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.
The taste and beneficial properties of tomatoes have been known for a long time. They improve your mood and even have healing properties. But what if the plant itself gets sick - its leaves begin to become covered with dark small spots, turn brown, dry out and fall off, and the stems and fruits turn black? What kind of disease is this? Let's try to understand the problem, find out methods of prevention and ways to combat the disease.
Late blight (lat. Phytophthora) is a fungal disease of vegetables of the nightshade family.(tomatoes, eggplants, potatoes and others). Science knows more than a hundred species of this fungus, which spreads by spores on the ground and through the air. Infection can be everywhere - in the soil, in plant organs, in seeds, even on gardening tools.
The fungus infects all vegetables and fruits growing in a garden or greenhouse. It penetrates everywhere, infecting household items and household utensils.
Phytophthora is a frost-resistant mushroom, persists in the ground for several years, harms vegetable crops and destroys them.
Photo
Reasons for appearance on tomatoes
The pathogenic fungus is a very viable organism and lives everywhere:
- on the ground;
- in the air;
- on the roofs, walls of greenhouses and country houses.
It appears on tomatoes for a number of reasons:
- a sharp change in weather conditions (in summer it is hot during the day, cool at night, and dew forms in the morning);
- poor evaporation (due to dense bushes and cramped beds);
- proximity of tomatoes to other vegetable crops infected with fungus (potatoes, peppers, eggplants);
- lack of air movement, poor ventilation (this applies to greenhouses and greenhouses);
- the presence of a large amount of nitrogen fertilizers in the soil;
- lack of useful microelements;
- the presence of lime in the area where tomatoes ripen;
- cloudy, rainy weather;
- frost resistance of late blight, which retains its viability on the harvested crop until spring.
Signs of illness
Late blight disease looks like rot. This is explained by the fact that the infection develops under the influence of moisture.
Tomato disease is determined by the following characteristics:
- the presence of a whitish coating;
- dark brown spots on leaves, fruits, stems;
- withering and drying of the entire vegetable crop;
- unpleasant smell of vegetables;
- unsuitable for consumption.
How does the disease develop?
- A light coating appears on the back of the sheet.
- Then yellow spots with darkened areas form, increasing in size, they destroy the leaf, which turns black and falls off.
- Next, the tomato fruits begin to turn black on the bottom - most of the moisture collects there, and then they become soft, emit an unpleasant odor, and become unsuitable for eating.
- The same thing happens to the stem of a tomato - a coating appears, the stem turns black and withers.
The disease spreads within 7-10 days. Crops growing in the area become infected with spores of the pathogenic fungus and die. Please note that late blight disease has no cure. The best way out is to remove the diseased tomato from the garden and give healthy vegetables preventive treatment.
How to fight, how to treat seedlings?
To combat the disease of tomatoes - late blight, there are many folk remedies and chemicals. The adaptability of the fungus to different drugs suggests that the means to combat it need to be changed more often.
Folk remedies
Not all owners of dachas, vegetable gardens, and farms want to use chemicals. Many people prefer to get rid of pathogenic fungus using traditional methods. Such compositions for treating seedlings and treating tomato diseases are environmentally friendly and consist of natural products.
Garlic infusion
- Garlic (leaves, arrows, roots) - grind 100 grams in a meat grinder, add water (250 grams), leave for a day.
- Next, strain the infusion through cheesecloth, dilute it with water (10 liters), add potassium permanganate (potassium permanganate) - 1 gram.
It is necessary to treat tomatoes with garlic infusion every 10-15 days.
Milk serum
Dilute the serum with water in equal proportions. The plant can be treated with this solution once a week starting in July.
Infusion of straw or hay
- Fill rotted hay or straw with water in the amount of 10 liters.
- Add a little 46% nitrogen and leave for 3 to 4 days.
- Strain the solution and spray the tomatoes after two weeks.
Milk with iodine
Dilute low-fat milk (1 liter) with 10 liters of water, add iodine (15 drops). Spray the resulting liquid over the tomatoes 2 times a month.
