Late blight causes. What to do with late blight on tomatoes in open ground

Late blight (late blight) is a nightmare for gardeners growing tomatoes and potatoes. The disease begins spontaneously, quickly affects plants and, if no action is taken, destroys the plantings along with the harvest. It’s not for nothing that when translated from Latin, “phytophthora” sounds like “plant destroyer.”

Late blight on tomatoes is difficult to treat, so the main thing when fighting it is prevention

Why late blight occurs on tomatoes, how to deal with it - read about all this below.

• Late blight first appears on the lower, older leaves in the form of gray-green watery spots without a clear outline. These spots quickly become brown, dry, often with a light green border of withering tissue. Gradually, the affected areas spread over all leaves.
• As the disease matures, a white coating of millions of spores forms on infected tissues.
• Dark brown spots develop on the stems and petioles, and a white fungal coating also forms on them. If the petioles are damaged, the leaf may fall apart into fragments.
• Dark brown “greasy” spots appear on affected tomato fruits. Initially, they are harder than the rest of the tissue, but they can also become soft and rotting - when putrefactive bacteria are connected.
• In rainy, cool weather, entire fields of tomatoes become brown and dry, as if after frost.

This is what late blight looks like on tomatoes (the photos below show lesions caused by late blight: spots, fungal plaque, spoiled fruit):

Lesions of tomato leaves due to late blight: brown spots with a gray-green border, spore growth is observed on the underside of the leaves under humid conditions
Black spots appear on the stems of tomatoes; in humid conditions they become covered with a white fluffy coating
Dark “greasy” spots appear on tomato fruits

Note!

Tomato fruits begin to rot quickly when affected by late blight. However, any unaffected part of the fruit is safe to eat, as the late blight pathogen does not produce a toxin.

Many of these symptoms are somewhat similar to other diseases that often affect tomatoes. And here it is very important to see the differences.

• For example, with Alternaria blight, dark spots are smaller in size and have a characteristic pattern in the form of concentric rings or a target.
• With septoria, the spots are small, often with a lighter center.
• Drought stress can also masquerade as late blight, producing large areas of dried tissue on the leaves. However, symptoms of drought stress always extend from the edge of the leaf, they lack the light green border of wilted tissue, and there is no white coating. In addition, no symptoms appear on the stems or fruits.

The difference in leaf damage with late blight (photo on the left) and Alternaria (photo on the right)

As a rule, all these “copycat” diseases affect only the tops or cause minor damage to the fruit. Although they may reduce the yield, they do not cause total loss. While late blight in just a few days can lead to the death of the entire plant, along with the fruits and the long-awaited harvest. This is a serious threat to both individual gardeners and commercial growers.

Where does late blight come from: causes of the disease

Late blight of tomatoes occurs when the plant is infected with the oomycete (fungus-like organism) Phytophthora infestans. Infection occurs through spores that are dispersed by the wind from diseased plant tissues to healthy ones.

This process becomes rapid under conditions of high humidity and moderate temperatures (15-22°C). Also, the disease often starts at high daytime temperatures (30-35°C), if conditions are very humid, and night temperatures are moderate (15-22°C). Similar weather in our country often occurs in late July-August. This period is precisely when late blight disease peaks.

It is known that the late blight pathogen does not live directly in the ground, but can overwinter in plant debris, including unharvested potato tubers. Tomato seeds may also be initially contaminated.

Often late blight “flies” onto tomatoes from infected potato plantings if they are located nearby (closer than 500 m). And if by this time the plantings are not protected with an appropriate fungicide, the weather is favorable for the development of the pathogen, and there is a lot of drip moisture on the leaf, then the rapid development of infection cannot be avoided.

Note!

In addition to tomatoes and potatoes, other nightshades are susceptible to late blight: peppers, eggplants, nightshade, petunia. Grapes, strawberries, and cucumbers are less commonly affected. Plantings of these plants can also serve as a source of late blight infection.

Prevention of late blight

It is very difficult to get rid of already rampant late blight on tomatoes, since the disease is often uncontrollable and spreads quickly under favorable conditions. It is most effective to carry out preventive measures that can significantly reduce the likelihood of late blight in your garden.

