Mosaic on cucumber leaves. Treatment of cucumbers for mosaic

Cucumber mosaic, or cucumber mosaic virus, is a common viral disease that affects plants such as cucumbers, tomatoes, cabbage, bell and hot peppers, lettuce, beans and others. Cucumber mosaic is localized in living cells of susceptible plants, but the virus can persist in dry leaves, stems and soil for up to several decades.

There is no drug to treat cucumber mosaic, so plants affected by the virus must be promptly destroyed.

To defeat this disease, every gardener must understand how plants become infected, what properties the mosaic virus has, and what control measures need to be taken when plants are infected.

Pathogens

The disease is caused by viruses - Cummis virus 2, Solanum virus 1, Nicotina virus 1, and others. These viruses are so small that they are able to pass through the smallest bacterial filters, and that is why they are called filter viruses.

Cucumber mosaic destroys tissue cells, causing damage to chloroplasts, partial destruction of chlorophyll, breakdown of plastids and a decrease in carbohydrate levels. All this leads to the death of tissue areas and the death of the plant.

Until the moment when people did not suspect the existence of the mosaic virus, this disease caused enormous harm to agricultural plants, especially tobacco plantations. Today, several varieties of the disease are known, each of which has its own characteristics.

Tobacco mosaic

The mosaic virus was first discovered in 1892 by Dmitry Ivanovsky. The scientist noticed that when trying to filter a drug from infected tobacco, unknown particles remain in the filtered solution, which retain the ability to infect healthy plants.

Then it was assumed that the filtered solution contained either poison or some tiny creatures that the microscope could not see. This is how the tobacco mosaic virus (TMV) was discovered, and later it turned out that there are quite a lot of varieties of mosaic diseases.

Are you planting cucumbers in a greenhouse or open ground?

GreenhousePriming

Symptoms Most often, this disease affects tobacco, tomatoes, and peppers, but sometimes it can also be seen on cucumbers. A mosaic marble pattern and emerald-beige stains form on the affected leaves. Those parts of the leaf that remain green swell and become lumpy, and subsequently die. The disease affects the quality and quantity of the harvest, the shape and size of the fruit.
Struggle. Soil and dead plant tissue can infect plants planted the following year. Therefore, it is necessary to observe crop rotation annually, planting crops that are not sensitive to mosaic in the infected area.

IN open ground TMV can remain alive for up to 5 years.

Control measures should consist of cutting off the affected parts with a knife, and it is imperative to use a knife treated with alcohol, a solution of manganese or vitriol. To get rid of the virus that remains in the stems and soil, you should burn the affected dry stems exactly in the area where the cucumbers grew.

Ordinary mosaic

Common cucumber mosaic is caused by the Cucumber mosaic cucumovirus (CMV) virus and primarily affects crops grown in greenhouses.

Symptoms

Zonal mosaic, deformation and wrinkling of leaves of young seedlings. As the pathogen develops, the leaf begins to wrinkle, become covered with mosaic spots with dark green and light green areas, and the edges of the leaves curl downwards. The plant stops growing, its leaves become small, internodes become shorter, and the number of flowers decreases. In some cases, you may notice cracking at the base of the stem.

Other cucumber diseases -

Control measures

To kill this virus, you need to keep it at a temperature of 70 degrees for 10 minutes.

The incubation period depends on:

air temperature;
degree of cultural sustainability;
stages of development.

Thus, for resistant varieties the incubation period is about 20 days, for susceptible plants - 5-10 days.

Treatment of ordinary cucumber mosaic is overcome by composting plant residues for two months. In winter, the virus lives in the roots of quinoa, bindweed, woodlice, and thistle. Infection by seeds occurs only in pumpkins.

The fight against cucumber mosaic consists of the following preventive measures:

Throughout the season, as well as in the off-season, it is necessary to monitor the cleanliness of the site and promptly treat it from weeds.
Only sterilized or composted substrates may be used.
If cucumbers grow in a greenhouse, then you cannot plant a pumpkin near it, since it can retain the cucumber mosaic virus.
To destroy surface infection, special treatment must be carried out before sowing. seed material. How to treat seeds? For such purposes, it is recommended to use a solution of trisodium phosphate or potassium permanganate.
During the growing season, spray with a 3% solution of Farmayod-3 at the rate of 0.3 kg of solution per hectare of area.

