Abstract
Of all the agricultural pests and diseases that threaten citrus crops, citrus canker is one of the most devastating. The disease,
caused by the bacterium Xanthomonas axonopodis pv. citri, occurs in large areas of the world's citrus growing countries including
India. At least 3 distinct forms or types of citrus canker are recognized. Among these, Asiatic form (Canker A) is the most destructive
and affects most of the major citrus cultivars. Severe infection of the disease produces a variety of effects including defoliation,
dieback, severely blemished fruit, reduced fruit quality and premature fruit drop. Warm, humid, cloudy climate, along with heavy
rainfall and strong wind promotes the disease. Control of canker in countries or regions where the disease is not present include
quarantine or regulatory programme to prohibit introduction of infected citrus plant material and fruit, as well as continuous and strict
surveying in the field and the immediate destruction of infected trees. In countries where canker is present, integrated systems of
compatible cultural practices and phytosanitary measures consisting of resistant hosts, removal of inoculum sources, properly
designed windbreak systems, timely application of protective copper-containing and/or antibiotic sprays are generally the most
effective means of disease management. This paper reviews the current state of knowledge and understanding on pathogens and
strains associated with the disease and their identification, host-pathogen interaction, molecular mechanism of pathogenicity,
epidemiological aspects and management practices.