EN
Studies were conducted in 2004–2006 to determine weed infestation in oats/narrowleaf lupine mixtures according to the share of components in the mixture (100 + 0, 75 + 25, 50 + 50, 25 + 75, 0 + 100%). The significantly lowest number and air-dry weight of weeds were determined when oats was grown in a pure stand. Both the values were the greatest when narrowleaf lupine was cultivated in pure stand. A reduced share of oats and increased share of narrowleaf lupine in the mixture were followed by an increase in weed infestation. The experimental factor did not affect the species composition of weeds in the mixtures. The following species were dominant: Chenopodium album, Capsella bursa-pastoris, Agropyron repens, Veronica persica, Polygonum aviculare.