Viral diseases on tomatoes | Website about growing plants

Almost all tomatoes are affected by the viral infection this season. The manifestations of viruses on crops are less noticeable. At the end of summer, when more favorable conditions for tomatoes develop, the plants may form fruits with fewer “viral” defects, but they will not be the same as on healthy bushes.

Viral diseases have no cure. They are warned. Of course, not everything depends only on summer residents.They can treat the seeds before sowing, observe the nightshade crop rotation on their site, but they are not able to reduce the natural foci of viral infection, which have become much larger, since there is now more uncultivated land than two decades ago. Weeds that grow in abandoned areas are reservoirs of viruses.

What viruses are there?

Tomatoes are affected by tomato mosaic virus, cucumber mosaic virus, potato virus X, etc. It is difficult to protect plants from each of these pathogens. The infection picture becomes more complicated when plants are “attacked” by several viruses at once: a complex streak develops.

Tomato mosaic is a viral disease that is transmitted by seeds. Externally, the disease can manifest itself as variegated coloring, threadlike leaves, the appearance of dark streaks and stripes (streaks) on leaves, stems, petioles, and necrotic spots form on the surface of the fruit.

Dead areas may form inside the fruit. More often this happens on lower fruits that develop in conditions of low light and high humidity.

Another mosaic virus, the common mosaic virus, is transmitted by aphids. And this disease causes threadlike leaves. Some strains of common mosaic virus cause dieback of the tops of tomato bushes.

Carriers of another virus - tomato leaf bronzing - thrips are considered.

Tobacco thrips is the most common. This polyphagous pest can feed on hundreds of species of plants, but it prefers onions, from which it spreads to other crops.

Characteristic signs of damage by the bronzing virus are bronze spots on the surface of the leaf, death of the tops of the plant (however, new stems grow later).

The main vector of cucumber mosaic virus is aphid (melon, bean, peach, potato, etc.).

The very common melon aphid feeds on wild vegetation in the spring, and later, when everything in the field dries out in hot weather, it moves to vegetable crops. During a season, aphids can produce up to 20 generations.

Another polyphagous pest, the leafhopper, transmits stolbur. The leafhopper not only feeds on different plants; it needs a variety of them for normal development. The leafhopper is not very comfortable in weed-free beds, and therefore visits them less often.

Pest control is the main, but not the only link in the prevention of viral diseases of tomatoes and other crops. Even summer residents who are far from selection have long noticed that not all varieties and hybrids are affected by viruses to the same extent; there are also those that resist infection.

Therefore, when choosing varieties and hybrids for cultivation on your site, you need to be guided not only by the taste, color, size of the fruit, but also take into account the resistance of varieties and hybrids to viral and mycoplasma diseases. And rely not only on the annotations of the manufacturing companies, but also on your own observations.

Agricultural technology plays a large role in the prevention of viral diseases.

Tomatoes, starting from the seedling period, must be provided with light, water, and a balanced diet. The beds must be free of weeds, because aphids, leafhoppers, thrips bring infection to tomatoes and other vegetable crops from field bindweed, chicory, sow thistle, shepherd's purse, plantain, black nightshade and other weeds.

Sow seeds collected from healthy plants, preferably after 2-3 years of storage.The seeds are sorted, leaving only well-made, full-bodied ones, and heated for three days (on a radiator). Disinfect for 15-20 minutes in a solution of potassium permanganate (1 g per liter of water at room temperature - 20-25 degrees), then the seeds are washed for half an hour in running water and dried. Disinfection can be carried out immediately before sowing or 3-4 months before it.

During the seedling period get rid of plants with “deviations in appearance” (color and shape of leaves, developmental delays, etc.). They are also cleared from plants with signs of viral diseases in the garden bed, if there are only a few such bushes.

This is done in order to prevent the spread of the disease. If there are many affected plants, there is no point in removing them. They continue to be looked after in order to get at least some harvest.

Increases resistance to mosaic virus by spraying plants at the beginning of the growing season with a solution of boric acid (1 g per liter of water).

For it is better to use fertilizers complex fertilizers to avoid an overdose of nitrogen, which reduces plant resistance to viruses.

During the growing season, to prevent fungal and bacterial diseases, use biological protection agents (alirin-B, gama-ir, phytosporin-M, phytolavin).

In the fall, remove and bury plant debris deeply (at least to the tip of a shovel).