How to deal with late blight on potatoes? Phytophthora preparations

Long since the most terrible disease of potato is late blight. It was previously believed that this dangerous fungal infection spreads only together with planting material and is not able to tolerate an extreme decrease in ambient temperature in the winter. However, nowadays late blight, which affects potatoes, has undergone mutations and acquired new properties. Therefore, gardeners have to fight the disease throughout the year.

How to deal with late blight on potatoes? What drugs and folk methods should be used to kill the infection? Are potato varieties resistant to late blight? The answers to these and other questions can be found in our article.

What is late blight?

Late blight is a dangerous disease that affects cultivated plants, popularly referred to as brown rot. Typically, the infection begins to destroy garden plantings in late summer. In the absence of targeted actions aimed at combating ailments, about 80% of the crop may suffer.

The causative agent of the disease is a fungal infection of Phytophtora infestans. Microscopic spores are capable of rapid reproduction under favorable conditions. First of all, late blight is formed on the leaves of potatoes. Then the infection passes to the shoots and gets to the tubers. With increased humidity, plants become covered with brown spots. The wrong side of such damage is covered with a white coating formed by spores of the fungus. In the event of an abundance of dew in the epicenters of the spread of infection, rot forms. With the onset of heat, the plants begin to dry out.

If the potato is infected with late blight, the surface of the tubers is covered with dark areas. The infection spreads deeper, and the crop gradually rots. It is noteworthy that even healthy tubers, after moving to the cellar, can become infected and begin to decompose.

Ways of infection of potato with late blight

To understand how to deal with late blight on potatoes, you need to know the ways in which fungal spores are spread. So, the disease can affect plants:

1. In cases of use of "sick" seedlings. Infected tubers can tolerate spores that enter the soil. When favorable conditions occur, the infection will certainly make itself felt.
2. During harvesting, when the tubers are in direct contact with the late top infected with late blight.
3. When spores of a fungal infection are washed away into the soil from plant shoots by sediments. Infection penetrates the soil and affects healthy tubers.

What is the insidiousness of the disease?

The main feature of late blight is the gradual uneven infection of cultivated plants. The absence of signs of disease on most bushes does not allow gardeners to identify the problem in time and prevent a catastrophe even at the stage of shoot maturation. Disputes imperceptibly to the eye are thrown by the wind to neighboring landings and, together with the rain, go to the upper layers of the soil. Potato shoots affected by late blight can acquire a brown tint in just a few days. With increasing humidity, the leaves begin to curl and dry. As a result, the gardener has to observe instead of lush bushes only sticking stems. If the owner of the site cannot decide how to process potato from late blight, soon tubers that turn into rot also become brown spots. Infection affects the still not fully ripened potatoes in neighboring areas.

Using quality seedlings

How to deal with late blight on potatoes? One of the most effective solutions is the selection of planting material. It is important not only to choose high-quality seedlings, but also to resort to its germination in greenhouse conditions before being placed in the soil. The solution reduces the ripening time of the crop and, accordingly, makes it possible to collect it before the onset of the period of "riot" phytophthora, which is observed around mid-August.

Phytophthora resistant potato varieties

One of the most rational solutions to combat fungal infection is the choice of seedlings that are not exposed to infection. How to deal with late blight on potatoes in this way? Preference should be given to the following varieties:

1. Good luck - different early ripening of tubers. The variety perfectly tolerates not only severe frosts, but also high soil moisture, under the conditions of which late blight is actually activated.
2. Reserve - characterized by the formation of branched rhizomes with an abundance of tubers. It acts as a medium early variety. Such potatoes are not afraid of drought and excessive soil moisture.
3. Dawn - early ripening potatoes. In addition to late blight, the variety is practically immune to common infections of a bacterial and viral nature.
4. Nevsky - a variety that is distinguished by excellent taste. When harvesting, a small amount of waste is observed. The tubers of such potatoes are able to withstand high humidity, droughts and a significant decrease in temperature. The variety is perfectly stored in cellars.
5. Blue - for such a potato is characterized by an average ripening period of tubers. Shoots, like crops, are resistant to fungal infections.
6. Lugovskoy is a popular mid-early variety. Tubers are perfectly stored in almost any environment. So that the crop is not affected by a fungal infection, regular cultivation of the soil is required when cultivating the variety.
7. Nida is a potato variety that is not exposed to late blight and nematodes. However, tubers do not tolerate excessive soil moisture and drought.
8. Timo is an early variety with high yields. Tuber is not afraid of late blight spores, since they fully ripen until the infection spreads.

