[Objective] This study aimed to investigate the safe dosage of imazethapyr for an imazethapyr resistant millet variety and its effect on weed control. [Method] The Imazethapyr resistant millet ＂M1508＂ was used as the experimental material and the experiment was arranged in a split plot design with two factors： herbicide application time and herbicide dosage. Application time was taken as the main plot with six treatments： A1 （preemergence treatment）, A2 （postemergence treatment on the 3rd d）, A3 （postemergence treatment on the 6th d）, A4 （postemergence treatment on the 9th d）, A5 （postemergence treatment on the 12th d）, A6 （postemergence treatment on the 15th d）; spraying dosage（B） with nine treatments： B1 （0 ml/hm2 , taking water as control）, B2 （750 ml/hm2 ）, B3 （1 125 ml/hm2 ）, B4 （1 500 ml/hm2 ）, B5 （2 250 ml/hm2 ）, B6 （3 000 ml/hm2 ）, B7 （4 500 ml/hm2 ）, B8 （6 000 ml/hm2）, B9 （7 500 ml/hm2 ）; water was added at 675 kg/hm2 . [Result] Imazethapyr showed a good herbicidal effect, and the imazethapyr resistant new variety M1508 also had a high drug resistance; the dosage range of 750 -7 500 ml/hm2 was safe for millet; considering the weed control efficacy, the yield and weeding cost comprehensively, postemergence treatment on the 6th day at 1 500 -2 250 ml/hm2 was the best for herbicide application. [Conclusion] Matched chemical weeding techniques to imazethapyr resistant millet varieties were preliminarily identified, and the efficacy of imazethapyr on weed control and its security on millet were investigated, providing references for the application and promotion of imazethapyr resistant millet varieties.
