We study mosaic plant diseases
The variety of plant viral diseases is huge. Moreover, it is very difficult to diagnose which virus the plant is infected with. The general viral nature of the disease in a plant can be assumed if spots or strips of a color other than the leaves themselves form on its leaves. A large group of plant viral diseases is formed by mosaic diseases.
Mosaic plant diseases are a group of viral diseases characterized by a mosaic (motley) color of the affected organs (mainly leaves and fruits), alternating spots of various sizes and shapes, with green or white color of varying intensity. The shape of the leaf blade changes, the plant lags in growth. The mosaic is transmitted through seeds, with the juice of diseased plants during a dive of seedlings, when it is pinching, the contact of sick and healthy plants and slightly injured, for example, in the wind.
Mechanical virus carriers - aphids, bedbugs, ticks, soil nematodes. Viruses enter plants through damaged tissue; stored in soil, plant debris and seeds. Of the mosaics, the most harmful are: the mosaic of tobacco and tomato, the green mosaic of cucumber and the white mosaic, the speckled mosaic of potato and the wrinkled mosaic of potato, the beet mosaic, the mosaic of cabbage, as well as the mosaic of soy, peas, beans, mosaic diseases of fruit, shrub and ornamental plants.
Symptoms of Mosaic Diseases
The first signs of damage are found on young growing leaves; they appear faint brightening along the veins, light yellow rings and star spots. Subsequently, the spots become greenish-white, when they merge, the entire sheet turns white or yellow. Sick plants look oppressed, with small leaves. White mosaic develops more strongly at a temperature of 30 ° C and when the plants are too thickened. The causative agent of the disease is transmitted with plant sap when caring for it. The pathogen is preserved in the peel and seed germ, plant debris, in the inventory and in the soil.
Mosaic disease prevention
There are no effective methods to combat mosaic diseases. The only remedy is the prevention of diseases and the cultivation of varieties resistant to mosaic. In the case of a relatively mild infection, you can try to cut out diseased areas of the plant, however, if the infection is strong, the plant must be destroyed.
Resistance to disease decreases with a sharp fluctuation in temperature, too high temperature (30 ° C) and too dense placement of plants. Observe thermal conditions. Quite often, the virus spreads with plant pests, carefully monitor their appearance, take measures to destroy them. If a disease is detected, it is necessary to take preventive measures - isolate the plant, disinfect the equipment. In case of death of the plant, the pot should be thoroughly disinfected, the soil should be discarded.
The exact definition of a specific viral disease, as already noted, presents great difficulties. Direct control of viruses with chemicals is not possible. It is much simpler and more reliable to prevent the disease by fighting sucking insects, which, as a rule, are carriers of viral pathogens. The carriers of indoor color viruses are aphids and thrips. But very often, the infection is brought before the plant goes on sale through damaged sections of the roots or wounds on the stems and leaves.
All affected parts of the plant must be removed and destroyed. After work, wash your hands immediately with soap and water, and wipe the used equipment with alcohol. Take cuttings only from healthy plants. In dry and hot times, the plant should be shaded and sprayed more often.
Varieties of mosaic diseases
The causative agent of the disease is C virus. Small yellow-green patches appear on the young leaves, and then wrinkles. Plant growth slows down, flowering is inhibited. The fruits become variegated and warty.
Often diseased plants wilt. From diseased plants to healthy viruses, the aphids are transmitted. In addition to pumpkin, this virus affects nightshade and umbrella crops. The pathogen hibernates in the roots of perennial weeds.
Green speckled mosaic
Distributed only in protected ground. External signs of the disease have much in common with an ordinary mosaic. The virus is stored in the seeds. It is transmitted contact when caring for plants.
They only affect plants in greenhouses. Yellow and white star-shaped spots appear on the leaves. Often the entire leaf blade becomes white, only the veins remain green.
Deformation of the leaves is not observed. On the fruits, yellow and white stripes develop. The virus is transmitted by contact when caring for plants, but it is not transmitted by insects. It is stored in seeds and on plant debris.