Xanthomonas citri is a bacterium that causes citrus canker, a disease affecting various citrus plants, including oranges and lemons. This pathogen leads to the formation of lesions on leaves, stems, and fruit, which can reduce crop yield and quality. The bacterium spreads through rain, wind, and contaminated tools, making it a significant concern for citrus growers. Effective management strategies include using resistant plant varieties, applying protective sprays, and practicing good sanitation to minimize the risk of infection.