Long since the most terrible disease of potato is late blight. Previously it was believed that this dangerous fungal infection spreads only with planting material and is not able to tolerate an extreme decrease in ambient temperature during the winter period. However, nowadays late blight, which affects the potato, has undergone mutations and acquired new properties. Therefore, gardeners have to fight the disease throughout the year.
How to deal with blight on potatoes? What drugs and traditional methods should be used to destroy the infection? Are there potato varieties resistant to phytophthora? Answers to these and other questions can be found in our article.
What is late blight?
Late blight - a dangerous disease that affects cultivated plants, popularly called brown rot. Usually, the infection begins to destroy garden plantings at the end of the summer. In the absence of targeted actions aimed at combating the disease, about 80% of the harvest may suffer.
The causative agent of the disease is fungal infection Phytophtora infestans. Microscopic spores have the ability to proliferate under favorable conditions. First of all, phytophthora is formed on the leaves of potatoes. Then the infection passes to the shoots and gets to the tubers. With increased humidity, plants are covered with brown spots. The inside of such damage is covered with white bloom formed by spores of the fungus. In case of loss of abundance of dew in the epicenter of the spread of infection rot forms. With the onset of heat the plants begin to dry out.
If the potato is infected with blight, the surface of the tubers is covered with dark areas. The infection spreads deep, and the crop gradually rot. It is noteworthy that even healthy tubers, after moving to the cellar, may be infected and begin to decompose.
Ways of infection of potato late blight
To understand how to deal with late blight on potatoes, you need to know how the fungal spores spread. So, the disease can affect plants:
- In cases of use of "sick" seedlings. Infected tubers are able to carry on themselves disputes that fall into the soil. Upon the occurrence of favorable conditions, the infection will surely make itself felt.
- When harvesting, when the tubers are in direct contact with the late blight infected tops.
- When the spores of a fungal infection are washed into the ground from the shoots of plants by precipitation. Infection penetrates the soil and infects healthy tubers.
What is the cunning of the disease?
The main feature of late blight is a gradual uneven infection of cultivated plants. The absence of signs of disease on most bushes does not allow gardeners to identify the problem in time and prevent a catastrophe at the stage of ripening shoots. Disputes invisibly to the eye are thrown by wind on the next plantings and together with the rain they go to the upper layers of the soil. Potato shoots affected by the blight can become brown in just a few days. When the humidity of the environment increases, the leaves begin to curl and dry. As a result, the gardener has to observe only protruding stems instead of lush bushes. If the owner of the site cannot decide how to treat the potatoes from the phytophthora, soon the tubers are also covered with brown spots, which become rotten. Infection affects not yet fully ripe potatoes in neighboring areas.
Use of quality seedlings
How to deal with blight on potatoes? One of the most effective solutions is the selection of planting material. It is important not only to choose quality seedlings, but also to resort to its germination in greenhouse conditions before being placed in the soil. The decision reduces the time of crop ripening and, accordingly, makes it possible to harvest it before the onset of the period of “violence” of phytophtoras, which is observed around mid-August.
Potato varieties resistant to phytophthora
One of the most rational decisions to combat fungal infection - the choice of seedlings that are not exposed to infection. How to deal with blight on potatoes in this way? Preference should be given to the following varieties:
- Good luck - different early maturation of tubers. The variety perfectly tolerates not only serious frosts, but also high soil moisture, under the conditions of which late blight is actually activated.
- Reserve - characterized by the formation of branched rhizomes with an abundance of tubers. Performs mid-grade. Such potatoes are not afraid of drought and excessive soil moisture.
- Dawn - potatoes early ripening. In addition to late blight, the variety is almost immune to common bacterial and viral infections.
- Nevsky - a variety that has excellent taste. When harvesting, there is a small amount of waste. Tubers of such potatoes are able to withstand high humidity, droughts and a significant decrease in temperature. The variety is well kept in cellar conditions.
- Blue - for such potatoes are characterized by the average time of ripening of tubers. Shoots, like the crop, are resistant to fungal infections.
- Lugovskoy - demanded mid-early variety. Tubers are perfectly stored in almost any conditions. In order for the crop to not infect a fungal infection, the cultivation of a variety requires regular soil loosening.
- Nida is a potato variety that is not exposed to infection with blight and nematodes. However, tubers do not tolerate excessive soil moisture and dryness.
- Timo - an early variety of high yield. Tubers are not afraid of late blight, as they fully ripen before the infection spreads.
Choosing the right site for planting potatoes
Preventing infection with phytophlorosis allows the choice of a site for planting potatoes. Preference should be given to areas without pronounced lowlands. As noted earlier in our material, late blight prefers moisture. And the water after precipitation is concentrated just in all possible recesses of the soil. To prevent fungal spores from affecting neighboring areas, it is important to make wide aisles when planting potatoes.
If phytophthora is found on potatoes - what to do? Avoiding crop loss potentially allows the use of the hilling method of bushes. When the shoots begin to grow and close up in rows, you need to tuck up the ground beneath them. The solution will open the infected leaves. There will also be access to direct sunlight to the soil, which will reduce its moisture level.
To prevent the spread of an unpleasant disease, before placing the tubers in the cellar, they must be thoroughly dried. If there is a drought, you can lay out the crop right on the land. When there is precipitation, drying should be carried out under sheds. It is recommended to place potatoes for long-term storage only after sorting. It is imperative to eliminate tubers that have clear traces of late blight. After all, with the beginning of the next season with such a seedling, the fungal infection will again move to the soil and infection of healthy plants will occur.
Chemistry for spraying potatoes
In order to spray using the following drugs from phytophthora:
- Agat-25K is an effective preparation of biological origin, which is used for the treatment of seedlings. It contributes to the improvement of the protective properties of plants, has a stimulating effect on the growth of crops.
- "Fitosporin M" - is an effective fungicide. Suitable for the treatment of planting material in order to combat the development of fungal infections.
- "Ridomill Gold MC" - is used in order to prevent late blight. During the season it is necessary to process potatoes at least 3-4 times.
- "Thanos" - the active ingredients of the drug cymoxanil and famoxadone can destroy the spores of the pathogenic fungus within a few seconds. The tool is not washed off from the shoots of plants, even with strong precipitation.
- "Maxim 025 FS" - used for handling seedlings. Effective in the case of complex use along with other chemical agents.
The cause of late blight can be mutated and develop resistance to the effects of certain substances in the composition of preparations for the treatment of cultivated plants. Therefore, it is important to periodically alternate the above means and resort to combining them.
Soil treatment preparations
How to cultivate the land after potato phytophthora? The following chemicals will come to the rescue:
- "Glyocladin" - is available in tablet form. Folds one dragee into each well when planting potatoes. The active ingredients in the composition prevent the formation of fungal infections and prevent rot from spreading.
- "Baikal M" - has the form of a liquid solution. It is based on beneficial microflora, which destroys the phytophthora mycelium, and also effectively fights the development of other fungal infections. The soil is irrigated with the product several weeks before the intended planting of potatoes.
- "Apirin B" - the drug contains Bacillus subtilis in its composition. Microorganisms in this category have the ability to slow down the vital processes of fungi, which leads to their destruction.
What else to cultivate the land after potato phytophthora? Effectiveness is also demonstrated by such substances as Bordeaux mixture, copper sulphate. These compositions should saturate the soil in the process of digging the site.
So we examined how phytophthora potato is destroyed, methods of dealing with this fungal infection. Finally, I would like to highlight a number of preventive measures that will prevent the return of the disease.
If it is not possible to purchase seedlings of varieties that do not undergo late blight, then it is worth resorting to full-fledged crop rotation. At least for a year on the site should not be cultivated potatoes. Instead, sow mustard or radish. Shoots of such plants are recommended to be periodically cut and buried in the ground. As practice shows, the decision makes it possible to several times reduce the likelihood of phytophthora returning with the arrival of the next season.
Before planting potatoes, it is necessary to identify the infected material. For this purpose, the tubers are removed from the cellar and left under a well ventilated canopy for several weeks. The temperature should remain at the level of 15-18 o C. As soon as some tubers turn white, it is urgent to remove them, and process the rest of the seedlings with fungicides.
