosulfuron-ethyl)及本達隆(bentazon)三種已登記之水田除草劑，配合雲林莞草在一期及二期作氣候下之生長與繁殖特性，進行防治時機及用藥量之藥效試驗，作為此雜草防除策略擬訂之依據。本試驗選擇直徑約1.5 公分之雲林莞草健康種球，種植於裝有一般田土之栽植盆內，於種後7日以不同劑量之供試藥劑分別處理已萌發之種球，並比較施藥前後株數、株高、葉數、鮮重及地下部種球數等藥效評估指標之差異。結果顯示在一期作氣候環境下，丁拉免速隆以登記量或2倍劑量處理，對雲林莞草種球萌芽株數等生長勢相關之性狀有明顯抑制作用，於二期作下各測試劑量之表現，則與對照處理均無明顯差異。百速隆對雲林莞草種球生長之影響，於二期作下，與丁拉免速隆之作用趨勢相近，一期作之抑制效果則呈劑量相關反應，且2倍劑量對植株鮮重及地下部種球數之抑制率高達90%以上。本達隆對雲林莞草各項生理性狀之抑制作用，不受期作氣候環境之影響，以1/2登記量之最低測試劑量處理後，植株即呈死亡現象。綜合三種測試藥劑在一、二期作氣候環境下，對雲林莞草種球生長之抑制作用，顯示丁拉免速隆在一期作下之有效劑量為2倍登記量，二期作下2倍登記量之最高測試劑量亦無法顯現控制效果。百速隆於一期作下使用1/2登記量即達顯著防治效果，二期作下之抑制作用呈現劑量相關反應。至於本達隆以1/2登記量處理後，於一、二期作下均達極顯著之抑制效果。

Bolboschoenus planiculmis is considered as a noxious weed causing serious damage to crop production. The reproductive ability of this weed species through rhizomes and tubers provides this species with a unique competitive advantage over many crops. This research was conducted to investigate the efficacy of three herbicides, i.e., pyrazosulfuron-ethyl, mixture of butachlor + bensulfuron-methyl, and bentazon, at three doses in the first and second cropping seasons for controlling the perennial weed in transplanting rice field of Taiwan. When it was sprayed at 0.66 kg a.i./ha (half of the recommended rate) in two seasons, bentazon completely controlled tuber growth and there was no re-growth up to seven weeks after spraying. The fresh weight of tuber was also reduced drastically after herbicide application. At 7 days after tuber emergence, an application of pyrazosulfuron-ethyl at 0.05 kg a.i./ha (recommended rate) had an excellent weed control in the first cropping season, and provided a less suppression of tuber growth and reproduction in the second cropping season. Mixture of butachlor and bensulfuron-methyl at 1.5 kg a.i./ha (two-fold of the recommended rate) prevented tuber formation significantly in the first cropping season, whereas it showed poor control in the second season.