The influence of catch crops on fungal diversity in the soil and health of oat

The aim of the research was to determine the quantitative and qualitative composition of soil-borne fungi in the cultivation of oat, as well as to assess the healthiness of this cereal. The experiment considered spring barley and potato as forecrops, and white mustard or lacy phacelia cultivated after spring barley as catch crops before oat. The population of fungi showing antagonistic effect towards selected fungi pathogenic to cereal was determined. The most fungi (pathogenic and antagonistic) were found in the soil under oat cultivation after spring barley, while the least after potato. The cultivation of oat after spring barley with the use of catch crops significantly influenced a reduction in the number of fungi obtained from the soil. On the other hand, catch crop cultivation increased the share of antagonists in the soil fungus population. Among the species recognised as antagonistic, Clonostachys rosea, Trichoderma viride, T. koningii, and T. harzianum predominated. The introduction of catch crops, especially white mustard, also positively influenced the healthiness of oat. The average disease index for the tested oat cultivars grown after potato and after spring barley with white mustard and lacy phacelia as catch crops was 11.02, 12.78 and 15.90, respectively, whereas after spring barley it was 21.75.