During the period of mass collection by tubers, it is worth partially cutting off the potato tops and loosening the soil. The preventive measure will accelerate the ripening of the crop and will lead to a build-up of dense rind potatoes.
If after harvesting phytophthora was noticed on potatoes, what to do in such situations? It is necessary to collect all the dry tops abroad and land. With the onset of the next season, it is necessary to water the potatoes as little as possible in cool weather, because these are the conditions that are optimal for the activation of late blight spores.
As you can see, in no case should you underestimate the seriousness of such a disease as late blight. In the absence of a targeted fight against the spread of fungal spores, not only the potato harvest, but also other solanaceous crops may suffer. Therefore, it is necessary to timely treat the plants and the soil with appropriate chemicals, pickle and sort the seedlings, use varieties resistant to infection.
Description and signs of the disease
Phytophthalosis of potato belongs to the category of fungal diseases, the causative agent of which is the lowest oomycete group of fungi Phytophthora infestansdeveloping on dead solanaceous residues. The spread of the disease is carried out by means of spores of the fungus, which are spread either by wind or washed by rain from the aerial part of the bush and through the soil capillaries fall on the roots. The duration of the incubation period is 3-16 days. The activity of the fungus on depleted soils and in the presence of pathogens on planting material increases, and this period is reduced to 3-4 days.
The presence of phytophtoras in many regions is manifested on leaves and stems in the second half of summer, but in the southern regions potatoes with early ripening can be affected already in June, after the first rains. In conditions of high humidity for 1.5-2 weeks from a few plants can get all the planting. In the absence of effective treatment after 17-20 days, the plantations perish.
Late blight poses a serious threat not only to potatoes, tomatoes, peppers, eggplant, but also to strawberries, buckwheat, raspberries, castor beans.
The first clear sign of the disease is the presence of dark spots of irregular shape along the edges of the leaf plates, which quickly become brown in color and increase in size. White markings are visible on the underside of the leaf — the oomycete zoosporangia. Rain or wind, they are easily transferred to healthy potato bushes, and infection occurs instantly. Dark spots are clearly visible after 3-5 days. If long-term cool and wet weather persists, the affected leaves begin to rot, and in the heat to dry. Below is a photo of potatoes affected by blight.
The affected plant stems are folded and may even break. Spores of the fungus linger longer on the stems than on the leaves.
On the tubers, the pathogen is detected by dents on the skin that have a brown or dark gray color. The completely affected root crop becomes lead-gray in color, its flesh is mucous and soft with a rusty hue.
Considering that phytophthora on potatoes is quite tenacious and difficult to destroy, besides it is not afraid of low temperatures, it is recommended to familiarize yourself with its main ways of propagation:
- Spores of fungus on planting material. If before planting the tubers were not carefully examined and did not undergo disinfection, then, once in the ground, the pathogenic microorganisms begin to become more active and infect healthy plants.
- Affected leaf tops during harvesting is in contact with the crop. When diseased vegetation comes in contact with tubers, they become infected. To protect the crop, before harvesting it is recommended that you first remove all tops from the site.
- Excessive moisture becomes a source of infection of the leaves and stems. Frequent precipitation and abundant dew contribute to the development of late blight. Through moisture, the fungus is transferred from the ground part of the bush to the ground.
- Not removed for the winter plant residues. Overgrown on the remaining vegetable residues in the garden fungus becomes the cause of the disease.
- Infection of plants by airborne droplets. Wet and windy weather is the source of the spread of the fungal disease. In such circumstances, disputes in a matter of minutes can be 2-3 km from the affected area. Therefore, the nightshade is better to plant as far as possible from each other.
How to deal with late blight potato
Fungicides are used everywhere, which provoked the emergence of microorganisms resistant to many drugs within populations. Processing of potatoes from phytophthora chemicals should be carried out correctly, because the pathogen is plastic and able to quickly develop resistance to toxic substances. To destroy the fungus on the bushes and root vegetables, will have to use several means. The approach should be comprehensive.
Ways of infection
Asking the question: “Phytophthora on potatoes - how to fight” - be sure to determine the ways of infection of the plant with fungus. There are many different ways of spreading fungal organisms, and it is very difficult to deal with them without certain skills and drugs. The pest perfectly maintains low temperatures of soil in the winter and quietly gets accustomed on new landings. Among the most known ways of infection it is important to highlight the following:
- the fungus was present on the planting material. Most often, the problem is seen in those cases when landing tubers were chosen randomly, during which infected tubers fell into the ground. Now the reproduction periods of fungal microorganisms will be very fast, and the probability of losing most of the crop will increase significantly,
- diseased tops contacted with tubers during harvesting activities. In such a case, the already harvested crop may become infected. To avoid such a development of events, it is necessary to remove the tops from the field before the future assembly of fruits,
- the fungus is transmitted from the leaves and stems to the root through moisture. If it rains and abundant dew for a long time, the disease will be transmitted from the ground portion of the potato to the ground,
- также проблема распространяется с помощью мусора и сорняков, которые остались в почве на зиму,
- не исключается вероятность заражения воздушно-капельным путём, когда грибок передаётся от других зараженных растений. As a result of research, it was possible to determine that in wet weather, spores often move 2-3 kilometers away. For this reason, it is better not to plant solanaceous vegetables at a short distance from each other.
How to deal with blight on potatoes: effective methods
The problem of controlling the blight disturbed people for many years. For this reason, gardeners have invented a mass of effective methods and preparations that will allow them to process and fight the disease as efficiently and productively as possible. But, find a universal solution, which completely eliminate the appearance of such fungal microorganisms in the garden, unfortunately, is impossible. Depending on the area of planting and personal preferences, people can use natural or chemical means.
In any case, you must follow strict instructions and tips on dosage. With a very low concentration of funds, any results may not be commonplace. If the concentration is excessively high, a bad effect on the fetus and the plant as a whole is not excluded. In addition, some drugs can be dangerous for people who will eat root vegetables. You need to process potatoes with chemicals in the following steps:
- when preparing the soil before planting. The fact is that in the soil can remain colonies of fungi from last season. For soil treatment use drugs "Thanos", "Ridomil" and a number of biological fungicides,
- also as a good tool to combat phytophtora used method of processing potatoes, which is taken as planting material. For this purpose, special crop stimulants and growth regulators are used, including Agat 25, Zircon and many others.
Spraying of soil is carried out at different stages of growth:
- to the closure of the rows. As a treatment agent, the drug “Tanos” is used, which is famous for its excellent efficacy in the fight against Alternaria,
- on initial budding stage. In this case, it makes sense to apply systemic fungicides, which ply all parts of the plant after ingestion.
As for the general recommendations on the treatment of plants with chemicals, the activities are best carried out until the height of the stems reaches 20 centimeters. Early varieties need to be processed first.
The drug shows maximum efficiency when it hits the area on both sides of the leaves, even the lower ones. Multiple repetition of procedures is needed in those cases if the problem has turned into an epidemic and needs systematic treatment.
The fight against late blight on potatoes using Bordeaux mixture and folk compositions
The drug based on Bordeaux mixture in a ratio of 100 grams of vitriol and 120-150 grams of lime in a bucket of water performs well. If you do not respect the basic proportions, a strong concentration of copper sulfate may cause burnplants. The composition is applied at different stages of potato development. They can process the tubers before planting or during germination, a few days after germination and a month after planting in the ground.