Salt
Add 1 glass of salt to 10 liters of water and stir. Treat with this liquid once a month.
Copper sulfate solution
Dilute 2 tablespoons of copper sulfate in 10 liters of water. Spray vegetable seedlings.
Yeast
At the first signs of late blight, treat the tomatoes with a yeast solution - dilute 100 grams of yeast in 10 liters of water.
Treatment with specialized preparations
Before sowing, seeds must be treated with special chemicals, designed to combat fungal plant diseases in 7-10 days.
When planting seedlings in the ground or greenhouse, parts of plants damaged by late blight must be cut off, and in case of severe damage, it is better to throw away the entire bush if treating the plant is useless. Treat the remaining crops with chemicals.
In the store you can find several drugs to combat fungus at an early stage of plant growth. Available for sale:
- Fitosporin-m- 60 rubles per package weighing 200 grams.
- Alirin-B- 20 tablets costing 70 rubles.
- Ordan fungicide- 25 grams for 50 rubles.
- Baikal EM1- costs 110 rubles. for 500 ml.
- Radiance Em1- concentrate for 3,000 liters costing 450 rubles.
- Bordeaux mixture- 250 grams cost 51 rubles.
- Previkur-Energy- bottle (60 ml) for 360 rubles and others.
All drugs are used strictly following the instructions. The entire process of tomato growth and temperature conditions in the greenhouse must be controlled, because This disease manifests itself only under certain conditions and develops very quickly.
You should not forget to fertilize the soil with phosphorus and potassium, but do not overuse nitrogen.
Other methods
- In the fight against late blight, it is proposed to use Trichopolum tablets, which are sold in every pharmacy at a price of 87 rubles. For treatment, you need to dissolve 1 tablet in a liter of water.
- A good remedy for treating seedlings is bleach.
- To disinfect with a sulfur bomb, it is necessary to caulk all the cracks so that when fumigating the room, smoke does not escape from the greenhouse. The number of tablets used depends on the volume of the building. The saber burns for several hours, but this drug lasts for three days.
- Another way to protect a plant from fungus is to sprinkle the seedlings, after planting in the ground, with ash between the rows before watering. This treatment is repeated when the inflorescences form fruits.
- Copper wire with a diameter of 1 mm helps in the fight against fungal infection - it must be cut into strips up to 2 cm long, then inserted into the stem of the plant.
Prevention measures
Prevention of tomato diseases from late blight must begin in advance - in the fall of the previous year.
- At the end of the harvest, remove all remaining plants to prevent fungus.
- Thoroughly disinfect all garden equipment.
- On a cleared area of land, plow through and place nettles in the depressions in a layer of 5-10 cm.
- Plant plants to improve the soil structure and prevent the growth of weeds (mustard, peas).
- At the seedling stage, begin to strengthen the immunity of the vegetable crop.
- Rotate locations for different vegetables every year.
- It is necessary to water the tomatoes with a small amount of water in the morning so that moisture does not collect on the ground and tomatoes.
- Avoid drafts and air stagnation.
- Plant the plants further apart from each other, without creating crowding and without causing stagnation of moisture.
- Feed tomatoes with essential microelements to strengthen the plant’s immunity. For example: zircon, humate and others.
Are there varieties resistant to this disease?
Tomatoes that are resistant to this infection will help you avoid late blight. These tomatoes include:
- "Lark F1".
- "La-la-fa F1."
- "Soyuz 8 F1".
- "Tatiana".
- "Black".
- "Blagovest".
- "Budenovka".
- "Tsar Peter".
- "Dwarf".
- "Blizzard".
But even when using tomato varieties with increased resistance to late blight, preventive measures and agricultural practices should not be neglected.
So, to prevent tomatoes from getting late blight, it is necessary to regularly take preventive measures to improve the health of the area in which they grow. For prevention and treatment, use chemicals and folk remedies. When growing tomatoes resistant to late blight, do not neglect the measures taken to prevent and spread fungal infection.
