Disease name: Try lemon
The scientific name: fawcettii
The type of disease: Bacterial pathogen
Disease family: Sphaceloma fawcettii
- Definition of the disease:
Lemon scab is a serious fungal disease that affects all varieties of lemon, and also affects all parts of the lemon tree.
- Symptoms:
Light brown wart-like blisters or crusts form on the leaves, stems, and fruits. The scales are gray or pink at first and become darker as the infestation ages. Old lesions of the crust become rough to the touch and become cracked and fissured, while the leaves become stunted, wrinkled, and have irregular torn edges.
- Disease life cycle:
Mushroom spores are produced in peels and then spread through wind and rain spray. Insects may also help spread it over long distances. The spores need 4 hours to germinate, after which they can become susceptible to infection. Leaves, stems, and fruits are infected when they are young, but they become resistant to infection when they are Full size.
- The causes of disease:
Leaf moisture is the most important factor in determining infection. When conditions are appropriate, lemon leaves are susceptible to infection when the flow of new growth is less by 25%, and immature lemon fruits are more susceptible to infection than ripe ones.
- Suitable conditions for the disease:
- Wet conditions favor the development of the disease.
- Most germs come from infected young lemon fruits.
- Temperature does not appear to have a significant effect on disease.
- Losses due to disease:
The fungus causes deformation of the leaves and causes an unattractive infection on lemon fruits. The infection reduces the market value of the fruits but is unlikely to affect the quality of production. The infection on seedlings in the nursery is more serious as it makes it difficult to graft, such as the rough lemon and lemon rangpur. , and the trifoliate poncerus.
- Control:
- Fungicides can be used to control fungi. They should be applied to plants in nurseries at the beginning of leaf growth to prevent infection, but it is important that the instructions for use are followed carefully to avoid harming the plants or the environment.
- Copper (copper oxide) or chlorothalonil are suitable options.
- Treating mature lemon trees is not recommended, as they produce multiple crops such treatments are unlikely to be economical.
- Preventive measures:
Prevention is the best way to control lemon scab. This can be achieved by selecting resistant varieties and applying good agricultural practices, establishing nurseries to produce seedlings and cuttings away from commercial farms where the disease may be present, and pruning trees regularly to remove sources of spores and improve air movement.
English 
Arabic