Remediation of an ALS resistant Apera spica-venti population - a three-factorial long-term experiment

Abstract

A multi-year experiment, was started to remediate a field with a high population of wind bent grass (Apera spica-venti), in the region of Hanover. The wind bent grass on this field is ALS resistant. The crop rotation is winter rape-winter wheat-winter wheat. The experiment consisted of 3-factors. The first factor presented the tillage (ploughing once/mulch drilling). The application of Kerb Flo (propyzamide) in years when rape was grown (with Kerb Flo / without Kerb Flo) was integrated into the experiment as a second factor. The third factor was the treatment with 9 different cereal herbicides in years of cereal cultivation. The results show, that ploughing once significantly reduced the population of wind bent grass in the subsequent 3 years. However, the population increased again afterwards. The application of Kerb Flo, mainly in plots with cultivator treatment, had a positive effect on the number of wind bent grass plants in the following year of cereal cultivation. In addition, the Kerb Flo application had a positive effect as it caused a rotation in the mode of action (Kerb Flo = HRAC group K). The application of cereal herbicides led to different effects. The herbicide Broadway (florasulam and pyroxsulam, HRAC: B) showed the most reduced efficacy on the wind bent grass population. This once more confirmed the ALS resistance of the wind bent grass on this field. Concerning the cereal herbicides best results were obtained when the soil herbicide Herold SC (diflufenican and flufenacet) was applied in autumn.