Useful video
We invite you to watch a video on how to recognize Phytophthora disease and how to deal with it:
Phytophthora (lat. Phytophthora)– a genus of fungus-like microorganisms that cause late blight in plants. More than seventy species of late blight have been described, but, according to experts, there are up to five hundred varieties that have not yet been described. The name "late blight" consists of two Greek words, translated meaning "plant" and "destroy." Late blight primarily affects nightshade crops - potatoes, tomatoes, eggplants and peppers.
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Late blight (late blight) - description
The disease late blight, or brown rot, usually appears in the second half of summer, sometimes destroying up to 70% of the tomato and potato crop. The causative agent of the disease is the protozoan fungus Phytophtora infestans, which is distinguished by its ability to multiply very quickly, for which it is called an infectious plant eater.
Most often, the leaves of the lower tier are affected first, but gradually the disease reaches the tops of the shoots. In humid conditions, brown spots appear on the leaves, covered underneath with a white fluffy coating - fungal spores. Dark brown stripes appear on plant stems. When the weather is wet, the spots and stripes rot, and in dry weather they dry out. As the disease progresses, plant leaves turn into dry crusts.
Dark areas appear on the skin of diseased tubers, which begin to rot and decompose, and even healthy-looking tubers can begin to rot already in storage.
Late blight spots also appear on plant fruits, growing in breadth and depth. Not only mature fruits are affected, but also completely green ones, and even those tomatoes and peppers that were picked healthy from the bush still turn black.
Fight against late blight
Protection against late blight (late blight)
In order to avoid the appearance of late blight in the garden, regular preventive work is carried out, including treating plants against late blight with chemicals. We will tell you how to spray your garden and vegetable garden against late blight a little later, but now we offer you a list of agrotechnical measures that will help you protect your crops from this infection:
- grow varieties resistant to late blight;
- observe crop rotation;
- try not to plant nightshade crops close to each other, because as soon as late blight appears on potatoes, after a week or two you can find it on tomatoes, peppers or eggplants;
- do not allow plantings to become dense, because one of the reasons for the rapid spread of late blight is crowded conditions and poor ventilation;
- Another reason is sharp changes between day and night temperatures, so try to plant seedlings in the ground when all the frosts have passed, or find a way to cover the seedlings at night;
- If possible, do not allow air humidity to increase - mulch areas, do not pour water on plants when watering;
- exercise moderation when applying fertilizers, especially nitrogen;
- Harvest the crop at the stage of technical ripeness, try to prevent the fruit from overripening;
- remove from the stems all leaves growing below the fruits and flowers that do not bear fruit;
- remove diseased plants and affected fruits from the garden without regret and burn them;
- try to defeat the disease using traditional methods, as they are less toxic to plants and humans, but if your efforts do not produce results, choose a suitable remedy for late blight from fungicides that are sold in stores.
Late blight treatment
Protection against late blight is provided by agrotechnical and chemical methods. We have just introduced you to agrotechnical methods of protection. As for chemical preparations against late blight, there are many of them, but late blight gets used to them very quickly, so you will have to carry out treatments alternating fungicides.
The first preventive treatment against late blight in the spring is carried out immediately after planting the seedlings in the ground. The timing of subsequent treatments of vegetables against late blight can be correlated with the behavior of ordinary forest mushrooms: as soon as their growth begins, it means that the garden needs to be sprayed against a fungal infection, even if it has not yet appeared. Treatment is carried out in the first half of a dry, clear and windless day.
Soil treatment against late blight
In order to destroy late blight spores in the soil, fungicides and microbiological preparations are used. For preventive purposes, fungicides are applied to the soil in early spring, at least a month before planting seedlings or potatoes, and microbiological agents can be applied at any time except during the flowering period of plants, since they can harm bees. In the fight against the disease, copper-containing preparations for late blight: copper sulfate, Bordeaux mixture, Fitosporin-M, Trichodermin and Ordan.
