Abstract
Dendroflora is an important component of all urban ecosystems, acts as an accelerator of biogeochemical processes in the soil and serves as a filter to clean the air of toxic compounds. However, the progressive growth of the impact on the urban ecosystem invariably leads to a different kind of dendro-pathogenic problems caused by abiotic and biotic factors. Therefore, the aim of our study was the development of a biological product based on microorganisms - antagonists of phytopathogens and based on the results of microbiological and ecological studies to highlight indigenous strains of Bacillus, having antagonistic activity against a variety of phytopathogenic microorganisms, i.e. trunk rots pathogens of elm