Green speckled mosaic

The development of green mosaic is caused by the CVD virus. The disease most often affects cucumbers grown in a greenhouse. Bushes that grow in open ground are extremely rarely affected.

The virus can cause crop loss of up to 50%. Green mosaic is also called English cucumber mosaic.

Symptoms

The disease occurs in both adults and young crops. Affected bushes grow poorly, light veins form on the leaves of cucumbers, sheet plates deformed. Spotting appears on the fruits, they become shortened, deformed and taste bitter. If you cut into the fruit of an infected cucumber, you will find that its seeds are underdeveloped. Sometimes the surface of the fruit may become covered with necrotic spots.

The disease can appear as early as 20-30 days after planting seedlings in the ground. As a rule, green mosaic affects pumpkin crops, but in some cases a disease of nightshades, as well as watermelons, cucumbers, and melons is observed.

If the source of infection is seeds, then two weeks after planting, young seedlings begin to get sick, and after a month the plants may die. If the source of infection is soil or weeds remaining in the soil from last year, the first signs of cucumber disease will appear a month after planting the seedlings.

It should be noted that the cucumber green mottled mosaic virus damages both the seed coat and the embryo.

After the plant is infected, the virus begins to spread through the vessels deep into the stem, and then into root system. If, while weeding in a bed with infected cucumbers, their leaves or stems are damaged and the juice gets on neighboring bushes, they will become infected. In addition, healthy plants can become infected even if they come into contact with diseased ones, which leads to an increase in the number of affected bushes.

Control measures.

To protect cucumbers from this virus, it is necessary to use uninfected seeds. To grow a healthy seed bush, set up a high agricultural background, plant seeds there and carefully look after them, preventing the proliferation of weeds.

Many gardeners don’t know what to do if it’s not possible to grow cucumbers for seeds yourself? In this case, a special diagnostic method should be used to determine the absence or presence of infection in seed purchased in a store. To do this, you need to select 10 seeds and homogenize them in phosphate buffer, then add them to the homogenate, crushed to a fine fraction quartz sand. After 10 days, diseased seeds will be covered with mosaic spots.

To prevent cucumbers from getting sick, they should be treated for aphids and other insect pests, since they are the ones who transfer pollen from diseased bushes to healthy ones. Cucumbers must be planted away from pumpkin crops.

As a preventive measure, as well as at the initial stage of the disease, it is recommended to spray cucumbers with one of the following means:

10% solution of low-fat milk.
10% milk skim.
10% solution of skim milk and 5% alcohol solution of iodine.

Treatment of green mosaic of cucumbers is the same as for ordinary mosaic virus. Thus, preparations such as trisodium phosphate and potassium permanganate are used to treat seeds.

If you are planning to spend heat treatment seeds, then the temperature will have to be increased to 90 degrees, since at lower temperatures the virus does not die. But after treatment at such a high temperature, the seed material will become unusable, so this preventive method must be excluded.

Control measures applied to cucumbers grown in a greenhouse should include recording the affected bushes and their timely removal.

White mosaic

Symptoms

First, fuzzy yellow-white spots near the veins begin to appear on young leaves. The spots are shaped like rings or stars. After some time, they acquire a greenish-white color, and as the disease progresses, the spots merge with each other, and the entire leaf becomes white or yellow. Plant growth is inhibited, which affects the quantity and quality of the harvest.

Especially favorable conditions for white mosaics are greenhouses with warm air and severe plant density. Places where pathogens are stored are fruit peels, plant residues, seed embryos, soil and equipment.

Struggle.

Control measures should be aimed at reducing the temperature in the greenhouse below 30 degrees, as well as thinning the plants and timely removal of weeds. It is necessary to remove diseased parts of plants or entire bushes. If at least one spotted mosaic sheet is found on the site, then it is necessary to disinfect work equipment as often as possible.

It should be remembered that treating cucumbers with chemicals is useless, so the fight should be aimed at preventing the spread of the disease and destroying sucking insects, which are the main carriers of the virus.

