Jop, BeataMarczewska-Kolasa, KatarzynaWójtowicz, TomaszKucharski, MariuszSynowiec, Agnieszka2025-10-292025-10-292025-09-25Journal of Plant Protection Research 65 (3), 2025ISSN: 1427-4345 eISSN: 1899-007X10.24425/jppr.2025.155789https://bc.iung.pl/handle/123456789/3832Silky bentgrass (Apera spica-venti L.) is one of Central Europe’s most troublesome mono cotyledonous weeds of winter crops. This study aimed to analyze the competitiveness of biotypes of silky bentgrass against winter wheat, depending on the type of soil substrate and nitrogen fertilization. In this research, in a pot experiment during two seasons, the effect of bentgrass plants, of different sensitivity/resistance to herbicides, on winter wheat was studied in an additive model. It was carried out on sandy or clay soil, either non-ferti lized or fertilized with nitrogen. The competitive indices were calculated based on several wheat morphological and yield features. Multivariate analysis was incorporated to interpret the data. As a result, it was found that wheat performance was affected by bentgrass com petition. No clear effect of soil type and nitrogen fertilization on the competitiveness of A. spica-venti biotypes was demonstrated. Only in one season was the pyroxsulam-resistant biotype competitive to the winter wheat when grown on fertilized clay soil. Further re search with varied numbers of winter wheat and bentgrass is advised to assess crop-weed effects further.enadditive competition modelcrop performanceherbicide resistanceArticle