Signs of late blight on tomatoes. Late blight (late blight) on tomatoes: photos, control methods

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Late blight is considered the most common and dangerous disease of tomatoes. Even with the availability today of strong protective agents for prevention and treatment, late blight annually, from mid-summer, destroys almost half of the tomato plantings, and therefore most of the harvest. We will tell you how to protect tomatoes from late blight using chemical, environmental and folk remedies. And also - methods of preventing the disease and what.

What is late blight and its symptoms

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In total, there are about 50 species of this oomycete; not only tomatoes, but also other garden and garden plants suffer from late blight:

potato,
eggplants,
physalis,
cabbage,
pepper,
strawberries and strawberries,
raspberries,
buckwheat.

The following flowers can also get sick:

orchids,
violets,
gloxinia,
cacti,
peonies,
gladioli, etc.

Late blight also occurs on trees:

oak,
bouquet,
conifers,
nut,
Lavra

The spores and mycelium of this microscopic fungus overwinter well in the soil, on plant debris, even on garden tools, and the next season, if conditions are favorable (high humidity and warmth), they begin a new cycle. Tomatoes most often suffer from late blight, starting in the second half of summer.

Tomato late blight is also called brown rot, because the main symptom is browning of the leaves and then the fruits.

Symptoms of the disease are:

At the initial stage, brown spots appear on the bottom of individual leaves, and an oily film appears on top. It is clearly visible after getting wet. The first signs are in the photo.
The spots gradually increase in size, spread, and the inflorescences turn yellow and fall off.
As late blight develops, gray-brown spots spread to tomato bushes and appear on the fruits.
The leaves dry out en masse, the tomatoes begin to rot with an unpleasant odor. The spots on the stems become dark, and there may be a black coating on top.

You can see what late blight looks like on tomatoes in this video. This will help to recognize it and begin saving plants in time.

Late blight of tomatoes does not appear every year, but only when suitable conditions for its development are created. The causes of late blight are almost always present in the soil; it is very tenacious, and the triggering factors are most often the following:

long rains, temporary cold snap;
dew fall
dense plantings, which causes air stagnation;
close placement of beds with potatoes;
improper watering (by leaves);
excess nutrition;
presence of pests;
excessive liming of the soil;
deficiency of such elements: potassium, iodine, copper, manganese.

The disease develops very quickly - a bush with leaves and fruits can be completely infected in just a few days. Spores are spread by wind, water and gardeners themselves. And especially favorable conditions are created in greenhouses that are poorly ventilated.

How to treat tomatoes against late blight

The sooner treatment of tomatoes against late blight begins, the greater the chance of saving the bushes. The first spraying is carried out as soon as the first symptoms and signs appear - brown spots on the lower leaves. There are different ways to fight how to save tomatoes if they are already sick:

the most effective remedies for late blight on tomatoes are chemicals, but they are not entirely safe for health;
eco-preparations – natural biological substances that suppress the development of fungi;
folk remedies.

But the best way to combat it is prevention, which should begin immediately after planting the seedlings. A prerequisite in order to get rid of this scourge on tomatoes is parallel processing of potato plantings on the site.

Fungicides - chemical means of combating late blight

Other chemical preparations for late blight: Strobi, Acrobat MC, Revus, Quadris, Profit Gold, Oxychom, Efal.

Bordeaux mixture is one of the oldest and most reliable methods of treating soil against late blight in the spring before planting tomato seedlings and bushes in open ground and greenhouses. Copper sulfate and lime should be diluted in classic proportions to obtain a 3% solution. The dosage of copper sulfate for Bordeaux mixture is indicated in the instructions for the drug. Pure copper sulfate is used in the same way; it must be prepared at the rate of 1% solution.

There are also less aggressive methods of combating late blight on tomatoes - using a number of antimicrobial and antifungal pharmaceutical drugs.

The most effective remedy is furatsilin. Since this product has an antimicrobial and antifungal effect and does not deteriorate, it can be prepared for 3 treatments per season in the proportion of 10 tablets per bucket of water.

The scheme for treating tomatoes with furatsilin is as follows:

the first treatment is carried out during flowering;
the second - when the ovaries appear;
the third - with the beginning of the ripening of the first fruits.