In addition, it is possible to deal with late blight on potatoes using folk methods that do not have an aggressive impact on the culture, but at the same time quickly eliminate the further development of fungal organisms. Among the popular and effective means of highlighting the following:
- garlic. We take 150 grams of garlic in any form (teeth, arrows or leaves), grind in a meat grinder and pour a glass of water. Then we filter the mixture and pour water in the amount of 10 liters. To the composition is added 1 gram of potassium permanganate. Such a the tool is perfect for all types of plants solanaceous family. Processing is carried out twice a month,
- field horsetail. Take 1-2 kilograms of plants and fill with 10 liters of water. Leave the composition for 3-4 days so that it is well infused. Due to the rich in silicon composition of the drug quickly acts on the development of fungal formations and strengthens the immune system of potatoes,
- ash. It is a good spray solution. You can use 1 liter of ash in the proportion of 10 liters of water and 200 grams of soap. For effective exposure to contaminated potatoes, you can use both dry ash and spraying solution,
- milk serum. To maximize the impact on the disease, it is necessary to dilute serum in equal quantities with water. Processing plants need to start from the beginning of July. Then the procedure is repeated, depending on the need,
- compost and urea. The optimal proportion is 1 kg and 1 tbsp. l The proportion is picked at 10 liters of water. Insist such a solution for 4-5 days, after which you need to carry out spraying,
- Pills "Trichopol" work well with which they treat the plant once every two weeks.
Methods of struggle and preventive measures
If the weather conditions match, the development of the disease will occur very quickly. You should pay due attention to preventive measures to combat blight. Pay attention to a number of features, and you may not have to deal with the problem in the future.
- It is important to choose only healthy planting material. It is recommended to warm it well before landing in two weeks. Once again, review the ground and make sure that it is suitable. Be sure to remove the tubers with the smallest symptoms of the disease.
- Choose only resistant varieties. And although there are absolutely no resistant varieties, the difference in response to susceptibility is still present.
- Remove post-harvest residues. Often they perform role of source of infection. It will not hurt to completely mow the tops before digging, after which it is removed from the field. Often the tubers with the affected leaves remain healthy until the moment they come into contact with diseased tops.
- Maintain crop rotation. Do not forget that the causative agent of fungal diseases may be present on other solanaceous. In addition, it can be found on buckwheat, castor beet, strawberries and other cultures. Therefore, planting potatoes after tomatoes or eggplants is unwise.
- Early cleaning will be a good preventive measure. This is especially important when the weather is rainy, conducive to the development of fungi.
- Do not allow the growth of tops. This contributes to the rapid development of fungal microorganisms.
- Stick agrotechnology. If the basic features of care and maintenance are not observed, this can cause the development of a variety of problems, including phytophtoras.
- Correctly distribute the dressing. Bring the optimal amount of nitrogen, since an excess of increases the likelihood of disease progression.
When growing potatoes, be careful and responsible. Even the most insignificant events can save your harvest from death in the future.
What kind of disease causes
Phytophthoracosis of potatoes is generated by the same name fungus - blight. The fungus is pathogenic, belongs to the family of oomycites, is a representative of the lower category of fungi. Homeland parasite - South America, as, indeed, the potato itself. The first is rotting from phytophthora tops, then the infection penetrates the tubers. In winter, the fungus is stored in the soil and plant residues of tops, tubers.
The disease is transmitted through phytospores, falling on the stem of potatoes and its tubers from the leaves of the plant. Transmission occurs by soil capillaries. From the moment the fungus spores enter the plant until the disease occurs, it takes from 3 to 16 days: this is the incubation period of late blight.
Note that if potato plantations are stunted and weakened, then the incubation period is significantly shortened and lasts only 3-4 days.
Usually, the tubers become infected just before the start of the harvest or during it. And if the plant infected with late blight received direct contact with tubers, part of the harvested crop can also be infected: through the eyes. The risk of infection of the new crop increases significantly if the potatoes were dug up carelessly, with numerous cuts of tubers.
We note that in recent years, farmers have increasingly begun to notice the emergence of a particularly dangerous type of phytophtora - the Mexican. This fungus spreads extremely quickly and, if measures are not urgently taken, does not leave a chance for harvest.
In addition, phytophthora gains resistance to many drugs and it becomes more difficult to cope with it. The development of the fungus is now observed even under adverse conditions. By the way, the literal translation of the name of this fungus sounds like "plant killer." To date, the annual loss of potato harvest due to phytophtora is 20%.
Non-compliance with crop rotation is one of the main reasons. If solanaceous crops also grew on the field, the spores of the fungus could well remain in the soil.
Waterlogging is an important cause of the problem. Phytophthora fungus loves moisture and develops poorly in arid conditions. If high humidity is combined with a warm temperature (+ 15-25 degrees), then the conditions for the reproduction of fungus on potatoes are created, we can say, ideal.
Too dense, dense plantings also lead to blight. The fact is that in thickened plantings a shadow is created, high humidity is preserved, that is, ideal conditions for the development of the fungus.
We find out what signs they say about the defeat of potatoes by late blight.
Spots on the leaves
This is an early sign of a fungus infestation of a vegetable. The spots have a dark shade and appear on potato leaves. At first they appear on the edges of the foliage, but gradually creep away, increasing in size. Hue spots - brown-brown.
If urgent measures are not taken, soon the entire above-ground part of the bush becomes brown. In addition to a change in color, the leaves are also deformed: they become twisted, shrunken.
How to deal with it? Methods of struggle
Consider all ways to eliminate late blight of potatoes: both chemical and folk remedies. Also find out how to handle planting at the time of flowering.
Before you begin to consider drugs, you must immediately say that you can not completely cure the already infected fungus potatoes. However, it is possible to stop the spread of infection: the use of potent chemicals is intended for this purpose.
In anticipation of the flowering of potato buds recommended spraying drug Epin. If the variety is stable and the weather is dry and warm, you can use more “lighter” products: Silk, Immunocytophate, Krezacin.
In the case when at this stage signs of the disease are already visible, more potent drugs should be used: Ridomil Gold, Oksikhom, Ridomil MC. The treatment after one and a half to two weeks is repeated: but only if the buds have not yet had time to blossom.
After 10-12 days, carefully examine the bushes. And if the risk of infection with phytophtora remains high, it will be necessary to use “heavy artillery” in the form of drugs Revus, Efal, Scor, Ditan.
Attention: if there is no infection, the drugs should be diluted in a concentration of half that specified in the instructions.
In addition to specialized chemicals, growth stimulants can also be used. These drugs are created on a biologically safe basis and help strengthen the immunity of plants, enhance their growth, and activate development: a kind of "vitamins" for plants. For potatoes, Ecosil, Oksigumat, etc. preparations are suitable. They can also be used during flowering.
The recipe is quite effective and is often used by summer residents for processing small potato patches.
To make the infusion, you need to take 100 grams of garlic, chop the heads finely and insist in a 10-liter bucket of water. Infuse the mixture should day under a closed lid. After time the infusion filter and conduct spraying of the beds. For the desired effect, it is necessary to process the bushes in 4 stages with a weekly interval.
This substance, though of chemical origin, is considered in the horticultural business to be practically a “folk remedy,” just like Bordeaux liquid: because of its frequency and versatility. So, vitriol needs to be diluted with water in the proportion of 2 grams of the substance per bucket. Spraying is carried out in two stages: interval - 10 days.
Copper sulfate can also be used for the preparation of mixed solutions: for example, with potassium permanganate and boric acid. In this case, in 3.3 liters of water dissolve one tablespoon of these ingredients.
When the mixture is cool, it is poured into a 10-liter bucket, adding water to the edges in a container. Treatment with the mixed composition is carried out twice: at the end of July and at the beginning of August with an interval of 7-10 days.
In this case, the dry matter should be diluted in the proportion of 60 grams per 15-liters. Spraying the resulting solution produced in 3-4 stages, with the need to withstand at least a weekly interval between approaches.
This well-known simple substance can also become an excellent and, importantly, a safe helper in the fight against late blight. For the preparation of home fungicide must be dissolved in five liters of water Art. spoon of baking soda, 3 spoons of vegetable oil and 1 teaspoon of liquid soap. The mixture should be used immediately after preparation, it is not subject to storage.
If the fungus has just started its offensive actions, you can stop its spread even with the help of fermented milk products. The following mixture is made: a liter of spoiled kefir is dissolved in ten-liter veda of water.
All mixed and insist 3-4 hours. After the specified time, the mixture must be filtered and used. Spray the potatoes with kefir mixture once a week until the fungus stops spreading.
