Phytophthora tomato disease. Phytophthora: fight and treatment, remedies for late blight

Most of the summer residents, growing tomatoes, are familiar with such a problem as late blight. It is tomatoes that are more susceptible to disease than other vegetables, which manifests itself in the blackening of fruits and leaves, which affects the amount of the crop.

Phytophthora always lives in the soil and appears in the second half of summer, when it is already quite cold and damp at night, which means there is a good environment for its development. Now gardeners use both chemicals and various folk methods to deal with scourge. We will consider all methods in this article.

What is phytophthora?

If you are not familiar with such a disease, then you simply did not grow tomatoes. You need to personally know the enemy in person, or rather, the signs of the onset of late blight disease in order to quickly begin the fight against it.

Late blight (or late blight) is a disease caused by a fungus. There are about 50 species of these fungi. The word "late blight" is translated as "destroying the plant."

Fungi reproduce asexually using spores.

Mycelium of fungi lives in the remains of diseased crops, in the soil, in garden tools and, having overwintered, begins its cycle anew under favorable conditions for it (high humidity is the most important of them).

Depending on the type of fungus itself, there are several types of late blight:

1. Phytophthora cactorum Schroet. Appears on trees of the beech family (oak, beech), pine (coniferous), wild rose;
2. Phytophthora cinnamomi Bonds. Trees of the beech and walnut families are affected by this fungus;
3. Phytophthora infestans. The well-known phytophthora of potatoes and other vegetables of the nightshade family;
4. Phytophthora fragariae. Raspberries, buckwheat and strawberries are affected. Fixed in North America, Europe. In Russia, cases of infection are rare.

Phytophthora on tomatoes appears most often at the end of summer. In another way, it is brown rot, which first affects the leaves, and then the fruits of tomatoes.

The leaves are covered with brown spots from below.

In the rain, tomato leaves affected by phytophthora seem to be covered with a light-colored oil film. Tomato inflorescences turn yellow, darken and fall off.

The spots on the fruits of tomatoes of different sizes are gray-brown in color. The disease spreads throughout the tomato plantation quickly, in just a couple of days. The bush is quickly oppressed and gradually dies off. Therefore, the beginning of the epidemic is easy to miss.

The first signs of late blight on tomatoes

Phytophthora is a fungal disease that most often affects tomatoes and potatoes, eggplant and pepper are a little less affected.

Main features:

• The stem of the plant is covered with irregularly shaped brown spots;
• Inflorescences are yellow or dark, quickly fall off;
• Leaves have dark spots. Then the leaves dry up and fall off;
• The fruits are covered with gray-brown or black spots.

Photo disease on tomatoes

Below you can see what the disease looks like on plants in order to recognize it in time.

How does defeat begin?

High humidity is a trigger for the fungus that causes Phytophthora. When moisture appears, spores first infect the leaves, starting from its lower part.

They are covered with a white coating, which gradually passes to the upper part in the form of brown spots.

Following the leaves, the inflorescences are affected (they dry up and fall off), and then the fruits themselves. Gradually increasing spots of gray-brown color, almost black in places, cover the entire fruit.

The peel becomes thin, and the flesh begins to rot and smell unpleasant. In just a few days, the entire crop is affected by late blight, and without proper attention from the gardener, it will be lost.

Causes of the disease

Before you start an effective fight against phytophthora, you need to know what causes the onset of the disease. Consider the main ones that cause late blight on tomatoes:

• Close proximity to potatoes (more often the disease begins with it);
• Dense plantings and lack of ventilation between the bushes;
• A large difference between night and day temperatures and abundant dew in the morning (more often this occurs in August), as well as the absence of heat;
• Frequent and heavy rains in the second half of summer;
• Excessive watering in July-August during fruit ripening, as well as irrigation on the leaves;
• Excess nitrogen;
• Increased lime content in the soil;
• Lack of potassium, copper, iodine, manganese in the soil.

Knowing the main reasons, you can avoid care errors in advance and save your crop.

What to do if the disease appeared in the greenhouse?

In a greenhouse, phytophthora on tomatoes, with proper care, may not appear. The main thing is to observe the wet and thermal conditions, as well as to do preventive treatment.

You should not make close plantings, do not plant other tomatoes and potatoes next to the greenhouse in order to reduce the risk of transferring the disease from them to the greenhouse.

You need to water rarely, but in large volumes. Prevention in the greenhouse begins precisely with the disinfection of the premises and equipment. And if late blight got into a greenhouse with tomatoes, then it develops even faster than in open ground: the warm and humid climate inside it contributes to this.

Measures applicable in open ground

Tomatoes planted in open ground are most susceptible to the fungus that causes late blight.

If agricultural technology has not been observed, then with an increase in humidity, the appearance of frequent rains and a large amount of dew, late blight will definitely appear.

Here, the disease is easier to prevent than to try to fight it when it has already manifested itself. When obvious signs are visible, it is already difficult to deal with it and a large crop loss is guaranteed.

Methods and methods of struggle

As soon as the phytophthora appeared on the bushes with tomatoes, the gardeners face the question of how to get rid of the scourge. In total, there are 2 ways to treat late blight:

• Chemical (using preparations containing chemically active substances in the composition);
• Folk (more often used food as the main active ingredient).

Important! When processing tomatoes, it is worth processing potatoes, especially if they are planted nearby. Often, late blight passes from potatoes to tomatoes.

Fighting with chemicals

Let us analyze the main, most popular preparations among summer residents and gardeners, which are used to treat tomatoes.

Spraying with Hom

Hom is a fungicide characterized by contact action. The active substance is copper oxychloride, which acts on the surface and does not penetrate into the leaf and fruit.

It is suitable for prevention, it protects the plant well, but it absolutely does not cure an already ailing bush.

It is not able to accumulate, which means that fungi do not get used to the drug and each application will be effective.

Can be processed up to 5 times per season. Lasts up to 2 weeks, but is easily washed off by rain. Last treatment at least 20 days before harvest. Prepare a solution according to the instructions, dissolving 40 gr. drug per 10 liters of water. You cannot store it. Use in the evening or in the morning in clear weather. Hazard class - the third, requires protective clothing and safety precautions.

