Causes and treatment of mosaic on cucumbers: we fight the disease effectively and prevent its occurrence

You can buy cucumbers at any time of the year in almost every store or market. However, a vegetable grown with your own hands is much sweeter and more aromatic.

What to do if spots appear on its leaves, the plant withers, and the fruits lose their appearance and taste? Most likely, a mosaic infestation has occurred and immediate action should be taken. Find out which ones exactly in our article.

What kind of disease is this

Mosaic is a viral disease that affects tissue at the cellular level. Chloroplasts are damaged and chlorophyll is destroyed. At the same time, the processes of photosynthesis and the formation of nutrients are inhibited. Areas of tissue die and the plant dies.

The pathogen attacks many plants: cucumbers, tomatoes, cabbage, peppers, tobacco and others.

For reference. The virus remains viable in soil for decades.

How does it show up on cucumbers?

Mosaicism can be diagnosed by light (white or yellow) spots on the leaves. Over time, the affected leaf plates become deformed and dry out. Some types of mosaics lead to the appearance of dark green stains on the tops.

The virus also infects fruits: cucumbers become distorted, become stained and become bitter.

Why is it dangerous?

Mosaic viruses are not dangerous to humans. Damage consists of partial or complete loss of yield due to the pathogen.

Spread and persistence of infection jeopardizes the well-being of healthy plants and future plantings.

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Types of mosaics

There are several types of mosaics. The most common are tobacco, common, green speckled and white.

Attention! Several types of mosaic disease can develop on one plant at once.

Tobacco

Tobacco, tomatoes, and peppers are more susceptible to tobacco mosaic. Cucumbers are rarely infected.

The causative agent of this disease is tobacco mosaic virus (TMV) – was one of the first to be opened.

Symptoms of the disease:

• beige stains forming a mosaic pattern on the leaves;
• the green parts of the leaf blade are swollen, tuberous;
• withering and dying of foliage with the development of the disease;
• underdeveloped, ugly appearance of the fruit.

Ordinary

The appearance of ordinary mosaic is caused by the Cucumber mosaic virus (CMV). In addition to cucumbers, this variety attacks tomatoes, beans, and cabbage.

Signs of CMV on cucumbers:

• dark green and light green areas randomly located on the leaves;
• edges of the leaf blade turned down;
• cracks at the base of the stem;
• shortened internodes;
• fallen flowers;
• speckled, wrinkled, twisted fruits.

The common mosaic virus dies at a temperature of 60-70ºС within 10 minutes. It is not transmitted through cucumber seeds.

Green speckled

Another name for the disease is English cucumber mosaic.

Pathogen – highly specialized cucumber green mottle mosaic virus (CGMV), or Cucumber green mottle mosaic virus (CGMMV). It attacks only plants of the pumpkin family.

Most often develops in closed ground. Both seedlings and adult plants are susceptible to infection.

Symptoms appear after a sharp rise in temperature to 30ºC:

• leaves become wrinkled;
• the veins acquire a light shade;
• plants quickly wither;
• cucumbers are covered with spots in the form of a mosaic.

The pathogen CGMMV is resistant to heating up to 90ºС, freezing, drying.

White

White mosaic is often accompanied by green speckled and is caused by the Cucumis virus 2A (CV2A) virus.

Favorable environment for the development of the disease becomes a combination of warm air in greenhouses and dense plantings.

Signs of white mosaic:

• small yellow spots near the veins;
• spots in the form of rings or stars of a greenish-white color;
• white leaf color due to fusion of spots;
• slow growth.

The virus persists in soil and seeds.

Causes

The mosaic virus may not appear for a long time. Favorable conditions are required for activation.

Conditions for development

The pathogen begins to develop on weakened plants:

1. Sudden changes in temperature – decrease to 13ºС, increase to 30-32ºС – negatively affect the growth and health of plants.
2. Lack of moisture deprives the superficial root system of cucumbers of nutrients. Excessive watering without loosening leads to the formation of crusts on the soil surface and a lack of oxygen at the roots.
3. Lack of minerals (potassium, magnesium, phosphorus) reduces immunity to infectious diseases.
4. Dry air in greenhouses causes plants to actively evaporate moisture, which leads to an imbalance of salts in tissues.

All of the above leads to stress and reducing the resistance of the vegetable.

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Sources of infection

Infection of vegetables occurs in several ways:

• use of contaminated seeds;
• contact with contaminated plants or plant debris;
• spread by pests - virus carriers (aphids, thrips, mites);
• from weeds, in the roots of which the infection persists;
• planting in contaminated soil.

Treatment of mosaic on cucumbers

It is impossible to cure a plant from mosaic, you can only localize the development of the disease.

At the first sign of infection remove affected leaves and shoots and burn them outside the site. The instrument is disinfected with boiling water, alcohol or a solution of potassium permanganate.

Important! There are no specific antiviral drugs for plants; viruses are not sensitive to pesticides.

For minor damage (up to 20% of foliage) You can treat the area with a weak solution of potassium permanganate. At the initial stage, the development of the disease is stopped by spraying with a solution of whey diluted with water in a ratio of 1:10, with the addition of 15 drops of pharmaceutical iodine per 10 liters of the mixture.

To reduce the risk of spread infections on healthy plants, you can use insecticides that destroy the vector pests.

Comfortable conditions for plants should be restored: optimal humidity, watering mode. It is useful to fertilize with microfertilizers.

In advanced cases with extensive infection, plants are destroyed: burned in the area where they grew. This way the soil is also disinfected by fire.

Preventive measures

The main fight against mosaic lies in prevention. The following measures will help protect the area from disease::

1. Crop rotation prevents the accumulation of viruses in the soil. Cucumbers should be returned to their original place no earlier than after two years.
2. Seed disinfection. Before planting, you need to soak them in a 1% solution of potassium permanganate for 50 minutes.
3. Annual replacement of the top layer of soil (10-12 cm) in greenhouses.
4. Weeding and removal of all plant debris from the site. The roots of perennial weeds retain viruses during the winter.
5. Timely destruction of pests (aphids, mites, thrips and others).
6. Do not thicken the plantings. For 1 sq. It is recommended to plant no more than four plants.
7. Disinfection of garden tools after picking seedlings, pinching, etc.
8. Regular abundant watering and fertilizing.

Useful tips

A few tips and recommendations from experienced gardeners will help you in the fight against mosaic disease of cucumbers:

• plant disease-resistant varieties and hybrids, for example, Thumb Boy f1, Masha f1, Pasadena f1, City Cucumber f1;
• To maintain an optimal microclimate in the greenhouse, place several buckets of water. During the daytime, water evaporation will maintain the required humidity; when the temperature drops at night, the liquid will release the accumulated heat;
• To prevent diseases, use the water-based drug “Farmayod”. To prepare the working solution, take 1 teaspoon of the product per 1 liter of water. Treat plants, greenhouse structures, garden tools.

Conclusion

Mosaic disease is a serious threat to cucumbers. In advanced cases, you can lose the entire harvest. Various types of virus cause tobacco, common, green mottled or white mosaic. The disease manifests itself as light spots and deformation of the leaves. The fruits lose their presentation and become bitter.

There are no special remedies against the mosaic virus, so the fight comes down to prevention. It is important to keep the area clean, promptly weed and remove plant debris, promptly destroy pests and create comfortable conditions for the growth of vegetables.In case of extensive damage, only complete destruction of the plants helps.