Each gardener, planting certain crops on a personal plot, is eager to get an unprecedented harvest as a result of his work, which would compensate not only for cash costs, but also for the time and effort spent. However, there are situations in which he althy plants are affected by various diseases, for example, verticillium wilt. This problem may appear when growing strawberries, tomatoes, potatoes, cucumbers. Verticillium wilt is one of the most detrimental diseases that most often affects greenhouse plants.
How does infection progress?
The causative agent of this disease is a special imperfect fungus that is found in the soil. This pathogenic microorganism enters the plant through the roots, which may have microtraumas. Also, its penetration is facilitated by the presence of a large number of root hairs. Further, the fungus lives in the root collar or in the conductive processes of the stem, where they exert their negative effect on the entire plant inoverall.
Features of defeat of tomatoes
The first symptoms that indicate that verticillium wilt of tomatoes begins appear during the period of active flowering. At the same time, the lower leaves begin to turn yellow, most of them become dry and fall off as a result. The upper leaves remain green but curl up.
In the early stages of the development of the disease, the root system looks he althy, but the first impression is deceptive. The roots die with the course of the disease, and this leads to the appearance of secondary phytopathogens.
When examining a cut of a stem, even with the naked eye, you can see a ring of vessels that are affected. They are brown in color. Over time, when the verticillium wilt of tomatoes progresses, vascular necrosis spreads further along the stem, reaching a height of 1 m. It is this feature that distinguishes this disease from similar root rot.
Verticillium wilt of strawberries
The first symptoms appear, as a rule, on new plantings during the formation of whiskers. If the disease affects old plantings, then most often problems begin at the time when the harvest time is right.
Symptoms may vary as they depend on whether a particular strawberry variety is susceptible to Verticillium or not. However, it is the withering of the aerial part of the plant that distinguishes this disease from other similar fungal ones that affect the roots. But stillit is better to contact a specialized laboratory to make a correct diagnosis, and then choose a treatment.
Infected strawberry leaves look wilted, withered, devoid of moisture. Their color changes along the edges and becomes red-yellow or dark brown. New leaves on such a plant, although they are formed, are in small quantities, and almost immediately curl along the veins. If the plant is too heavily infested, it will stop growing, and tendrils and petioles may develop streaks or patches of brown or bluish-black. Growth retardation also affects the roots of strawberries, in addition, they can turn black at the tips.
With severe damage, wilting and death of plants is observed massive, but if only some parts of the plantations die off, then the damage is not too serious and proper treatment will help get rid of the pathogen.
Methods of struggle
If verticillium wilt is diagnosed, treatment will only help if it is started early in the development of the disease. But it is better to simply destroy the infected plant. It is also necessary to carry out disinfection of the soil. To do this, carry out fumigation (fumigation, destruction with toxic vapors or gases) and solarization (biocidal treatment).
Prevention Methods
Popular agricultural practices that can protect plants from exposure to the causative agent of verticillium:
- use of varieties and hybrids that are resistant to this genus of fungus;
- when growingcrops in the greenhouse, before planting new plants, the old substrate must be sterilized or steamed, and not only the surface layer;
- during the growing season, if the plant is still affected by verticillium, it must be removed along with the root system, then a container with soil must be installed in this place so that the new earth does not come into contact with the infected.
And one more piece of advice: in open ground conditions, the soil needs to be healed, for which crops such as rye, vetch, white mustard should be periodically planted in different areas. It is recommended to sow them almost at the very end of the season, and carefully plow the garden in the fall. The resulting plant residues will rot over time, as a result of which saprotrophic organisms will accumulate in the soil, which, in turn, inhibit the growth of pathogenic microflora.