The present research aimed at evaluating the de-weeding influence of the stubble crops including species composition, number and weight of air-dried weed in spring oats grown in monoculture. The experiment was set in four replications by means of the split-blok method on the stand after spring barley. The type of stubble crops (white mustard, fiddleneck, winter rapeseed, and a mixture of legumes: narrow-leafed lupine+field pea) annually ploughed after the oats harvest was the experimental factor. Only mechanical nursery operations were applied during the experiment; it consisted in harrowing made at 3-4 leaves stage. The highest number of weeds per 1 square meter area was recorded in oats cultivated after a mixture of legumes (narrow-leafed lupine+field pea). As compared to the mixture of legumes, the number of weeds per 1 m 2 was significantly lower after a winter rapeseed, fiddleneck and on the control object. For three experimental years, ploughed stubble crops did not significantly modify the weight of air-dried weed in oats canopy. Chenopodium album was the dominating weed on all experimental plots. The lowest number of this species was observed on the control object, while the highest in oats sown after white mustard.