Here's what you need to do to prevent late blight from appearing in tomatoes:

• Choose varieties that are resistant to late blight. Although no tomato variety is completely immune to late blight, some of them are the most resistant to this infection. Pay attention to early tomato varieties that have time to ripen before the August outbreak of late blight.
• Maintain the distance between tomatoes based on the recommendations for the variety. Maximum ventilation and lighting of all parts of the plant will help it resist disease. Use trellises and supports. When growing tomatoes in a greenhouse, open the windows often for ventilation.
• Excessively limed soils are a favorable environment for the development of late blight. The lime content can be reduced by adding peat to the soil.
• Don't plant tomatoes in one place. Change the location of the plantings every year, return to the same place after 2-3 years. Do not plant tomatoes after potatoes, peppers and other nightshades that are susceptible to late blight. Also, if possible, place beds with nightshade “relatives” away from each other.
• Do not let the bottom leaves of tomatoes touch the ground. To do this, tear off the lower leaves up to the first cluster and mulch the beds.
• Avoid overhead watering. Water the tomatoes at the root to keep the foliage dry. This makes it difficult for late blight and other diseases to spread. Avoid overhead watering methods (using sprinklers). It's best to water your tomatoes in the early afternoon to allow the leaves to dry before dark.
• Pay attention to the weather. Learn to recognize weather conditions that contribute to the spread of late blight. The disease spreads quickly in cool, wet weather, while dry weather tends to keep the disease at bay. If late blight is detected in your region, begin preventive spraying with fungicides.
• After harvesting, destroy all tops of tomatoes and potatoes, dig up all potatoes from the ground. Oomycetes that cause late blight can successfully survive the winter in infected potatoes and on tomato tops. You can't give them this chance!

Traditional methods: how to fight late blight on tomatoes without chemicals

Folk remedies for late blight on tomatoes are good because they are absolutely harmless; after treatment with them, tomatoes can be eaten immediately, without a waiting period. However, such measures are effective only as a “proactive” action, that is, as a preventive measure for late blight.

Kefir

1 liter of kefir, which has previously been left in a warm place for 2 days and fermented, is poured into a bucket with 10 liters of water. The mixture is mixed and used to spray tomatoes every 2 weeks from the moment the seedlings are planted in the ground. As the “late blight” period approaches, spraying is increased to once a week.

Kefir + garlic

Make the same kefir mixture (1 liter of fermented kefir + 10 liters of water) as in the previous recipe, and then “season” it with a paste of 50 g of garlic. Stir, wait 2 hours. Spray tomatoes every 2 weeks.

Garlic

Pour 200 g of garlic into 1 liter of water. Infuse in a dark place for 2 days, then filter through cheesecloth or a sieve. Add water to 10 liters and add 1.5 g of potassium permanganate. The resulting mixture is sprayed onto the plants every 12-15 days.

Whey + iodine

1 liter of fresh whey is poured into 9 liters of warm water and 20 drops of iodine are added to the mixture. Mix thoroughly and pour into a spray bottle. Spraying is carried out every 2 weeks.

Salt

Prepare a saline solution from 10 liters of water and 1 cup of table salt. Tomatoes are sprayed with this solution once a month before harvesting.

Yeast

100 g of pressed yeast is dissolved in 10 liters of warm water (about 30-35°C, so that the hand is warm, but not hot). This solution is used immediately for spraying and watering tomatoes. The yeast solution simultaneously protects plantings from late blight and strengthens plant immunity.

Copper wire against late blight on tomatoes

You can save tomatoes from late blight in a very unconventional way - using ordinary copper wire as a protective agent. The stem of the plant is pierced with it, as a result of which it receives microdoses of copper, which protect it from late blight.

The recipe is simple: take a thin copper wire, sand it with sandpaper and cut it into 3-4 cm pieces. Pierce the tomato stem from below (10 cm from the soil) with a piece of wire and bend its edges down. Do not wrap around the stem.

The method of piercing the stems with copper wire promises a quick and long-lasting effect in the fight against late blight

Biological preparations against late blight (Fitosporin, Trichodermin, Planriz, etc.)

So-called biological preparations are often used as preventive methods to combat late blight on tomatoes. They, like folk remedies, can protect plantings from fungal organisms if used before the outbreak of the disease.

Biological preparations contain various living microorganisms that are natural enemies of the oomycetes Phytophthora infestans and many other pathogenic fungi. When these “good” organisms settle on a plant, they displace their “bad” neighbors or completely prevent them from settling in an already occupied place.

Fitosporin-M- the most famous of these drugs, which includes the bacterial culture Bacillus subtilis or Bacillus subtilis. This is precisely the enemy of late blight spores. In addition to Bacillus hay, Fitofsporin-M paste contains humins - natural fertilizers that heal the soil and stimulate root formation. Spraying and watering with Fitosporin to protect against late blight is carried out every 10-15 days during the growing season of tomatoes.

Trichodermin– a preparation based on the microscopic fungus Trichoderma. It is notable for the fact that it is capable of suppressing more than 60 different pathogenic microorganisms, including the causative agent of late blight (as well as powdery mildew, blackleg, fusarium, etc.). Spraying with Trichodermin is carried out every 10-20 days, depending on weather conditions and the likelihood of late blight development.

Planriz– a biofungicide based on the bacteria Pseudomonas fluorescens, also contains biologically active substances – growth stimulants. The drug effectively protects tomatoes from late blight and many other fungal diseases, and also increases the yield and speed of fruit ripening. Preventive spraying is performed every 10-20 days.

