Biological activity of Pythium oligandrum against Phytophthora species

Influence of Pythium oligandrum as an a.i. of Polyversum on population dynamic of Phytophthora cryptogea in peat and development of Phytophtora rot on gerbera, Lawson cypress and yew-tree were evaluated. Drenching of peat, artificially infested with P. cryptogea, with Polyversum immediatelly after gerbera planting resulted in significant decrease of colony forming units number within 4 weeks. Concentrations of the biopreparate used had no significant influence on its greater, biological activity. Drenching of plants with Polyversum at conc. 0.05 or 0.1%, after planting into peat infested with P. cryptogea or P. cinnamomi, resulted in the strong suppression of Phytophthora foot or root and stem rot of gerbera, cypress and yew-tree.