Rhizobium radiobacter formerly known as Agrobacterium tumefaciens. is the most important bacterial pathogen causing crown gall disease on over 750 different plant species including ornamentals, vegetables and fruit trees. This pathogen causes crown galls on root and stems of plants and rarely on, above-soil parts of plants. Biological control is successfully used in disease management; however, such strategies are quite ineffective in disease contaminated soils or seedlings. Thus, growers and scientists are mostly focused on disease resistant cultivars or rootstocks.