Another reliable remedy for treating diseased tomatoes is boric acid. It also serves as a fertilizer for the bushes. It is necessary to strictly follow the recipe for the quantity of boric acid sprayed on the bush: dilute 1 teaspoon of acid in 10 liters of hot water, cool the solution to 35 degrees and treat the bushes with the prepared mixture, paying special attention to the lower part of the leaves.

In addition, the following preparations can be used to process tomatoes:

hydrogen peroxide at the rate of 1 tbsp. per 1 liter of water, used as prophylaxis for seedlings and after planting;
calcium chloride is used when the bushes are severely damaged, you need to prepare a 1% solution (dilute a 200 ml pharmacy bottle in 2 liters of water), spray all blackened areas and moisten the stalk especially thoroughly;
experienced vegetable growers also recommend using a solution of potassium permanganate - making a pale pink mixture in warm water, spraying the bushes once a week and watering the ground under the bushes.

Use of biological products

What to do if late blight has already appeared on tomato bushes, but you don’t want to use aggressive chemicals?

Now many gardeners prefer safe biological preparations to grow environmentally friendly products. They show high effectiveness both as prevention and when infection has already occurred.

Fitosporin is considered the most effective remedy today. This is a biological product with beneficial microorganisms that destroy pathogenic microbes and fungi. It is used both as prevention and treatment. There are subtleties on how to properly water tomatoes with phytosporin against late blight:

dosage – 2 tsp. with a small slide for 10 liters of settled or rain water;
the water should be at a temperature of about 30 degrees, but not higher than 35;
Do not use iron and aluminum buckets to prepare the solution;
before treating plants with Fitosporin, the solution must be left in the sun for 3-4 hours to activate and multiply beneficial bacteria;
Treatment of tomatoes with Fitosporin should begin 2 weeks after planting the seedlings and should be carried out every 10 days.

Analogues of Fitosporin are EM-preparations Baikal-M and Siyanie, Baktofit, Planriz, Fitophtorin, Arilin.

Trichopolum (Metronidazole). This antifungal pharmaceutical drug has already proven its effectiveness against late blight. The solution should be prepared as follows: grind 2 tablets into powder and stir in 1 liter of water. The powder is washed off with water, so treatment should be carried out after rain.

Late blight on tomatoes: how to fight with folk remedies

Iodine treatment is a proven folk remedy. You need to water the soil under the bushes with an iodine solution (20 drops per bucket of water).

Milk and iodine are a traditional folk remedy for the prevention of late blight and other fungal diseases. Instead of milk, you can use kefir, as long as the dairy products are low-fat.

Treatment with milk and iodine is carried out as follows: pour a liter of milk or kefir into a 10-liter bucket of water and add 25 drops of pharmaceutical iodine, stir and treat the bushes both above and below. This protection is best combined with spraying every other time with a yeast solution.

An effective remedy is whey and yogurt. Lactic acid bacteria suppress the development of pathogenic microflora. Whey should be diluted 1:1, and yogurt and kefir – 1:2.

Mustard is often used by gardeners, but it has already been proven that this treatment is practically useless - its antibacterial properties are not enough for such a strong pathogen as a fungus.

A salt or soda solution will create a protective film on the surface of leaves and fruits. For a bucket of water you need to take 1 kg of salt or 0.5 kg of soda. It is necessary to spray so that the solution does not get on the soil. This product is good for use in greenhouses.

A very original preventive and effective method for late blight on tomatoes, as reviews indicate, is copper wire. Its essence is that thin copper wire, stripped of oxides with sandpaper, is cut into pieces 4 cm long, then the tomato stem is pierced with it in the area of the lower pair of leaves. And the ends of the wire are bent down (you cannot wrap the stem). The action is based on supplying tissues with free copper ions, which destroy the fungus that penetrates them.

Treatment with infusion of tinder fungus. Find a mushroom in the forest no smaller than a tea saucer, chop it, pour 100 g of this crumb into 1 liter of boiling water, leave until it cools, strain and process the diseased tomatoes. They say it helps. The second treatment is after 10 days.

Toothpaste is another original way to save tomatoes. To do this, dilute the tube in water at a temperature of about 30 degrees and process the tomatoes.

