EN
In the experiment carried out in 2001–2004 the influence of irrigation and cultivation system (organic, integrated and conventional) on weed infestation of spring barley was investigated. No effect of irrigation on the number of weeds and their weight was stated. The highest number and weight of weeds were found in the organic system but they didn’t differ significantly in comparison to conventional one. The most the numerous species of weeds were Veronica ssp. and Chenopodium album L.