Downy mildew the other day. Downy mildew: prevention and treatment of the disease. Measures to combat downy mildew

Downy mildew is akin to an epidemic: it can easily leave us without a harvest of cucumbers, zucchini, and pumpkins. In the garden beds, you need to start fighting this disease in the fall. What measures need to be taken to prevent it from returning again in the spring?

Downy mildew, or downy mildew, affects the pumpkin family: cucumber, melon, squash, zucchini, pumpkin, watermelon. The first symptoms appear already in the 5-7 leaf phase, and from mid-summer the disease can become an epidemic. The disease develops on the surface of a moistened leaf; 5-10 days after infection, yellowish spots appear, limited by veins. With sharp fluctuations in day and night temperatures, combined with rain or heavy dew, the spots become numerous and merge. A grayish-purple coating consisting of spores forms on the underside of the leaf - they spread the disease throughout the area. Later the leaf turns brown and dies.

During rainy seasons, 10-15 generations of summer zoospores (biflagellate cells living in water) can develop. They die within a few hours if they fail to penetrate the leaf tissue. Therefore, the absence of water drops on the leaf is the best prevention of the disease.

The downy mildew pathogen overwinters in the form of oospores - this is a dormant stage with a thick shell. They form inside the affected tissues at the end of the season and remain in the soil or plant debris, remaining viable for several years. Reducing the number of oospores in the soil is the main task of the gardener in the fall.

What to do in the fall

At the end of the season, after harvesting, the plants should be sprayed with contact preparations against peronospora. After 3-5 days, collect plant residues and burn them. Do not dig up the earth! If you place another crop in such a bed the next year, the likelihood of cucumbers being infected will sharply decrease.

Disease prevention

Choose resistant varieties and hybrids.
Ventilate greenhouses well.
For prevention, spray cucumber plantings with systemic preparations.
Maintain optimal growing conditions in greenhouses.
It is advisable to use drip irrigation or avoid evening watering - the leaves of the plants should not become covered with dew and become wet during the watering process.

One of the most common diseases is considered peronosporosis, or downy mildew– a fungal disease caused by the lower fungus Peronospora. The causative agent of the disease can persist in plant debris, seeds and become active in humid conditions - during rains or simply in damp weather.

Listen to the article

Downy mildew - description

In plants affected by peronosporosis, yellowish-green oily spots of angular or round shape, limited by veins, appear on the upper side of the leaves. Then a barely noticeable gray-violet coating forms on the underside of the leaves. The spots gradually enlarge, merge, and as a result the leaves droop, wrinkle and dry, crumbling into fragments that can infect neighboring plants. Due to the death of leaves, the process of fruit set and their development slows down - the fruits become pale and tasteless. With severe damage, the disease downy mildew can destroy the plant in a very short period of time.

Downy mildew affects all groups of cultivated plants - vegetables, garden and indoor flowers, fruit trees and shrubs. During one growing season, the pathogen forms up to 20 generations and sprays millions of zoospores. The spread of downy mildew is facilitated by insect pests - whiteflies, aphids and others.

Measures to combat downy mildew

Treatment of peronosporosis

Treatment of peronosporosis is carried out with a sulfur solution - 50-80 g of the substance is dissolved in 10 liters of water and both the plants and the soil under them are treated with this composition. Downy mildew is also treated with fungicides Fitosporin-M, Gamair, Planriz, Alirin-B or Glyokladin, treating the garden or vegetable garden with their solutions at intervals of two weeks. A month before harvest, it is advisable to stop treating with fungicides and switch to folk remedies for downy mildew.

However, the fight against peronosporosis is not only about treating plants with medicinal preparations. You can save your plot from infection by observing agrotechnical conditions for growing plants and taking preventive measures against diseases and pests.

Downy mildew - prevention

Plant protection from peronosporosis begins with preventive measures. You can significantly reduce the risk of your plants being affected by fungal diseases if you clear the area of plant debris in the fall and dig the soil to a depth of 25-30 cm. If during the past growing season you had to get rid of harmful microorganisms, treat the soil in the area with a one percent solution in the spring potassium permanganate or a two to three percent solution of copper sulfate, then be sure to dig up the soil. You can also disinfect the soil with biological preparations Fitosporin-M, Gamair or Alirin-B.

For preventive treatment against peronosporosis of plants in early spring, before buds open, use a seven percent solution of urea, a ten percent solution of ammonium nitrate or a fifteen percent solution of ammonium sulfate. In the green cone phase, trees are treated with a one percent solution of Bordeaux mixture, then spraying with this preparation is repeated after flowering and in the ovary formation phase. Also, after flowering, biological products Integral, Gaupsin, Mikosan, Gamair, Fitosporin-M or Planriz are used to spray plants - a drug against peronosporosis, which can be used to treat plants even a day before harvesting the fruits.

To reduce the risk of plant diseases, it is very important to observe crop rotation on the site, returning crops to their original places no earlier than after 3-5 years. If you grow a crop in one place from year to year, this will lead to the accumulation of infection in the soil and, as a consequence, to weakening and disease of the plants.