In addition to these recipes, you can also spray potatoes:
- whey or sour milk, diluting them with water beforehand,
- Trichopolum purchased at a pharmacy, diluted in a ratio of 1 tablet per liter of water,
- iodine diluted in this way - 15 drops per liter of water,
The vitriol and iodine can not only protect against phytophthora, but also become a good supplemental root top dressing. But dairy products are not top dressing: they simply create a film on the tops of the potato, which prevents the penetration of the fungus into the plant tissue.
Of course, traditional preparations are absolutely safe, they do not harm the soil and the crop, but they can not always be effective. If late blight has already significantly hit the potatoes, do not waste time and effort on popular recipes: immediately take up chemicals.
Attention: during the flowering of potatoes, you can only use folk remedies, or purchased preparations with a biological composition.
Selection and preparation of planting material
The future health of the potato and the safety of the entire crop depend on the quality of the tubers intended for planting. A couple of weeks before the proposed rooting, inspect the tubers, warm them, remove the specimens with signs of infection.
If among the planting material found infected with late blight copies, be sure to immediately remove them. For the sake of safety, the remaining part of the tubers must be treated with the anti-fungal agent Agat (per liter of water 12 g) or Immunocytophyte (per liter of water 3 g).
You can choose a variety resistant to phytophthora lesions: There are a lot of similar varieties on the modern potato market.
And if you choose potatoes of early varieties, this, to some extent (sometimes significant), will also help to prevent phytophthora. The fact is that the phytophthora appears on a potato bed at a certain time: early varieties by this time can already be harvested.
When choosing a landing site, it is important to consider which predecessors grew on it. Since the potato is a culture of solanaceous, it is recommended to avoid planting it after the same solanaceous plants: tomatoes, eggplants. Compliance with this simple recommendation will stop the infection of potato blight initially.
It is ideal to keep three “empty” years between plantings of potatoes for the same bed. At this time, other cultures that have no relationship with Solanaceae can fill the site. But planting a year later also gives its positive results, besides, such alternation is much easier to carry out in the conditions of our cramped summer cottages.
- Water the potatoes in a timely manner, but without over-wetting the soil.
- Remove the tops from the field immediately, like weeds after weeding.
- Tools after working in the potato field is recommended to be decontaminated.
- Spraying spend in a timely manner, increasing the preventive measures in wet weather, and certainly - with the appearance of the first signs of the fungus.
- Sunlight and the high temperature of the air of the phytophtor very much does not like Therefore, we recommend growing plants in areas open, blown by the wind, well lit and warmed up.
In order to reduce the risk of potato infection with phytophthora, varieties with genetic resistance to this fungus can be planted initially. Let's get acquainted with these varieties.
Resistant to late blight domestic potato variety. Клубни в данном случае получаются правильной продолговатой формы, ровные, мякоть их белая и чистая. Идеальный универсальный вариант для приготовления разных вкусных блюд.
Тоже отечественный ранний сорт, известный своим высоким иммунитетом и устойчивостью к грибковым заболеваниям.
Картофель средних сроков созревания, может похвастать длительностью хранения без какой-либо потери вкусовых и товарных качеств.
Red variety with the highest level of resistance to phytophthora. In addition, the tubers are well and long stored.
Next, we list the varieties in which the tops are highly resistant to the dangerous fungus: Russian Souvenir, Onega, Valor, Bolinsky. Varieties with phytophthora resistant tubers: Flint, Handsome, Visa, Mustang.
Important: late potato varieties have the least resistance to fungi.
We learned what a potato blight is, why the disease occurs and how to cope with it. Fungal pathology is very common, but no less dangerous for it: the phytophtora is able to destroy the entire crop at the root. You should not relax while growing potatoes: the struggle must be waged on many fronts, and certainly with fungal pathogens.
Fight against potato phytophthora - by chemical and biological means
Late blight, or brown potato rot is a very common sickle disease, affecting strawberry, buckwheat and castor oil to a lesser extent. Name - translation from 2 Greek words: "plant" "destroy." In Russia, the loss of potatoes from the disease - ≈ 4 million tons per year.
Infection of tubers can go (as often happens) from infected foliage: when it rains with water or when it comes into contact with potatoes when harvested. In rainy and warm weather, the disease spreads rapidly and can hit the whole field.
Typical symptoms of the disease
The potatoes are planted and the first beautiful green shoots have already appeared. Plants are gradually gaining strength. Shrubs become large sprawling. To be a good harvest, but one day you suddenly notice that your potato beds have changed, the bushes are no longer so attractive.
Symptoms of the disease are darkening on the parts of plants, later on the spots grow, in the tubers - the mycelium develops deep into. A secondary infection is often settled on the affected organs and completes the destruction of the crop, turning the potato into a putrefactive mass. In wet weather, a light deposit of a fruiting mycelium develops from the bottom of the leaf.
Facts from the story. Late blight caused the great famine in Ireland in 1845-1849. In just a few years, the country's population fell by a quarter ... In order to be saved, people tried to emigrate. On ships that had previously served to transport slaves, weakened by hunger and disease, people floated to America.
Mortality on ships reached 20-30% ... These well-developed vessels called this: "coffin-ships" - coffins, literally - the coffin-ship ... Songs still stand about the "Great Potato Golod", monuments stand, people remember ...
Control and prevention of the disease
In suitable weather, the disease develops very quickly, so first of all pay attention to the prevention of the disease.
Selection of resistant varieties. Absolutely stable does not exist, and yet the difference in the susceptibility of various varieties is significant.
Removal of post-harvest residues. These are the source of infection. Mowing the foliage before digging and removing it from the field helps: with infected leaves, there may well be uninfected tubers. Until they meet with diseased tops.
Maintaining crop rotation. We take into account that the pathogen, as described above, develops on other solanaceous birds (still on buckwheat, castor bean and strawberries, but less so on them), therefore planting potatoes after tomatoes or eggplant is a bad idea. Crop rotation is one of the important measures in the prevention of various plant diseases.
Early cleaning. With keeping tubers for some time in a dry place for ripening. It helps, especially in rainy, mushroom-friendly weather.
Avoid overly thickened landings. In such cases, the disease develops faster. Hilling. In addition to the usual goals, this technique also protects the tubers from infection.
Selecting a landing site. In lower areas, humidity is higher, moisture is often stagnant, which is necessary for phyto тоttor. Do not overdo the liming! Favorable disease ...
Spatial isolation. As different potato fields, and the fields of other plants of the family of solanaceous - tomato, eggplant, because phytophthora affects them as well.
Wisely we use top dressing. The introduction of nitrogen drives the tops and often increases the yield, but increases the incidence. But the introduction of potassium or micronutrients, in particular copper - on the contrary, protects the plants.
We begin the first treatments before signs of the disease appear!
This is especially important if the weather is rainy, foggy. The appearance of edible mushrooms in the forests is very approximate, but still a sign: it's time to start processing.
And spray periodically, once every two weeks or a decade. How to process potatoes from phytophthora? Any fungicides, the choice is yours - in the store, at companies or in the bazaar, a huge range, we buy and make according to the instructions.
On the other hand, what if it helps? So sprayed:
- Milk, skimmed or whey (diluted).
- Tincture of garlic.
- Trichopolum (buy at the pharmacy) tablet / liter of water.
- Iodine (buy there). However, it is usually combined, when spraying milk, 10-15 drops / liter of iodine are added.
- Tincture on superphosphate.
- A weak solution of copper sulphate.
Iodine, vitriol, superphosphate, you can also add potassium fertilizer - this is not only and not so much protection against late blight, but also foliar feeding of plants.
It is difficult to say which is better; all firms praise their own, but anyway, any drugs are thoroughly tested before they go on sale. And further. We look through and remove the diseased leaves, of course, if time and planting space permits - you cannot handle a huge field like that.
How to deal with blight on potatoes
Phytophthora is a big problem for gardeners who grow potatoes and other solanaceous crops. This fungal disease affects all parts of the plant, from flowers to fruit. Spores of this fungus develop better at elevated temperature and humidity.
Under such conditions, spores can germinate in a few hours and within a day or two infect the entire plant. At temperatures below 15 degrees Celsius and high humidity spores germinate in 1-3 days.