Treatment with Furacilin

Furacilin is an antibacterial drug for humans. But many summer residents use it to treat tomatoes from phytophthora.

The solution can be prepared for the whole summer at once, because. due to its bactericidal properties, it does not deteriorate. You need to crush 10 tablets and dilute in 10 liters of water.

You need to spray 3 times per season: before flowering, when the first fruit ovaries appear, when the first tomatoes ripen. The drug is not dangerous for humans.

How to treat Fitosporin?

Fitosporin – It is a biological pesticide that contains bacteria.

The “medicine” penetrates the plant tissues and kills all pathogenic bacteria with the help of beneficial microorganisms.

This drug is biologically safe, the fruits of tomatoes can be eaten immediately, after thoroughly washing.

It goes well with other chemicals. Suitable for prevention as well as treatment. Features of the preparation of the solution (2 tsp per 10 liters of water):

• Use warm water no higher than 35℃;
• Do not use metal containers;
• Leave the solution in the sun for several hours to activate beneficial bacteria.

The whole plant needs to be treated. Frequency - every 10 days during the season (if it started to rain, then immediately after the rain). A similar bacteriological composition and method of application for drugs Baktofit, Baikal-EM, Fitoftorin, Planriz.

Use of Trichopolum or Metronidazole

Trichopolum – This is a drug (antimicrobial and antifungal action) for people with the active substance metronidazole (to reduce spending, you can buy a drug with the same name).

Used by gardeners not so long ago.

The solution is made as follows: 2 tablets per liter of water. Processing - every 10 days or after rain (if tomatoes grow in open ground), because it does not linger on the leaves.

How to defeat the disease Ordan?

Ordan – It is a fungicide with 2 active ingredients: copper oxychloride and cymoxanil.

Penetrates inside the plant, remains a little on the surface.

The therapeutic effect is 2-4 days, and the prophylactic effect is up to 14 days.

Hence comes the frequency of application. Prepare a solution for tomatoes as follows: 25 gr. for half a bucket of water (bucket - 10 liters.). Do not eat fruits for 5 days.

Attention! The drug Ordan has a third class of danger to humans: it requires protective equipment and measures.

Measures of struggle with folk remedies

Adherents of natural farming, as well as people who use traditional methods of cultivating the land, but reject the use of chemistry in growing tomatoes, use only folk methods of combating late blight of tomatoes. Let's analyze the most popular of them.

Using whey or kefir

Lactic acid bacteria contained in dairy products suppress the pathogenic flora of phytophthora.

It is used for preventive purposes and for treatment. The action of different milk products is the same, although it is whey that gives the maximum effect.

Different ratio to water: whey is diluted 1:1 (or 1:2) with water, a liter of kefir is diluted in 10 liters of water. Instead of kefir, you can take milk and add about 20 drops of iodine. Let the solution stand, then spray. The procedure can be carried out at least every day.

soda treatment

Soda, a product whose usual place is a kitchen cabinet, can be used for late blight of tomatoes.

In half a bucket of water, you need a tablespoon of soda and a little liquid soap for a “sticky” effect.

Repeat every week or after rain.

The use of salt to fight

Salt is able to deal with such a scourge as late blight. After it gets on the leaves and fruits and dries, it will cover everything with a thin white layer, which will prevent the entry of fungi into the plant.

This is only a preventive measure, because. fights on the surface. For saline you need 250 gr. salt dissolve in a 10-liter bucket of water. Spray the entire plant. After the rain, it is worth repeating.

Vinegar

This product is often used as a remedy against late blight.

Half a glass of table (9%) vinegar should be diluted in a bucket of water and spray the entire plant.

It is good to alternate this procedure with other folk and chemical methods.

Toothpaste

This unusual method is also used by many summer residents. There are many substances in toothpaste that have a bactericidal effect.

To combat the disease, you need to take a tube of toothpaste and dilute it in a bucket of water.

For convenience, first stir the paste in a small amount, and then combine with the rest of the water. Toothpaste is better as a preventive measure. Repeat every time after rain, can be combined with other methods.

Spraying with garlic tincture

Garlic has a strong odor and good bactericidal properties. Garlic can be planted along with tomatoes.

To combat the disease, pour 1.5 cups of chopped arrows and heads of garlic with 10 liters of water and leave for a day.

After you need to spray all the bushes with a solution. You need to repeat every 2 weeks.

Boiling water (hot water)

The cheapest way. To do this, clean water must be brought to a boil and poured into a watering can with a special nozzle in the form of a shower head.

Water the tomato bushes with hot water carefully, raising the watering can higher so as not to damage the plant.

Repeat the procedure once a week.

Interesting! It has been established that the spores of the harmful fungus die at temperatures above +30°C.

Ash

Ash solution effectively fights late blight on tomatoes.

You need 5 kg. dissolve the ashes in 10 liters of water and infuse for 3 days, stirring regularly.

After the volume of the solution is brought to 30 liters, add any liquid soap as an "adhesive".

Spray 3 times throughout the season: a week after planting in the ground, before flowering and after the first ovaries appear. Another way: add a glass of tobacco dust to a bucket of ash. Before use, wear a respirator and goggles.

Yeast

An almost constant ingredient in baking is also good for late blight.

It can be used at the first signs of tomato disease and in advance during the appearance of ovaries.

For this 100 gr. yeast must be dissolved in a bucket of warm water, let it brew a little and then spray the whole plant.

Hay protection

And you need to take already rotten, rotted hay.

Approximately a kilogram of hay should be poured with 10 liters of warm water and about 100 gr. urea.

Leave to infuse for 3 days and then treat the tomato bushes with the prepared mixture. Hay stick perfectly prevents the development of phytophthora.

Other ways to combat late blight tomato

There are other ways to treat tomatoes from this scourge. We list the main recipes that gardeners use.

Iodine treatment

A well-known antiseptic agent can be used in combination with other folk remedies (with milk, kefir, ash solution) for a more effective fight.

Dosage: for 10 liters of water - 20 drops of iodine.

