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SYMPTOMS OF BACTERIAL DISEASES

When bacterial diseases affect large sections of an entire leaf or plant, BLIGHT results. This photo shows bacterial blight of geranium caused by the bacterium Xanthomonas campestris pv. pelargonii. Because bacterial pathogens tend to be restricted in their movement by veins, often blighted areas on leaves caused by bacteria have a wedge shape. The widest area of the wedge is at the edge of the leaf, the narrowest area near the petiole.