Treat the seeds before sowing - keep them for a quarter of an hour in a thermos with water at a temperature of 45-50 ºC or in a one percent solution of potassium permanganate. Before planting in open or protected ground, immerse the roots of seedlings in a Trichodermin solution prepared according to the manufacturer’s instructions for 2-3 hours. Grow fungal disease-resistant varieties and hybrids. Do not compact the plantings, but thin out the crown of trees and shrubs in a timely manner - fungi thrive in cramped spaces. Follow all agrotechnical requirements and carry out plant care activities on time. Immediately remove and burn severely affected specimens.

Downy mildew on vegetables

Downy mildew of cucumbers

Most often, downy mildew disease appears on cucumbers in August - just at this time the night temperature begins to drop, and condensation forms on cucumbers, which is an ideal environment for the proliferation of downy mildew spores. Downy mildew on cucumbers can occur due to a lack of potassium, phosphorus or excess nitrogen in the soil. Downy mildew on cucumbers develops especially quickly in a greenhouse, where there is a favorable environment for the formation of dew. What are the measures to combat downy mildew on cucumbers? When you detect the first signs of the disease, treat the plants in the greenhouse with a solution of fungicides Ridomil Gold, Efal, or copper oxychloride. In open ground, it is better to spray cucumbers with Strobi, Quadris or Acrobat MC.

However, remember that if you are a couple of days late, you may not have time to save the plants from death, so at the beginning of the growing season, draw up a preventive action plan and follow it strictly. If you take preventive measures, your cucumbers will be protected not only from downy mildew, but also from most fungal diseases. To protect cucumbers from downy mildew you need:

grow cucumbers resistant to downy mildew - for example, varieties Katyusha, Kumir, Photon, Zodiac, Rodnichok, Debut or Golubchik;
carry out pre-planting heat treatment of seeds for 15 minutes in water at a temperature of 50 ºC;
prepare the soil for planting - treat the soil with Fitosporin-M or Gamair and then carry out deep digging;
In the greenhouse it is necessary to regulate air humidity. As soon as spots begin to appear, the affected leaves should be removed immediately, leaving no petioles;
increase plant resistance to pathogens by applying potassium-phosphorus fertilizers. Do not oversaturate the soil with nitrogen;
treat cucumbers on the green leaf with a solution of the biological product Planriz, made on the basis of an extract from herbs.

Downy mildew on onion

At the first signs of the disease, you should immediately exclude organic and nitrogen fertilizers on onions, continuing to add only phosphorus-potassium fertilizers to the soil. It is also necessary to stop watering the area for a while to reduce the humidity level. How to deal with downy mildew on onions? For this purpose, the beds are treated with a one percent solution of Bordeaux mixture, a suspension of Arbamide or Polycarbacin. To prepare a suspension, add 30-40 g of Polycarbacin or Arbamide to 10 liters of water. After a week or two, the treatment for peronosporosis is repeated. Spraying with Bordeaux mixture should be stopped 3 weeks before harvest.

If you treat onions with chemicals, you should not eat their greens.

Downy mildew on sunflower

Sunflower affected by downy mildew begins to lag in growth, its stems do not thicken, the root system remains undeveloped, chlorotic spots form on the upper side of the leaves, and a whitish coating on the lower side. Few of the affected plants reach the flowering stage and form reduced inflorescences with small, non-developing seeds. In total, there are six forms of damage to this crop by downy mildew.

You can save sunflowers from peronosporosis by treating the plant with Pictor, Ridomil Gold, Abacus, Amistar Extra and others. In the case of sunflower, to protect against peronosporosis, it is very important to adhere to cultural practices and crop rotation.

Fighting downy mildew on shrubs

Downy mildew on grapes

Downy mildew on grapes is called mildew. This is the most dangerous disease of European crop varieties, introduced to the south of France from North America in 1878. If this disease is not controlled, it can cause serious damage to the vineyard. Downy mildew, or mildew, affects leaves, shoot tips, inflorescences, tendrils, ridges and young grape berries.

It is necessary to begin treating grapes against mildew even before the first symptoms of the disease appear, that is, it is necessary to carry out preventive treatment of the plant with Acrobat TOP, Cabrio TOP, Delan and Polyram. Treatments are carried out before flowering, and then during heavy and frequent dew, rain and high air humidity once a week, and in dry weather once every two to three weeks. During the season, from two to eight sprayings are carried out.

Downy mildew on flowers (garden)

Downy mildew on roses

The defeat of rose bushes by downy mildew, in contrast to powdery mildew, which first affects the leaves of plants located in close proximity to the ground, begins from the top of the bush. This happens at a time when the rose buds are still the size of a pea, and the development of the disease is rapid: yesterday everything was fine, but today everything has become terrible - the leaves from the roses are falling off, the flowering wave is disrupted. Downy mildew manifests itself on a rose as brown spots on the leaves, and if a yellow border forms around them, the leaves fall off the bush instantly.

And yet, this is not a fatal disease. If your roses are growing in a greenhouse, the first step is to turn on the heating at night to reduce the humidity. This cannot be done in open ground, but you can treat the bushes with Ordan, Thanos, Ridomil, Previkur, Acrobat, Consento or Revus.

Downy mildew on houseplants

Indoor plants can also suffer from downy mildew - yellow spots of irregular shape appear on the upper side of their leaves, which darken and become necrotic as the disease progresses. A gray coating forms on the underside of the leaves, gradually turning black. The leaves turn yellow and die. The disease progresses in acidic and heavy substrates, and the situation is aggravated by poor ventilation and crowded conditions on window sills or shelving.

