ABSTRACT
The long-distance spread can occur by the movement of infected citrus planting material, or by the movement of plant material infested with huanglongbing infected psyllids. Citrus problems such as physiological disorders, pest, and disease damage and nutritional deficiencies are the main causes of low yield of citrus fruits, but disease having a negative impact on fruit quality as well as the marketing of the citrus fruits. Citrus greening or huanglongbing is one of the most important and severe diseases of the citrus tree. It has reduced citrus fruit yields and quality in all types of citrus wherever it occurs in Asia, from China and the Philippines to the Arabian Peninsula, and to Africa. Bacterial cells over the season in leaf, twig, and on fruit canker lesions. During warm, rainy weather, they ooze out of lesions and, if splashed by rain onto young tissues, bacteria enter them through stomata or wounds.