Treat the soil, for example, with a two to three percent solution of copper sulfate, then dig up the area, and then water the soil with a solution of one tablespoon of Fitosporin in 10 liters of water, using this amount per 1 m² of area. Areas under flowers or strawberries are spilled with a solution of Alirin or Ordan, which is also used to prevent grape diseases.
Treatment of a greenhouse against late blight is carried out differently: in early spring and autumn, sulfur bombs are lit in it. When carrying out processing, do not neglect safety rules and try to stay as far as possible from the smoke.
Late blight on tomatoes - how to fight
Prevention of late blight on tomatoes
As they say, it is better to prevent late blight on tomatoes than to successfully fight it later, especially since late blight is difficult to completely defeat. How to protect tomatoes from late blight? Plant tomato seedlings in soil treated against late blight, after planting, mulch the area, and as the tomatoes grow, remove their lower leaves and shoots. Plant corn, peas or climbing beans around the perimeter of the tomato beds. Preventive treatment of tomatoes against late blight immediately after planting in the ground is carried out with Fitosporin-M or Trichodermin.
Late blight on tomato seedlings
If late blight appears on seedlings, remove the affected specimens and spill the substrate with Fitosporin-M solution. Or plant the seedlings in a new, sterile substrate, spilled with a solution of Fitosporin, treat the soil in the garden bed where you plan to plant the seedlings with the same preparation. But do not forget that at least a month should pass between treating the area with a fungicide and planting seedlings in the soil, and if you do not have this time, then it is better to treat the soil in the garden with Alirin.
How to treat tomatoes against late blight
In rainy summers, treatment of late blight on tomatoes will have to be carried out in 4-5 sessions with a break of 7-10 days. The last chemical treatment of tomatoes against late blight is carried out no later than three weeks before harvesting. How to spray tomatoes to increase their immunity and resistance to infection? Treatment with growth regulators Exiol (1 ml per 3 liters of water) or Oxyhumate (10 ml per 1 liter of water) has a good effect on increasing the resistance of tomatoes to disease.
The causative agent of the disease affects plants not only in open ground - sometimes late blight in a greenhouse can destroy most of the tomato crop. Phytophthora on tomatoes in a greenhouse is destroyed by the same means as in open ground, but with all precautions dictated by safety precautions, since it is easier to get poisoned by chemicals indoors than in the fresh air.
It should be understood that a single treatment of tomatoes against late blight will not give any results; this disease cannot be defeated at all, you can only suppress its development, but for this you will have to be patient.
Remedies for late blight on tomatoes
Treatment for late blight is carried out with such drugs as Bordeaux mixture, Ridomil Gold, Tattoo, Quadris, Baikal EM, Radiance. The treatment solution is prepared in accordance with the manufacturer's instructions. Late blight on tomatoes can be suppressed only after several treatment sessions with an interval of 7-10 days. And do not forget to alternate fungicides, since pathogens easily get used to the drugs. Try to use a stronger drug with each subsequent session.
Late blight of potatoes
Late blight on potatoes - treatment
Late blight of potatoes has the same symptoms as late blight of tomatoes - spots on the leaves that quickly spread throughout the plant, curling and drying of the leaves. When potato tubers become infected, hard spots appear on them.
How to treat potatoes against late blight? To prevent the development of the disease, there is a scheme for processing potatoes:
- the first time the tops are sprayed with a systemic fungicide when they reach 25-30 cm in height. Preparations such as one percent Bordeaux mixture, copper sulfate (2 g per 10 l of water), copper sulfate (20 g per 10 l of water) are used for spraying;
- be sure to treat the potatoes before flowering with Epin, Oxyhumate or Exiol, and if weather conditions are not conducive to the development of the disease, then limit yourself to spraying the bushes with plant resistance inducers - Silk or Krezacin:
- after a week or two, the potatoes are treated with contact fungicides - copper oxychloride, Efal or Ditan M-45 in accordance with the instructions, but if the treatment is preventive in nature, then the dosage is halved. In case of severe infection, Oksikhom, Ridomil MC or Ridomil Gold MC are used for treatment, and after 10-14 days, spraying with these drugs is repeated. After flowering, potatoes can be treated with Bravo; re-treatment with this drug is carried out after 7-10 days;
- At the stage of tuber ripening, it is advisable to use the drug Alufit for spraying.