The following biofungicides are also used to combat late blight of tomatoes:

• Baktofit;
• Gamair;
• Alirin-B;
• Mikosan.

Chemical control of late blight on tomatoes

Despite the huge number of safe folk and biological means of protecting tomatoes from late blight, sometimes it is necessary to use “heavy artillery” in the form of chemical fungicides. They are effective when the first signs of the disease appear. And also practically do not give a chance for late blight as a preventive measure.

Copper-containing drugs

Treating tomatoes against late blight with copper-containing preparations is a classic of the genre. Just a few decades ago, no one had even heard of systemic fungicides, but late blight was fought with copper sulfate and Bordeaux mixture - and very successfully.

Copper sulfate

To prepare a solution 2 tbsp. spoons of copper sulfate are diluted in a small amount of hot water, and in another bowl, also in hot water, 30-40 g of laundry soap are dissolved. Then, vitriol concentrate is poured into the soapy water, stirring constantly. Add water so that the total volume of the solution is 10 liters.

A solution of copper sulfate is used 2 times per season: 1st time after planting the bushes in the ground, 2nd time before the flowers appear.

The waiting period (that is, the period after which the fruits of the treated plant can be used for food) is 20 days.

Copper sulfate is an effective time-tested remedy for late blight.

Bordeaux mixture

The drug can be bought ready-made or prepared independently from 100 g of copper sulfate and 100 g of slaked lime.

To prepare your own Bordeaux mixture:

• 100 g of copper sulfate is poured into a plastic bucket, and a small amount of hot water is poured into it. Stir well until the crystals are completely dissolved. Add more water so that the total volume is 5 liters.
• In another plastic bucket with 5 liters of water, dissolve 100 g of slaked lime.
• A solution of copper sulfate is poured into the milk of lime.
• The fungicidal liquid is ready and can be sprayed on plants.

Bordeaux mixture is used as a method of combating late blight on tomatoes according to the same scheme as a solution of copper sulfate. Only 2 sprayings during the growing season: after planting the seedlings in the ground and before the flower cluster appears.

The waiting period is 20 days.

You can prepare Bordeaux mixture yourself from two ingredients: copper sulfate and lime.

HOM

Contact fungicide with one active ingredient – ​​copper oxychloride. The waiting period is 20 days.

Oksikhom

A contact-systemic drug consisting of two components – copper oxychloride (as XOM) and oxadixil. If copper oxychloride acts as a contact fungicide, forming a protective film on the surface of the plant, then oxadixil is a systemic agent that penetrates plant tissue. Thanks to the combined action, the effectiveness of the drug is less dependent on weather conditions than purely contact HOM, and is able to protect untreated parts of the plant (as well as new shoots that have grown after treatment).

The waiting period is 20 days.

The video will tell you about the fight against late blight using copper-containing preparations:

Other effective chemical fungicides

Ridomil Gold

An effective systemic contact drug, effective for the prevention and treatment of late blight on tomatoes. Contains mancozeb (contact action) and mefenoxam (systemic action). The waiting period for tomatoes is 10-14 days.

Quadris

One of the most progressive systemic fungicides, the active substance is azoxystrobin.

The waiting period for tomatoes is 5 days.

Also used against late blight:

• Strobe;
• Speed;
• Acrobat;
• Thanos;
• Previkur;
• Penncozeb.

Rules for combating late blight on tomatoes

Knowing effective drugs against a disease is not a guarantee of a cure for it. You need to understand how to properly combat late blight on tomatoes.

To do this, adhere to the following rules:

• Phytophthora spores very quickly develop resistance to a particular drug. Therefore, during the summer, try to alternate 2-3 effective fungicides with different active ingredients (chemical or natural origin).
• When you detect the first signs of late blight damage to tomatoes, remove the affected leaves and stems without regret. Burn them. Don't compost!
• Remove the fruits from the affected plant when they are green for ripening. Wash them and soak them in hot water (about 60°C) for 2-4 minutes.
• Carry out spraying in the evening or on a cloudy day, in the absence of wind.
• Pay attention to the waiting period after spraying with chemicals.

If you start the fight against late blight in a timely manner, your tomatoes will not be affected by this scourge and you will get a rich, healthy harvest.

Most gardeners, cultivating tomatoes in open ground on their plots, have encountered late blight. Unlike other vegetable crops, tomatoes are most often affected by this disease, the main symptom of which is blackening of the foliage and fruits. Today, there are many ways to combat this scourge, which will be discussed in more detail below.

Late blight, or late blight, is a fungal disease. Its causative agent is considered to be fungi, of which there are approximately 50 species.

The name “late blight” translated means “destroying the plant.”

Fungi reproduce by spores, and they are found in the soil, in the remains of diseased plants, and on garden tools. After winter ends, when favorable conditions occur, the fungus begins to actively develop.