Measures to combat downy mildew on indoor plants are the same as on garden plants:

hydrothermal treatment of seeds before sowing (holding the seed for 15 minutes in water at a temperature of 50 ºC);
removing affected leaves from the plant;
carrying out five flower treatment sessions at weekly intervals with one percent Bordeaux mixture or fungicides Oksikhom, Kuproksat, Ordan, Bravo or Quadris.

Remedies for downy mildew (preparations)

Remedies for downy mildew can be chemical or folk. The most popular chemical preparations for peronosporosis are:

Acrobat MC– a fungicide of systemic-local and contact action that is dangerous to human health;
Alirin-B– a biological preparation for suppressing fungal diseases on plants and in soil, similar in its effect to Fitosporin-M;
Bordeaux mixture– a broad-spectrum contact fungicide hazardous to human health;
Gamair– a biological bactericide that suppresses fungal and bacterial diseases in the soil and on plants;
Glyocladin– a biological fungicide that suppresses pathogens of fungal diseases. Trichodermin analogue;
Oksikhom– systemic contact fungicide with a wide spectrum of action, dangerous to human health;
Polycarbacin– systemic fungicide with protective and therapeutic action for fruit and vegetable crops;
Bravo– protective contact fungicide with a duration of action of 10-14 days;
Previkur– a systemic fungicide with a wide spectrum of activity against root rot and downy mildew;
Ordan– contact-systemic fungicide, moderately hazardous to human health;
Ridomil Gold– a fungicide of contact-systemic action, dangerous to human health;
Trichodermin– biological fungicide for the treatment and prevention of root diseases of ornamental and indoor plants;
Fitosporin-M– microbiological contact action fungicide to protect plants from fungal diseases;
Quadris– a fungicide with systemic therapeutic and preventive action, which has the unique property of prolonging the fruiting of crops by 2-3 weeks;
Revus TOP– a fungicide that protects and cures plants from fungal diseases.

Folk remedies for combating downy mildew

When the fruits on the trees, berries and vegetables begin to ripen, treatment with chemicals that are toxic to humans should be stopped and the plants should be sprayed with folk remedies to combat downy mildew.

What time-tested means can be used to destroy downy mildew?

You can pour one liter of skim milk into 9 liters of water, add 10 drops of five percent iodine to the solution and spray the plants with this mixture.

Two glasses of wood ash need to be brewed with two to three liters of boiling water, then strain the liquid through a napkin folded 3-4 times and pour into a bucket of water.

A solution of 1-2 g of potassium permanganate (potassium permanganate) in 10 liters of water is effective against peronospora on plants. Rating 4.47 (17 votes)

Back
Forward

After this article they usually read

Seed propagation in the garden strawberries we are used to, unfortunately, leads to the appearance of less productive plants and weaker bushes. But another type of these sweet berries, alpine strawberries, can be successfully grown from seeds. Let's learn about the main advantages and disadvantages of this crop, consider the main varieties and features of agricultural technology. The information presented in this article will help you decide whether it is worth allocating a place for it in the berry garden.

Often, when we see a beautiful flower, we instinctively bend down to smell its fragrance. All fragrant flowers can be divided into two large groups: nocturnal (pollinated by moths) and daytime, whose pollinators are mainly bees. Both groups of plants are important for the florist and designer, because we often walk around the garden during the day and relax in our favorite corners when evening comes. We are never overwhelmed by the scent of our favorite fragrant flowers.

Many gardeners consider pumpkin to be the queen of garden beds. And not only because of its size, variety of shapes and colors, but also for its excellent taste, healthy qualities and rich harvest. Pumpkin contains a large amount of carotene, iron, various vitamins and minerals. Thanks to the possibility of long-term storage, this vegetable supports our health all year round. If you decide to plant a pumpkin on your plot, you will be interested in learning how to get the largest possible harvest.

Scotch eggs - incredibly delicious! Try to prepare this dish at home, there is nothing difficult in preparation. Scotch eggs are a hard-boiled egg wrapped in minced meat, breaded in flour, egg and breadcrumbs and deep-fried. For frying, you will need a frying pan with a high side, and if you have a deep fryer, then that’s just great - even less hassle. You will also need oil for frying so as not to smoke in the kitchen. Choose farm eggs for this recipe.

One of the most amazing large-flowered tubs of Dominican Cubanola fully justifies its status as a tropical miracle. Warm-loving, slow-growing, with huge and in many ways unique bells of flowers, Cubanola is a fragrant star with a complex character. It requires special conditions in the rooms. But for those who are looking for exclusive plants for their interior, a better (and more chocolatey) candidate for the role of indoor giant cannot be found.

Chickpea curry with meat is a hearty hot dish for lunch or dinner, inspired by Indian cuisine. This curry is quick to prepare but requires some prep. The chickpeas must first be soaked in plenty of cold water for several hours, preferably overnight; the water can be changed several times. It is also better to leave the meat in the marinade overnight so that it turns out juicy and tender. Then you should boil the chickpeas until tender and then prepare the curry according to the recipe.

Rhubarb cannot be found in every garden plot. It's a pity. This plant is a storehouse of vitamins and can be widely used in cooking. What is not prepared from rhubarb: soups and cabbage soup, salads, delicious jam, kvass, compotes and juices, candied fruits and marmalade, and even wine. But that's not all! The large green or red rosette of leaves of the plant, reminiscent of burdock, acts as a beautiful background for annuals. It is not surprising that rhubarb can also be seen in flower beds.

