【目的】冀谷33是抗咪唑乙烟酸谷子(Setaria italica)品种,在生产实践中通过喷施咪唑乙烟酸除草剂可达到间苗、除草的目的,适应规模化、集约化种植。论文旨在通过研究咪唑乙烟酸对冀谷33生长发育的影响及对后茬作物的安全性,为冀谷33的应用和推广提供依据。【方法】试验于2013年5月至2015年6月在河北省农林科学院谷子研究所郄马试验站进行,试验设置0、56.25、75、112.5、150、225 g a.i./hm^26种咪唑乙烟酸剂量水平。对冀谷33生长发育的影响试验在田间进行,用药后7、10、13、16、20、25和30 d,分别调查统计苗高和鲜重;成熟期调查株高、穗长和穗径,并统计小区产量;并对小米、谷壳、植株和土壤中的残留进行检测。对后茬作物的影响试验在网室进行,研究其药后30、60 d和药后1年播种的8种后茬作物白菜、冀谷19、冀谷33、甜菜、高梁、玉米、小麦、棉花的安全性。【结果】56.25-225 g a.i./hm^2剂量下,冀谷33正常生长,无明显药害。药后不同时期对冀谷33苗高、鲜重的影响结果表明,喷药谷子苗高和鲜重与对照相比差异不显著;药后13—16 d处于拔节期初期,为苗高敏感期,药后20—25 d处于拔节期末期、孕穗期初期,为苗重敏感期,之后抑制逐渐解除,收获时冀谷33生长发育正常,产量高于对照。只有喷施225 g a.i./hm^2咪唑乙烟酸的植株中检测到(0.01±0.006)mg·kg^(-1)少量残留,低于检测限LOQ,其余处理均未检出。随着咪唑乙烟酸施药时间的增长,对后茬作物的抑制作用有所减轻,在药后1年播种的后茬作物中,株高差异显著,仅对白菜、高梁产量有显著影响。在夏谷区喷施咪唑乙烟酸的田地,冀谷33可与玉米、小麦、棉花轮作种植。【结论】施用56.25-225 g a.i./hm^2咪唑乙烟酸对冀谷33安全,对其生长发育和产量没有显著影响。随着咪唑乙烟酸施药时间的增长,对后茬作物的抑制作用有所减
[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.
