How to treat tomato gray leaf spot

1. Symptoms of the disease

Gray leaf spot generally only affects the leaves of tomatoes. In the early stages of the disease, dark circular spots will appear on the surface of its leaves, and they will expand around along the veins, usually in irregular shapes. Then the middle of the leaf will fade to grayish white or grayish brown, the lesions will become sunken, and the leaves will become thinner. Eventually the leaves will crack and become perforated, and in severe cases they will fall off.

2. Causes

Tomato gray leaf spot is a disease caused by a fungus. If disinfection is not done properly in winter, the pathogens will remain on the seeds. When the temperature and humidity are suitable for their growth in the second year, they will begin to infect the plants. In addition, it can also be spread through wind and rain, expanding the area of ​​infection. If the plant is weak, it is more susceptible to these diseases.

3. Treatment Methods

When you find that the plant is sick, you need to immediately cut off the diseased leaves and bury or burn them in a concentrated area. This will completely eliminate the pathogen and prevent the possibility of recurrence. Afterwards, use drugs such as carbendazim or thiophanate-methyl to spray the plants. The spraying area should be comprehensive. Although it only infects the leaves, some residues may remain on the stems or branches.

4. How to prevent

To prevent tomato gray leaf spot, you must first choose good seeds. Generally, you should choose varieties with strong disease resistance, which can reduce the possibility of disease. Secondly, we must strengthen daily management, apply phosphorus and potassium fertilizers in time, and improve the plant's disease resistance. In addition, during periods when people are prone to disease, it is also necessary to do a good job of dehumidification and increase ventilation to prevent the growth of germs.