Description of potato alternaria, treatment and main measures to combat the disease

Fungal pathologies are a scourge for vegetable crops. Thus, alternariosis of potatoes and other nightshade crops leads to the loss of a third of the crop. For pathogenic fungi, the ideal breeding environment is an air temperature of 25-30 degrees Celsius and high air humidity. And such conditions appear in June-July, when the potatoes are preparing for flowering. Therefore, the disease is dangerous for a garden plant, slowing down its growth, stopping full development.

What is the pathology of a vegetable?

Dry spot of potatoes is called Alternaria. The disease is widespread among plants of the Solanaceae family. Potatoes and tomatoes suffer most from the infection. Taking into account the fact that the fungus is activated in hot weather, then mid-season and mid-late varieties of vegetable crops fall under the infection.

To understand the danger of a fungal infection, you need to know its description. The stems and leaves of potatoes are affected by spores. The fungus penetrates the tubers if the fruits are damaged during harvest. Often across contaminated land potato tubers also get sick.

The fungus is characterized by vitality, and its spores are carried by rain, wind, infecting other plants. This is how foci of infection are formed. After wintering in plant waste, pathogenic microorganisms begin to colonize the plant planted in spring.

Causes of infection

The disease is based on infection with conidia and mycelium preserved on the plant tops and tubers of the old crop lying under the snow. As soon as hot weather with light rains sets in, Alternaria fungi begin to activate. By releasing acid, they provoke necrosis of leaves and stems of potatoes. The description of the mycelium of this species is as follows:

• interlaced fibers;
• branched and thin structure;
• lack of thread color.

Factors contributing to the development of fungal pathology include:

• hot weather;
• weakness of the protective functions of plants;
• depletion of soil with potassium and nitrogen;
• excess phosphorus in the soil;
• damage to potatoes by pests;
• infected planting material.

Interestingly, the fungus has adapted to the harsh conditions. It can be active even at low temperatures.

Vegetable disease symptoms

Potato Alternaria can be detected by pronounced signs:

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1. Two weeks before flowering, dry brown spots with a diameter of 1–3 centimeters are found on the lower leaves. They appear in the middle of the leaf plate, spreading to the edges.They resemble concentric rings in shape.
2. The rounded-oblong spots spread, leading to complete drying of the leaves.
3. Leaves are dry and break easily.
4. A month after infection with the fungus, a bloom with fungal spores is visible on the green parts of the potato.
5. If a potato tuber is infected, then this can be determined by the presence of dark spots. At the same time, the affected part of the potato is covered with a network of brown wrinkles arranged concentrically in a circle.
6. Inside the cut potato are areas of dry rot, which are a dark, dense mass.

If the disease is determined in time, then the plant can be saved by choosing the appropriate treatment.

Ways to eliminate Alternaria

IN potato growing season it is necessary to fight a fungal infection with the help of chemicals. Treatment of diseased plants with preparations is suitable:

• Profit.
• Thanos.
• Utan.
• Cupricoloy.
• Bravo.

Profit Gold, containing toxic substances, acts both internally and externally on an infected plant. After treatment with the agent, a protective film is formed on the leaves and stems, which cannot be destroyed by precipitation. Fungi and spores are killed and the potatoes are healthy within two weeks.

Fungicide Thanos is considered safe for humans and pets. The components of the preparation penetrate into the plant tissues, killing the fungus.

Bravo belongs to the preventive drugs. The product contains chlorine, which has a detrimental effect on the fungus and prevents it from multiplying.

Use chemicals as directed. Be sure to protect hands with rubber gloves before spraying, eyes with special glasses, and mucous membranes of the nose and mouth with masks.

Control measures include biological agents with which tubers are treated before planting. The preparation Planriz will protect the seed material of the vegetable from Alternaria. The product is based on soil bacteria that are active against fungi. In addition, microorganisms enhance the growth of potatoes. Treatment with the drug can be carried out by spraying potato seedlings.

Bactofit is referred to as biological type fungicides. Tubers are treated with it before planting. You can spray the vegetable planting three times during the growing season.

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Before planting, the seeds of the vegetable are treated with Maxim. The working solution is prepared from ten milliliters of the product, diluting them in five liters of water. One liter of the finished product is usually consumed per kilogram of potatoes. Prepare a solution before processing, since it can only be stored for a day.

How to prevent the onset of the disease?

The prevention of Alternaria in nightshade crops includes:

• destruction of the remains of the tops after harvesting the vegetable;
• compliance with the rules of crop rotation;
• timely application of fertilizers with a sufficient amount of potassium, nitrogen;
• accurate digging of tubers without damaging them;
• pre-sowing processing of seed material;
• spraying the potato field with drugs against fungal infections three to four times per season.

The cultivation of potatoes is not difficult. But you need to know that you cannot plant a culture in one place for more than three years. Do not place beds with tomatoes and other nightshades nearby.

Potato varieties resistant to Alternaria

You can plant on the site such varieties of vegetable crops that are resistant to fungal infection:

1. Early ripe potatoes Lyubava has a white color of tubers. During the cooking process, the potatoes do not boil, preserves the whiteness of the pulp During the growing season, the plant rarely becomes infected with Alternaria fungi.
2. The Bronnitsky variety has increased resistance not only to Alternaria, but also to scab, black leg, late blight.
3. The yellow-skinned Andretta belongs to an early-maturing vegetable crop. After sixty days, you can harvest the tubers.The popularity of the variety in the excellent taste of yellowish pulp, resistance to low temperatures, Alternaria.
4. Nevsky potatoes have a growing season of 90 days. The advantages of growing a variety include its immunity to scab, Alternaria, late blight.
5. Dolphin tubers are dug 45 days after planting. The vegetable is appreciated for its high yield, excellent taste of small fruits. The plant is distinguished by its resistance to scab, late blight and alternaria.
6. The late-ripening Temp species is considered resistant to bacterial and fungal infections. It is adapted to temperature extremes and tolerates drought.

Correctly selected seed material is also important in the prevention of fungal pathology.