Choosing the right place to plant potatoes

The choice of a site for planting potatoes allows you to prevent infection of the crop with late blight. Preference should be given to areas without pronounced lowlands. As noted earlier in our material, late blight prefers moisture. And the water after precipitation is concentrated just in all kinds of recesses of the soil. So that fungal spores do not affect neighboring areas, it is important to make wide aisles when planting potatoes.

Hilling

If late blight is detected on potatoes - what should I do? The use of hilling method of bushes potentially helps to avoid crop loss. When the shoots begin to grow and close in rows, under them you need to high up the soil. The solution will allow the infected leaves to open. Also, direct sunlight will open access to the soil, which will reduce its moisture level.

Proper harvesting

To prevent the spread of an unpleasant disease, you must carefully dry them before placing the tubers in the cellar. If drought is observed, you can lay out the crop directly on the land. When precipitation occurs, drying should be done under awnings. Putting potatoes for long-term storage is recommended only after sorting. It is mandatory to eliminate tubers that have obvious signs of late blight. Indeed, with the beginning of the next season with such seedlings, the fungal infection will again move to the soil and healthy plants will be infected.

Chemistry for spraying potatoes

For spraying use the following drugs from late blight:

1. "Agat-25K" is an effective drug of biological origin, which is used for the treatment of seedlings. Helps to increase the protective properties of plants, has a stimulating effect on crop growth.
2. "Fitosporin M" - acts as an effective fungicide. Suitable for processing planting material in order to combat the development of fungal infections.
3. "Ridomill Gold MC" - is used to prevent late blight. Potatoes need to be processed at least 3-4 times throughout the season.
4. "Thanos" - the active substances of the drug cymoxanil and famoxadone are able to destroy the spores of a pathogenic fungus within a few seconds. The product is not washed off from the shoots of plants even with heavy rainfall.
5. "Maxim 025 FS" - is used for seedling processing. Effective in case of complex use along with other chemicals.

The causative agent of late blight can undergo mutations and develop resistance to the effects of certain substances in the composition of preparations for processing cultivated plants. Therefore, it is important to periodically alternate the above funds and resort to their combination.

Soil preparations

How to cultivate the land after late blight of potatoes? The following chemicals will come to the rescue:

1. "Gliocladin" - available in tablet form. Folds one dragee into each hole when planting potatoes. The active substances in the composition of the product prevent the formation of fungal infections and prevent rot from spreading.
2. "Baikal M" - has the form of a liquid solution. It is based on beneficial microflora, which destroys phytophthora mycelium, and also effectively fights the development of other fungal infections. The soil is irrigated with the product a few weeks before the intended planting of potatoes.
3. “Apirin B” - the preparation contains the bacterium Bacillus subtilis. Microorganisms of this category have the ability to slow down the vital processes of fungi, which leads to their destruction.

What else to cultivate the land after late blight potatoes? Efficiency is also demonstrated by such substances as Bordeaux mixture, copper sulfate. The indicated compounds should saturate the soil in the process of digging the site.

Prevention

So we examined how potato late blight is destroyed, methods of combating this fungal infection. In conclusion, I would like to highlight a number of preventive measures that will prevent the return of the disease.

If it is not possible to purchase seedlings of varieties that are not susceptible to late blight, then it is worth resorting to a full crop rotation. Potatoes should not be cultivated on the plot for at least a year. Instead, you must sow mustard or radish. The shoots of such plants are recommended to be periodically cut and buried in the ground. As practice shows, the solution makes it possible to reduce the likelihood of phytophthora return several times with the coming of the next season.

Before planting potatoes, it is necessary to identify contaminated material. For these purposes, the tubers are removed from the cellar and left for several weeks under a well-ventilated canopy. The temperature should remain at the level of 15-18 ° C. As soon as some tubers turn white, it is urgent to remove them, and treat the remaining seedlings with fungicides.

During the period of tuber mass gain, it is worth partially cutting off the potato tops and loosening the soil. A preventive measure will accelerate the ripening of the crop and lead to the growth of a dense peel by the potato.

If after harvest, late blight was observed on potatoes, what should be done in such situations? It is necessary to collect all dry tops abroad of the land and burn. With the onset of the next season, potatoes should be watered as rarely as possible in cool weather, because it is precisely these conditions that are optimal for activating late blight spores.

Finally

As you can see, in no case should you underestimate the severity of such a disease as late blight. In the absence of a targeted fight against the spread of fungal spores, not only the potato crop, but also other nightshade crops can suffer. Therefore, it is necessary to timely treat the plants and soil with appropriate chemicals, pickle and sort seedlings, and use varieties resistant to infection.