If it so happened that the potato was struck by phytophtora, then you need to react in time and reduce future losses.
Basic preventive methods
Disease prevention is the best way to get a good harvest. Therefore, starting from autumn, the gardener should do at least 2 - 3 main activities.
In our lands, phytophthora is not a big threat if you carefully sort out the seed, discarding diseased tubers. Severe frosts destroy most of the pathogens of phytophthora in the soil. The main thing that did not remain organic solanaceous residues on the plot (stalks, old potatoes).
It is necessary to carry out sevosmeny regularly, it is desirable that solanaceous crops are not grown in the same place for at least 2-3 years. If this is not done, then the soil should be disinfected with Bordeaux mixture, especially in the southern regions, where winters are quite warm.
Pick up early resistant or early potato varieties. Today, a lot of potato varieties resistant to phytophthora have been bred, but they have poor taste qualities.
Potatoes in our lands are affected by late blight or early August. Therefore, using early varieties, you can harvest until late blight begins to develop.
Chemical processing of potatoes
Strongly affected potato bushes are very difficult to cure, in most cases it no longer makes any sense, it is easier to simply destroy them to prevent further spread of the disease.
For the treatment of easy infection of potato with phytophtora, it is necessary to use special preparations at various vegetative stages of plant development.
At this point, you can use: Arcene (80 grams per 15 liters of water), Ridomil MC (40 grams per 15 liters), and oxyfine (30 grams per 15 liters of water). The first treatment is not necessary, because in most cases, in our area the phytophtora does not infect new potatoes.
After flowering, potatoes need to be processed 3-4 times with special preparations in the range of not more than 1 week. To do this, use drugs: ditamin M-45 (30 grams per 15 liters of water), copper oxychloride (60 g per 15 liters of water), cuproxate (40 grams per 15 liters of water).
The most effective, but rather expensive, is the prevention and treatment of late blight of potatoes with Syngenta preparations. Such measures are applied only in case of total infection of potato with late blight.
Often, plants are treated with growth promoters that increase potato resistance to phytophthora. The following drugs are best suited for this role: oxyhumate - 150 ml, ecosil - 5 ml, Epin - 3 ml, epin plus - 3 ml or ecoil VE - 5 ml per 15 liters of water.
Non chemical treatment
Many consumers do not want to eat potatoes that have been processed with a large number of chemical means of protection against pests and diseases. To develop new methods of controlling phytophthora, it is necessary to know the development cycle of this disease. Therefore, gardeners often use non-chemical (folk) methods and means of combating late blight, these include the following.
A proven tool is a daily infusion of 100 grams of finely chopped garlic in 10 liters of water. After infusing the solution, strain and spray the potatoes with it. Such treatments should be repeated every week for one month.
To combat the blight, sour-milk products are often used, which is prepared as follows: 1 liter of sour kefir is diluted in 10 liters of water.
After that, the solution is stirred and infused for several hours. Next, the solution must be drained and spray them plants. Treatment should be repeated every week until the end of the period of active development of the disease.
Bordeaux liquid is the most common and quite effective means for the prevention of fungal diseases in various plants, including potatoes.
Bordeaux liquid is prepared simply using the available elements (copper sulfate - 100 grams (dissolves in 5 liters of warm water), quicklime - 100 grams (dissolves in 5 liters of water)).
After all three solutions have cooled, they must be mixed to obtain a final solution of 10 liters. Such a mixture of potatoes is treated 2 times: at the end of July and at the beginning of August with an interval of 1-1.5 weeks.
During the active development of phytophtoras (end of July - beginning of August), the bed with potatoes before dew appears should be covered with one of the materials: agrofibre, plantex, agrin, spunbond, agrotex, lutrasil. In the morning you need to take shelter. Infection will not be if the bushes of potatoes are not wet with dew.
Before the rain, potatoes also need to be covered during this period.
Mulchuvanya soil light material to reduce the heating of the lower parts of plants. Effective is to cover the soil in the garden with potatoes with a thin layer of lime (1-2 mm).
Therefore, it is better to use simple preventive measures, so that you do not spend time and money on fighting this insidious and very tenacious disease.
Phytophthora on potatoes: how to fight?
Phytophthalosis of potatoes is one of the most common and most unpleasant diseases of the queen of the fields. Of course, the destructive effect of potato phytophthora cannot be compared with tomato's late blight when the entire crop is mown in the blink of an eye.
But if you carelessly treat the prevention and treatment of potato phytophthorae - the harvest will definitely not please you.
Symptoms and methods of infection
Late blight is a fungal disease, that is, it spreads through spores. Best of all the fungus feels during periods of prolonged wet weather. In this case, late blight can spread over fairly long distances without loss of activity, which leads to uncontrolled infection of large areas of potatoes.
At the same time, potatoes are covered with brown-gray hard spots, the pulp under which becomes reddish.
Late blight can infect potatoes in several main ways:
- When using a patient of planting material - it will serve as a focus of the fungus, which will soon spread to healthy tubers,
- When harvesting potato crops, when the tubers have contact with diseased tops,
- With the defeat of the stems and leaves of potato spores phytophthora are washed away during the rain, penetrating into the ground and hitting the tubers.
How to deal with the disease of potatoes
From the terrible disease - blight suffer many landing. Spores of the fungus are present in the soil, and can also get to the site from the outside. Phytophthora spreads very quickly, affecting all parts of the plant. How to deal with this disease on potatoes will tell you our article.
How to deal with blight on potatoes
It has long been considered: the most dangerous illness of solanaceous potatoes, including potatoes, late blight is transmitted only with planting material. In our soil, the harmful fungus does not overwinter in our conditions. However, in recent years, this truth from agricultural textbooks seems to have been questioned. Phytophthalosis of potatoes has acquired new properties and seems to have gone on the counteroffensive. Therefore, it is necessary to fight the blight all year round.
Phytophthora (Phytophthora - comes from the Greek, literally means "plant destroyer") - parasitic fungi that cause brown rot in plants. Now found their 80 species.
Late blight is a fungal disease of plants caused by blight. In Europe, phytophthora was first discovered in 1830 and in ten years covered the entire territory - from 1843 to 1847 a real epidemic broke out here (agronomists say “epiphytotics”).
In the 1840s, the late blight epidemic reached a catastrophic level in Ireland, where the population was most dependent on this staple food. The result of epiphytotics was the death from starvation of about 1 million people and emigration from Holland to more than 1 million people.
These dramatic consequences of late blight epidemics have arisen due to the lack of chemical and genetic methods to combat this disease. In our country, late blight disease is widespread. It causes the greatest harm to potato plantations in the north-western part of Russia.
Blast of blight is usually associated with rainy weather. But the disease devours potato plantings especially quickly if cool, wet nights alternate with warm wet days. With such favorable weather for him, the fungus can spread hundreds of kilometers.
And since the potato has a long growing season, it is susceptible to illness throughout the summer, the danger of epiphytotics remains always and everywhere where there are comfortable conditions for the development of the fungus.
Usually the potato gets sick in the second half of the growing season when the plants bloom. Leaves at the bottom are initially affected - there are more stomata. These natural holes penetrate the thin processes of the hyphae of the fungus. From the moment of infection of the plant to the first symptoms of the disease, it takes only 4 days.
At the beginning of mass flowering from the bottom of the lower leaves of the plant dark brown spots appear with grayish bloom. Their size is increasing rapidly. In a few days, the tops can turn into a brown rotting mass. The causative agent of the disease is a lower fungus, parasitic on a live plant, capable of developing on dead plant residues of potatoes or tomatoes.
Phytophtora mushroom parasitizes most of its life on the living tissues of potatoes - leaves, stems, tubers in the form of mycelium. From diseased seed tubers, he quickly switches to seedlings, and from them to potatoes of the new crop. Slightly depressed spots of lead color, irregular in shape appear on the peel.
Under the skin of such a spot, the tuber's tissue is first reddish in color, and then darkens. With a strong infection, the stain dilutes. In the soil, the fungus usually does not last long. But it is usually. In recent years, a more aggressive form of phytophtora, which was previously found only in Mexico, has appeared.
