Abstract
Tomato plants (Rumba Ożarowska cultivar) grown in the greenhouse of the University of Warmia and Mazury in Olsztyn were treated with the biological control agent Polyversum WP, the growth promoter Biochikol 020 PC, the growth regulator Asahi SL, a mycorrhizal inoculum, and the fungicide Bravo 500 SC. Untreated plants served as the control. After fruit harvest, soil, stem and root samples were collected, and fungi were isolated in the laboratory. The applied biological and chemical control agents effectively reduced the abundance of fungi, including pathogenic species, colonising tomato plants and soil. The fungicide Bravo 500 SC showed the highest efficacy. Amongst the biological control agents, Biochikol 020 PC and the mycorrhizal inoculum were most effective in controlling stem colonisation by pathogens, while Polyversum WP offered the best protection of tomato roots and soil.