To strengthen the immunity of plants in greenhouses, you can hang open jars of iodine.

How to treat with hydrogen peroxide?

This is an additional source of oxygen for plants.

It has oxidizing properties and destroys the pathogenic flora of phytophthora.

Add 2 tbsp per liter of water. hydrogen peroxide and spray the entire plant, especially the lower part of the leaves. Repeat no more than once a week.

How to protect "Bibs" for tomatoes?

Such a device with a "childish" name is covering the soil around a tomato bush with several layers of newspaper, cardboard (or mulching with pre-shredded paper).

Bibs allow you to water less, because. retain moisture in the soil in sufficient quantities, and therefore does not create excessive moisture. In addition, it prevents the transfer of spores from the soil to the plant itself.

Copper wire against adversity

Copper is detrimental to phytophthora fungus spores. A simple and effective way to combat the disease is to wrap the plant near the root collar with copper wire.

For a better result, a small piece of wire (about 4 cm) needs to be pierced at the base of the stem.

The ends must be bent to the ground. Copper wire will help strengthen the plant's immunity and prevent late blight from spreading.

Important! The plant itself must already be well developed, otherwise you can ruin the bush.

Potassium permanganate

This remedy has antiseptic properties.

It is good to use together with other folk methods (garlic, ash, milk).

Calcium chloride

Another drug from the pharmacy perfectly fights phytophthora fungi. It saves the fruits well when the leaves are already affected. To do this, dilute calcium chloride with water in a ratio of 1: 3 and process the fruits of tomatoes.

How to stop copper sulphate infection?

One of the most popular remedies for the treatment of tomatoes from phytophthora.

The main active ingredient is copper, which perfectly copes with adversity.

To prepare a solution of 1 tbsp. preparation and a little liquid soap add to 10 liters. water so that the drug stays on the leaves longer.

Zelenka

An antiseptic in the amount of 40 drops per bucket of water is a good remedy for late blight of tomatoes.

It can be used for prevention and also as a treatment.

Boric acid

Attention! The most effective way is the alternation of the use of iodine, boric acid, brilliant green, manganese. Frequency - once a week.

Bordeaux mixture

Another drug with a copper content (consists of copper sulfate and quicklime).

To prepare the solution, you need to take 100 gr. copper sulfate and 150 gr. quicklime per 10 liters of water, and mix in strict sequence: first blue vitriol in water, and then lime.

The liquid is quite toxic, so you need to use protective equipment.

How to process?

The basic processing rules are as follows:

• The weather should be clear and calm;
• The best time is early morning or evening;
• If the drugs are toxic, then you need to use protective equipment and observe safety precautions;
• Do not use metal utensils for preparing solutions, especially chemical ones, and mixing devices (preferably plastic, glass, wood).

Varieties resistant to late blight

There are no such varieties that, in principle, do not suffer from late blight. There are varieties that can resist it more than others. Most often they are hybrid varieties. For a good harvest, it is worth planting early-ripening tomatoes, the harvest of which can be harvested before the mass defeat of late blight. Phytophthora resistant varieties:

• Snowstorm;
• Budenovka;
• Kostroma;
• Pink dwarf;
• Parterre;
• Profitable;
• Otradny;
• oak forest;
• Skylark F1;
• De Barao;
• Berry;
• Solar;
• Grotto;
• Snezhana;
• Cameo etc.

Prevention of late blight on tomatoes

To reduce the risks of infection of tomatoes with phytophthora and save the crop, you need to carry out competent agricultural technology. Basic Rules:

1. Crop rotation for tomatoes. Do not plant tomatoes after potatoes, peppers, eggplants, avoid their close proximity. Good precursors for tomatoes are onions, cucumbers, beets, turnips, cauliflower, and carrots. Do not return tomatoes to the same bed before 4 years;
2. The place for tomato plantings should be sunny;
3. Choose varieties either early ripe or hybrid varieties most resistant to phytophthora;
4. If there is a lot of lime in the soil, then when planting, add peat to the hole, and then sprinkle sand around the bush. Put the onion peel in the holes;
5. Don't plant tomatoes too often;
6. Tomatoes need to be watered under the root, trying not to touch the leaves and fruits. In the second half of summer, you can not do this procedure at all (the exception is extreme heat without rain), but only regularly loosen the soil around the bush. It is better to water the plants in the morning so that excess moisture is gone during the day. Ideal for drip irrigation.
7. Mulching bushes;
8. Planting white mustard, calendula, marigolds, as well as onions, garlic next to tomato bushes;
9. Remove stepchildren and unnecessary leaves in time;
10. Increase the immunity of tomatoes: feeding with potassium and phosphorus, spraying with immunomodulators;
11. Ventilate the greenhouse regularly;
12. Nitrogen fertilizers are appropriate only in the first half of the growing season, the rest of the time, frequent fertilizing with nitrogen will provoke the growth of phytophthora.

The rules are quite simple. By observing them, you can avoid the mass destruction of tomatoes and not even encounter late blight at all. Any disease is easier to prevent. Then your garden with tomatoes will definitely give an excellent harvest.

Important! Prevention is the best way to deal with this scourge. Proper care will help preserve the crop.

Common mistakes

Most often, the main mistakes are the lack of preventive measures to prevent the disease.

• During the rampage of the disease, you should not water the bushes at all, so as not to increase the humidity.
• Another mistake is the use of many methods at the same time, especially chemical ones. Surely you can manage and save part of the crop, but the plants themselves may die, and the fruits become poisonous due to the large number of chemicals used.

FAQ

Questions about this disease often arise. Let's answer the most common ones:

Is it possible to water tomatoes infected with late blight?

If the weather is cloudy, the air temperature is low, it is even recommended not to water the infected bushes. You just need to loosen the soil.

Is it possible to eat tomatoes with phytophthora?

Fruits of tomatoes with black spots, damaged by the disease, few people want to eat. It is not worth eating, even after removing the damaged areas, because. the spores of the fungus have already completely penetrated the pulp of the fruit. Those tomatoes that the fungus touched only from above can be eaten after heat treatment.

How to save fruits damaged by phytophthora?

