The process of care for tomatoes in a greenhouse requires many operations, among which an important place is given to the prevention and control of disease. Greenhouse conditions have a number of advantages in comparison with open ground. The ability to maintain favorable for the growth of tomatoes, temperature is the main advantage of the greenhouse.
The disadvantages of greenhouses include weak circulation and high risk diseases.
Due to weak air circulation, the accumulation of moisture that encourage the development of mold and rot. In conjunction with high temperatures, such conditions are becoming favourable for the development of pathogenic microorganisms causing diseases of tomatoes.
Diseases of tomatoes are divided into two categories: fungal and viral diseases. The first caused by microorganisms — fungi, which multiply rapidly in warm and humid environment, and the second viruses. Viral disease transmitted most often through insect pests.
Fungal diseases of tomatoes
Late blight of tomatoes. This is one of the most common diseases to deal with which is very difficult.
Signs of late blight on leaves appears white coating on stems and lower leaves you can see the brown spots. The disease affects the fruits under the skin of the affected tomatoes you can see the brown spots. The main reason for the development of Phytophthora — sudden changes in temperature temperature and a high humidity in the greenhouse.
Methods of struggle: the treatment of seedlings before transplanting in the greenhouse with fungicides, creation of favourable climate, maintaining optimum temperature, daily airing of the greenhouse.
Grey rot. The disease develops under conditions of high humidity and low temperature.
The signs of the disease: the appearance of small spots on the fruit, in the process of development of the disease beginning to exude liquid with an unpleasant odor, the appearance of grey mold.
Methods of struggle — the removal of diseased fruits, the heating of greenhouses, ventilation and treatment with fungicides.
Alternaria blight. This disease is also called a dry spot, it affects the stems and leaves, and sometimes fruit. The development of the disease starts from lower leaves and gradually going up.
The symptoms first on the lower leaves have large patches of round shape. Then the leaves begin to turn yellow and wither. Gradually, the leaves and stem die off.
Methods of struggle: treatment with antifungal drugs if the plants show signs of disease. If the plants already have fruit the ovary, then the treatment is carried out at biologics.
Preventive measures: replacement of the soil every 1-2 years, pre-sowing seed treatment, seedling treatment with fungicides, regular airing of the greenhouse remove side shoots of tomatoes.
Mosaic. Vector-borne diseases are pests that feed on SAP from the leaves. Additionally, infection of plants can occur if you remove side shoots or at planting of the infected seeds.
The main symptom of the lesion is a mosaic appearance on leaves spots of different colors. On one Bush at the same time appear yellow, brown and unusual green spots.
Control measures: seed soaking before sowing in a weak solution of potassium permanganate, selection of varieties with high resistance to mosaic.
Mycoplasmosis. The disease can take half of the harvest of tomatoes. Source of infection — vonkova for ordinary high rot leafhopper. Contamination of land by weeds also increases the likelihood of infection.
Signs: deformation of flowers, their intergrowth, deformation of the fruits, they become stiff, lose their taste.
Control measures include destruction of weeds and maintenance of cleanliness of the beds, apply insecticides against leafhoppers remove infected plants.
The bronze. The second name — virus wilting. The carrier of the disease — tobacco thrips.
Symptoms — necrosis, Curling and deformation of leaves, the appearance of them brown bands.
Control measures: spraying of plants by insecticides against the thrips, removal of diseased plants.
To prevent viral diseases to combat pests, use sterile tools when cutting and remove side shoots of each plant.