EN
The presence of microorganisms in the substrate is detected with increasing frequency using chemical methods. During the first 9 weeks ergosterol concentration in sterile or not sterile soil inoculated with one of the damping−off fungi reached 966 µg/g, while number of colony forming units (cfu) went up to 247×103 cfu/g. Ergosterol concentration was correlated with the size of the soil fungal community estimated in terms of the number of colony forming units in soil. Pearson's correlation coefficient was 0.700−0.946 for sterile and not sterile soil. Higher content of ergosterol was observed for F. sambucinum var. sambucinum, H. haematococca and T. cucumeris while higher average content of cfu was observed for H. haematococca and T. cucumeris.