The aim of this research was to study the influence of L. plantarum ONU87 on the development of crown gall infection in grape plants by artificial inoculation of R. radiobacter C58. Methods. Grape shoots were inoculated by pathogenic and antagonistic cultures. A total of 295 Pinot Black grape shoots were used. The cut off basal ends of grape shoots were placed into bacterial suspensions or into control liquids, kept for an hour and then immediately planted and left in a greenhouse for rooting. The morphological parameters of the grapes were evaluated in 30 days. In 90 days, rhizobia were isolated from the treated grape shoots and their pathogenicity was detected by PCR. Results. It was established that the treatment of grape shoots, previously artificially infected with R. radiobacter C58, by the L. plantarum ONU87 strain reduced the amount of infected samples by 76.8% and stimulated growth and development of grapes. An increase in the number of viable grape shoots reached 18.8% in comparison with the ones infected with phytopathogenic rhizobia. The number of buds that bloomed increased by 21.5–33.9%. Conclusions. The obtained results, the better condition of the experimental plants treated by L. plantarum ONU87 and the absence of negative effects of the large numbers of the introduced microbiota, allow to consider the lactobacilli treatment as a way to significantly reduce the infection of grape shoots with pathogenic rhizobia during their cultivation.