EN
Pathogenic fungi that occur naturally in agrocenosis play important role in regulation of weed appearance. The exploitation of fungi against Cirsium arvense and other weed species is the most reasonable in ecological farms, where traditional chemical control is not allowed. Our experiments and some other studies show possibilities of biological control of some weeds in Poland. The current work is focused on the assessment of using Puccinia punctiformis and Sclerotinia sclerotiorum as potential bioherbicides. Due to possible epidemiological risk of fungi applied against weeds to cultivated plants, it is necessary to minimize this phenomenon and continue research work concerning especially S. sclerotiorum. It seems, the most suitable crops for weed control with fungi are meadows and grazings.