Today, the trend is to experiment with unusual combinations and non-standard colors in the garden. For example, plants with black inflorescences have become very fashionable. All black flowers are original and specific, and it is important for them to be able to select suitable partners and location. Therefore, this article will not only introduce you to an assortment of plants with slate-black inflorescences, but will also teach you the intricacies of using such mystical plants in garden design.

3 delicious sandwiches - a cucumber sandwich, a chicken sandwich, a cabbage and meat sandwich - a great idea for a quick snack or for an outdoor picnic. Just fresh vegetables, juicy chicken and cream cheese and a little seasoning. There are no onions in these sandwiches; if you wish, you can add onions marinated in balsamic vinegar to any of the sandwiches; this will not spoil the taste. Having quickly prepared snacks, all that remains is to pack a picnic basket and head to the nearest green lawn.

Depending on the varietal group, the age of seedlings suitable for planting in open ground is: for early tomatoes - 45-50 days, average ripening periods - 55-60 and late ones - at least 70 days. When planting tomato seedlings at a younger age, the period of its adaptation to new conditions is significantly extended. But success in obtaining a high-quality tomato harvest also depends on carefully following the basic rules for planting seedlings in open ground.

Unpretentious “background” plants of sansevieria do not seem boring to those who value minimalism. They are better suited than other indoor decorative foliage stars for collections that require minimal care. Stable decorativeness and extreme hardiness in only one species of sansevieria are also combined with compactness and very rapid growth - rosette sansevieria Hana. The squat rosettes of their tough leaves create striking clusters and patterns.

One of the brightest months of the garden calendar pleasantly surprises with the balanced distribution of favorable and unfavorable days for working with plants according to the lunar calendar. Vegetable gardening in June can be done throughout the entire month, while the unfavorable periods are very short and still allow you to do useful work. There will be optimal days for sowing and planting, for pruning, for a pond, and even for construction work.

Meat with mushrooms in a frying pan is an inexpensive hot dish that is suitable for a regular lunch and for a holiday menu. Pork will cook quickly, veal and chicken too, so this is the preferred meat for the recipe. Mushrooms - fresh champignons, in my opinion, are the best choice for homemade stew. Forest gold - boletus mushrooms, boletus and other delicacies is best prepared for the winter. Boiled rice or mashed potatoes are ideal as a side dish.

I love ornamental shrubs, especially unpretentious ones and with interesting, non-trivial foliage colors. I have various Japanese spirea, Thunberg barberries, black elderberry... And there is one special shrub, which I will talk about in this article - viburnum leaf. To fulfill my dream of a low-maintenance garden, it is perhaps ideal. At the same time, it is capable of greatly diversifying the picture in the garden, from spring to autumn.

Plant diseases on the site always bring a huge amount of trouble to the gardener. Without taking timely measures, you can lose most of the harvest, so it is important to know the “enemy” by sight. One of the most insidious diseases of onion crops is downy mildew. What is powdery mildew on onions, how to deal with it, preventive measures - this will be discussed in the article.

Description of the disease

The scientific name of this scourge is peronosporosis, although most often gardeners know the disease under the name downy mildew on onions. This is because when onion plants are damaged, their leaves become covered with spots with a gray or purple coating. The disease is dangerous and insidious, caused by a fungus and affects almost all types of onions. To a lesser extent, harmful conidia are formed on mucus, leek or garlic, but this does not mean that these plants do not suffer from peronosporosis.

Under what conditions does the disease develop?

In order for the mycelium to germinate, an appropriate level of air humidity (at least 95%) is required, as well as warmth. In rainy weather, especially with wind, the plants in the garden become infected very quickly, and if you do not start processing the onions promptly, you may lose the entire harvest.

The conidia of the fungus do not survive in dry and hot weather, so the onset of the disease may subside slightly. But as soon as the rains come, the epidemic will resume again.

The fungus most often affects dense plantings, which create ideal conditions for the development of the disease. Downy mildew also spreads on ridges located in low places, in the shade, that is, where there is little sun.

Signs of downy mildew

Most often, the source of the disease is poor-quality planting material. Moreover, even when sorting the sets, it is very difficult to understand whether the onion is sick or not.

Gray spots begin to appear on the feathers of the onion. The surface of the leaves turns yellow (see photo).
The feather on top begins to fade, dry, and sag. In this case, usually only the top of the leaf is affected; the lower part of the feather may be green.
Over time, a dark gray or purple coating appears on the spots. Also, dust sticks to the leaves, so the plant itself looks dirty.
The diseased top of the leaves begins to die.
The infection moves into the bulbs, which significantly slow down in growth.

IMPORTANT! Bulbs affected by downy mildew look quite normal in appearance (see video). But when stored for storage, such vegetables begin to rot and deteriorate. In addition, they are carriers of infection.

The onion is then affected by secondary fungi; a characteristic sign of this is a black sooty coating. Sometimes, in hot weather, the course of the disease stops and the fungus seems to die off. But in the next season, if there is rain, without proper processing and compliance with crop rotation rules, onions planted on this ridge do not retain immunity and may get sick.

Remembering that it is easier and simpler to prevent any disease than to treat it, gardeners should carefully consider all preventive measures. How to get rid of fungus?

