EN
Field experiments carried out in the 2005-2007 time period were aimed at assessing the use of competitive potential against weeds of spring cereals cultivated in mixtures, for the purpose of reducing the herbicide application selected for the research. In the experiments, a mixture of the active substances, florasulam + 2,4 D (Mustang 306 SE), was applied at a recommended dose (0.5 l/ha) and then at a reduced dose (0.3 l/ha). The research objects were the spring wheat cultivar Bryza, spring barley cultivar Antek, and oat cultivar Cwał. The cereals were grown in two-species mixtures, and in pure sowing. The effect of a decreased herbicide dose was compared to the effect of the recommended dose, and the control. The research included two-time analysis of crop weed infestation (weed species composition, number, and fresh weight of weeds), determination of the number of productive culms, number of grains per ear (panicle), the thousand grain weight, and grain yield of spring cereals. The obtained results confirmed that spring cereals cultivated in mixtures had a higher competitive potential against weeds in comparison with individual species which were pure sowed. The use of the reduced herbicide dose proved to be effective in weed control and ensured a significant increase in grain yields of spring cereals. The applied herbicide doses did not affect grain number per ear and the thousand grain weight.