三种苗前除草剂对茅苍术杂草防治效果及安全性评价

为了筛选出防效好、残留少且对环境影响较小的茅苍术苗前除草剂,选取常用的3种苗前除草剂乙草胺、乙氧氟草醚和二甲戊灵,研究其除草效果,对叶绿素荧光参数的影响,农药残留情况及其对土壤微生物真菌和细菌群落的影响。结果表明,乙草胺的除草效果较好,株防效和鲜重防效都达到了80%以上,对茅苍术叶绿素荧光参数影响较小,农残较少,对土壤细菌和真菌群落无显著性影响;乙氧氟草醚和二甲戊灵对叶绿素荧光参数有影响,短时间内有一定的土壤农残。综合防效和安全性,优选乙草胺作为茅苍术的苗前除草剂。

Effects of three pre-emergence herbicides on weed control in Atractylodes lancea and their safety evaluation

This study aimed to screen pre-emergence herbicides with good control effect, low residue, and less environmental impact in Atractylodes lancea field. Three pre-emergence herbicides including acetochlor 50% EC, oxyfluorfen 24% EC, and pendimethalin 33% EC were selected and used after sowing of A. lancea in field experiment. Their efficiency of weed control and effects on chlorophyll fluorescence parameters of A. lancea were investigated, meanwhile, pesticide residues and effects on soil microbial communities were also determined. The results showed that acetochlor had the better effect for weed control, with the plant control efficacy and fresh weight control efficacy of more than 80%. It had less effect on chlorophyll fluorescence parameters of A. lancea , less pesticide residues, and no significant effect on soil bacteria and fungal communities. Oxyfluorfen and pendimethalin had impact on chlorophyll fluorescence parameters, and there were certain soil pesticide residues in short time. In contrast, the safety and stability of acetochlor are higher than those of the other two herbicides. Acetochlor can be used for pre-emergence herbicide in A. lancea due to its control effect, low residue, and less environmental impact.