Now the disease can occur earlier, before the phase of budding - flowering. Its harmfulness has greatly increased.
A characteristic symptom of late blight of potatoes or tomatoes was the massive destruction of the stems. The development of the disease is observed even under conditions that were previously considered unfavorable for phytophthora. Significantly decreased resistance to fungus of zoned potato varieties.
The increase in phytophthora severity is associated with changes in the composition and properties of the pathogen itself. If earlier it wintered only in the form of mycelium on tubers, now in the affected tissue sex structures are formed - the so-called oospores. They can accumulate in the soil, becoming an additional source of infection.
Of particular danger is the fact that, in addition to potatoes and tomatoes, the causative agent of late blight parasitizes on some wild species of the nightshade family. For example, on the bitter sweetheart. Moreover, such an "intermediate host" enhances the formation of oospores, it itself serves as the accumulator of infection.
The first symptoms of the disease are manifested now at any stage of growth, plant development, starting from germination. Первые инфекционные пятна нередко обнаруживаются как на верхних и нижних листьях, так на стеблях у основания или в точке роста. Бывает, что даже молодые побеги или всходы уже оказываются полностью заражёнными. Они сразу отмирают.
Поражённая ботва с ооспорами гриба, попадая в почву, будет служить постоянным источником накопления покоящихся структур.
Они несколько лет сохраняют там свою жизнеспособность. After a dormant winter period at low temperatures, oospores in spring with high soil moisture germinate, infecting healthy potato sprouts.
In this way, primary foci of infection are created, giving rise to the development of the next phytophthora population. When tubers are planted in such soil, they also become infected with late blight. The disease can manifest itself at any stage of potato growth and development.
Manifestations of the disease
A literal translation of the name of the disease says: "I destroy plants." Phytophthora are more susceptible to the members of the nightshade family: tomatoes, potatoes, eggplants and peppers. You can see signs of fungi on strawberries, buckwheat and other crops.
"Symptoms" are familiar to most gardeners firsthand, but such information will still be useful. Manifestations of blight:
- The aboveground part of the plant becomes brown.
- The fleshy part of the leaves curls and dries out.
- Potato tubers have spots that grow deeper.
- The plant dies, the tubers are not suitable for food.
At the same time, the fungus spreads simply at an amazing speed and in a short time can destroy the entire crop. Every year losses from this scourge make from 20% of all plantings. Of course, there is no reason to put up with such injustice, because most of the threatening factors can be eliminated on their own.
Folk processing methods
Such methods are harmless to humans, but ineffective with a strong defeat. It is best to combine prevention with regular spraying than to save the crop with all sorts of chemicals. The best recipes from phytophthora for potatoes:
- Milk solution. 10 liters of water is taken liter of milk or kefir.
Approximately 100 grams of chopped mushroom brew a liter of boiling water and leave for 24 hours. Then strain the mixture and dilute with 9 liters of water.
You can powder planting wood ash. For prophylaxis, be sure to add a tablespoon of ash to each well. This simple and inexpensive tool is notable for its effectiveness against phytophthora, but it may not be enough.
Purchased funds, as a rule, are more efficient and do not require frequent use. On the other hand, it is an additional chemical load on the crop and financial investments. If the disease is firmly rooted in the area, it is necessary to take into account the peculiarities of the use of a drug, as well as to accurately follow the dosage means.
Overview of special drugs for late blight potato:
- Copper sulfate. For 10 liters of water you need to take 200 grams of the substance.
- Bordeaux fluid. Improved analogue of the previous mixture.
To do this, separately mixed by a teaspoon of copper sulfate, potassium permanganate and boric acid. The resulting solutions are connected, the output of the mixture is 10 liters.
The number of sprays should not exceed three times. Can be used for other crops.
When buying a suitable product, it should be borne in mind that a certain amount of time must pass before harvesting. Processed potatoes, as a rule, are not suitable for food for some time, so with such processing it is important to observe the dosage and instructions for use.
Disease resistant potato varieties
An important factor influencing the degree of damage to potatoes is its variety. It has long been noticed that even the most productive potatoes degenerate with time and become small and few. The same rule can be applied to late blight.
If earlier the variety was distinguished by enviable resistance, then with further cultivation it can be noted that the insidious disease affects the plant more and more. This can be prevented if the varieties are regularly changed, giving preference to those resistant to the fungus. Suitable varieties resistant to phytophthora potatoes:
- Potato variety Nevsky.
- Red Scarlett.
- Lapis lazuli.
They are subject to potatoes, tomatoes, peppers and eggplants, as well as to a minor extent other cultures. To determine the best way to protect against such a disease, you need to know the enemy by sight, and also adhere to conditions that are comfortable for the plant to grow.
Source: "gidfermer.com, ogorod23.ru"
Phytophthora on potatoes: ways to combat the disease
In the years 1845-1849, a terrible disaster occurred in Ireland. All potato fields were affected by tuber rot disease. This event went down in history as the Great Potato Hunger, which killed more than a million people. And the disease that provoked this tragedy is nothing but blight.
The article will tell you how to deal with late blight on potatoes, what drugs and traditional methods to use. Late blight is a widespread and extremely dangerous disease of all plants of the Pancake family. Its pathogen is Phytophthora infestans.
A native of Phytophthora from South America, from where the plants on which it is parasitized were introduced. In the life cycle of this fungus, there are two stages: sex and asexual. Its reproduction and development occurs as follows:
- On the hyphae of the phytophtora, sporangia are formed with flagellated mobile zoospores.
- Zoospores move with drops of water and fall on the leaves and stems of potatoes.
- Dropping flagella, zoospores germinate in plant tissue and form a new mycelium. If the spores are washed away from the leaves by rain and fall into the soil, the potato tuber will also become sick.
Migrates of phytophthora in two ways: by spreading zoospores with the wind and water droplets (fog, rain) and on planting tubers of potatoes.
An important condition for plant infection is moisture on vegetative organs, which lasts at least 4-5 hours. The aggressiveness of the Phytophthora infestans species is so great that from one infected potato bush the fungus can spread to the whole field in just two weeks.
Symptoms and errors contributing to the development of the disease
Infection spreads through the bush from the bottom up. First, lower leaves are affected. Watery spots appear on them, which quickly grow, become brown. On the lower side of the leaf plate a whitish plaque develops — the sporangia of the fungus. On the stems of late blight has the appearance of dark spots.
Late blight appears as depressed black-gray spots on the surface. Penetrating deeper, the fungus leaves brown marks. Secondary bacterial infections are often associated with late blight, causing rapid decomposition of tubers.
Often, gardeners themselves unwittingly become culprits of late blight epiphytotics, not only in their own, but also in nearby areas. This happens when you make 3 mistakes.
- Error number 1. Non-compliance with the rules of crop rotation.
If at the cultivation of other crops, at least, they are rotated, the potato plot in the average Russian vegetable garden has been located in one place for many years.
Error number 2. Location of potato plots in the lowlands.
It is believed that planting potatoes on high ridges allows this crop to be cultivated on moist heavy soils. However, this method helps to protect the tubers from getting wet, but not from phytophthora.
Error number 3. Thoughtless liming of the soil.
Many gardeners pour lime into the soil from the heart and anywhere. A phytophthora this component is vital. In the laboratory, it multiplies only in the presence of lime.
Chemical control methods
Chemical processing of potatoes from phytophthora should be carried out meaningfully. This fungus is plastic and quickly develops resistance to poisons. The widespread use of fungicides has led to the emergence within the populations of strains that are resistant to many drugs.
Therefore, one purchased money will not be enough. It is necessary to approach the protection of potatoes against late blight systemically.
- Agat-25K. Biofungicide based on the metabolites of the bacterium Pseudomonas aureofaciens.
When used, resistance to fungi is not formed. Used for preplant treatment of tubers and spraying in all phases of the growing season.
Ridomil Gold MC. Combined chemical fungicide that combines two active ingredients - mefenoxam and mancozeb.
