Stolbur is usually called one of the most common and dangerous diseases encountered by gardeners (mostly in the southern regions of Ukraine) of tomatoes and other vegetable crops. Typically, infection with this disease has such a detrimental effect on vegetables, including tomatoes, that their yield is sharply reduced by half, or even more. How can you identify tomato stolbur, and what control measures will help cope with it?
How does stolbur affect infected tomatoes?
The appearance of stolbur in vegetables is associated with their infection with the Lycopersicum virus 5 Smith virus, which belongs to the category of phytoplasma microorganisms. 2 types of disease have been identified:
- causes streaks to appear on fruits;
- leads to a change in foliage color to anthocyanin color.
With a large number of pathogenic microorganisms in a plant, this leads to disruption of vital processes that occur in its cells and tissues, which leads to clogging of blood vessels and the development of chloroticity.
Phytoplasmas, as a rule, begin to be located in plant cells along the cytoplasmic membranes. The stronger and more dangerous the manifestations of phytoplasmosis and its consequences for tomatoes will be, the greater the number of their cells that are filled with harmful phytoplasma microorganisms. Also, under the influence of stolbur, there is a sharp decrease in the volume of dry substances contained in the vegetable crop, which also worsens the commercial quality of the resulting fruits.
Symptoms indicating infection of tomatoes with phytoplasmosis
Typically, the manifestation of stolbur occurs on the foliage, flowers and fruits of tomatoes. At the beginning, a change in the color of the plant stems occurs: the tops, shoots, and then the lower leaves of the tomatoes become pinkish-purple, which is due to the high content of anthocyanins in the cells.
The foliage of diseased vegetable crops becomes small in size, chlorotic, and curls upward, resulting in the leaves of tomatoes taking on a boat shape. Due to the fact that the tissues are overfilled with starch, the foliage and stems become rough and brittle.
The affected tomato flowers begin to deform, the sepals increase in size, which can often still grow together, as a result of which they become bell-shaped. Stamens and pistils cannot develop sufficiently, and the petals become small, colorless or greenish.
Important! Such infected flowers, as a rule, are sterile, but if they do form fruits, they are small, woody, and unevenly colored. These tomatoes are prohibited for consumption.
In what ways can stolbur spread?
Phytoplasmosis is an extremely Western disease, the spread of which occurs due to sucking insects, for example, various types of cicadas. In the winter season, mycoplasmas, which are single-celled microorganisms of the causative virus, can persist for a long time in the root systems of perennial weeds, namely milkweed, plantain, etc.
Important! Cicada larvae also usually overwinter there and, by eating the sap of diseased plants, become infected with the virus themselves. Adult insects begin to disperse in mid-summer and, accordingly, infect weeds and vegetable crops with phytoplasmosis.
The rate of development of mycoplasma and its activity changes every year, which is associated with changes in the wintering conditions of insects carrying the disease. If climate conditions do not have a favorable effect on the rate of development, reproduction and migration of vectors (for example, in the region there are very cold and little snow winters), the harmfulness of the tomato column decreases. The opposite effect is observed in areas with high air and ground temperatures.
What are the ways to combat phytoplasmosis
There are no measures to combat tomato stolbur as such. When a plant is already infected with a disease, there is no way to cure it; all that remains is to quickly get rid of the diseased bush in order to protect the rest of the plants.
For this reason, it is recommended to prevent tomato stolbur by carrying out certain preventive measures.
These include:
- disinfection of seeds - they should be kept for 20 minutes. in water that has been preheated to 50 degrees, or disinfect them using a one percent solution of potassium permanganate;
- it is necessary to carefully observe the norms of spatial isolation of tomatoes and other vegetable crops from each other - the distance between areas must be at least 500 m;
- need to be done promptly and regularly mulching the soil under tomatoesusing straw as mulch between rows;
- carry out measures that are primarily aimed at increasing the rate of fruiting of tomatoes (for example, properly selected fertilizing during this period), so that most of the harvest can be harvested before the disease appears;
- periodically, as necessary, fight weeds that accumulate infection, and do this both in the field and on roadsides;
- You can spray tomatoes with insecticides to combat sucking insects, which transmit this disease (three times during the growing season of the plant).
In conclusion, it should be noted that you need to properly monitor and care for vegetable crops, including tomatoes. As a result, it will be possible not only to count on large volumes of tomato harvests, but also to prevent infection of plants with various dangerous diseases.
If you follow the recommendations presented above regarding preventive measures, then you will not be afraid that signs of phytoplasmosis will suddenly appear on your tomatoes. Vegetable crops will actively develop and delight the gardener with abundant tomato harvests for a long time.