Good fruits from an infected bush can be eaten with proper processing: the fruits must be held for 10-15 seconds in water with a temperature of 60℃. After they need to be dried and left to ripen.

How to save plucked tomatoes?

Green tomatoes can be put into conservation for the winter, having previously processed well. Red fruits are best eaten immediately or canned as well.

Useful video

Learn more about the fight against late blight from the video below:

Conclusion

In conclusion, it should be said that the most important thing in the treatment of tomatoes from late blight is prevention. If you take all preventive measures, then problems with this scourge can be avoided.

Which way to treat tomatoes from phytophthora to choose is a personal matter for every gardener. None of the listed methods guarantee complete elimination of the disease. To effectively combat the onset of tomato disease, it is better to alternate methods and methods so that the fungus does not get used to and does not develop immunity to drugs.

Late blight of tomatoes is one of the most. The disease is caused by a fungal infection of the plant and is distributed almost throughout the world.

In this material, we will consider the causes, risk factors, distribution, symptoms of infection, as well as prevention and treatment measures.

Late blight, or late blight (from other Greek words "plant" + "destroying, annihilating, disastrous")- a common plant disease caused by a fungal infection.

Tomato late blight is ubiquitous. Tomato fungus infection Phytophthora cactorum is observed everywhere - without exception, all European countries, also in the USA, Canada, Iran, India, Mexico, Japan, Georgia, Armenia, Ukraine, etc. In Russia, late blight of tomatoes is most common in the Volgograd and Saratov regions, Krasnodar Territory, Primorsky Territory, as well as in the Leningrad, Samara and Voronezh regions, etc.

Mycelial organisms live in the soil, in the underground and aboveground parts of plants. The fungus overwinters in plant debris. Late blight progresses in warm and humid weather, with prolonged precipitation. The disease most often affects fruits, to a lesser extent - trunks and leaves.

Symptoms and diagnosis

The external manifestations of late blight are ambiguous and depend on environmental conditions, which makes this disease difficult to diagnose and does not allow it to be detected and taken measures in a timely manner.

As a rule, late blight is diagnosed by greenish-brown spots on fruits and leaves, stems and roots. The spots are indistinct. Tomatoes are affected in the period of milky ripeness and in the stage of ripening. The spots quickly increase in size, and in a short period of time affect the entire fetus. The inside of the tomato becomes dark brown, and the fruit itself is soft. Late blight rots are often dry and hard, and this distinguishes them from rots caused by bacterial infection or other fungi.

On the tops of the disease, the disease is noticeable by brown spots, and on the leaves on the reverse side one can observe a small whitish-grayish coating (the result of sporulation of the fungus). With the course of the disease, leaves and individual branches dry out. Foliage loses color and becomes pale colored.

Measures of protection and control against late blight

Prevention

The BASIC protection of tomatoes from late blight comes down to a set of preventive measures:

1. Seed treatment before sowing (seeds are treated with disinfectants, for example, Fentiuram, TMTD, by soaking for 2.5 hours 10-14 days before sowing);

2. Compliance with planting regulations (avoid thickening of plantings of tomatoes);

3. Providing crop rotation (alternate crops when planting);

4. Prohibition of planting next to crops favorable for the development of late blight (for example, with potatoes);

5. Loosening and aeration of the soil;

6. Regular application of fertilizers and trace elements (iodine, manganese, copper, potassium and phosphorus);

7. Support for the immunity of tomatoes (treatment of plants with stimulants "Epin", "Zircon", "Energen", or biological preparations of the type until the ovaries appear);

8.Processing and disinfection of garden tools;

9. Cleaning and elimination of plant residues after harvesting (autumn digging of the soil together with infected tops is not allowed);

11. Cultivation of varieties and hybrids resistant to fungal diseases, selection of high-quality planting material, etc.

Late blight treatment

Control measures when late blight is detected and for prevention include spraying with solutions of fungicides -,, "Kaptan", "", "Ftalan", "Kuprozan", "Polycarbocid", copper oxychloride ("HOM", "Polyhom"), "Tsineb ”, “Ordan”, “Tattu”, “Polymarcin”.

Recently, preference has been given to biological products - EM-preparations "Baikal-M" and "Siyaniye", "Planriz", "Fitoftorin", "Alirin", etc.

"Folk methods" of combating late blight

"Folk remedies" for tomatoes from diseases are of great practical importance. Firstly, they are absolutely safe, and secondly, this is a whole group of effective and proven prophylactic agents that have been proven by many years of practice.

Iodine, furatsilin, boric acid, sour-milk whey, yeast infusion, potassium permanganate, hydrogen peroxide, ash and many other methods are widely used.

In a separate material on the site, TOP-12 of the most used and effective are proposed for use.

Findings and Conclusions

1. To reliably protect a tomato from late blight, it is important EARLY take preventive measures.

2. All spray treatments (curative and preventive) are carried out REGULARLY- 4-6 times per season, with an interval of 1-2 weeks. The consumption rate of the working fluid is not less than 0.3-0.5 liters. for each tomato plant.

Late blight is a terrible word for a gardener, gardener and agronomist. This is a disease caused by a fungus of the genus Phytophthora infestans, which mainly affects nightshade, and some other cultivated plants, such as strawberries or cucumbers.

Phytophthora symptoms

Signs on tops: at first small, then growing (rapidly in wet weather) dirty brown spots. After some time, a light gray coating of spores can be seen on the surface of the spot.

Phytophthora is extremely contagious and external signs - spots on the leaves, appear already on the 3rd-4th day of infection. If the weather is dry, then the leaves quickly dry out and wrinkle, turning into a herbarium, if it is wet, they wilt and rot.

Phytophthora is also noticeable on the stems: oblong brown spots without clear boundaries. Gradually covered with a gray coating of spores.

Fruits affected by phytophthora are initially covered with dark spots of irregular shape, gradually spreading over all tissues. Sometimes the spots are depressed, wet.

Symptoms on tubers: Depressed, sharply defined dark spots appear, if peeled off, under it is reddish-brown tissue. Sometimes sporulation is observed on the surface of tubers.