Having spent 3-4 preventive spraying for a season, it is possible to exclude the infection with late blight completely. For the treatment of already infected plants is not used.
Using biological preparations for processing potatoes, they should not be combined with copper-containing fungicides, such as "Abig-Peak" or Bordeaux mixture. Copper neutralizes the activity of beneficial bacteria.
Grandfathers fight methods
Validated folk remedies can supplement and enhance the effect of chemical and biological preparations:
- Garlic infusion. For 10 liters of water, take 100 g of crushed garlic cloves. Insist for 24 hours and sprinkle potatoes once a week throughout the season.
- Kefir. In 10 liters of water dilute 1 liter of old kefir. Spray the planting 1 time per week. Fermented milk bacteria create an acidic environment unsuitable for phytophthora on potato tops.
- Iodine-milk solution. In 10 liters of water dilute 1 liter of milk and 20 drops of iodine. Sprinkle potatoes 1 time in 2 weeks.
- Copper + boron + manganese. For 10 liters of water, take 1 teaspoon of copper sulfate, potassium permanganate and boric acid.
It is better to use caution when using the recommendations Metronidazole (Trichopol) to use against phytophthora. This drug is active against anaerobic bacteria. A phytophthora is not a bacterium.
Agrotechnical methods against late blight of potatoes
To combat the blight is important proper agricultural technology. The main techniques to help avoid infection of potatoes are as follows:
- Sparse landing
- Potash supplements,
- Utilization tops,
- Disinfection of landing holes.
The last intake, along with pre-sowing treatment of tubers, minimizes the risk of introducing phytophthora from the outside, with planting material. To treat the holes in them make the following funds:
Tablets that heal the soil through the growth of soil fungus Trihoderma harzianum. Effective in the fight against many mycoses, as well as white and gray rot. In each well when planting enough to put 1 pill.
Microbiological preparation containing strains of beneficial microflora, destructive for phytophthora. The soil is spilled with a solution for 2-3 weeks before planting potatoes.
Bacteriological preparation in the form of powder or tablets, containing the bacterium Bacillus subtilis, killing phytophthora and many other parasitic fungi. Diluted means watering the soil for 3-4 days before planting potatoes.
Phytophthora on potatoes - what is it?
Late blight is a fairly dangerous disease for plants of the genus Solanaceae.
The cause of this disease is a fungus from the category Oomycetes.
Segregating phytospores, this fungus spreads through capillaries in the soil and infects the stems and tubers of the plant.
Within a maximum of two weeks, the fungus progresses rapidly and, as a result, can kill large quantities of the crop.
Ways to combat late blight and prevention
It is much easier to describe the prevention of the disease than the methods of control, as there are quite a few of the latter.
As for prevention, everything is simple.
Here are some tips:
- Do not plant potatoes in groups.
- The soil for sowing should be well-groomed and healthy.
- Try to avoid lowlands and plant potatoes on flat areas - high humidity in the lowlands is favorable for the spread of the disease.
- In addition, the lighting should be good, shadow areas should be avoided. This also applies to the airing area.
- Take care of good drainage.
- In the autumn process the soil.
- The place where you plan to plant potatoes, preferably, should be after a perennial plant. Such as beets, corn or flax.
- Tomatoes, peppers and eggplants should be planted away from the potatoes, but radish or mustard - closer.
Experienced gardeners and gardeners also advise before planting to select healthy tubers, heat them at a temperature of 15 to 18 ° C for two weeks, in the open air.
Then inspect them for infection. If any spots appear, it is better not to use such tubers.
In addition, it is also advised not to use varieties such as Verb, Tomic, Sante, Rosara and Arina. They are less resistant to the disease. A variety of Nevsky, Spring, Red Scarlet and Luck - the most stable.
But even they do not guarantee that your crop is protected from this dangerous disease.
How to treat phytophthora on potatoes?
As for directly dealing with the disease, there are quite a few ways.
First, the primary processing of tubers. Having processed them with potassium-phosphorus composition, you will increase resistance to the disease. Use industrial doses of the solution. Planting tubers to do a deep and good spud. Watering should be done with a hose, it is advisable not to use the "drop". Finding the affected plant - immediately remove it from the site.
If, nevertheless, it was not possible to protect plants from late blight, they are treated with chemical means. But even this will not cure the plant.
To do this, it is necessary to carry out chemical treatment at the stage when the plant reaches about 30 cm in height.
To do this, use the tool "Ridomila".
After that, re-spraying is done at the stage preceding flowering. In this case, use another tool. Experts advise Epin.
In addition, infected plants are sprayed with an agent called Oxy. But this is only if only certain plants are susceptible to infection. Spraying results should be observed 2 weeks after spraying.
If the risk of infection remains - you should apply more stringent measures in the form of strong drugs. These include: "Ditan", "Efal", "Revus".
The period after flowering should also occur with spraying.
To do this, every 10 days, apply the tool "Bravo".
Folk ways of dealing with late blight
Among the means of controlling late blight, there are also folk methods.
After all, not everyone wants to process their crops with harmful chemicals.
Such remedies include various infusions, such as garlic or horsetail.
Also use soap and ash, tablets of Trihopol, a mixture of milk, iodine and water, as well as urea and compost, diluted in water.
The proportions of these solutions are fairly easy to find. But it is better to explore different points of view, since they are very different from each other. Use your experience in determining the right option.
With the information received, you can save your crops from death and experience pride and satisfaction, having a healthy and abundant harvest.
And the household will remain only grateful to you for a delicious, healthy, and most importantly - homemade food.
Hopefully, phytophthora will bypass your potatoes!
What to do?
Phytophthora is a fungal plant disease. The causative agent is a fungus. The main symptom of phytophtora is blackening, dark spots, and rot on leaves and stems. Spores of fungus from the leaves can fall into the ground, infecting potato tubers. Instances close to the surface of the earth are damaged during growth.
What experts recommend doing:
- To begin with the prevention - to make phosphate-potassium fertilizers. Ash is perfect for this.
- Spud potatoes several times per season. A thick layer of earth will prevent the spread of fungus.
- About 10 days before digging the crop, cut the tops to prevent the fungus spores from reaching the fruit.
- Do not hesitate with the harvest, clean the potatoes in dry weather.
- Grow resistant varieties and plant only healthy tubers.
- Plant tomatoes, eggplants, peppers and potatoes at different ends of the plot. All nightshade susceptible to phytophthora infection. And if the fungus struck the tomatoes, it will immediately spread to the potatoes and so on.
- Treat potatoes with modern chemical preparations from phytophtoras.
- Treat potatoes with folk remedies.
What to process?
Authors of videos on Youtube advise for processing potatoes from phytophthora chemical preparations “Ridomil Gold”, “Skor”, “Sherlan”.
When to process? The first time you can process the potatoes with the drug "Ridomil Gold" - at the time of formation of leaves, before flowering, during the active growth of the foliage. The second time - in 2 weeks. This is followed by treatment with another drug (with another active ingredient), for example, “Skor”.
Also two treatments with an interval of 2 weeks. Грибковые заболевания имеют свойство привыкать к одному и тому же фунгициду. Обработку лучше проводить в сухую погоду.
В период между обработками эти препараты обеспечивают длительную защиту растениям: уже инфицированным листьям и новому приросту. Therefore, we can conclude that these drugs can be used in the event that the late blight on potatoes has already appeared.
Chemical preparation "Sherlan" kills spores of phytophthora. It acts almost like a disinfectant. Provides protection at many stages of fungus development. Rain-resistant and absorbed by the leaves within 1 hour after treatment.
Some authors recommend Bordeaux liquid for potatoes: bluestone + lime (kits are sold in gardening stores.
After flowering, it is permissible to process potatoes 3-4 times at intervals of 7 days with special preparations: Ditamin M-45 (30 grams per 15 liters of water), copper chloroxide (60 g per 15 liters of water), cuproxate (40 grams per 15 liters of water) .
We advise you to study information about this in more detail in other sources.
To fight the blight, when the tubers have already grown, is meaningless. The last treatment with chemical preparations is allowed no later than 20 days before harvesting.
