本文報導2,4-D當做萌後殺草劑時之施用時期、劑型、方法及濃度對水稻發生藥害和水田雜草防除之效果。於水稻有效分蘗決定期及最高分蘗期(一期作為移植後35及45日,二期作為25及40日)使用時藥害最不明顯且殺草效果最佳。2,4-D異丙基酯(2,4-D-IPE)粒劑較2,4-D鈉鹽(2,4-D-Na)粉劑的藥害小,但兩者藥效相若;2,4-D鈉鹽粉劑撒施較噴施藥效相當。微量施用2,4-D鈉鹽粉劑具有賀爾蒙效應,使水稻株型發生改變,但並不影響產量。
The application of 2,4-D rovided good weed control with remarkably mild rice toxicity at either middle-tillering stage or late-tillering stage (35 and 45 DAT in the first crop, 25 and 40 DAT in the second crop). 2,4-D-IPE was less toxic than 2,4-D-Na to ric plants, whereas weed control effects were almost the same. Split application not only had better efficacy on weed control, but also caused less injury than spray application to rice plants. Lower rates of 2,4-D caused the change of plant type, but without influence on rice yield.