不同土壤封闭除草剂对南方大豆玉米带状复合种植地的防草效果

Effects of Different Pre-Emergence Herbicides in the Fields with Maize-Soybean Intercropping in Southern China

为解决南方大豆玉米带状间作复合种植杂草难以防治的问题,选用土壤封闭除草剂单剂、复配剂及土壤封闭除草剂单剂+草甘膦异丙胺盐等共8种,开展了复合种植生育中期及后期土壤封闭除草剂对杂草的株防效和鲜重防效研究。结果表明:土壤封闭除草剂复配剂平均效果好于单剂;鲜重防效高于株防效;随着生育进程的推进,株防效和鲜重防效随之降低,株防效降低幅度大于鲜重防效;药后97 d,土壤封闭除草剂鲜重防效依次为精异丙甲草胺+草甘膦异丙胺盐>噻磺·乙草胺>异丙甲草胺>精异丙甲草胺>二甲戊灵>扑·乙>乙草胺,防效分别为84.8%、83.04%、81.52%、80.11%、78.36%、77.35%、67.54%,均可作为湖南及南方大豆玉米带状间作复合种植土壤封闭除草剂使用;唑嘧磺草胺在南方作为土壤封闭除草剂仍需进一步研究。

To control refractory weeds in the fields with maize-soybean intercropping in southern China,field experiments were carried out with eight pre-emergence herbicide treatments including single pre-emergence herbicides,combined pre-emergence herbicides,and single pre-emergence herbicide+glyphosate-isopropylammonium.The control effects on the plant number and fresh weight of weeds in the middle and late stages of crop growth were evaluated.The results showed that combined pre-emergence herbicides outperformed single herbicides,and the control effect on fresh weight was greater than that on plant number.The control effects on both plant number and fresh weight,especially that on plant number,decreased over time.On day 97 after herbicide application,the control effect on fresh weight followed the trend of s-metolachlor+glyphosate-isopropylammonium>thifensulfuron-methyl·acetochlor>metolachlor>s-metolachlor>pendimethalin>prometryne·acetochlor>acetochlor,reaching 84.8%,83.04%,81.52%,80.11%,78.36%,77.35%,and 67.54%,respectively.These pre-emergence herbicides can be used in the fields with maize-soybean intercropping in southern China.The application of flumetsulam as a pre-emergence herbicide in southern China remains to be further studied.