Choose a cloudy, but windless and rainy day for spraying. And if it rains after the treatment, it needs to be repeated. It is necessary to process potato tops until they completely die.
Prevention of potato late blight
In order to protect potatoes from late blight, it is necessary to choose the right place for planting them, grow only varieties resistant to late blight, and carry out preventive treatments in a timely manner.
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From late blight on tomatoes and potatoes
Are your tomatoes and potatoes turning brown, and black spots starting to appear on the leaves, stems and fruits? The plants were probably attacked by late blight. But don't despair! We will tell you how to deal with late blight.
This is a common fungal disease that primarily affects nightshade crops and occurs most often in cool and damp weather. Phytophthora spores can be found in the ground, on seeds, plant debris, walls and roof of the greenhouse, gardening tools, etc. And in order to prevent the spread of spores to plants, it is necessary to follow preventive measures.
Prevention of late blight
1. Well-limed soils are a favorable environment for the development of late blight. Therefore, you should not get carried away with liming. If a lot of lime has accumulated in the soil, you need to restore the natural balance of the soil: add peat and pour coarse sand into the furrows.
2. Fungi prefer a moist environment, therefore it is important to water the plants in moderation and not allow the plantings to become thicker. Water potatoes and tomatoes in the morning so that most of the moisture has been absorbed into the soil by the end of the day. And when growing tomatoes in a greenhouse, be sure to ventilate it.
In addition, humidity often increases during sudden temperature changes (for example, at the end of summer, when the day is still hot and the nights are already cold).
At this time, plantings in open ground should be covered with spunbond overnight. First of all, this concerns tomatoes, since not only late blight, but the cold itself can destroy them.
3. Plants with weak immunity are susceptible to any infection. Therefore, make sure that your tomatoes and potatoes receive enough essential microelements (iodine, manganese, copper, potassium and phosphorus). Then garden crops will have less chance of getting late blight.
And to strengthen the immunity of plants, you need to observe crop rotation. So, good predecessors for potatoes are cucumber, zucchini, pumpkin, squash, cabbage, legumes, root vegetables, onions, and for tomatoes – white and cauliflower, cucumber, zucchini, pumpkin, legumes, onions, root vegetables.
4. The development of late blight can be prevented by growing varieties and hybrids that are resistant to fungal diseases. Choose high-quality planting material - and you will not need drugs against late blight.
Treatment of late blight
Chemical remedies for late blight on potatoes and tomatoes are very effective, but it is not recommended to use them during the ripening of the crop. Therefore, in the second half of summer it is better to spray plants with biological preparations.
So, you can buy Fitosporin in a specialized store, dilute it with water according to the instructions, carry out the first spraying when the ovaries appear, and then spray the plants every 10-14 days. In addition, using a solution of Fitosporin, you can treat the soil against late blight: before sowing or planting plants, water the soil or add the biological product to the irrigation water several times during the growing season.
How to treat tomatoes and potatoes against late blight with folk remedies
We will present the most effective and time-tested folk recipes for safe remedies that our grandmothers used to save their green pets from dangerous late blight.
Infusion of garlic with potassium permanganate
100 g of garlic (bulbs, arrows and leaves can be used) are crushed (in a meat grinder, garlic grinder or simply cut into very small pieces), poured with 1 glass of water and left for 24 hours. Then the mass is filtered, 10 liters of water and 1 g of potassium permanganate are added. The resulting solution is sprayed onto the plants every 10-15 days. On average, 0.5 liters are used for each bush.
Trichopolum
This drug (and its analogue, Metronidazole) can be bought at the pharmacy. 1 tablet of Trichopolum is dissolved in 1 liter of water and the tops are sprayed with this liquid once every 2 weeks.
Milk serum
The whey from sour milk is diluted with water in a 1:1 ratio and from the beginning of July the plants are sprayed every 2-3 days.