How infection occurs

The spread of the phytophthora pathogen occurs with the help of asexual spores - zoosporangia, which are highly resistant in the external environment and are able to stay not only in the soil, but also in the air for a long time.

In a favorable environment (the presence of free water), zoosporangia form a large number of zoospores, which also germinate in plant tissues. And free water in the soil and air is formed after rains, irrigation, dew or fog.

The longer the moisture remains on the leaves, in the axils of the stems, the faster pathogens develop - the entire process of spore germination takes 4-5 hours. It is more difficult with soil moisture - there is longer contact of moisture with the surface of tubers and roots, so infection is faster.

Penetration of the infection occurs through all parts of the plant and stages of development: tubers, root system, leaves and infected seeds.

What conditions contribute to the development of phytophthora

In the old days - until about the middle of the last century, phytophthora was more demanding on conditions, for optimal development it needed from 10 to 20 ° C, and did not reproduce sexually - the pathogen remained in the form of mycelium inside potato tubers and spread with infected planting material.

However, since about the 1970s, scientists have identified a new generation of phytophthora - as a result of genetic recombinations, populations capable of sexual reproduction were formed. They form oospores (resting stage) that can overwinter in the soil.

This new phytophthora is much more terrible - it is less dependent on temperature and moisture. If earlier signs of phytophthora appeared on potatoes only by July or August, now they can be found at the very beginning of summer. The pathogen is able to infect Solanaceae in the range from 3 to 27°C, and the period of liquid moisture retention on leaves or tubers has been reduced from 7 hours to 4-5.

Only hot and dry weather helps to stop the development of phytophthora.

Phytophthora development

The pathogen Phytophthora infestans is a heterothallous fungus, i.e., for the formation of genital organs, it is necessary to merge two genetically isolated populations with different types of mating. Phytophthora has two of them, designated A1 and A2, when merged, the female and male genital organs (oogonium and antheridium) are formed.

Previously, it was believed that the presence of both types of phytophthora is typical only for Western Europe, but authoritative sources paint a different picture: modern pathogen populations found on the territory of the Russian Federation are diverse. In the European part of Russia, there are populations of both types A1 and A2. In the Asian part of Russia, predominantly A1 type, in regions closer to China - only A2 (a). Therefore, an ordinary gardener and gardener has something to attend to.

Phytophthora development cycle

Of course, not in all regions of Russia there is late blight capable of sexual reproduction. Thus, according to the latest data from the institutes of phytopathology, in most regions of Siberia, only A1 type (a) is noted. But some scientists in the most modern studies (2010-2012) conclude that in a number of regions of Russia, oospores formed as a result of crossing strains of opposite mating types overwinter in the soil and cause the development of late blight in the next growing season (Kuznetsova Maria Alekseevna, All-Russian Research Institute of Phytopathology Moscow region) (b).

It is impossible to distinguish the cause of the development of late blight on tomatoes or potatoes along the routes of infection - whether it came with seed material or from soil with oospores, it is impossible for any reason. Neither the timing of the onset of the disease, nor the location of the lesion is an indicator.

The sad thing is that the breeding of new varieties of tomatoes or potatoes that are resistant to late blight only slightly delays the onset of the lesion and slows down the rate of development of the disease. And the concept of sustainability often concerns only the aerial part, if the crop is visible for tomatoes, then it is more difficult with potatoes - tubers are more susceptible, and digging up potatoes in autumn, with green tops, you find that the crop has died.

While breeders struggle to create resistant nightshade varieties, evolution also does not stand still, and as a result of mutation of local phytophthora strains or the importation of infected seed material (for example, from Mexico), more and more aggressive strains of Phytophthora infestans are spreading. They break through all the boundaries of resistance in previously immune species.

Phytophthora oospores are very viable in the external environment, for example, it is known that in the climatic conditions of the Netherlands they remain viable for 3-4 years (depending on the type of soil), and are even able to survive the winter in the more severe conditions of Finland.

Video of a simple way to protect tomatoes from late blight

But still, there is a fly in the ointment and a spoonful of honey: unlike zoosporangia, oospores are formed inside plant tissues and presumably acquire their harmfulness (readiness to germinate) only after the surrounding tissues (tops or tubers) rot. This means that the sooner the disease is detected and the affected plants are destroyed (burned), the better. If the site cannot be completely completely rid of the infection, then the contamination with the phytopathogen can be significantly reduced.

The fight against phytophthora

Phytophthora preparations

Here is an approximate arsenal of tools than to spray tomatoes from phytophthora:

• Alirin-B is a biological preparation against plant diseases, contains Bacillus subtilis bacteria. Consumption rate from phytophthora: 2 tablets per 10 liters of water when watering plants, and 2 tablets per 1 liter of water when spraying. Re-treatment after 5-7 days, up to 3 treatments in total.
• Gamair is a biological drug against late blight, the consumption of the drug is 1 tablet per 5 liters of water, when watering, and 2 tablets per 1 liter of water when spraying. Processing is repeated every 7 days, three times.
• Oksihom (copper oxychloride + oxadixyl) is a contact-systemic fungicide against late blight. Dilute 1 sachet (4 g) per 2 liters of water. Plants are sprayed as needed up to three times with an interval of 10-14 days.
• Ordan - (copper oxychloride + cymoxanil) - in the form of a wetting powder. Sprayed twice with an interval of 7-14 days, at the rate of 25 g per 5 liters of water.
• Ridomil Gold (mancozeb + mefenoxam) is a combined fungicide against phytophthora, a very effective remedy, for personal households it is available in sachets of 10 g. You need to dilute 1 sachet (10 g) in 2 liters of water. This is enough to process 40 sq. m. planting tomatoes. Spray the first time during the period when the tops of the bushes close in the beds, the second time after 10-14 days.
• Fitosporin-M is a biofungicide in the form of a dark brown paste, liquid or powder. In gardening, either powder or paste is used. For spraying, dilute 10 g of powder per 5 liters of water, paste 3 teaspoons of concentrate per 10 liters of water, more about.

On an industrial scale (farms), more powerful fungicides are used, for example, Bravo, Quadris - they all have hazard class 2, are produced only in canisters (price per canister is from 2000 to 6000 rubles) and are prohibited for use in personal farms.