It is necessary to plan plantings every year, excluding planting onions on the same ridge repeatedly. You can return the onion to the same place only after 3-4 years.
Onions are usually planted after crops such as cabbage, pumpkin or cucumbers, which are the best predecessors. This reduces the possibility of infection.
Ridges with perennial onions and annual crops of this family should not be located nearby.
To grow any type of onion, you need to choose sunny, well-warmed areas of the garden.
In late autumn, it is necessary to dig up the beds (and not only onion beds), apply fertilizers, and remove all plant debris from the garden. Deep autumn plowing or digging will get rid of the larvae of harmful insects, as well as spores of a dangerous fungus.
It is necessary to follow onion planting patterns, without thickening the rows and carrying out mandatory thinning and loosening. Water the plantings moderately, avoiding waterlogging of the soil.
The correct selection of varieties that are resistant to this scourge also helps in the fight against peronospora. Of course, there are no varieties and hybrids that are not at all affected by powdery mildew, but there are such as Stuttgarten Riesen, Centurion, Kasatik, Antey, which are resistant to infection by condidia.
Sets and nigella seeds must be warmed up and soaked in special disinfectant solutions before planting. This will destroy fungal spores and prevent disease.

ON A NOTE! If the bulbs are heated in water at a temperature of 38-40ºC (about 8-10 hours) before planting, then the likelihood of infection will be minimized.

It is also necessary to strictly control the doses of fertilizers. Excessive fertilizing with nitrogen, as well as abundant watering, can lead to the appearance of disease.
Sick plants must be removed and burned.

Summer residents do not have huge fields, but even small plots require care and attention. Following simple rules will help you avoid diseases and keep your onion plantings healthy.

How to deal with downy mildew

What to do if the “enemy” in the form of peronosporosis has already appeared and how to cure onions? Considering that this disease is insidious and has an explosive nature, it is important to respond to this very quickly and begin treatment at the first signs that the onion is sick. Methods, like preparations, can be different, but onion protection must be comprehensive. Some people prefer to fight only with folk remedies, others immediately use drastic measures of struggle - heavy" artillery in the form of "chemistry". Chemicals

Bordeaux liquid

They immediately take Bordeaux mixture as “allies”, preparing a 1% solution from it. Spraying is carried out both for the purpose of prevention and when identifying the first spots on the onion.

IMPORTANT! Gardeners should know that if onion feathers have been sprayed, they cannot be used for food!

Twenty days before harvesting, any treatment with special means should be stopped.

Arcerides

Treating plants with Arceride has a good effect. It is a brown powder that is diluted in water. Dilute it strictly according to the instructions, for onions - 30 grams per 10 liters of water. The maximum number of treatments for onion plantings per season is three times, intervals are two weeks. The protective effect of this product is manifested not only during plant growth, but also during onion storage.

ON A NOTE! Low-toxic Arcerid can be used to combat both peronospora and late blight (on potatoes), as well as mildew (on grapes).

This drug has a systemic effect.

Polycarbacin

A contact fungicide is Polycarbacin, which blocks the development of fungal spores and limits plant damage. Proportions: take 40 grams of product per bucket.

Kurzat

This drug contains copper oxychloride, which not only suppresses conidia and spores, but also has bactericidal properties. Kurzat also contains cymoxanil, which prevents internal infection.

It is advisable to treat plants with Kurzat before signs of disease appear, which will increase the effectiveness of its effects. The drug is one of the most reliable remedies for powdery mildew, used in the early stages of plant growth, and it is not toxic to animals and insects. Proportions: 60 grams of Kurzat per bucket of water, spray every two weeks. We process 3-4 times per season.

Thanos

Granular powder that is effective when processing onions to prevent downy mildew. It is usually recommended to use it in the phase when onion plants have 4-6 leaves.

The drug contains two potent components: famoxadone and cymoxanil, thanks to which Thanos is both a preventive and therapeutic agent.

Among the advantages: efficiency in use, the ability to use the product on various crops.

Fitosporin

Treatment of onions with Fitosporin, whose activity is enhanced by the GUMI elixir, is also effective. 20-30 ml of the drug are diluted in a bucket of water. Sprinkle onions when the first signs of disease appear.

Folk remedies

Chemical preparations give a good effect, but we must remember that this is still “chemistry”, and one cannot talk about the complete environmental friendliness of the resulting vegetables. Meanwhile, gardeners quite successfully use various folk remedies that are safe to use and effective. Onions treated with such compounds can be used for food in the summer (for greens).

Wood ash

One can only be surprised at the benefits of ordinary wood ash, used both as a fertilizer and as a means of combating many diseases and pests. It also helps with downy mildew, for which it is necessary to pollinate onion plantings with ash.

ON A NOTE! Before any use of ash, it must be sifted!

Treatment can be carried out two to three times a season, preferably on dry days.

Dusting can be replaced by spraying. To do this, pour boiling water (two liters) into the ash (about two glasses) and let it sit. Then filter, add water to a bucket and spray onion.

Herbal treatments

Another infusion recipe that is effective for prevention, as well as for treating plants, is infused weed grass. To prepare a medicinal “tea,” weed herbs are crushed, poured into a bucket (about half), poured with boiling water and infused for 4-5 days. Then this green strained infusion is sprinkled on the onions.

