1Department of Herbology and Plant Cultivation Techniques, University of Life Sciences in Lublin, Poland.
2Department of Botany, Ukrainian National Forestry University, 79057 Lviv, Ukraine.
A strict field experiment with crops sown in crop rotation and monoculture was carried out in the years 1988-2012 at the Experimental Station Uhrusk belonging to the University of Life Sciences in Lublin, south-eastern Poland. The study was aimed at evaluating the structure of weed communities occurring in crop rotation and monoculture of cereals. The highest weed density m-2 was determined in the second (1992-1996) and the third crop rotation (1997-2000), whereas the highest weight of weeds was noted in the third crop rotation. Weed community in cereals sown in crop rotation and monoculture was constituted by species belonging to 6 syntaxonomic classes: Stellarietea mediae, Artemisietea vulgaris, Molinio-Arrhenatheretea, Agropyretea intermedio-repentis, Koelerio glaucaeCorynephoretea canescentis and Bidentetea tripartiti.