Phytophthora and scab: which potato varieties are resistant to these diseases?

Phytophthora and scab: which potato varieties are resistant to these diseases?

We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

In summer cottages, vegetables are mainly grown, and a large area for planting is given to potatoes. As a result, the required crop rotation is not always possible.

Potatoes are quite often affected by diseases that arise as a result of the annual planting of vegetable crops in the same place. This kind of ailment includes scab that affects potato tubers. The article describes how to deal with this ailment, gives a detailed description of the disease and recommendations for treatment.

General Provisions

Scab in plants is an infectious, sometimes bacterial disease associated with extensive damage and deformation of the surface of an agricultural crop.

It is caused by a group of microscopic pathogenic organisms, bacteria and actinomycetes. Basically, scab affects the outer tissues of leaves, stems, flowers, fruits.

The main symptoms of this disease:

  • exfoliation of the cuticle;
  • violation of the integrity of the surface of the peel;
  • the appearance of spots in an irregular shape;
  • the presence of a medium-sized sore and warts with a dry rim on the fetus.

Potatoes, like other vegetable crops, are highly susceptible to scab. Today, at least four types of the disease are known. They, in turn, are characterized by certain features and differ from each other. Accordingly, prevention and treatment measures may also differ. Distinguish:

  1. common scab;
  2. silvery;
  3. powdery;
  4. black.

Silver scab - this type is the most insidious, spores can persist well even at a temperature of + 3 ° C, thus infecting neighboring tubers during storage. The silvery scab is caused by the Helminthosporium solan fungus, which only spreads in the skins of potatoes. The tuber can be stored for a long time without any special symptoms of decay, but it will lose moisture and dry out. The first sign of the disease is a significant thinning of the peel. Also dangerous symptoms are the appearance of a silvery hue and brown spots.

Powdery scab is a fairly common type, which manifests itself in the form of a mucous coma that moves independently. Aggressively affects not only the fruit of the vegetable, but also the underground part of the stem. When storing potatoes in humid places, the process of decay develops. And in the infected areas of the tuber, late blight and dry rot rapidly develop. Powdered scab feels good in dry soil at a temperature of + 12-15 ° C. The life span of the fungus is 5 years.

Where and when is it formed?

The scab causative agent is in the soil, so it is not always possible to completely destroy it. Bacteria mainly hibernate in fallen leaves, and the peak of the exacerbation of the disease falls in the spring, when it becomes warm and humid outside.

Also, for the successful development of such an ailment, certain parameters are important:

  1. air temperature + 25-30 ° С;
  2. sandy, loose, dry soil;
  3. the presence of a large amount of organic fertilizers in the soil, in particular humus;
  4. alkaline earth;
  5. lack of manganese and boron in the soil, and an excess of calcium and nitrogen;
  6. air humidity not less than 70%;
  7. lack of immunity in the root crop to this disease.

Why is it dangerous?

Potato tubers affected by a fungal disease do not harm human health. I.e if you eat the contaminated product, you definitely won't get to the hospital... However, whether it will be pleasant to cook it is another question.

Scab is an unpleasant phenomenon that lowers the nutritional value of potatoes; it loses a significant amount of starch. It also reduces the keeping quality of the root crop and causes rotting. The scab is the cause of the loss of the quality of the crop, the loss of the presentation, infects the seeds, affects the resistance of plants to other diseases.

Which culture is striking?

Fungal disease is not only a disease of vegetable crops, but also the main enemy in the garden. Pathogenic microorganisms affect:

  • potatoes;
  • beets;
  • carrot;
  • citrus fruit;
  • apples;
  • pears;
  • cherries;
  • grapes;
  • houseplants.

This disease causes the greatest damage to potatoes, apples, pears, impairing their appearance and quality of fruits. In this case, the fungal infection is different in each case. This disease occurs mainly in temperate latitudes.

How to find?

The appearance of this ailment is noted on the tubers, trunk, leaves and even flowers.

The microscopic parasite infects the skin and looks like dark, dry spots that are unpleasant to the touch. In the process of the development of the disease, the fruits are deformed, the leaves become weak and crumble ahead of time.

Unfortunately, in the early stages, the disease is practically not diagnosed. It can be recognized only after the potato tubers are dug out of the soil.

Scab progresses actively in wet, rainy weather. This is due to the fact that the spores of the fungus develop in a liquid-droplet medium, where, after the defeat of one tuber, it spreads to the neighboring one, until everyone is sick.

A photo

In the photo you can see how the potato tubers affected by scab look.

Principles of protection and control

However, the positive moment in this situation is the factor that scab can and should be fought... For this, a whole range of measures should be planned for the treatment of root crops.

How to get rid of?