Medical alcohol is used to disinfect equipment. Before treating parts that have come into contact with contaminated soil and plants with alcohol, it is recommended to carry out preliminary disinfection with boiling water. Preventive measures also include the use of varieties that are resistant to mosaic and protecting plants from the sun in hot, dry times.

General prevention

Since mosaic is not affected by chemicals, it is first necessary to use varieties that are insensitive to the virus.

Mosaic-resistant varieties: Ofix F1, Pasadena F1, Semcross F1, Othello F1. Tolerant hybrid varieties F1 includes: Lord, Verenta, Arina, Zozulya.

The main preventive methods include:

Fight against aphids (for this you can use any remedy against these insects).
Use only healthy material for planting.
Destruction of infected units, as well as soil from under bushes.
Planting plants at a large distance from each other.
Removing weeds from the site.
Blade disinfection garden tools using boiling water, alcohol, vitriol solution (4 tablespoons per 11 liters of water), or manganese solution (2 tablespoons per 1 liter of water).
Annual alternation of planting cucumbers with other plants.
Removing the top layer of soil in the greenhouse (10-12 cm) and replacing it with fresh soil.

The variety of viral plant diseases is enormous. Moreover, it is very difficult to diagnose which virus a plant is infected with. The general viral nature of the disease in a plant can be assumed if spots or stripes of a different color than the leaves themselves form on its leaves.

A large group of viral plant diseases consists of mosaic diseases..

Mosaic plant diseases are a group of viral diseases characterized by mosaic (variegated) colors of the affected organs (mainly leaves and fruits), alternating spots of various sizes and shapes, having a green or white color of varying intensity. The shape of the leaf blade changes, the plant lags behind in growth. Mosaic is transmitted through seeds, with the sap of diseased plants during picking seedlings, during pinching, contact of diseased and healthy plants and slight mutual injury, for example, by wind. Mechanical carriers of the virus are bedbugs, soil. Viruses enter plants through damaged tissue; are stored in soil, plant residues and seeds. Of the mosaics, the most harmful are: tobacco and tomato mosaic, green cucumber mosaic and white mosaic, speckled potato mosaic and wrinkled potato mosaic, beet mosaic, cabbage mosaic, as well as soybean mosaic, peas, beans, mosaic diseases of fruit, shrubs and ornamental plants.

Symptoms

The first signs of damage are found on young growing leaves; they appear faintly lighter along the veins, light yellow rings and star-shaped spots. Subsequently, the spots become greenish-white, and when they merge, the entire leaf turns white or yellow. Sick plants look depressed, with small leaves. White mosaic develops more strongly at temperatures of 30°C and when the plants are too dense. The causative agent of the disease is transmitted with plant sap when caring for it. The pathogen is preserved in the peel and embryo of seeds, plant residues, on equipment and in the soil.

Prevention

There are no effective methods to combat mosaic diseases. The only remedy– disease prevention and breeding varieties resistant to mosaic. In the case of a relatively mild infection, you can try to cut out the diseased areas of the plant, however, if the infection is severe, the plant must be destroyed.

Resistance to the disease decreases with sharp temperature fluctuations, too high temperature(30°C) and too dense placement of plants. Observe the thermal regime. Quite often, the virus spreads with plant pests; carefully monitor their appearance and take measures to destroy them. If a disease is detected, it is necessary to take preventive measures– isolate the plant, disinfect equipment. If the plant dies, thoroughly disinfect the pot and throw away the soil.

Control measures

Accurate identification of a specific viral disease, as already noted, is very difficult. Direct fight against viruses chemicals impossible. It is much easier and more reliable to prevent the disease by combating sucking insects, which, as a rule, are carriers of pathogens of viral diseases. The carriers of indoor flower viruses are aphids and thrips. But very often the infection is introduced even before the plant goes on sale through damaged areas of the roots or wounds on the stems and leaves. All affected parts of the plant must be removed and destroyed. After work, immediately wash your hands thoroughly with soap and wipe the equipment you use with alcohol. Take cuttings only from healthy plants. In dry and hot times, the plant needs to be shaded and sprayed more often.