Abstract
A method of controlling the pathogenic agent Agrobacterium tumefaciens consists of the use of biological control means through preimmunization with avirulent or weakly virulent sources and the microbial antagonism, or with products of their metabolic activity. The paper presents research conducted under laboratory conditions with the use of „in vitro” methods for establishing the virulence of bacterial strains belonging to the Bacillus spp., on Agrobacterium tumefsciens pathogenic agent. During the attempts of limiting and preventing tumorgenesis triggered by the Agrobacterium tumefsciens pathogenic agent in vine plants, the effectiveness of certain biological products has been tested, thus following the administration of biological products based on Bacillus subtilis. In accordance of strands used for preparing the biological product inhibit the evolution of bacterial colonies of bacteria, and pathogenic action of the Agrobacterium tumefsciens bacterium. The inhibition of pathogen ranges from 100% to 17.99% and calculated concentration limits variations value has been between 1.97 and 2.98, compared to the untreated witness.