Tomatoes are most often affected by the disease in the last weeks of summer. In diseased bushes, the inflorescences first turn yellow, and then darken and die. It also damages the fruits, spots form on their surface, and they begin to quickly deteriorate.

The disease spreads very quickly, and the affected bushes rapidly wither and die over time. If the necessary measures to combat late blight are not taken in a timely manner, then the harvest will be lost.

The first signs of tomato disease

In order to promptly begin treatment of tomatoes affected by late blight, you need to know the first signs of this disease:

• At first, dark brown spots form on the underside of the foliage; over time, it begins to dry out and fly off;
• brown spots of irregular shape appear on the surface of the stem;
• darkening or yellowing of inflorescences are observed, which quickly dry out and die;
• Black or brownish-gray spots form on the fruits.

In order for the fight against late blight to be effective, it is necessary to know exactly what causes contribute to the development of the disease. Such reasons include:

• dense plantings (there is practically no ventilation between the bushes);
• heavy and frequent rains, which are observed in the second half of the summer;
• there is too much nitrogen in the soil;
• tomatoes lack copper, manganese, potassium or iodine;
• tomatoes grow next to potatoes;
• sharp changes in day and night temperatures, heavy dew in the morning (most often observed in August), coolness;
• excessive watering in July and August, when the fruits begin to ripen, as well as watering on the foliage;
• the soil contains too much lime.

Tomatoes grown in open ground, if agrotechnical rules are not followed, are very often affected by late blight. As a rule, this occurs when humidity increases as a result of regular heavy dew in the morning or frequent rains. To combat late blight, gardeners use chemical, biological and folk remedies.

Chemicals

Below we will describe those chemicals that are most often used by summer residents in the fight against late blight:

1. Home. Contact action fungicidal agent. Copper oxychloride, which is the active substance of the drug, does not penetrate inside the bush. It is used for preventive purposes, treating tomatoes up to 5 times during the season. He is not able to cure a sick plant. Working solution: 4 g of product per 1 liter of water. The drug is dangerous to humans, so all necessary precautions must be taken during processing.
2. Furacilin. This antimicrobial agent intended for humans is also used to combat late blight. To prepare the solution, dissolve one tablet in one liter of water. The treatment is carried out three times during the season: before the bushes bloom, before the first ovaries form, after the fruits begin to ripen. The product is absolutely safe for humans.
3. Metronidazole or Trichopolum. This is also a medicine intended for people, which summer residents have recently begun to use in the fight against late blight. To prepare the solution, dissolve a couple of tablets in a liter of water. Spray the bushes systematically once every week and a half or after rain, as the product is easily washed off with water.
4. Ordan. This fungicidal agent penetrates inside the bush, so the fruits after treatment are not used for food for five days. To prepare the solution, combine 1 liter of water and 5 g of the drug. Sick plants are sprayed once every 2–4 days, and healthy bushes are sprayed once every half month for preventive purposes. The drug is dangerous for humans.

Biological remedies are much more effective than traditional ones, but they are active only at air temperatures above 15 degrees. The most popular drugs:

1. Baktofit. This bacterial fungicidal agent significantly reduces the number of pathogenic fungi in the soil after just a few hours after application. The solution is prepared according to the instructions indicated on the package.
2. Trichodermin. This is a complex biological agent that actively destroys pathogenic fungi in the soil and also helps to increase its nutritional value. Pour the solution onto the soil and loosen it. To increase the effectiveness of the drug, when preparing the solution, it is recommended to use whey or kefir instead of water.
3. Planriz. This highly effective product contains live bacteria. The solution is very simple to prepare; for this, a liter of water is combined with 5 grams of the product. They use it to cultivate the soil just before planting tomato seedlings.
4. Fitosporin. This remedy is used very widely in the fight against late blight. The soil is treated in the spring; to do this, it is spilled with a solution consisting of 10 liters of water and 6 ml of the drug.

Many gardeners try to avoid the use of chemicals, since they are not always safe for humans, because most of these products contain poisons. That is why, to protect tomatoes from late blight, they try to choose exclusively folk remedies that are not highly effective, but they do not harm human health at all. The most popular folk remedies:

1. Kefir. It is used for prevention purposes, as well as for the treatment of late blight. To treat the bushes, prepare a solution from one bucket of water and 1 liter of kefir. If desired, you can replace kefir with milk, but in this case, add 20 drops of iodine to the solution. You can also use a whey solution in a ratio of 1:1 or 1:2 to spray tomatoes. Treatment with any of the solutions can be carried out at least daily.
2. Soda. Dissolve 1/5 of a tablespoon of soda in one liter of water and add a little liquid soap. Spray tomatoes once every 7 days or after the rain has passed.
3. Salt . The saline solution is used as a preventive agent, because after drying it covers the surface of the bush with a thin white layer that will prevent pathogenic fungi from penetrating inside the tomato. To prepare the solution, take 25 grams of salt per 1 liter of water. All above-ground parts of the bush are treated; when the rain passes, spraying is repeated.
4. Vinegar. Pour 100 milligrams of nine percent table vinegar into 10 liters of water. All parts of the plant are treated with the resulting solution. It is recommended to use it alternately with other drugs and folk remedies.
5. Garlic tincture. First, chop the garlic heads and arrows. Take one and a half glasses of the resulting mass and combine it with a bucket of water. The infusion will be ready after a day. Plants are treated with it twice a month.
6. Wood ash. To prepare the solution, you need to mix 1 bucket of water and five kilograms of ash. The infusion will be ready after three days, do not forget to stir it regularly. The finished infusion is filtered and such an amount of water is added to it so that the total volume is 30 liters. Before processing, add a little soap to the product. In total, during the season, treatments are carried out three times: 7 days after planting the seedlings in the soil, shortly before the start of flowering and after the formation of the first ovaries.

Ash can also be used to pollinate bushes. To do this, one bucket of ash is mixed with 1 tbsp. tobacco dust. During pollination, do not forget to protect your eyes and respiratory organs; for this, use a respirator and safety glasses.

1. Yeast . Dissolve 10 grams of yeast in a liter of warm water, let the mixture sit, after which it can be used to spray tomatoes. Treatments with the product are carried out during the formation of ovaries or when the first symptoms of the disease are detected.
2. Hay. 1 kilogram of rotted hay is combined with 1 bucket of water, which must be warm. 100 g of urea is added to the mixture. The infusion will be ready after three days; all you have to do is strain it.

In order to increase the effectiveness of any of the products, you need to adhere to the basic processing rules:

• choose a fine and calm day;
• spray the bushes early in the morning or in the evening;
• When using toxic products, safety precautions must not be neglected;
• Mixing products and preparing solutions cannot be done with tools or in containers made of metal.

In order to protect tomatoes from late blight and preserve the harvest, you need to remember about preventive measures:

1. The area where peppers, potatoes and eggplants were previously grown cannot be used for planting tomatoes. Also, areas with these crops are not recommended to be located next to each other. In the same area where tomatoes grew, they can be planted again only after at least four years. The best are cucumbers, turnips, carrots, onions, beets and cauliflower.
2. Tomatoes are grown in a well-lit area.
3. Experts advise using early or highly resistant hybrids to late blight.
4. If the ground contains an excessively large amount of lime, then during planting, pour a little peat into the hole and put onion peels, and cover the surface of the soil near the bush with sand.
5. Plants should be well ventilated, so they are not planted too densely.
6. Water is poured exclusively at the root, and this procedure is carried out in the morning. From mid to late summer, watering is recommended only during prolonged drought.
7. The surface of the soil around the tomatoes is covered with a layer of mulch.
8. It is recommended to grow calendula, onions, marigolds, white mustard or garlic next to tomatoes.
9. Conduct in a timely manner.
10. Strengthen the health of plants; for this they are fed with potassium-phosphorus fertilizer, and also treated with immunomodulators.
11. It is recommended to apply nitrogen only from the beginning to the middle of the growing season. If it is added to the soil in the second half of summer, this will increase the likelihood of bushes being affected by late blight.

Very often, even experienced gardeners do not know the answers to some questions regarding late blight on tomatoes. Below you will find answers to the most popular questions.

How to preserve tomatoes damaged by late blight?

Fruits from an affected bush that are not damaged by the disease can be eaten only after treatment with hot water. To do this, use them for 10–15 s. immerse in very warm water (about 60 degrees). Then they are dried and waited for them to ripen. After processing, red fruits can be eaten or preserved. By the way, green tomatoes can also be preserved for the winter after processing.

Is it possible to eat tomatoes with late blight?

If tomatoes have black spots, it is not recommended to eat them even after removing the affected areas. Fruits that have been damaged very slightly by the disease can only be eaten after treatment in hot water.

How to treat the soil after late blight?

As a rule, the soil on which bushes affected by late blight grew is treated in early spring after the snow cover melts or before planting seedlings. For this, the following chemicals are used: Bordeaux mixture, copper oxychloride, copper sulfate, Oksikhom or Farmayod, etc.

Varieties resistant to late blight?

Today there are no tomato varieties that are not at all affected by late blight. However, there are varieties that have very high resistance to the disease, for example: Budenovka, Pink Dwarf, Dokhodny, Dubrava, De Barao, Solnechny, Snezhana, Metelitsa, Kostroma, Parterre, Otradny, etc.

How to treat tomatoes against late blight - video

How to avoid late blight? Prevention and methods of control - video

Each gardener decides for himself which method of treating tomatoes for late blight to choose in a particular case. But it should be taken into account that neither chemicals nor folk remedies guarantee complete relief from late blight. Experienced summer residents recommend alternating various means and methods, and also not forgetting about preventive measures.

