ABSTRACT The grass species Alopecurus myosuroides Huds., Lolium multiflorum Lam. and Bromus sterilis L. are abundant and dominant weeds in European winter wheat fields. They cause significant yield losses and impede grain harvest. Many populations of these grass weeds are resistant to one or more herbicide modes of action in Europe. Therefore, additional non‐chemical control measures are needed to suppress these weed species. In this study, grass weed panicle cutting, chaff milling and a combination of both treatments were examined as potential control measures to reduce the entry of grass weed seeds into the soil seed bank. An untreated control and a standard herbicide application served as control treatments. Five field trials in winter wheat were carried out in 2023/2024, two with A. myosuroides at the University of Hohenheim (UHOH, Germany) and the Julius Kühn‐Institute (JKI, Germany), two with L. multiflorum at UHOH and Bavarian State Research Centre for Agriculture (LfL, Germany) and one with B. sterilis at the Czech University of Life Sciences (CZU, Czech Republic). For the cutting treatment, panicles of the three grass weeds were cut closely above the winter wheat canopy and removed from the field two times during the vegetation period. As part of the second treatment, winter wheat chaff was collected during or after harvest and processed after harvest with a stationary impact mill. Herbicide efficacy, grass weed panicle density, grass weed seed density and seed germination rate were measured for each treatment. Grain yield was assessed at the time of winter wheat harvest. Cutting above the wheat canopy reduced panicle density of A. myosuroides on average by 22%, B. sterilis by 47% and L. multiflorum panicle density by 63%. At the second date of cutting, almost all panicles of B. sterilis were below the wheat canopy. Therefore, only one cut was performed in the field trials at CZU. Post‐harvest milling destroyed on average 39% of the A. myosuroides seeds, 78% of the L. multiflorum seeds and 90% of the B. sterilis seeds in the chaff fraction. However, these grass weeds retain only 40%–60% of their seeds on the panicles until harvest, which impedes the efficacy of the treatments. Therefore, the combination of cutting and milling led to a reduction in weed seed density of only 10% for A. myosuroides , 63% for B. sterilis and 85% for L. multiflorum . In conclusion, panicle cutting and chaff milling constitute effective strategies for long‐term population control of L. multiflorum . The data of a single, non‐repeated study show that B. sterilis weed seed return can also be reduced with panicle cutting and chaff milling. However, both treatments did not decrease weed competition and yield losses in the year of treatment. Therefore, these measures need to be combined with other preventive and direct weed control measures.
Gerhards et al. (2026) studied this question.