Use hay, especially rotted hay, to mulch plantings - this is an excellent preventive measure. And at the first manifestations of late blight, you need to fill a bucket a third with rotten hay, add water and leave under the lid for 3-4 days. Then dilute 50 g of urea in 1 liter of water and add to this infusion. Treat the bushes with the resulting mixture. There will be treatment with Bacillus subtilis (it suppresses the pathogen) and feeding.

Yeast treatment is an excellent preventative method and can save already diseased bushes in the initial stages. A pack of live yeast 100 g should be diluted in 0.5 liters of warm low-fat milk, add 1 tbsp. sugar and leave for 30-40 minutes until intensive fermentation begins. Stir this starter in a bucket of water at about 30 degrees and treat the bushes and the soil under them.

Treatment of late blight with garlic

There are several ways to use this garden phytoncide.

Pass 0.5 kg of garlic cloves directly with the peel through a meat grinder, add 3 liters of water and place in a dark place for 5 days. Then dilute half a glass of this infusion in a bucket of water. Add 50 g of laundry soap diluted in 0.5 liters of hot water. Spray the bushes with this solution.
Grind 1.5 cups of garlic into porridge, dilute 1.5 g of potassium permanganate in 1 liter of hot water. Stir all this in 10 liters of warm water. Treat the bushes with this solution every 10 days.
Make an infusion of garlic stalks - half fill a bucket with herbs, add water and leave for 1-2 days. Before use, strain the infusion and dilute it by half.

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

Tomato varieties that are not afraid of late blight

There are no varieties yet that show complete resistance to this harmful disease. But some, early ripening ones, manage to harvest before a mass outbreak of the disease. And there are so-called blight-resistant varieties, most often these are new-generation hybrids, which, with proper agricultural technology, rarely become infected with fungus, even if diseased bushes grow nearby. The list is as follows:

White filling
Blizzard
Kostroma
Siberian early ripening
Budenovka
Oak
Pink dwarf
Harvest
Dubrava
All types
Cold resistant
Tarasenko hybrids
Solar
Cameo
Pepper-shaped
Etoile
Berry
Combitomat
Ballad
Masterpiece 1
Ephemera
Vladimir Vysotsky
Yablonka Russia
Sprint Timer, etc.

Hybrids and hybrid varieties

Lark F1
Chimgan F1
Cupero F1
Black bunch F1
Zhenaros F1
Honey drop F1

Prevention of late blight on tomatoes

You can reduce the likelihood of developing the disease by following these rules:

Organization of competent crop rotation. The best predecessors are cucumbers, onions, garlic, beets, and carrots. Tomatoes can be returned to the garden only after 4 years.
Do not plant next to potatoes, eggplants, or legumes.
Choose the sunniest place in the garden. Even slight shading is a provoking factor.
Preventive soil treatment in the greenhouse and garden in the spring - using
Selection of early and resistant varieties and hybrids.
Place onion peels in the holes for prevention.
Maintaining the optimal distance between bushes.
Water only at the roots.
Mulching of plantings or regular loosening, weeding.
Application of green manure (in autumn after harvesting and in early spring before planting seedlings).
Using side-by-side plantings - mustard, marigolds, calendula, onions, garlic, and dill are suitable.
Timely pinching, recommended shaping of bushes, removal of dead leaves.
Regular feeding and treatment with preventive protective agents.
Nitrogen fertilizers are recommended to be used in the first half of summer, then only phosphorus-potassium fertilizers and ash.
Ventilation of greenhouses and organization of ventilation of plantings (gartering, pinching).
During an outbreak of late blight, watering should be avoided.
Do not use several treatment methods at the same time, especially chemicals.
Destroy infected bushes and fruits by burning.
Do not allow tomatoes on the bushes to overripe.

Many tomato varieties are susceptible to fungal diseases. Gardeners often encounter the phenomenon of late blight on tomatoes. Another name for the disease is late blight. Timely recognition of the fungus and proper treatment will help save the harvest.

Fungal spores tolerate low temperatures well, quickly become active in a humid, warm climate and begin to multiply rapidly.

Preventive treatment of contaminated soil before winter or spring will help avoid the loss of a new crop.

Development factors

Late blight of tomatoes is spreading at lightning speed. The peak of infection occurs at the end of June. The disease is transmitted from a plant infected with spores to healthy seedlings.