  1. For planting, choose a variety that is scab resistant and suitable for the conditions in your region.
  2. Before planting, the tubers should be carefully inspected; patients should not be planted.
  3. Store potatoes in a cool, dry place.
  4. Poison root vegetable seeds with potent chemicals. For example, Maxim, Fitosporin, Polycarbocin.
  5. Try to change where potatoes are planted. After all, pathogenic microorganisms can live in one place for up to 5 years.
  6. Do not plant potatoes in the garden where carrots and beets grew, because they also suffer from this ailment.
  7. After the entrances and during flowering, the bushes should be treated with Epin, Zircon growth stimulants.
  8. Fresh manure must not be added to the soil before planting.

How to heal the earth?

After harvesting potatoes, in the fall, the beds should be planted with siderates, which are better to use mustard, legumes or cereals.

They are natural antiseptic and disinfectants, prevent the growth of pathogenic fungi, and protect crops from the attack of harmful insects.

When the synderates grow by about 20 cm, the plot is dug up, mixing the shoots with the ground. In the spring, you can sprinkle mustard powder on the soil.

Since scab develops well in alkaline soils with a lack of manganese and boron. Therefore, it is recommended to add the following types of mineral fertilizers to the soil in spring:

  • ammonium sulfate;
  • superphosphate;
  • potassium magnesium;
  • sulphate copper;
  • manganese sulfate;
  • boric acid.

The varieties are resistant to this disease and late blight.

If, with all the above actions, there are no results, then you should change the potato variety and choose a more scab resistant one. For instance:

  1. Bronitsky grade. This potato is valued for its resistance to scab, Alternaria, black leg. Has excellent taste characteristics. Ideal for French fries. The color of the pulp is white. Productivity 350-550 kg from 100 sq.m. Fruit weight is about 100 grams. Ripening period 80-85 days.
  2. Alena is an early ripening variety. The tuber is rounded. The color is red. The pulp is white. The variety is also not exposed to potato cancer, is not afraid of drought, however, it is less resistant to late blight. Well suited for the frying process. Productivity 170-100 kg from 100 sq.m. Fruit weight is about 87-156 grams. Ripening period 60-70 days.
  3. Snow White medium early potatoes. Differs in excellent keeping quality, resistance against diseases. It has a pleasant appearance: white smooth peel and very small eyes. Productivity 160-250 kg from 100 sq.m. Fruit weight is about 65-117 grams. Ripening period 70-80 days.
  4. Resource - this species is quite valuable for its endurance. It tolerates drought well, is resistant to diseases and mechanical damage. It tastes good. Fruit color is light yellow. Productivity 400-450 kg from 100 sq.m. Ripening period 80-85 days.
  5. Pace - a late variety of vegetables. The tubers are round, flat. Light yellow color with creamy pulp. Stored and transported well. Good palatability, especially preferable for purees. Productivity 550 kg from 100 sq.m. Fruit weight is about 80-130 grams. Ripening period 120-130 days.

Planting material certainly affects the quality and quantity of the harvested crop. Elite potato varieties are more resistant to fungal and bacterial diseases. Harmful insects bypass them, and also have excellent taste characteristics.

  1. Spring - super early grade. Among the positive aspects of this vegetable: high yield, good taste characteristics, practically not susceptible to fungal diseases. Spring has oval tubers and a light pink color. Productivity 320-400 kg from 100 sq.m. Ripening period 70-75 days.
  2. Nevsky - a time-tested variety. It is tasty, fruitful, and has good immunity. The tuber is even and smooth, the shape is oblong, the color is light yellow. The pulp is white, and may not turn black for a long time. Productivity 250-350 kg from 100 sq.m. Ripening period 75-85 days.
  3. Red Scarlett no wonder it bears such a name. The fruits are brightly distinguished, beautiful, regular in shape. The color of the peel is pink, the eyes are small. In this case, the pulp is light yellow. Has a long shelf life. Productivity 250-550 kg from 100 sq.m. Fruit weight is about 80-120 grams. Ripening period 75-90 days.
  4. Luck another variety that lives up to its name. It is early, high-yielding, stable, not susceptible to disease. Therefore, it is considered a really successful specimen among the rest of the brethren. Oval tubers and yellow skinned. Productivity 300-550 kg from 100 sq.m. Fruit weight is about 120-150 grams. Ripening period 60-70 days.

If all the recommendations and preventive measures are followed, it is possible to completely eradicate the infection in 2-3 years. However, it is worth noting that when planting resistant varieties, preventive soil cultivation must still be done. Thus, provide yourself with potatoes for the whole year.

Watch a video on how to process potatoes so that they do not get scab disease:

Watch the video: Tomato Diseases (May 2022).


  1. Mac An T-Saoir

    Congratulations, brilliant idea and timely

  2. Malagis

    This is a very valuable opinion

  3. Mikaran

    hmm simple))

  4. Grolmaran

    Bravo, that the necessary phrase ..., the admirable thought

  5. Tojanris

    I agree, this magnificent thought falls by the way

  6. Samugar

    Your phrase, just the grace

Write a message