Phytophthora treatment

An approximate scheme for the treatment of phytophthora begins with prevention, before planting seedlings in the ground. Dilute with oxychom (or blue vitriol) according to the instructions and pour the planting holes.

In the phase of mass flowering (around the end of June, in the twentieth), carry out the first treatment of tomatoes with Ridomil Gold (or copper-containing), carefully spraying the leaves. Then after two weeks (when the fruits are already set, but still green), spray again. Subsequently, the crop actively ripens, and it is impossible to use chemistry for treatment - it accumulates in the fruits. Therefore, if phytophthora still appears, in August you can spray it twice with phytosporin.

Remember that when spots appear on the fruits, this is no longer the beginning of the disease, but its rapid development and it is too late to take any measures! Biological products are somewhat weaker than chemical ones, but safer.

(a) S. Elansky, A. Smirnova, Yu. v. Dyakov, A. Dolgova, A. Filippov, B. i. Kozlovsky, I. Kozlovskaya, P. Rousseau, K. Smart, W. Fry Genotypic analysis of Russian isolates of Phytophthora infestans from the Moscow region, Siberia and the Far East // Journal of Phytopathology, 2001, 149 (10), pp. 605. -611

(b) Kuznetsova M.A., Ulanova T.I., Rogozhin A.N., Smetanina T.I., and Filippov A.V. (2010) Role of oospores in the overwintering and year-on-year development of the late blight pathogen on tomato and potato. In: Proceedings of the 12th EuroBlight Workshop (Arras, France, May 3-6, 2010).

Phytophthora on tomatoes can lead to premature death of plants and the loss of most of the crop, but there are proven methods to both fight the disease and prevent it. Next to the site about how to process tomatoes from late blight in open ground and in a greenhouse.

What is phytophthora on tomatoes

Late blight (phytophthora) on tomatoes is a fungal disease that affects leaves, stems and fruits and develops when grown in open ground, in a greenhouse and under film shelters. This disease can destroy a plant in just a few days.

It is especially often manifested in the northern, central, northwestern and Far Eastern regions of Russia, less often in the steppe part of the Stavropol Territory, in the regions of the Lower Volga region. The disease progresses in cold and rainy weather.

Signs of late blight on tomatoes:

• Brown spots appear on the leaves, with high humidity they begin to get wet.
• A white cobwebbed coating forms on the underside.
• Diseased leaves dry out quickly.
• On the petioles and stems, brown oblong spots are visible, but without plaque.
• Large vague brownish-brown spots appear on the surface of the fruit, and brown rot inside.

The disease is spread by spores, which are formed mainly on the affected leaves in rainy weather or at high relative humidity (above 80%).

Late blight of tomatoes - photo

Causes

Late blight is caused by the fungus Phytophthora nicotianae var. nicotianae, which exists as resting spores in the soil. When the ground is wet, they are released and carried to the nearest tomato roots.

Phytophthora on tomatoes can develop both during the growing season of plants and during ripening and storage of fruits. It often happens that tomatoes are laid for ripening without signs of illness, and after a few days it manifests itself. This may be because the infection occurs immediately before harvesting, and when the tomatoes are transferred to ripening in a warm room, favorable conditions are created for the development of the disease.

Infection of fruits is also possible after harvesting, if tomatoes are left in bulk in heaps or deep boxes in a warm room for a long time. Under such conditions, they sweat and the formed droplets of moisture on their surface contribute to the germination of adhering spores and tissue damage.

The causative agent of the disease can safely overwinter in the affected plant debris, not harvested in the fall, in the soil and potato tubers. Therefore, more often and earlier, tomatoes are affected by late blight in areas where this crop is grown in the same place for several years, last year's tops are not harvested, and potatoes and tomatoes are grown side by side.

Tomato varieties for open ground resistant to late blight

Late-ripening tomato varieties or plants of late planting dates are most severely affected by phytophthora, since favorable conditions for the development of the disease usually occur in the second half of summer and early autumn.

Many varieties and hybrids of tomato are quite susceptible to late blight, the following are considered relatively resistant:

• Siberian early;
• Khabarovsk pink;
• Khabarovsk standard;
• fruitful;
• Oak;
• Gavroche;
• Krasnodar;
• cold resistant;
• Mars;
• Stresa;
• Semko 98 and others.

Due to their precocity, they often leave a strong defeat of the variety:

• Lightning;
• Ground Gribovsky;
• White filling 241;
• Lunar.

To protect the tomato from the disease, you must:

• plant seedlings at a distance of 30-35 from each other;
• stepchild plants in a timely manner, avoiding thickening inside the bush;
• carry out top dressing during the growing season with phosphorus and potash fertilizers, which increase the resistance of the tomato to late blight.

Prevention of late blight on tomatoes in a greenhouse

Phytophthora enters greenhouses and film shelters from the open ground from the affected potato or tomato. The first foci of the disease appear on plants located near doors and windows, under shelters through which moisture penetrates (torn film, broken glass, etc.).

In protected ground, late blight can spread very quickly with high humidity or abundant condensation on the inner surface of the greenhouse or film shelters.

In addition to high air humidity, the best conditions for the development of this disease in protected ground are created when the temperature in greenhouse facilities is maintained at 14-23 °C. At temperatures above 25 ° C, the spores of the fungus die, and at 30 ° C, the mycelium also dies.

In rainy cloudy weather in the second half of the growing season, when it is difficult to reduce air humidity even in film structures, late blight can be very dangerous.

To prevent late blight on tomatoes in a greenhouse:

• remove the affected parts of plants when the first single foci of the disease appear;
• observe the optimal (below 70%) relative humidity inside the shelters, for which regularly ventilate greenhouses or hotbeds and do not water the plants by spraying water.

During an outbreak of late blight, it is necessary to ensure that the fruits do not come into contact with the soil, it is advisable to collect them more often and ripen indoors. Before laying for ripening, the fruits should be warmed up for 1–2 minutes by immersing them in hot water (60 ° C).

