Bacterial spot xanthomonas euvesicatoria pv. There are three distinct syndromes of the disease.
Fruit quality and size will be reduced.
Citrus fruit diseases. Typical lesions of the disease are raised tan to brown in color and have a water soaked margin and yellow halos. Citrus canker is a highly contagious bacterial infection of citrus trees causing yellow halo like lesions. Citrus canker lesions are raised unlike the sunken twig scars from hail injury or the roundish discoloring on fruit from cold and sunburn.
Huanglongbing citrus greening candidatus liberibacter asiaticus. Stubborn disease bud mite chimera and tristeza also can cause misshapen fruit. Citrus canker is a bacterial disease caused by the bacterium xanthomonas axonopodis.
Black pit fruit pseudomonas syringae. Citrus canker is a disease caused by the bacterium xanthomonas citri subspecies citri. Other less common diseases which may plague lemon trees are.
Citrus canker is spread by wind driven rain and can be spread mechanically by transportation of trees infected limbs and fruit. From there the fungus can infect young citrus and create blemished fruit. Leaves will exhibit yellow flecking leaf cupping and light green to yellow leaf veins.
Report to agricultural officials this exotic disease if found in california. Stubborn disease bud mite chimera and tristeza also can cause misshapen fruit. Fruit can develop a lopsided shape if trees are infected with citrus greening.
Greasy spot is another. Armillaria root rot dothiorella blight tristeza twig dieback stubborn disease exocortis. Canker creates lesions on leaves fruit and stems and can damage overall tree health and fruit production.
Branches and trunks will exhibit pitting and if it is serious they will take on a ropey appearance. Note the notch on the left margin of the leaf which is symptomatic for this disease. Citrus variegated chlorosis xylella fastidiosa.
The first symptom of citrus chlorotic dwarf on a leaf of a rough lemon seedling after inoculation. Infection causes lesions on the leaves stems and fruit of citrus trees. Melanose is a fungal infection of young citrus fruit caused when spores produced by the asexual stage of the disease phomopsis citri grow in dead tree wood and twigs and then spread to leaves under cool wet conditions.
Quick decline stem pitting and seedling yellows. Melanose is a fungal infection of young citrus fruit primarily but not exclusively grapefruit. Citrus diseases citrus canker.