It is possible to spread spores by wind from neighboring garden plots that contain diseased vegetable crops of the nightshade family. A summer resident can bring the infection into his greenhouse or garden along with his clothes after contact with infected plants.

The speed at which the fungus spreads is also influenced by the following factors:

prolonged rains;
violation of agrotechnical conditions for growing tomatoes;
weeds that activate fungal growth;
density of seedlings.

High humidity, 20-25 degrees Celsius are optimal conditions for the growth of the fungus. Therefore, rainy summers often cause outbreaks of late blight.

Failure to observe crop rotation and infrequent weeding of vegetable crops are the reasons for the appearance of the disease on a personal plot. Therefore, experienced gardeners do not recommend planting nightshades for longer than 4-5 years in the same place. You should also avoid such things as potatoes and tomatoes. Fungal spores found in infected tubers can spread to tomatoes and vice versa.

The activation of late blight is primarily facilitated by weeds such as woodlice, quinoa, and sow thistle. Their appearance in the garden must be carefully monitored and promptly destroyed.

Tomato bushes planted close to each other create favorable conditions for the development of pathogenic microorganisms (lack of light, high humidity). Therefore, plants should be planted at a distance of at least 0.5 meters from each other.

What does late blight look like?

It is quite difficult to recognize a fungal disease at the initial stage. Therefore, in order not to miss the disease, you should examine the tomato bushes from time to time to identify the first signs of infection.

In closed ground with high humidity, the disease initially manifests itself in the form of a white fluffy coating on the back side of the leaf blade. These symptoms are a signal to treat tomatoes against late blight in the greenhouse.

In open ground, the leaves of seedlings may turn light green in places. Also locally, leaf blades and stems begin to darken, dry out and curl. The manifestation of the disease on seedlings and tomatoes can be clearly seen in the photos below.

Diseased fruits are covered with gray, brown, lilac-brown or black spots. A tomato affected by late blight becomes very hard to the touch.

The location of the rot is always dry, which makes it possible to differentiate late blight from other types of fungi and bacteria.

Fruits that seem healthy at first glance may already be affected by the fungus if there are infected tomatoes on the branches nearby. Manifestations of late blight may occur later, after harvest.

With secondary infection, the fruits quickly and completely rot, emitting a specific putrefactive odor.

Methods for treating tomatoes from late blight

Treatment of tomatoes for late blight is carried out using special chemicals - fungicides. For minor pathogen damage, folk remedies are used for preventive purposes.

List of fungicides

Chemicals (pesticides) used to control fungal diseases are called fungicides. Protection of tomatoes from late blight is carried out with the following drugs:

Acrobat MC;
Healer;
Ditan M-45;
Infinito;
Ridomil Gold;
Ordan;
Thanos;
Tattu;
Quadris;
Bordeaux mixture.

Fungicidal preparations against late blight on tomatoes are used for both therapeutic and preventive purposes.

Acrobat MC

The active substances of the drug are mancozeb and dimethomorph, which have a local-systemic effect. Pesticidal components inhibit the development of fungi in plant tissues. Complete death of pathogens occurs within 48-72 hours after spraying tomatoes with a fungicide. The drug is not toxic to plants and worms.

To prepare the working solution you will need 20 g. chemical and 5 liters of water. To protect tomatoes from late blight as much as possible, after 2 weeks it is recommended to re-treat with Acrobat MC.

Healer

The drug contains mancozeb and metalaxyl. The first substance forms the plant’s external protection from fungi, creating an invisible film on the leaves and stem of the vegetable. The second component penetrates the tomato tissue and destroys pathogenic microorganisms.

The solution for late blight on tomatoes is prepared according to the 25 g scheme. pesticide per 10 liter bucket of water.

The Healer's analogue drug is Metaxil.

Ditan M-45

The main active ingredient of the pesticide is mancozeb. Additionally contains manganese and zinc, which help strengthen the plant’s immunity.

Spraying tomatoes against late blight is carried out with a solution prepared at the rate of 10 g. substances per 5 liters of water. The flow rate of the working fluid should be 300-500 liters per 1 hectare of plantings or 3-5 liters per 1 hectare.