From late blight on tomatoes and potatoes

Are your tomatoes and potatoes turning brown, and black spots starting to appear on the leaves, stems and fruits? The plants were probably attacked by late blight. But don't despair! We will tell you how to deal with late blight.

This is a common fungal disease that primarily affects nightshade crops and occurs most often in cool and damp weather. Phytophthora spores can be found in the ground, on seeds, plant debris, walls and roof of the greenhouse, garden tools, etc. And in order to prevent the spread of spores to plants, it is necessary to follow preventive measures.

Prevention of late blight

1. Well-limed soils are a favorable environment for the development of late blight. Therefore, you should not get carried away with liming. If a lot of lime has accumulated in the soil, you need to restore the natural balance of the soil: add peat and pour coarse sand into the furrows.

2. Fungi prefer a moist environment, therefore it is important to water the plants in moderation and not allow the plantings to become thicker. Water potatoes and tomatoes in the morning so that most of the moisture has been absorbed into the soil by the end of the day. And when growing tomatoes in a greenhouse, be sure to ventilate it.

In addition, humidity often increases during sudden temperature changes (for example, at the end of summer, when it is still hot during the day and the nights are already cold).

At this time, plantings in open ground should be covered with spunbond overnight. First of all, this concerns tomatoes, since not only late blight, but the cold itself can destroy them.

3. Plants with weak immunity are susceptible to any infection. Therefore, make sure that your tomatoes and potatoes receive enough essential microelements (iodine, manganese, copper, potassium and phosphorus). Then garden crops will have less chance of getting late blight.

And to strengthen the immunity of plants, you need to observe crop rotation. So, good predecessors for potatoes are cucumber, zucchini, pumpkin, squash, cabbage, legumes, root vegetables, onions, and for tomatoes – white and cauliflower, cucumber, zucchini, pumpkin, legumes, onions, root vegetables.

4. The development of late blight can be prevented by growing varieties and hybrids that are resistant to fungal diseases. Choose high-quality planting material - and you will not need drugs against late blight.

Treatment of late blight

Chemical remedies for late blight on potatoes and tomatoes are very effective, but it is not recommended to use them during the ripening of the crop. Therefore, in the second half of summer it is better to spray plants with biological preparations.

So, you can buy Fitosporin in a specialized store, dilute it with water according to the instructions, carry out the first spraying when the ovaries appear, and then spray the plants every 10-14 days. In addition, using a solution of Fitosporin, you can treat the soil against late blight: before sowing or planting plants, water the soil or add the biological product to the irrigation water several times during the growing season.

How to treat tomatoes and potatoes against late blight with folk remedies

We will present the most effective and time-tested folk recipes for safe remedies that our grandmothers used to save their green pets from dangerous late blight.

Infusion of garlic with potassium permanganate

100 g of garlic (bulbs, arrows and leaves can be used) are crushed (in a meat grinder, garlic grinder or simply cut into very small pieces), poured with 1 glass of water and left for 24 hours. Then the mass is filtered, 10 liters of water and 1 g of potassium permanganate are added. The resulting solution is sprayed onto the plants every 10-15 days. On average, 0.5 liters are used for each bush.

Trichopolum

This drug (and its analogue, Metronidazole) can be bought at the pharmacy. 1 tablet of Trichopolum is dissolved in 1 liter of water and the tops are sprayed with this liquid once every 2 weeks.

Milk serum

The whey from sour milk is diluted with water in a 1:1 ratio and from the beginning of July the plants are sprayed every 2-3 days.

Late blight is a problem familiar to most gardeners. This fungal disease annually threatens the harvest of many plants: potatoes, peppers, eggplants and other plantings. This includes tomatoes. Appearing on one bush, late blight soon covers all plants.

In a couple of days, the entire crop can die if measures are not taken in time. In this article you will learn how to identify late blight infection in tomatoes, how to save tomatoes from late blight if they are already sick, and what are the preventive measures.

Phytophthora is a fungus that develops in conditions of high humidity. It infects the plant directly from the soil or is carried by the wind from diseased bushes to healthy ones.

Most often, the first signs of the disease appear on the leaves. They are covered with dark gray and brown spots, sometimes with a white fluffy coating on the back side. The stem is also covered with spots. The inflorescences turn yellow, darken and soon fall off.

Fruits are also affected. Brown or black spots of uneven shape appear on them. Over time, they merge into one spot. The tomato changes shape, becomes ugly, softens and eventually rots, emitting an unpleasant odor.

Late blight can appear on fruits even after harvesting. Infected vegetables begin to darken and rot during storage and ripening.

