Potato Alternariosis: description and treatment, basic control measures

Fungal pathologies are a scourge for vegetable crops. So, alternariosis of potatoes and other nightshade crops leads to the loss of a third of the crop. For pathogenic fungi, the ideal breeding ground is an air temperature of 25-30 degrees Celsius and high 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 its full development.

What is a vegetable pathology?

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

To understand the danger of a fungal infection, you need to know its description. Stems and potato leaves are affected by spores. The fungus penetrates the tubers if the fruits are damaged during harvesting. Potato tubers often get sick through contaminated soil.

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 settle on a plant planted in spring.

Causes of infection

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

• woven fibers;
• branched and fine 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 in potassium and nitrogen;
• excess phosphorus in the soil;
• potato pests;
• infected planting material.

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

Symptoms of vegetable disease

Alternaria potato can be detected by pronounced signs:

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. Shaped like concentric rings.
2. Round-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 plaque with fungus spores is visible on the green parts of the potato.
5. If a potato tuber is infected, it 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 potatoes are areas of dry rot, which are a dark dense mass.

If you identify the disease in time, you can save the plant by choosing the appropriate treatment.

Ways to eliminate Alternariosis

During the growing season of potatoes, it is necessary to fight a fungal infection with the help of chemicals. Suitable treatment of diseased plants with drugs:

• Profit.
• Thanos.
• Utanom.
• Kuprikoloy.
• Bravo.

Profit Gold, containing toxic substances, acts both from the inside and outside on the 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 within two weeks the potatoes are he althy.

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

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

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

The control measures include biological agents used to treat tubers before planting. The drug Planriz will protect the seed material of the vegetable from Alternariosis. 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 a biological type fungicide. They process tubers before planting. You can spray vegetable plantings three times during the growing season.

Before planting, vegetable seeds 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. The solution is prepared before processing, since it can only be stored for a day.

How to prevent disease?

The prevention of Alternaria in nightshade crops includes:

• destruction of leftover haulm after harvesting vegetables;
• compliance with crop rotation rules;
• fertilize in a timely manner with enough potassium, nitrogen;
• careful digging of tubers without damaging them;
• pre-sowing seed treatment;
• Spraying a potato field with drugs against fungal infections three to four times a season.

Cultivation of potatoes is not difficult. But you need to know that it is impossible to plant a culture in one place for more than three years. Beds with tomato and other nightshades should not be placed nearby.

Alternaria resistant potato varieties

It is possible to plant vegetable varieties on the plot that are resistant to fungal infection:

1. Early ripe Lyubava potatoes have white tubers. During the cooking process, the potatoes do not boil soft, retain the whiteness of the pulp. During the growing season, the plant is rarely infected with Alternaria fungi.
2. The Bronnitsky variety has increased resistance not only to Alternaria, but also to scab, black leg, late blight.
3. Yellow-skinned Andretta is an early ripe vegetable crop. After sixty days, you can harvest the tubers. The popularity of the variety in the excellent taste of yellowish flesh, 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. Delphin tubers are dug up 45 days after planting. The vegetable is valued for its high yield, excellent taste of small fruits. The plant is resistant to scab, late blight and alternariosis.
6. Late-ripening Temp is considered resistant to bacterial and fungal infections. It is adapted to temperature extremes, endures drought.

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

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