It is better to take the disease under control at the very beginning of the season. It should be remembered that prevention is better than cure.
It was possible to find a few sensible folk remedies, with the help of which we could successfully fight the blight on potatoes. Basically, folk remedies are used on the phytophthora on tomatoes. But one source finally got a solution recipe. According to the author, quite effective:
After each of the three solutions are individually cooled, they are combined. It turns out a solution of 10 liters. They are treated with potatoes twice: at the end of July and at the beginning of August with an interval of 1-1.5 weeks.
Specifically, we are not fighting with blast on the potato. Even in the wettest summer, it did not pose a danger to our harvest. The only measure is to mow and harvest the tops 3 days before digging up potatoes. It happened that a potato that had had late blight in the summer was kept poorly. Then all the tubers in the basement were sorted out, discarding the sick.
How to deal with blight on potatoes
Late blight (Phytophthora) is a fungal disease affecting plants, shrubs and trees. Seeing the symptoms at an early stage and treating a progressive infection is not easy. The effects of lesions on potatoes can be seen in the photo.
Symptoms of infection and factors phytophthora provocateurs:
- Brown bloom on the lower leaves of the plant.
- Dark swept away on the stems.
- The underside of the leaves with a whitish bloom.
- Gray-black spots on tubers.
The disease begins with the aerial parts, inevitably turning into roots. Fruits are covered with rotten foci. The situation is aggravated by a favorable climate - warm, wet weather.
In such conditions, a secondary bacterial infection develops, massively affecting the entire landing.
Pathogen spores are carried by precipitation, wind. Mycelium of the fungus remains in tubers, which germinate safely in spring. Often, the gardeners themselves create “paradise” for late blight, with the following actions:
- Planting potatoes for more than two years in a row. If there is no possibility to change the area, then use the green manure plants. For example, green peas. By early May, the green manure is plowed into the soil and planted early potatoes. In August, after harvesting, the field is sown with mustard or oilseed radish. Before the frosts, the field is plowed again. The site can be divided for varieties of different maturity dates, so the earth can be continuously healed by ground cover plants. Since autumn, the field is sown with winter oats and rye.
- In the spring they are plowed under medium early varieties. After harvesting the mid-late potato, the field is given under the cress. For winter, the salad is plowed into the ground.
- Excessively introducing lime. Substance promotes active reproduction of the fungus. To reduce the acidity, it is better to use deoxidizing sideratami: mustard, oats, rye, lupine, phacelia.
- Placing a bed in lowlands and on heavy soils. Even high furrows will not protect potatoes from phytophtoras in places with constant stagnation of moisture.
Chemistry against Phytophthora
The parasite is capable of producing drug resistance. In the population of the fungus there are strains that do not respond to modern potent drugs. Usually fungicides alternate.
- Agat-25 K. Used for processing planting material. Strengthens the natural immunity of the plant, stimulates growth. Biological product.
- Fitosporin M. Not able to cause addiction. Suitable for pre-treatment and spraying of plants at any time of development. Microbiological preparation (fungicide).
- Reedomill Gold MC. The basis of the drug: mefenoxam and mancozeb. Used only for the prevention of disease. 3-4 seasons are enough for a season.
- Thanos. In the basis - the action of the active substances of famoxadone and cymoxanil. Kills spores of the fungus within 2 sec. High resistance to precipitation.
- Maxim 25 FS. For processing planting material. Used in combination with other drugs.
Preparations for entering into the soil:
- Glyocladin. It is displayed in landing holes (1 tablet). Prevents the development of mycosis, rot.
- Baikal Um. Contains a useful microflora that kills phytophthora mycelium and other types of pathogenic fungi. The soil is spilled with a solution for a couple of weeks before planting the crop.
- Apirin B. The bacterium Bacillus subtilis kills phytophtora and other fungi.
- Chloroxide copper. The solution is normally poured into the wells.
- Colloidal sulfur. The solution is also effective in the fight against spider mites (2 tbsp. Per 10 liters of water).
Folk methods of combating phytophorosis
Any chemical substances can accumulate in plant tissues. To get ecological products from your garden, there are many ways without aggressive drugs.
- Garlic infusion. Any part of garlic crushed on a food processor is poured over 1 tbsp. water. Insist day. Dilute to 10 liters of water and add 1 g of manganese. The solution sprinkled plants 1 time in two weeks.
- Infusion horsetail. The grinded parts of the plant are filled with water and kept for several days.
- Ash mulching. Ash is used at any stage of growth. Strengthen its action chips households. soap. The mixture is diluted with water and sprayed potatoes.
- Watering with whey. Instead of whey fit sour kefir.
- Iodized milky solution. On a bucket of water 1 l of milk + 15 drops of iodine. Spray the plants once every two weeks.
- Trichopol tablets. A solution in 10 liters of water 10 tab. drug. Spray 1 time in a couple of weeks.
- Compost and urea solution. 1 kg of compost + 2 tbsp. l urea is diluted in a 10 liter bucket of water. Insist week. Spray 1 time in 2 weeks.
- If the planting is not large, cover potato ridges with materials such as a spunbond. Shelter make the evening, in the morning after the dew is removed. Events begin to hold from the end of July.
Do not underestimate late blight. The fungus can cause large-scale infections. He suffers from not only potatoes, but also other nightshade, as well as pepper, eggplant, buckwheat, strawberries, cucumbers, onions.
Carefully sort and seed the seeds, inspect the plants for the first signs of illness, acquire resistant varieties, take urgent action.
How to destroy the disease of potatoes
How nice it is to come to your beloved cottage to see all the planted plants in "good health" - they grow and develop well, they have no shortage of lighting and nutrition, and at the end of the season you expect to get a good harvest of vegetables from your vegetable garden, including tasty, crumbly potatoes.
One of them - late blight of potatoes - almost the most common and dangerous fungal infection of this culture. The causative agent of late blight of potatoes - oomycetes (mycelial organisms) Phytophthora infestans, of the genus Phytophthora.
How to recognize this disease in its early stages?
On some lower leaves at their edges dark-brown spots appear that have borders with a still healthy part of the leaf in the form of lighter-colored patches. On the underside of the leaves in this place is clearly visible shaggy white bloom - spores of the fungus.
Within a few days of planting potatoes, they can be completely affected - the leaves turn brown, twist, dry up, only dark sticking stalks remain. The infected tubers are covered with dark brown hard spots, the rot spreads deep into the tubers, neighboring tubers become infected.
The risk of occurrence of this disease is especially high in wet weather (air humidity is more than 75% for two or more days, dew, fogs), as well as with significant day and night temperature differences — in such weather conditions preventive measures against late blight should be taken.
In order to strengthen the protective forces of plants, timely fertilizing with complex fertilizers, as well as “green” fertilizers (nettle infusion, decoction of horsetail) are needed.
Hilling is not only one of the methods of care, but also a preventive measure of protection against blight. Especially, when the landing in the ranks will soon begin to close - you need to spend a high hilling.
This will help prevent plant contamination, as the disease begins at the edges of the leaf plates that are densely in contact with each other - in combination with excess moisture, a favorable microclimate is created for the development of fungal infections.
Spraying before flowering with a weak solution of copper sulphate (for 10 liters of water - 2 grams of dry matter), as well as with any systemic fungicide (arceride, oxy, ridomil MC) according to the instructions on the package. As a preventive measure, one treatment will suffice, but if symptoms of the disease have already been identified, then repeat 3-4 times per season.
Fight against late blight
Damaged leaves must be torn off and destroyed (burned). Once every 7-10 days, spray chemical preparations - Ditan M-45, cuproxate, copper oxychloride - according to the instructions, alternating these preparations, using each of them no more than 2 times.
The best way to prevent this disease is to plant healthy material. Tubers need to be carefully rejected at the time of harvest, not to discard damaged, but to burn. The harvested harvest is well dried and again to sort before laying in storage.
It is important to choose the right places for planting - sunny, well-ventilated plantations that change every 1-2 years. To have beds with early potatoes at a sufficient distance from late varieties and other solanaceous crops, in order to avoid infection from each other.