 Since this bacterium cannot live in soil for more than a few weeks and survives as inoculum on plant debris, removal of dead plant material and chemical applications to living plants are considered effective control mechanisms.Classification of the "Xanthomonas" species that cause bacterial leaf spot is currently in flux.Up until a few years ago, bacterial leaf spot causing Xanthomonads were divided into four groups, A, B, C, and D, based on pathogenicity and physiological characteristics.