How to deal with late blight if tomatoes are already sick

Often, when the disease progresses, infected plants cannot be saved - they are urgently disposed of to avoid an epidemic. If the disease is detected in the early stages, then tomatoes can be cured, for which there is

Chemicals

The stronger the plant, the less susceptible it is to disease. Increase the immunity of tomatoes by feeding them with phosphorus-potassium fertilizers.

If infected, immediately remove the affected leaves and fruits, and then spray the bushes with a fungicide. After a week, only the fruits are treated with calcium chloride solution. A 10% solution is sold in pharmacies. It is diluted with water in a ratio of 1:3.

Note! Do not use chemicals when infecting ripe fruits. Chemical treatment is only appropriate when the fruits are still green.

Traditional methods

If you don't like chemicals and are concerned about the environmental friendliness and quality of the crop, try it. They are also effective in combating late blight:

1. One of the available tools is. This is an excellent disinfectant. Prepare a solution of 1 liter of milk, 1 bucket of water and 15-25 drops of iodine, spray the infected plants.
2. A simpler solution: mix milk and water in a 1:1 ratio and spray the tomatoes daily.
3. Garlic mixture. Chop 100 g of garlic and pour in 200 g of boiled water. Let it brew for a day and add 1 g of potassium permanganate. Dissolve in 10 liters of water and use the solution for spraying.
4. Many gardeners recommend a saline solution. It will create a film on the tomatoes that will protect the fruit. To do this, dissolve a glass of salt in 10 liters of water.

Agrotechnical techniques

If you do not want to remove the bush, try piercing the diseased plant with copper wire. This will enrich the tomato with oxygen and normalize chlorophyll levels, making it more resistant to disease.

Calcine the wire in a fire, cut a small piece about 5 cm long and insert it into the stem at a height of 10-12 cm above the soil level, bending the ends down.

Important! If it was not possible to save the plant from late blight, it is important to remove it correctly. Under no circumstances should you throw the bush into a compost pit, as when you subsequently fertilize the garden with humus, this will provoke new infections. Burn the diseased bush away from healthy ones.

How to save the harvest

Treatment of an infected crop in a greenhouse and in open ground has few differences. The main nuances are in preventive measures.

In the greenhouse

In the greenhouse, thanks to protection from excess moisture - rain, dew, fog - favorable conditions are created for the development of the late blight fungus. But this only works if the greenhouse is regularly ventilated.

It is better to treat infected plants with folk remedies, since chemical treatment in a closed and stuffy greenhouse poisons the air. After plants are cured or removed, pay special attention to the soil. After harvesting, it is treated with a solution of “Fitosporin” so that the fungus dies and does not infect the plantings next year.

In the open ground

Outdoors, tomatoes are more susceptible to disease, as rain and dew create favorable conditions for fungal growth. When infected, use chemicals, treating plants in clear weather in the morning or evening. On average, this is done once every 10-14 days. But keep in mind that many drugs are easily washed off by rain.

What to do if late blight has affected the fruits

Even if the disease has reached the fruits, do not despair. The harvest can still be saved and even eaten.

How to save

Collect fruits affected by late blight into a common container. Pour warm, almost hot water or potassium permanganate solution over the tomatoes for a couple of minutes. This will kill bacteria. Then thoroughly dry each vegetable and wrap it in paper to prevent the fruits from contaminating each other. Leave the tomatoes to ripen in a clean and dry place.

Is it possible to eat them

If late blight has not penetrated deep into the fruit, then the tomatoes can be eaten by cutting off the layer damaged by rot.

How to save green tomatoes

If a plant with unripe fruits is sick, then green tomatoes can be saved. Collect fruits without signs of disease - they should be whole, dense, without black or brown spots. Next, be sure to rinse with warm water - this will wash away bacteria from the fruit.

Then leave to dry in a warm place out of direct sunlight. The active sun will wrinkle the tomatoes, not allowing them to ripen. After a couple of weeks, you can harvest the first ripe tomatoes.

Preventive measures

It is known that it is better to prevent a disease than to treat it, therefore:

1. Before planting, be sure to disinfect the soil. This will reduce the possibility of late blight to a minimum.
2. Plant tomatoes after beets, cucumbers, onions, cabbage, and carrots.
3. Water your tomatoes early in the morning.
4. If tomatoes are growing in a greenhouse, be sure to ventilate the room to avoid condensation.
5. Do not forget to loosen the soil for better aeration of the roots.
6. Do not neglect feeding plants with biologically active and folk remedies.

When irrigating, make sure that water does not get on the plant and fruits - it is convenient to use drip irrigation systems for this.

It will be more effective if you feed the plants with phosphorus or potassium. And, of course, do not despair if the plants are sick - they can be saved if you put in enough effort.

Conclusion

Late blight annually affects tomatoes in regions with different climates. But infected fruits can be saved and even eaten, so don’t rush to get rid of them. Chemical and natural remedies and agricultural techniques will help in the fight.