Infinito

One of the effective remedies for late blight on tomatoes is the drug Infinito based on fluopicolide and propamocarb hydrochloride. Active substances stop the development of mycelium and prevent its re-propagation.

15 ml of pesticide is dissolved in 5 liters of liquid. For 1 hectare of area, the solution consumption should be in the range of 400-500 liters. If necessary, re-treatment can be carried out after 1-2 weeks. The frequency of applications per season should not exceed 4 times.

Ridomil Gold

The active components mancozeb and mefenoscam have a systemic effect, which destroy mycelia and prevent re-infection of tomatoes. The fungicide has hazard class 2 - “highly dangerous”.

The working solution is prepared in a ratio of 25 g. granules per 10-liter container of water. The liquid is mixed with the substance for several minutes until the product is completely dissolved.

Ordan

One package of granules weighing 25 g. diluted in a container of water with a volume of 8-10 liters. Recommended solution consumption per 100 sq. m. - 5-6 liters.

Ordan has a preventive effect for 1-2 weeks, which helps protect tomatoes from re-infection.

Thanos

The active substances famoxadone and cymoxanil have a synergistic effect, i.e. enhance each other's effect.

The drug is effective for use on tomatoes in open ground, as it is not washed off from the surface of the plants even after rain due to penetration into the waxy part of the leaves.

For 10 liters of water use 6 grams. active substance. Recommended consumption – 40-60 ml per 1 sq.m. It is recommended to combine use with treatment with Kurzat R to reduce the risk of late blight developing resistance to the drug.

Thanos has an immediate destructive effect on late blight spores and remains effective for 2 days.

Tattu

Mancozeb and propamocarb hydrochloride are the main active components of Tattu. For 10 liters of water you will need 60 ml of concentrated substance. The resulting volume is enough to spray an area of 200 square meters. m.

Before treating tomatoes against late blight in a greenhouse with this fungicide, you should wear a protective mask and gloves.

Quadris

The drug contains azoxystrobin, which destroys late blight and prevents its spores from spreading further.

The active substance does not accumulate in tomatoes. After exposure, the component breaks down into carbon, hydrogen, oxygen and nitrogen. This is an effective remedy for late blight, which can be used to treat the soil before planting nightshades, since the drug is not dangerous for soil-forming fungi.

Azoxystrobin predominantly accumulates in the leaves, and only a small part of the component penetrates the stems and fruits.

HOM

The pesticide consists of copper chloroxide, to which late blight does not have resistance. The main disadvantage of the drug is poor retention on the leaves. To ensure that the drug stays longer on the treated plants, it is recommended to add a small amount of milk to the solution.

Bordeaux mixture

One of the most popular drugs used in the treatment of tomato late blight. It is a mixture of lime milk and copper sulfate. To obtain a solution, it is necessary to dilute the 2 components separately, according to the instructions, after which the substances must be combined.

Application of biofungicides

One of the safest methods for protecting tomatoes from late blight in a greenhouse is the use of biofungicides.

Biological agents that help get rid of fungi include:

Agat-25;
Screen;
Mikosan;
Alirin-B;
Fitosporin.

Agat-25

The biofungicide is produced based on soil bacteria Pseudomonas aureofaciens H-16. Used for the prevention and control of late blight on tomatoes in greenhouses and open ground. The product suppresses the development of pathogenic fungi, stimulates plant growth and promotes the development of immunity in the latter.

To spray tomatoes, the drug is diluted in a proportion of 1 g per 4 liters of water. Repeated treatment is carried out after 10-12 days.

Screen

The product contains extrasol and azobacterin, which have a detrimental effect on late blight spores and protect the plant from re-infection.

To spray 1 liter of liquid, use 2 measuring caps of the drug. The product can be used to water the seedlings during transplantation to a permanent location. The concentration of the solution in this case should be 4 caps per the same volume of liquid as for foliar treatment.

Mikosan

The biological fungicidal agent is produced based on an extract from the tinder fungus. The active substance penetrates the affected plant tissue and destroys the cell walls of the mycelium. For spraying, 100 ml of medicinal liquid is diluted in 4 liters of water.

Alirin-B

The biofungicide contains Bacillus subtilis bacteria, which have an inhibitory effect on late blight.

The standard solution for preparing the solution is 2 tablets per 10 liters of water. The resulting volume of the drug is consumed per 10 m².