Saving onions with kefir

In the fight against downy mildew, good results are shown by treating plants with compositions based on fermented milk products. Can be used:

spoiled milk;
kefir;
curdled milk;
serum.

The effect is achieved due to lactic acid bacteria, which are destructive to fungal spores. For the composition, dilute the product in water (1:10), mix thoroughly, and then spray the beds with onions. The infusion does not need to be stored; it is made immediately before use.

Processing onions with potassium permanganate

Another recipe that uses potassium permanganate is used to prevent this disease. For spraying, make a pink solution and treat the onion plants once a week.

Garlic tincture

Many gardeners use garlic tincture as a preventive measure.

How to do it: take four heads of garlic, chop them, and stir them in a liter of warm water. The treatment must be done every day, the entire cycle lasts one and a half weeks.

Onion tincture

Surprisingly, onion peels can be used to combat powdery mildew on onions. Prepare the composition as follows:

onion peels (300 grams) are poured with water (one liter);
boil;
insist for two days;
diluted with water to a volume of 10 liters;
spray the plantings.

Mullein tincture

Another remedy is mullein infusion. Fresh mullein is not used to fertilize onions, but it is a fairly good remedy for treating downy mildew.

mullein is diluted with water (1:3);
leave to infuse for three days;
filter;
add water up to 10 liters;
spray onions twice a season, interval is 10 days.

The above folk remedies are still effective for preventing the disease, but if the disease has affected most of the plants, you will still have to use chemicals. But the most important thing is preventive measures and compliance with all rules of agricultural technology. By learning what powdery mildew on onions is and how to effectively combat it, you can prevent it from appearing on onions. This means that the gardener will definitely receive a good harvest of his favorite vegetable.

Similar articles It's interesting that

Symptoms of the disease

All weeds in the area are pulled out and processed, since only from them do aphids move onto cucumbers. In sunny weather, dilute 5 ml of commander in 10 liters of water (30°C), close the greenhouse and spray the space inside: walls, ceiling, paths, ground. For plants, make a solution 2 times thinner. They are not processed so generously, and the back side of the leaves is not forgotten. The dead aphid will soon be on the ground: after an hour it is “buried” - the soil is loosened to a depth of 1-2 cm.

There are quite a lot of gooseberry varieties resistant to this disease.

Spraying with a mixture of antibiotics helps well with powdery mildew: terramycin 100 units/ml, penicillin 100 units/ml and streptomycin 250 units/ml in a 1:1 ratio.

forma rosae on a rose, etc.,

But most often downy mildew of cucumber can appear during August, since at this time the night temperature drops. The plant produces condensation, and this is an ideal moist environment for the propagation of spores of this disease. This happens especially quickly in a greenhouse, where there is an even more favorable environment for dew to fall. In addition, unbalanced soil can lead to the appearance of downy mildew. For example, the soil lacks phosphorus, potassium, or has an excess of nitrogen.

Cucumber is a very ancient vegetable. It appeared 6 thousand years ago. It was originally grown in the tropics and subtropics of China and India. This product is a real storehouse of vitamins. It contains vitamins B, C, potassium, phosphorus, iron, magnesium, and also promotes the rapid absorption of animal fats. Therefore, meat dishes go very well with salads or cold cuts that contain this healthy vegetable. But, sadly, every year growing cucumbers becomes an increasingly more difficult process.

The names of both powdery mildews are similar

When fighting powdery mildew, you can use the following drugs:

Apple powdery mildew (Podosphaera leucotricha Salm.).

mushroom

The species that cause the most harm are:

What methods should be adopted to combat downy mildew?

Take 30 g of fresh hot chopped pepper and 200 g of tobacco dust. Pour 10 liters of hot (60°C) water, leave for 24 hours, stir and filter. Add 3 tbsp to the infusion. spoons of liquid soap and 2-3 tbsp. spoons of wood ash. Consume 1-2 liters per 1 m2. Repeat after 6-7 days.

Copper-containing preparations of contact or combined action (copper sulfate, cuprosate, oxychome, etc.).

Widespread disease. Damages apple trees, less often pears. A white or reddish coating appears at the ends of young annual shoots; this is the mycelium of the fungus and conidia. At first, the plaque is quite easily erased, but as the pathogen develops, it becomes denser, gray or brown in color, and black dots, the fruiting bodies of the fungus, appear on its surface. Shoots slow down, growth points dry out, leaves do not develop normally, become deformed, and ovaries crumble. Due to the fact that young shoots are affected, the disease poses a particular danger in nurseries. The pathogen overwinters in the form of mycelium in damaged kidneys.
Sphaerotheca pannosa

Uncinula necator,

Gray rot of onions appears soon after storage in the form of softening and wateriness on the neck of the onion. When pressing on the onion in the neck area, the tissue is dented, and a longitudinal section shows that the juicy scales become brown, as if boiled. On the surface of the bulb in the neck area, and sometimes under the dry scales, a gray coating appears from the sporulation organs of a fungus from the genus Botrytis. The disease intensifies with high air humidity and elevated temperatures during storage. Infection initially occurs in the garden during the harvesting period through a loosely closed neck, as well as through injured areas damaged by pests or labor tools during harvesting. During storage, the disease is transmitted from the contact of healthy bulbs through various types of damage with already rotten tissues of diseased bulbs. The infection persists in the planting bulbs, as well as in plant debris on the site.