Late blight is a common fungal disease that mainly affects plants from the Solanaceae family. Tomatoes suffer the most from it. The disease is insidious and so total that within one or two weeks it can destroy a tomato crop that you have carefully grown and almost brought to ripening. How to fight late blight on tomatoes? There are several solutions.
To choose the best methods of control, it is necessary to find out how this disease occurs, what its nature is, and what this fungus of the same name is “afraid of.”
Late blight affects almost all varieties of tomatoes, except those in which breeders have instilled increased resistance to this disease. But even sowing resistant varieties is not a 100% guarantee that your tomatoes will be protected from late blight damage. Therefore, preventive measures are of great importance.
The disease has the following “clinical picture”:
Blackening of tomato fruits does not always occur due to late blight. Sometimes this is a reaction to other problems or unfavorable growing conditions (poor soil, dryness, excess moisture, pest damage). But in most cases, this sign indicates late blight.
Late blight is caused by a fungus whose Latin name is Phytophthora infestans. The phrase has a rather harsh translation - “destroying a plant.” The disease fully corresponds to its name; if the causative fungus gets on a tomato bush or other plant, it is quite difficult to save the plant.
Causes
What conditions must be met for the late blight fungus to enter the plant and begin to multiply there?
Not enough air
It is well known that plants need moisture to take good care of them, but many people forget that air is no less necessary. Late blight thrives in environments where there is not enough air penetration. For this reason, it is necessary to plant tomatoes of all types, and this procedure is especially recommended for tall tomatoes.
Protected ground
Protective shelter can provoke the occurrence of disease. At night and during the day, the temperature in the greenhouse differs sharply. Due to these fluctuations, condensation collects on the film surface from the inside, which forms increased humidity. Phytophthora fungus spores require a moist environment to more easily penetrate the plant.
High humidity
The same effect is produced by prolonged rains and high air humidity when growing tomatoes in open ground.
During the rainy season, the likelihood of being affected by late blight increases, especially if the optimal temperature regime is not observed (for tomatoes it is +19°C...22°C).
Cool nights plus high humidity will almost certainly result in tomatoes becoming infected with fungal spores.
Along with tomatoes, potatoes, peppers, and eggplants are actively infected with late blight. When planning plantings, you should not grow these plants side by side, and you should, if possible, observe crop rotation or thoroughly disinfect the soil after harvesting.
How does infection occur?
Late blight is transmitted in all different ways: through infected stems, leaves, fruits and tubers; downwind and through the soil. The fungal spores are washed off with water when watering and are spread on the soles when moving around the area.
The fungus can live in the soil for several years, especially in soil that contains small amounts of copper compounds.
How to prevent late blight from tomatoes
Potatoes are the first to be affected by late blight. If you grow this crop, try to protect your tomatoes from infection. This can be done by disinfecting potato leaves and tops. Leaves that show signs of damage, mainly those located in the lower tier, should be removed from the bush. Additional hilling also helps, as a result of which the developing potato tubers are located further from the soil surface.
You can protect tomatoes by limiting the spread of fungal spores on them. You should not plant these two crops in close proximity, and if this cannot be avoided, you can create “living barriers” between them by sowing climbing beans or green peas in a thickened planting.
When growing tomatoes in greenhouses, care should be taken to ensure that not only humidity and temperature are controlled, but ventilation is also provided.
Before planting tomato seedlings, you must do the following:
- Prepare a suitable place. Avoid proximity to other nightshades, especially potatoes.
- Clear the soil of debris, all last year's organic waste, grass and anything else that may harbor the late blight virus.
- Provide ventilation (in the greenhouse), or select an area that is blown by the wind, but does not have a constant draft.
After planting the seedlings, during their growth period, before the fruits begin to form:
How to get rid of late blight
Even before the formation of the ovary, without waiting for signs of the disease to appear, it is better to spray the tomato bushes with 1% Bordeaux mixture.
