The experiment was carried out during 2016 – 2019 on the agricultural lands of the town of Kubrat, Bulgaria. The aim of the study was to establish the effect of some herbicides and herbicide combinations on weed density, as well as on the productivity and yield of winter wheat (Avenue cultivar). The experiment included 8 treatments: 1. Control – untreated; 2. Control (economic) – untreated, weed free; 3. Trimur (750 g/kg tribenuron-methyl) – 0.020 kg ha-1; 4. Sekator (25 g/l jodosulfuron + 100 g/l amidosulfuron) – 1.00 l ha-1; 5. Puma Super (69 g/l fenoksaprop-P-ethyl) – 1.00 l ha-1; 6. Axial (50 g/l pinoxaden) – 0.90 l ha-1; 7. Sekator – 1.00 l ha-1 + Puma Super – 1.00 ml ha-1; 8. Trimur – 0.020 kg ha-1 + Puma Super – 1.0 l ha-1.
All studied herbicides showed good control against the weeds and reduced their density. The structural elements of the yield after the herbicide application, except for the herbicide combination Trimur + Puma Super were higher than those of the untreated control. The herbicide combination Sekator + Puma Super controlled 90.0% of the broadleaf and 100% of the grass weeds and the highest grain yield of 6.550 t ha-1 average for the period was obtained. It is recommendable to use this herbicide mixture in wheat fields with mixed weed infestation. The lowest yield was obtained after the application of Trimur + Puma Super. This was probably due to phytotoxic damage caused by the incompatibility of these two herbicides.
Keywords: wheat, weeds, herbicides, grain yield.