It is also recommended to grow varieties resistant to powdery mildew in protected soil, and once a year remove and remove a layer of soil 3-5 cm thick. To prevent the disease, the frames of greenhouses and greenhouses are lubricated with sulfur.

As soon as you notice downy mildew on cucumbers, urgent treatment of the plant is necessary.

LetovSadu.ru

Plant diseases: powdery mildew and downy mildew

For example, plant early varieties, which makes it possible to get a harvest before the onset of cold weather, during which peronosporosis develops favorably. Since there is a risk that the seeds are already infected with this disease, it is recommended to treat them with a 0.1% solution of potassium permanganate before sowing.

Downy mildew of cucumbers or downy mildew is one of the widespread diseases of this vegetable. This is exactly the disease that can lead to the death of a plant and also significantly reduce its yield. For the first time in Ukraine, this disease appeared in garden plots in Kharkov in 1972. To this day, breeders have not been able to find a cure for this disease.

When powdery mildew appears.

It is difficult to get rid of heavily spread downy mildew (MPM), because the infection remains unnoticeable on the soil for up to 6-7 years.

Measures to combat powdery mildew and its photos

Cucumbers attract and attract not only people

Measures to combat powdery mildew on apple and pear trees.

The fight against gray mold of onions is based on proper cultivation in order to accelerate the ripening of bulbs and rapid drying of leaves: early planting, enhanced phosphorus-potassium nutrition with nitrogen limitation, placing onions in sunny places with good ventilation, timely removal of weeds. Immediately after harvesting, the onions are thoroughly dried in the sun, and then they are dried in a well-ventilated, warm room (in the attic). During storage, rotten bulbs must be promptly removed. Post-harvest and spring plant residues from onion harvesting must be burned and not used as fertilizer. These are effective measures to combat gray rot of onions.

To prevent the disease, the temperature regime should be observed. The daytime temperature in the greenhouse should be 24-26 °C during the day, and 20 °C at night.

Nowadays, combined fungicides are widely used for this: copper oxychloride, Efal, Ridomil Gold. These preparations are more suitable for spraying in a greenhouse. Acrobat MC has proven itself well on open ground.

Since harmful pathogens can remain in the soil for several years, it is recommended to burn the plants themselves after harvesting rather than add them to humus.

How to deal with downy mildew and photos of downy mildew

It is not difficult to identify downy mildew on cucumbers. It appears as massive brown and yellow spots on the foliage of the plant and affects it at all stages of development. You can visually see downy mildew in cucumbers in the photos posted by gardeners on the Internet.

Most often, a white coating of powdery mildew (MP) falls on the leaves when the fruits are set: at the end of June - July. The upper part is affected, then the back, and only then, if not prevented, the triumphal procession will also capture the stems with green foliage. The scourges dry out and die.

When downy mildew appears.

, and in general all living things.

Treatment with fungicidal preparations during the separation of buds, immediately after flowering and again after 15-20 days. Removing damaged shoots in the fall and early in the spring reduces the amount of the pathogen.

Exists

Photo gallery: powdery mildew and downy mildew (click to enlarge):

udec.ru

Onion diseases

Sphaerotheca mors

Downy mildew - downy mildew of onion

This disease is caused by putrefactive bacteria that penetrate poorly ripened and undried bulbs. When the disease develops severely, the bulbs rot in the field. However, most often rot is discovered during storage. At first, diseased bulbs are no different in appearance from healthy ones, but when cut, they can see softened brown tissue located between healthy scales. An unpleasant odor appears, and when stored at home, in addition, a mass of small flies begins to bother you. On the garlic cloves, deep-seated, light brown ulcers are noticeable, and when the tissue softens, an unpleasant odor is also detected.

Measures to combat downy mildew on onions

This fungal disease affects the leaves and stems of beans and peas, which turn yellow and dry out. At the same time, a powdery coating consisting of fungal spores is clearly visible on the affected organs. The disease can persist for a long time on plant debris. The development of infection occurs at an air temperature of 20-25 ° C and a relative air humidity of 70-80%. To protect legumes from powdery mildew, sources of infection should be destroyed, as well as preventive measures should be taken, which include treating plants with sulfur preparations 2-3 times every 10-15 days.

These substances have their own characteristics, but the main rule is timely preventive spraying of young plants that already have 3-5 leaves, and further processing at the time when the first fruits begin to appear.

Measures to combat gray rot of onions

This will be a real breeding ground for downy mildew fungi. Another very important point - never plant cucumbers, pumpkins, and zucchini every year in the same place. Choose a different area - this will certainly help avoid an outbreak of recurrent disease. Now regarding the soil in the greenhouse: after the end of the season and harvesting of the plant, you need to remove the top layer of soil. And then this area of the greenhouse needs to be treated with a 0.1% solution of potassium permanganate.

These spots tend to grow very quickly, which ultimately leads to drying out of the cucumber foliage. The disease affects both plants growing in a greenhouse and those grown in open ground.

Bacteriosis of onions and garlic.

Reliable methods of combating downy mildew.

The disease, like a jack-in-the-box, can occur at any time, even on seedlings. But its flowering occurs at the beginning of July, when cucumbers actively bear fruit. On the leaves above, multifaceted oily green spots “blur” and inexorably increase. They turn white underneath, then turn brown and dry out.

