Angled applications of foliar acting herbicides - influence of various factors under field conditions

摘要

Control of grass weeds with foliar acting herbicides constitutes a very difficult target using standard nozzles with a vertical downward angling of the spray. Angled applications can increase efficacy in some situations. This paper reports on the influence of various factors on efficacy of angled herbicide applications under field conditions. The largest improvement was found using a 60° forward angled spray in combination with a reduced boom height. Angled applications increased efficacy with fine,medium and coarse atomizing nozzles, and there was a tendency towards a larger influence of angling using coarse spray quality. Applications with foliar acting herbicides were tested on some important annual grasses at early growth stages. Angled applications improved control of Lolium perenne and Alopecurus myosuroides, had a small positive influence on control of Poa annua, and did not influence control of Apera spica-venti. The results can be explained by the growth habit where a predominant erect habit gives an improved control whereas species with a more prostrate habit is less influenced.