Department of Agrotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
The Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Gatton, Queensland, Australia.
PLoS One. 2020 Mar 2;15(3):e0229817. doi: 10.1371/journal.pone.0229817. eCollection 2020.
In conservation agriculture systems, farmers gain many advantages from retaining crop residue on the soil surface, but crop residue retention in these systems may intervene with the activity of pre-emergence herbicides. A pot study was conducted to evaluate the effect of different rates of pre-emergence herbicides [imazethapyr (100 and 150 g a. i. ha-1), isoxaflutole (100 and 200 g a. i. ha-1), metolachlor (1.5 and 2.25 kg a. i. ha-1), pendimethalin (2.25 and 3.38 kg a. i. ha-1) and prosulfocarb + metolachlor (2.5 and 3.75 kg a. i. ha-1)] on seedling emergence and biomass of Echinochloa colona and Chloris virgata when applied in the presence of sorghum residue at rates equivalent to (0, 3 and 6 t ha-1). When seeds of E. colona and C. virgata were not covered with sorghum residue, the seedling emergence and biomass of both weeds was inhibited by 93-100% and 56-100%, respectively, with the application (both rates) of isoxaflutole, metolachlor, pendimethalin and prosulfocarb + metolachlor. Using sorghum residue resulted in lower herbicide efficacy on both weeds. At 3 t ha-1 sorghum residue, E. colona emergence and biomass reduced by 38-100% and 30-100%, respectively, with application of isoxaflutole, metolachlor and pendimethalin (both rates) in comparison with the no-herbicide treatment. Similarly, the emergence and biomass of C. virgata was also reduced by 92-100% and 25-100%, respectively. The results of this study suggest that crop residue may influence efficacy of commonly used pre-emergence herbicides and that the amount of crop residue on the soil surface should be adjusted according to the nature of the pre-emergence herbicides to achieve adequate weed control.
在保护性农业系统中，农民从保留作物残茬在土壤表面获得了许多好处，但这些系统中的作物残茬保留可能会干扰芽前除草剂的活性。进行了一项盆栽研究，以评估不同剂量的芽前除草剂[咪草烟（100 和 150 g ai ha-1）、异噁唑草酮（100 和 200 g ai ha-1）、甲草胺（1.5 和 2.25 kg ai ha-1）、二甲戊灵（2.25 和 3.38 kg ai ha-1）和砜嘧磺隆+甲草胺（2.5 和 3.75 kg ai ha-1）]对高粱残茬存在时稗草和马唐幼苗出苗和生物量的影响，高粱残茬的施用量相当于（0、3 和 6 t ha-1）。当稗草和马唐的种子未被高粱残茬覆盖时，应用异噁唑草酮、甲草胺、二甲戊灵和砜嘧磺隆+甲草胺（两种剂量）会分别抑制 93-100%和 56-100%的杂草幼苗出苗和生物量。使用高粱残茬会降低两种杂草对除草剂的效果。在 3 t ha-1 的高粱残茬下，与无除草剂处理相比，应用异噁唑草酮、甲草胺和二甲戊灵（两种剂量）会分别导致稗草出苗和生物量减少 38-100%和 30-100%。同样，马唐的出苗和生物量也分别减少了 92-100%和 25-100%。本研究结果表明，作物残茬可能会影响常用芽前除草剂的效果，并且应根据芽前除草剂的性质调整土壤表面的作物残茬量，以实现充分的杂草控制。
