Stolbur is one of the most common (especially in the southern regions of Ukraine) and harmful diseases of tomatoes and other nightshade crops. The yield loss, in this case, can be more than 50%. All about how to protect plants in your garden. The causative agent of the tomato column is the Lycopersicum virus 5 Smith virus, which belongs to phytoplasmas organisms.
What Happens to a Tomato Infected Column?
There are two types of columnar: one causes striation and mottling of the fruit, the other causes anthocyanin color of the leaves. A strong population of the plant with harmful organisms provokes a disruption of the processes occurring in its cells and tissue systems, which leads to vascular blockage and chlorosis.
Phytoplasmas are located in plant cells mainly along the cytoplasmic membranes. The more tomato cells are filled with phytoplasmas, the stronger the disease manifests. The commercial quality of the fruit affected by the column is deteriorating due to a sharp decrease in their dry matter content.
Signs of Tomato Tail Infection
A column of tomatoes appears on the leaves, flowers, and fruits of plants:
- The tops, young shoots, and later the lower leaves become pink-purple in color as a result of the accumulation of anthocyanins in them.
- The leaves of diseased plants become small, chlorotic, twist up, acquiring the shape of a boat.
- From overfilling of tissues with starch, leaves and stems become coarse and brittle.
- Affected flowers are deformed, sepals increase in size, often grow together and take the form of bells. Stamens and pistils – underdeveloped; the petals are small, often colorless or green. Such flowers are usually sterile, and if fruits are formed on them, then they are small, ligneous, unevenly colored.
- Affected fruits are unsuitable for consumption.
Methods for Distributing Tomato Columns
Stolbur is a very contagious disease, spread by sucking insects, in particular, various types of cicadas. In winter, mycoplasmas (unicellular microorganisms – pathogens) persist in the roots of perennial weeds (plantain, thistle, spurge, elderberry grass, etc.). On the roots of weeds, the larvae of cicadas also winter, which, eating the juice of diseased plants, are affected by the causative agent of the disease.
In mid-June, adult cicadas settle and infect weeds and nightshade crops with a column. The intensity of the development of mycoplasmas can vary from year to year, depending on the wintering conditions of the disease vectors. If climatic conditions do not contribute to the development, reproduction, and migration of insects (in particular, in harsh winters with little snow), the harmfulness of the tomato column is reduced. The development of the column contributes to the high temperature of air and soil.
Measures to Combat the Column of Tomatoes
- Seed disinfection (disinfection for 20 minutes in water heated to 48-50 ° C, or a 1% solution of potassium permanganate).
- Compliance with the norms of spatial isolation of tomatoes and other nightshade crops among themselves (sites should be at a distance of at least 500-1000 m from each other).
- Mulching the soil between rows of straw.
- Carrying out activities aimed at accelerating the fruiting of tomatoes (for example, proper feeding during the fruiting period) in order to collect the bulk of the crop before the onset of the disease.
- A systematic fight against weeds that accumulate infection, both in field crop rotation and on roadsides.
- Spraying plants with insecticides against sucking insects – carriers of pathogens (3-4 times during the growing season). In particular, you can use drugs such as Actelik 500 EU, ke 0.3-1.5 l / ha, Bi-58 new 40% ke 0.5-1.0 l / ha, Mospilan 20% r.p. 02-0.3 kg / ha and others.