As soon as you notice that the pigmentation of the foliage or stems has changed, and even more so if the fruits that have set begin to turn black, remove infected plants and diseased plants immediately and burn them.
Potato and tomato tops, in order to avoid the proliferation of fungal spores throughout the area, are not placed in the compost pit, even if the plants are visually healthy.
Disinfecting treatment
There are many folk and agrotechnical treatment methods that will help prevent the onset of late blight, or protect plants if the disease has already occurred.
Any processing should be carried out in dry, windless weather. The rainier and colder the summer, the more treatments may be needed.
In addition to mineral and organic fertilizers, it is necessary to feed tomatoes with biological substances that will strengthen their immunity.
Folk remedies
Garlic
Infusion of garlic with potassium permanganate. It is prepared as follows. For 100 g of garlic heads, stems or young leaves, take a glass of water. Grind the garlic in any way, leave in water for 24 hours. Strain thoroughly and dip into a 0.1% solution of potassium permanganate, volume 10 liters (for this volume of water, to obtain a 0.1% solution you will need 1 g of potassium permanganate powder).
Spray the ovary for the first time, then 10 days later. After this, three more sprayings can be carried out at intervals of 12-14 days.
Serum
Ideally, it will be whole cow's milk and not powdered milk. It must be fermented to separate the whey. Dilute it with water in a 1:1 ratio. Spraying should begin at the beginning of July. This remedy is rather preventive, so the irrigation procedure can be carried out daily or every other day.
Iodine milk
To prepare this disinfectant you will need skim cow's milk. For 10 liters of water, take one liter. 20 drops of 3% iodine tincture are also added there. With the beginning of the formation of the ovary, iodine-milk irrigation can be carried out every two weeks.
Ash
Ash is used not for spraying, but for dusting. You can start a week after planting the seedlings. After watering, spray the sifted ash thickly onto the bushes and soil, including between the rows. When the fruits begin to set, repeat the procedure, but this time only dust the soil between the rows.
Yeast solution
Dissolve a 100-gram pack of raw baker's yeast in 10 liters of water. If the first signs of late blight are noticed, begin regular weekly spraying of yeast solution on the leaves and stems, especially in the lower tier.
Saline solution
For 10 liters of water, 200 g of table salt is consumed. It must be well dissolved. Processing is carried out on fruits that have already begun to form, but are not yet large. The salt film will protect the tomatoes from fungal attack, but spraying must be carried out in such a way that it is not immediately washed away by rain or when watering. Before spraying, carefully remove already affected fruits or leaves.
Agrotechnical methods
Copper sulfate
The inorganic compound copper sulfate is a real “lifesaver” for the gardener, helping in the fight against many diseases and pests. Late blight is no exception. To rid tomatoes of it, before flowering you need to treat them with an aqueous solution of this substance, in a proportion of 2 tbsp. powder per 10 liters of water.
The period of action of the drug is 30 days, so one high-quality treatment will be enough.
Calcium nitrate
Has a powerful protective effect. For 10 liters of water, calcium nitrate will require one tablespoon. It not only helps in the fight against late blight, but is also a nitrogen fertilizer that increases plant immunity. Tomatoes are sprayed once before flowering.
Fungicides
One of the most popular representatives of this class of biological substances is Fitosporin-M. They are starting to use it for protection at the seedling stage. Seedlings are dipped in a solution prepared according to the instructions before planting.
Then the plants are sprayed every 10 days until fruit sets. You can water the top layer of soil with the solution.
Other biological drugs:
- Alirin-B
- Gamair
- Oksikhom
- Ordan
- Ridomil Gold.
If folk remedies can be used almost throughout the growing season, the use of fungicides is limited to the time of fruit set and formation. And, although the effectiveness of chemicals is higher, it is better to take care of early treatment with harmless means.
Late blight poses a serious threat to tomatoes. This crop is not characterized by problematic cultivation, but this disease can be considered the most common and difficult to cure. In order for tomatoes to ripen healthy, gaining full consumer ripeness, varietal taste and weight, concern for the eradication of late blight on the site should be a priority in their care.