Fitosporin

The biological product has an antifungal effect due to Bacillus subtilis. It multiplies very quickly on plants and stops the growth of the fungus. Most often, the product is used for preventive purposes, both for greenhouses and for tomatoes grown outside.

Fitosporin is carefully diluted with water in a ratio of 1 to 2. If the dosage is observed, a paste-like liquid should be obtained, which is necessary for preparing the solution. A 10-liter bucket will require 2-3 tsp. facilities. The finished product must be sprayed on both infected and healthy tomatoes.

Folk remedies

One of the safer methods for dealing with late blight on tomatoes is considered to be the use of folk remedies by gardeners. Most often at home, solutions prepared from:

iodine;
brilliant greens;
whey;
kefir;

Fungi are afraid of an acidic environment, so summer residents often use kefir or whey to combat late blight.

2 liters of any fermented milk product is mixed with 8-10 liters of water. Add 20-30 drops of iodine or brilliant green to the solution.

Late blight on tomatoes in a greenhouse is no less common than in open ground. To combat its spores, you can use the above method with fermented milk products. It is equally effective for both open and protected ground.

Fungi are afraid of iodine vapor, so gardeners often use this product to destroy pathogenic microorganisms in greenhouses and greenhouses. In order to protect the plants, you will need several bottles of medicinal liquid and tea bags (you can use already used ones).

Infusion bags are immersed in iodine. After the excess liquid has drained from the glass, they are hung throughout the greenhouse. For 1 sq. m. you will need 1 iodized sachet.

After 2 weeks, the manipulations are carried out again. This procedure ensures the disinfection of greenhouses and prevents relapses of the disease.

It is important to know not only how to save tomatoes from late blight, but also how not to harm the plants and your health. Therefore, before processing, a number of recommendations should be followed:

Spraying should be carried out in calm weather to ensure uniform distribution of substances.
Plants should be treated before the first ovary. All treatments must be completed 20 days before harvest.
The frequency of treatments depends on the condition of the plants. It is advisable to repeat the procedure after 2 weeks, even if the tomatoes look healthy.
Chemical treatment is carried out no more than 2 times, then you can use Bordeaux mixture or copper chloride preparation.

To prevent resistance, the use of different groups of fungicides should be alternated.

How to prevent relapses of late blight

The following recommendations will help you avoid re-infection with a fungal disease:

observe crop rotation (change plots every 4-5 years);
avoid crowding of plants;
tear off the lower leaves of tomatoes before the first ovary for better ventilation and more light flow;
do not create a compost heap in the garden;
remove nightshade tops from the site and destroy them;
water the plants strictly at the roots;
when growing indoors, ventilate the greenhouse;
Do not use fresh manure as fertilizer.

After planting in a permanent place, it is recommended to treat with biological fungicides for preventive purposes. Fitosporin has proven itself well as such a remedy.

Every landowner dreams of growing a rich harvest. But useful crops sometimes stop bearing fruit, wither or even die. This occurs from damage to plant parts by putrefactive fungi or insects. As a result, the quantity of the harvest is significantly reduced, and so is the quality. The main task of a gardener is to protect the crops grown from diseases. The most common putrefactive process is late blight or late blight, which mainly affects the nightshade family. These include (blue ones), potatoes, and. This disease can also affect strawberries, castor beans, and buckwheat. The fight against late blight must begin immediately. This disease spreads quickly.

What is late blight

The popular name for this disease is late blight(fungus). First, dark spots form on the stems and leaves, then they turn grayish-brown and turn black. Parts of the plant dry out and fall off. The fruits also spoil. Vegetable crops that are still alive are rotting.

It is clear that this crop cannot be harvested. Infected vegetables are tasteless and even harmful to health.

Distribution of late blight

Late blight can become an epidemic for all plants. After all, putrefactive fungus reproduces by spores. If the fight is not started in time, late blight will spread throughout the entire garden. The wind carries spores that settle on healthy crops and their seeds, as well as on the ground, roofs of buildings, and garden tools.

The garden owner must be observant. Having noticed the appearance of the first signs of late blight disease, you need to immediately begin treatment. Otherwise, you may be left without a harvest at all, because it is precisely because of such rapid spread that healthy crops are in danger.