How to process tomatoes from phytophthora

Phytophthora on tomatoes is fought with both modern drugs and folk remedies proven for hundreds of years.

Popular preparations for the treatment of phytophthora

Chemical methods for the destruction of phytophthora are numerous, but the principle of action is the same. Tomatoes are treated with fungicides.

In amateur gardens and orchards, such preparations for late blight on tomatoes are often used, such as:

• Previcur Energy;
• Profit Gold;
• Fundazol;
• Phytosporin;
• Quadris;
• Topaz;
• Horus;
• Ordan;
• Fundazim;
• Bordeaux mixture;
• copper sulfate;
• copper oxychloride;
• trichopolum;
• and others.

Phytophthora adapts easily if the same preparations are used every year. Rotate funds each year, for example:

1. Copper Based Fungicide - Apply 3-5 times per season every 7 days. Apply after heavy rain or when signs of disease increase rapidly. If possible, schedule the time to leave at least 12 hours of dry weather after spraying.
2. Fitosporin - spray tomatoes when transplanting or when seedlings form 2-4 true leaves, and then at intervals of 1-2 weeks to prevent the disease. Dissolve 2 teaspoons of the drug in 10 liters of water at room temperature. Used as a spray, phytosporin penetrates the inside of the plant to prevent or resolve phytophthora.
3. Profit Gold is a new contact-systemic fungicide based on cymoxanil and famoxadone that controls most foliar diseases.
4. The drug Ordan based on copper oxychloride and cymoxanil for the treatment of tomatoes is diluted 25 grams in 5 liters of water. The first spraying is carried out in the phase of 4-6 true leaves. Subsequent - with an interval of 7-10 days.

In the open field

Tomato plants are sprayed when the first signs of the disease appear:

• 1% Bordeaux mixture;
• 0.4% copper oxychloride;
• 0.4% oxychome;
• 0.2% utane;
• 0.4-0.6% cartocid.

Tomatoes are treated with these preparations 2-4 times at intervals of 10-12 days, and under favorable weather conditions for the development of phytophthora, more often (after 7-8 days).

Folk remedies

Phytophthora on tomatoes at the very beginning of the disease can be destroyed by folk remedies. They are not as effective, but harmless to the human body.

Infusion of garlic

1. Take 100 g of leaves and arrows of garlic or 50 g of crushed cloves, pour 1 liter of water and leave for 2 days in a closed glass jar.
2. The resulting infusion is diluted in 10 liters of water and the plants are sprayed with it.
3. After 5 days, the treatment is repeated.

Garlic-manganese infusion

To combat late blight, tomatoes can be treated with garlic infusion with the addition of potassium permanganate.

In 100 g of minced garlic in a meat grinder (you can use not only cloves, but also leaves, stems and arrows), pour a glass of water, insist overnight. Then filter and dissolve this infusion in 10 liters of water, adding 1 g of potassium permanganate to it.

Infusion of onion skins

A kilogram of onion peel is poured into 10 liters of water, a handful of urea is added and left to infuse for 3-4 days. Tomatoes are treated with this infusion using a spray bottle.

Yeast processing

Dissolve 80 g of yeast in a bucket of water and spray tomatoes with the first symptoms of late blight with this solution.

Copper wire as a remedy for late blight on tomatoes

Spraying tomatoes from late blight can be replaced with "copper piercing". Some amateur gardeners suggest protecting tomatoes from late blight with copper wire. To do this, cut it into pieces 3-4 cm in length and insert it into the stem of a tomato at a height of 10 cm from the ground, bend the ends of the wire down.

Other "inventors" prefer to wrap pieces of copper wire around the roots of seedlings before planting tomatoes in the garden. They claim that this is an effective remedy for phytophthora, since a small dose of copper enters the plant and stabilizes the production of chlorophyll, promotes oxygen exchange, strengthens the immune system, thereby making tomatoes immune to this disease.

Iodine and milk from late blight on tomatoes

Everyone knows the antimicrobial effect of iodine, so the method of spraying tomatoes with milk and iodine is widely popular among gardeners. 10 liters of water is enough for 1 liter of skim milk and 20 drops of iodine.

Ash solution

This processing takes place in three stages:

• immediately after planting seedlings in open ground or greenhouse;
• before flowering tomatoes;
• just before the appearance of the first fruits.

Add half a bucket of wood ash to 10 liters of water, leave for three days, stirring occasionally. When the solution settles, drain the water and add a new one, bringing the volume of liquid to 30 liters.

Phytophthora serum on tomatoes

Processing tomatoes with phytophthora whey from curdled milk also gives good results. Serum should be diluted in a ratio of one to one. spray tomatoes daily from the first days of July.

in the greenhouse

When growing tomatoes in a greenhouse, it is necessary to additionally spray the plants with an interval of 20 days with Agat 25K (working fluid consumption 0.3 liters per 10 m 2).

Processing is carried out from the moment of formation of 2-3 true leaves on seedlings or shortly after planting it in a permanent place.

SAVE USEFUL INFORMATION ON YOUR FAVORITE SOCIAL NETWORK PAGE:

Most of the gardeners, cultivating tomatoes in the open field on their site, faced late blight. Unlike other vegetable crops, tomatoes are most often affected by this disease, the main symptom of which is the blackening of foliage and fruits. To date, there are many ways to deal with such a scourge, which will be discussed in more detail below.

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

The name "late blight" in translation means "destroying the plant."

Reproduction of fungi occurs by spores, and they are found in the soil, in the remains of plants affected by the disease, on garden tools. After the winter ends, with the onset of favorable conditions, the fungus begins to actively develop.

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

The disease spreads very quickly, while there is a rapid withering of the affected bushes, over time they die. If you do not take the necessary measures to combat phytophthora in a timely manner, then the crop will be lost.

