How to deal with late blight on tomatoes: step by step instructions

How to deal with late blight on tomatoes: step by step instructions

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Late blight is a disease caused by late blight fungus. A humid environment and warmth - actively help late blight to multiply. The disease is most widespread in the second half of summer. What plants exposed to phytophthora look like: brown blurry spots form on the leaves on the upper side, a whitish bloom on the lower side of the leaf - these are phytophthora spores.

Dark brown stripes appear on stems and petioles. Fruits are covered with vague brown-brown spots. Late blight may also appear on tomatoes plucked for ripening, if it began to develop at the time of harvest.

Tomatoes were brought to Europe, and then to Russia at the end of the 30s of the 19th century. And already in 1845 the entire tomato crop was lost due to late blight. There was a need to find methods of dealing with this disease. In the article you will read a detailed description of how to deal with this fungus in order to save tomatoes and get rid of phytophthora forever, whether plants need treatment, as well as a photo, and what measures must be taken to protect vegetables in the future.

An overview of the most popular remedies for controlling fungus on plants

Consider fungicides - drugs that are effective in combating fungal diseases.

  1. Phytosporin drug.

    Its cost in 2018 ranges from 30 rubles 10 grams. It is used mainly for prevention. 5 g of phytosporin is diluted in 10 liters of water and sprayed with plantings.

    But in case of rain in the open field, this prophylaxis is ineffective, since the water will wash the drug from the plants into the soil.

    After 7-10 days, the procedure must be repeated.

  2. Following Hom drug.

    It is effective not only against late blight, but also helps to cope with other garden misfortunes.

    Its cost in 2018 is 65 rubles for 40 grams.

    It is necessary to take 40 g of the preparation diluted in 10 liters of water. This amount is enough to process 10 square meters.

    The waiting period is 5 days.

  3. Proton Extra - a drug that protects against late blight.

    Its cost is 49 rubles for 20 UAH.

    Proton Extra is an effective fungicide. It has not only protective properties, which is good for prevention, but also healing properties.

    The solution is prepared as follows: 20 g of the drug is diluted in 10 liters of water. This amount is enough to process 1 weave. The active ingredients of the preparation are easily absorbed on the leaves, penetrate and remain on the plant. The period of action of the drug is approximately 12 days. Then the procedure must be repeated. How many times? Until you harvest.

You need to start a fight while sowing seeds in the soil. The seeds are soaked in a solution of potassium permanganate for 20 minutes, followed by rinsing in water.

Today there are a huge number of folk methods and means of combating late blight. Let's take a look at some of them.

  • The first assistant for gardeners is onion peel. Pour boiling water over half a bucket of husks. As soon as the liquid has cooled, strain, add water to 10 liters in volume. Spray the plant leaves from the underside.
  • The second is milk whey, which contains lactic acid. It protects the tomato and blocks the development of late blight. For 10 liters of water, take 1 liter of whey and 20 drops of iodine. If the tomatoes are blooming at this time, then add another 5 g of boric acid. Also spray the underside of the leaves first.
  • You can also prepare other spray solutions, which may include the following components:
    1. propolis tincture;
    2. extract from wood ash;
    3. baking soda;
    4. dandelion infusion;
    5. hay infusion;
    6. yeast infusion (100g per bucket of water);
    7. garlic solution.

Vegetable processing instructions

Spray the plant from the underside of the leaf with a spray bottle... It is there that the spores of the late blight pathogen are hidden. The plant becomes infected from the bottom up. If you do not see external damage on the plant, then you still spray the plant according to the same scheme.

But what if you have 20 acres of tomatoes. You can't crawl under every bush. Then take a broom, dip it into a bucket and spray the planting. The efficiency is several times less. But if there is additional labor, then you involve everyone in the process.

A photo

In the photo you can see what late blight of tomatoes looks like:


In the open field

  1. Give preference when choosing varieties of tomatoes to varieties that are resistant to late blight. For example, "Bogata Khata F1", "Fiddler of Fate", "Beta".

    When choosing tomato varieties, you can focus on indicators: stunted growth, early maturity.

  2. Observe the crop rotation. Plant garlic or onions after nightshades.
  3. Plants prone to late blight should be planted away from each other. Potatoes and tomatoes are not friends.
  4. The gap between the holes is 30-50 cm, the distance between the rows is 70 cm.
  5. Plant open ground tomatoes away from greenhouses.
  6. Use only healthy seed.
  7. When the first signs of late blight are found, treat all nightshade with fungicides.
  8. Remove weeds, lower leaves in time. Avoid thickening.
  9. Don't overdo it with nitrogen fertilizers. Resistance to late blight decreases significantly.
  10. Water in the morning, strictly in the holes. Do not let moisture get on the leaves.
  11. Apply fertilizers containing phosphorus, potassium to increase the resistance of tomatoes to disease.

In the greenhouse

Most of the measures for processing tomatoes from late blight in the greenhouse are the same as in the open field, but consider the nuances.

  1. Ventilate greenhouses. Do not allow an increase in humidity, Remove excess shoots and lower leaves in time.
  2. Choose greenhouse tomato varieties that are resistant to late blight:
    • "Tatyana".
    • "De Barao Black".
    • Carlson.

    The most resistant to late blight are hybrids:

    • "La-la-fa F1".
    • "Skylark F1".

Video clip about the preventive treatment of tomatoes from late blight:

Is it safe to eat fruits affected by the fungus?

There is no clear answer to the question whether or not you can eat tomatoes affected by late blight. If the whole fruit is affected, then most likely you yourself will not want to eat it. It must be remembered that late blight is a fungus, which means its mycelium has stretched its networks inside the entire product. The fruit is probably completely affected. Draw conclusions.

Better feed the dubious fruits to the cattle.

Land cultivation methods

Phytophthora spores are not afraid of winter, snow, low temperatures... They are safely hidden in the ground until the next season. And the "fire" that ate your tomatoes this year may repeat itself in the next gardening season. In addition to all of the above preventive measures, it is necessary to cultivate the soil.


Dig up the beds in the fall using a moldboard method. After this manipulation, phytophthora spores will appear on the surface. When digging, the shovel must be immersed in the ground with the entire bayonet. Let not all, but many spores can die during the winter. In the spring, before planting tomatoes, the soil is scalded with a solution of potassium permanganate. You will process the soil in the greenhouse, close all the vents and doors, and cover the garden bed in the open field with a film on top. Rain will not interfere with the decontamination process.


Baikal EM-1 and Baikal EM-5 are used to treat the soil before digging and two weeks before frost... The preparations Baktofit, Trichodermin, Fitoflavin, Fitosporin are used to treat the soil in the fall after digging. In early spring, the treatment is repeated. How the land is treated with fungicides: they dissolve the required amount of a substance in water and shed the soil to a depth of 10 cm. It is at this depth that phytospore spores hide.


After digging, the soil must be treated with Bordeaux liquid. Repeat this procedure in the spring. The liquid contains copper sulfate. It disinfects the soil and replenishes the need for sulfur and copper. With Bordeaux liquid, the soil can be treated only once every 5 years.

It must always be remembered that you need to cultivate the land 10 cm deep... Otherwise, everything is in vain. Disputes will stay on the site. Late blight is a dangerous and unpleasant disease of tomatoes.

It is impossible to recover from it at all. It can be prevented, its development can be slowed down. Observing agricultural practices and taking preventive measures, you will always have a rich harvest.

Watch the video: Organic Gardening: Preventing and Treating Tomato Blight (May 2022).