Carefully monitor your garden: it is easier to overcome tomato late blight if you notice it in the early stages. And, of course, the most effective remedy is prevention. With proper planting and care, you will not have to fight the disease.

Most gardeners, when growing tomatoes, have encountered a disease called late blight, which manifests itself in blackening of leaves and fruits. Tomatoes are more susceptible to this disease than other vegetable crops, so it is important to be able to identify it in time. In this article we will talk about what fruits affected by late blight look like and how not to confuse it with other tomato diseases.

The onset of the disease due to uneven spore damage may not be noticeable. At the early stage of infection, the lower part of the leaves becomes covered with a white coating that is difficult to detect, so the onset of the epidemic is very easy to miss. Gradually, the plaque spreads to the upper part of the leaves in the form of brown spots. Following the leaves, the inflorescences are affected, and then the fruits.

Late blight quickly spreads throughout the plantation, infecting not only tomato bushes, but also other vegetables. Within three days, the leaves will be covered with black spots, and the harvest will be lost.

What it looks like: description of signs and photos

Every gardener who decides to grow tomatoes needs to know the signs of the disease “by sight” and, if necessary, begin treatment immediately.

So, let's look at the signs of the disease in more detail.:

1. As already mentioned, late blight damage begins with the leaves - a white coating appears on the lower part, and small brown spots appear at the edges.
2. During rains, you may notice that the leaves seem to be covered with a light or white oil film.
3. The disease begins to progress: the leaf loses its green color, gradually turns yellow, and the edges of the leaves curl into a tube. Afterwards the greenery dries and falls off.
4. The stem of the plant becomes covered with brown spots of irregular shape.
5. The inflorescences acquire a yellow or lemon tint.
6. The next stage is when the inflorescences quickly turn black and fall off in large quantities.
7. Then the disease affects green fruits - brown blurry spots of various shapes and sizes appear on them.
8. Late blight quickly spreads from unripe fruits to mature, not yet harvested tomatoes, also manifesting itself as gray-brown spots.
9. The vegetable in the affected areas is initially hard, but later becomes soft due to the rotting process.
10. The spots quickly spread and penetrate inside, the fruits are severely deformed.
11. The tomato peel becomes thin, the flesh rots, and emits an unpleasant odor.
12. The fruit is easily pressed when pressed in places of rotting.
13. White filamentous mold forms on the plant.
14. When you cut into an infected vegetable, you can see a completely rotten core inside.
15. After this, it becomes almost impossible to save the crop - the trunks become covered with black spots, rot, the fruits fall off and eventually the bush dies.

Late blight develops most actively under conditions of frequent watering or during prolonged rains.

Given it is much easier to prevent a disease than to cure it later Therefore, it is important for the gardener to carry out daily inspection and watering of growing vegetable crops.

Now that you know about the first and subsequent signs of late blight on tomatoes, we suggest you study what the affected leaves and other parts of seedlings and adult plants look like in the photo.

What can late blight be confused with?

Before you start treating tomatoes, you need to understand whether your tomatoes are specifically infected with late blight. Rotting fruits and the appearance of plaque on stems and leaves can be signs of several diseases.

For example:

• Apex rot.
• Fomoz.
• Lack of water.
• Boron or magnesium deficiency.

Let's figure out how to distinguish late blight from other diseases:

1. Blossom rot affects only green fruits, and, as the name suggests, affects only the top. The vegetable gradually darkens, the flesh becomes hard and dehydrated; Unlike late blight, in this case the flesh is soft and emits an unpleasant odor.
2. If Phomosis is infected, tomato leaves become covered with small dark spots, and on the tomato itself, the lesion is noticeable near the stalk. Phoma can infect not only green, but also ripe tomatoes. Late blight and fomoz are very similar diseases, they are easy to confuse. Therefore, it is important to know that Phoma affects tomatoes near the calyx, while late blight can spread brown spots throughout the fruit.
3. If there is insufficient watering, the roots of the plant “emerge” from the soil to obtain moisture from the air. This leads to gradual spoilage of the fruit. It is easy to recognize a lack of watering, because with late blight the entire bush is affected, plaque and white mold appear, and if there is a lack of moisture, the fruits simply turn black and spoil.
4. A deficiency of magnesium and boron leads to only a slight gradual darkening of the fruit; there are no brown spots, rotting or mold - just darkening.

Most often, tomatoes are infected from potatoes, so it is not recommended to grow these vegetables next to each other. To disinfect the soil after harvesting tomatoes, rye is sown in the ground.

Now you know what tomatoes look like when infected with late blight and how to distinguish this disease from many other fungal diseases. Remember that the most important thing is to inspect vegetable crops daily and take the necessary measures even at the first sign of late blight.

Useful video

We invite you to watch a video on how to recognize Phytophthora disease and how to deal with it:

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