The first signs of tomato disease

In order to start the treatment of tomatoes affected by phytophthora in a timely manner, it is necessary to know the first signs of this disease:

• at first, specks of a dark brown shade form on the wrong side of the foliage, over time it begins to dry out and fly around;
• brown spots of irregular shape appear on the surface of the stem;
• there is a darkening or yellowing of the inflorescences, which quickly dry out and die off;
• spots of black or brownish-gray color are formed 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. These reasons include:

• dense plantings (ventilation between the bushes is practically absent);
• heavy and frequent rains, which are observed in the second half of the summer period;
• too much nitrogen in the soil;
• tomatoes feel a lack of copper, manganese, potassium or iodine;
• tomatoes grow next to potatoes;
• sharp changes in day and night temperatures, abundant dew in the morning (most often observed in August), coolness;
• too abundant watering in July and August, when the fruits begin to ripen, as well as watering over 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 the humidity rises 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 will be described those chemicals that are used by summer residents in the fight against late blight most often:

1. Hom. Fungicidal means of contact action. Copper chloride, which is the active substance of the drug, does not penetrate into the bush. It is used for preventive purposes, processing tomatoes up to 5 times during the season. He is not able to cure a sick plant. Working solution - 4 g of the product per 1 liter of water. The drug is dangerous to humans, so you need to follow all the necessary precautions during processing.
2. Furacilin. This antimicrobial agent, intended for humans, is also used to combat late blight. To prepare a solution, one tablet is dissolved in one liter of water. Processing is carried out three times during the season: before the bushes bloom, before the formation of the first ovaries, after the fruit ripens. The tool is absolutely safe for humans.
3. Metronidazole or Trichopolum. This is also a drug intended for people, which summer residents have recently begun to use in the fight against late blight. To prepare a solution in a liter of water, dissolve a couple of tablets. Spray the bushes systematically 1 time in a week and a half or after rain, as the product is easily washed off with water.
4. Order. Such a fungicidal agent penetrates into the bush, so the fruits after processing 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 with a frequency of 1 time in 2-4 days, and healthy bushes for prevention - 1 time in half a month. The drug is dangerous to humans.

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

1. Baktofit. This bacterial fungicide significantly reduces the number of pathogenic fungi in the soil after just a few hours after treatment. The solution is prepared according to the instructions 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. Spill the solution with the earth and loosen it. To increase the effectiveness of the drug during the preparation of the solution, instead of water, it is recommended to take whey or kefir.
3. planriz. The composition of this tool, which is highly effective, includes live bacteria. The solution is very simple to prepare, for this, a liter of water is combined with 5 grams of the product. They cultivate the land just before planting tomato seedlings.
4. Phytosporin. This tool in the fight against phytophthora is used very widely. The soil is treated in the spring, for 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, as 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 phytophthora. To process the bushes, a solution is prepared from one bucket of water and 1 liter of kefir. If desired, you can replace kefir with milk, but in this case, 20 drops of iodine are also added to the solution. Also, for spraying tomatoes, you can use a whey solution in a ratio of 1: 1 or 1: 2. Treatment with any of the solutions can be carried out at least daily.
2. Soda. In one liter of water, dissolve 1/5 of a tablespoon of soda and add a little liquid soap. Spray tomatoes 1 time in 7 days or after it rains.
3. Salt . Salt solution is used as a preventive agent, because after drying it covers the surface of the bush with a white thin layer, which will prevent pathogenic fungi from penetrating inside the tomato. To prepare a solution for 1 liter of water, take 25 grams of salt. All aerial parts of the bush are treated, when it rains, the spraying is repeated.
4. Vinegar. 100 milligrams of nine percent table vinegar are poured 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 in a day. Plants are treated with them 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 systematically. 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, a little soap is added to the product. In total, during the season, processing is carried out three times: 7 days after planting seedlings in the soil, shortly before 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 goggles.

1. Yeast . Dissolve 10 grams of yeast in a liter of warm water, the mixture should be infused, after which it can be used to spray a tomato. Treatments with the agent 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, it remains only to strain.

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

• choose a fine and windless day;
• spray the bushes early in the morning or in the evening;
• when using toxic agents, safety precautions must not be neglected;
• it is impossible to mix products and prepare solutions with devices and in dishes made of metal.

In order to protect tomatoes from late blight and save 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, plots 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. Best cucumbers, turnips, carrots, onions, beets and cauliflower.
2. Tomatoes are grown in a well-lit area.
3. Experts advise using early or highly resistant to late blight hybrids.
4. If the ground contains an excessively large amount of lime, then during planting, a little peat is poured into the hole and onion peels are placed, and the soil surface near the bush is covered with sand.
5. Plants should be well ventilated, so they are not planted excessively densely.
6. Pour water at the time exclusively under the root, and carry out this procedure in the morning. From the middle to the end of the summer period, watering is recommended only during a prolonged drought.
7. The surface of the soil near the tomatoes is covered with a layer of mulch.
8. Next to tomatoes, it is recommended to grow calendula, onions, marigolds, white mustard or garlic.
9. Conduct in a timely manner.
10. Strengthen the health of plants, for this they are fed with potassium-phosphorus fertilizer, and they are also treated with immunomodulators.
11. Nitrogen is recommended to be applied only from the beginning to the middle of the growing season. If it is introduced into the soil in the second half of summer, this will increase the likelihood of damage to the bushes by late blight.

Very often, even experienced gardeners do not know the answers to some questions that relate to the defeat of tomatoes by late blight. Below are the answers to the most frequently asked questions.

How to save tomatoes damaged by phytophthora?

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

Is it possible to eat tomatoes with phytophthora?

If there are black spots on the tomatoes, then it is not recommended to eat them even after removing the affected areas. Fruits that have been damaged by the disease quite a bit can only be eaten after treatment in hot water.

How to cultivate the land after phytophthora?

As a rule, the soil on which bushes affected by phytophthora grew is cultivated in early spring after the snow cover has melted or before planting seedlings. For this, the following chemicals are used: Bordeaux mixture, copper oxychloride, copper sulfate, Oksihom or Farmayod, etc.

Varieties resistant to late blight?

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

How to process tomatoes from phytophthora - video

How to avoid phytophthora? Prevention and ways to fight - video

Which method of treating tomatoes from phytophthora to choose in a particular case, each gardener decides independently. But it should be noted that neither chemicals nor folk remedies guarantee complete elimination of late blight. Experienced summer residents recommend alternating various means and methods, and also do not forget about preventive measures.