Citrus canker is a highly contagious bacterial disease that affects various citrus trees. The disease is caused by the bacteria Xanthomonas citri subsp. citri, which can cause lesions on leaves, stems, and fruit, leading to defoliation, premature fruit drop, and reduced yields. Citrus canker can also weaken the tree, making it more vulnerable to other pests and diseases. The disease is commonly spread through wind-driven rain, as well as through human activities, such as pruning and harvesting, which can move infected plant material from tree to tree. Citrus canker is a serious threat to the citrus industry, and many countries have strict regulations in place to prevent its spread.