Causes of late blight

It will be much easier to fight late blight if you have minimal knowledge about the nature of the disease, for example, under what conditions putrefactive fungi develop and from what they can die. Late blight progresses under the following circumstances:

Excess lime in the soil. The level of soil acidity is an important criterion for the successful growth and development of plants. But it happens that the pH value (medium reaction) does not correspond to the parameters. Gardeners add lime to neutralize the soil. But its surplus provides excellent conditions for late blight to live and reproduce.
Neglecting the thinning process. In dense thickets of plants, the fungus develops many times faster than in beds where vegetable crops are planted at a certain distance from each other.
A sharp difference in night and day temperatures. In this case, dew is formed, which is an additional source of moisture. It promotes the development of fungi.
Weak plants grown from seeds. You may have prepared the ground incorrectly. Therefore, vegetables lack the necessary microelements. They become weak and are more susceptible to disease.

Prevention of late blight

The best method of control is prevention. Preventing the development of plant diseases is much easier than eradicating them.

It is necessary to monitor the optimal soil acidity parameters. To prevent excess lime, add sand and peat along with it.
Follow the rules for the order of planting plants, especially nightshades.
Avoid overly dense plantings. Thin out the seedlings.
Garden crops must be provided with moisture, but not allowed to excess. To prevent water from accumulating on the soil surface, water the plants early in the morning, and in cloudy weather, refrain from irrigating the soil.
If tomatoes are grown in greenhouses, regular ventilation must be provided.
As the soil compacts, loosen it.
Treat plants against late blight. This is done by spraying with special means or solutions prepared according to folk recipes.
When choosing seeds for planting, purchase species that are resistant to fungi.

Fighting late blight using folk remedies

Often used as a fungicide Bordeaux mixture sky blue in color, which is used in crop production to combat fungal diseases. But there are many more means for spraying vegetable crops, made according to folk recipes. These solutions are used not only to combat the disease, but also for prevention purposes.

The spray mixture is prepared from whey and water in a 1:1 ratio. Tomato tops have been treated with this solution since the beginning of July. The frequency of spraying is carried out as needed. You can even use this mixture daily.
Pour 1 liter of skim milk and 15 drops of iodine into a ten-liter bucket of water. Tomatoes are treated with this solution 2 times a month.
To combat putrefactive fungus, dry ash is used. It is sprinkled between the rows half a month after planting. When fruit ovaries appear, repeat the procedure.
Finely chop 100 g of onion feathers or garlic arrows. Pour the mixture with 1 glass of water and leave for 24 hours. Then strain. Pour the resulting mixture into 10 liters of water and add 1 g of potassium permanganate. Treat plants 2-3 times a month.
Tomatoes are also sprayed with a solution prepared from 1 kg of rotten stems with the addition of 1 handful of granulated urea. The mixture is poured into 10 liters of water, left for 3-4 days, then filtered. The procedure is carried out 2-3 times a month.
At the first signs of late blight, plants are watered with water in which yeast is diluted in a ratio of 100:1.
At the first signs of the disease, prepare the following mixture: pour 100 g of crushed tinder fungus with a liter of boiling water. When the solution has cooled, strain and spray the vegetables. After half a month, repeat the procedure.
A mixture prepared from fresh and dry horsetail (250 g each), add a liter of water. Then put it on the fire and cook for half an hour. After straining, add another half a bucket of water. Spray tomato and potato tops when signs of late blight appear.

All the proposed recipes are quite effective. Choose any one. The one you have the ingredients to make. Observe the proportions and frequency of processing.

Phytophthora and chemicals for treatment against it

Many gardeners do not trust proven folk recipes. If you are one of them, use ready-made chemicals. They have a fairly large assortment. These are fungicides: Ecopin, Metalaxyl, Acrobat MC, Ditan M-45, Profit Gold, Obereg, Infinito, as well as cheaper options: Baksis, Fitosporin-M, Alirin-B, Baktofit, Gamair.

The most important thing when using chemicals is to strictly follow the dosage recommendations, which are described in the attached instructions. Important! Read it before you start fighting late blight. An overdose of chemicals can harm both plants and humans.

Rules for using products to combat late blight

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 tomatoes in the morning 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.