In the heat - insects, which, although they cannot crunch greens, suck the juices out of the vines. And during sudden coolness and excessive humidity, there are other misfortunes: melon aphids and powdery mildew.

Onion bottom rot

Strawberry powdery mildew (Sphaerotheca macularis Mag.).

downy mildew, peronosporosis,

on gooseberries,

The source of infection is plant residues in the soil, on which bacteria remain until they completely rot (up to 3 years). Therefore, rotten plants should be removed from the site. You can return onions and garlic to their original place, but not earlier than after 4 years.

Photo of onion disease (click to enlarge):

udec.ru

Powdery mildew description and control measures on FloralWorld.ru

Peronosporosis affects plant leaves. It develops both indoors and outdoors and often leads to the death of plants. Remember, if you are late by at least 1-2 days, the plant may die and cannot be saved. It is also important to avoid over-treating cucumbers with fungicides, because this is a direct path to the accumulation of pesticides and harmful substances in them. These drugs have the property of stopping the growth of fruits, as well as reducing yields. The most important rule is to avoid seed contamination. To do this, it is recommended to plant cucumbers in places where the occurrence of peronosporosis is unlikely or even impossible. The heat treatment method is very good for disinfecting seeds. To do this, place the seeds in water at a temperature of +50 degrees for 15 minutes.

Distribution: on cereals, Onion bottom rot affects onions and garlic in the field and during storage. In young plants, the leaves, starting from the tips, turn yellow and die. A white fluffy coating from the mycelium of the imperfect fungus Sclerotium forms on the roots and scales of young bulbs; the bulbs and cloves become watery and rot. Very small, poppy seed-sized black sclerotia appear on the surface of the affected tissue.

The spread of peronosporosis is facilitated by high humidity and air temperature, therefore, to protect plants in protected soil, an optimal microclimate should be maintained. Air humidity should be no higher than 80%, and the air temperature at night should not be lower than 20-22 °C. Downy mildew can persist in the soil and on plant debris, so you should dig up the soil in the fall and burn the plant debris. In this article we will talk about how to deal with powdery mildew and the treatment of downy mildew (perenospora).

Symptoms:

Try to maintain normal soil moisture during the growing season of the plant without overwatering.

Prevention:

pumpkin;

Safe and environmentally friendly methods of control.

Control measures:

Reliable methods of combating downy mildew

There are never enough aphids:

Treatment with fungicidal preparations. The first spraying is carried out during the budding period, the second after harvesting. When choosing a place for planting, keep in mind that it should be well ventilated. Thickening should be avoided by watering without excess. Removing weed varieties Bakhmutki and Sudden.

everywhere.

Sphaerotheca pannosa

When storing onions and garlic, an abundant plaque with small sclerotia develops on the bottom of the bulbs and on the cloves. Sources of infection in the field are soil and affected bulbs. When favorable conditions occur in the field, sclerotia produce mycelial sprouts, the growth of which forms an abundant coating of mycelium.

To protect pumpkin crops from peronosporosis, they are sprayed with a 0.4% solution of copper oxychloride, a 0.4% solution of polycarbacin or Bordeaux mixture. To prepare it, mix 100 g of lime and 100 g of copper sulfate with 10 liters of water. Before planting in open ground, it is recommended to feed the seedlings with ammonium nitrate.

Powdery mildew is one of the most common fungal diseases affecting pumpkin crops. It is usually found in greenhouses and greenhouses, but under favorable weather conditions (high air temperature and humidity) it quickly spreads in open ground.

Grow those hybrids that are less susceptible to this disease (Katyusha, Debut, Rodnichok, Golubchik, Idol, Zodiac and Photon). These varieties are grown both in open ground and in greenhouses. The most popular variety of cucumbers grown in open soil is Phoenix 640.

At the first signs of plaque, a medicinal solution is prepared. Take 1 liter of liquid mullein and 1 tbsp. spoon of urea, stir in 10 liters of warm water (25°C), leave for 3-4 hours, filter and spray the leaves from below and above in the morning in warm weather.

At the first signs of the disease, you need to stop watering and fertilizing for 6-7 days. Then the cucumbers are sprayed with a solution of HOM (40 g per 10 liters of water) with the addition of soap. The greenhouse is quickly ventilated and the plants are additionally covered with film at night.

Before you know it, entire colonies of boogers have already occupied the entire plant. It costs them nothing to infest an entire garden bed; they fly and reproduce en masse; it is not possible for a simple summer resident to track both processes. Nevertheless, we can defend ourselves quite successfully.

American powdery mildew, Spheroteca (Sphaerotheca mors uvae (Schw.) Berk, et Curt).

At the beginning of the disease, small powdery spots appear on flowers and leaves. They are easily erased, but then appear again and increase in size, becoming a rich gray or purple color. Gradually the mycelium thickens and becomes almost brown. Powdery coating can be on both sides of the leaf. The leaves gradually dry out, are taken out and fall off, the buds and flowers fall off, and the growth of the plant stops. The most favorable conditions for the development of the disease are high humidity of about 60-80% and warm air within 18-20C.

forma persicae on a peach,

Another causative agent of the disease is Fusarium rot (a fungus from the genus Fusarium), which persists in the soil in the chlamydospore stage on plant debris for up to 5 years. Infection of newly planted bulbs occurs through the bottom, mainly through damage caused by the onion fly. In this case, the bottom becomes rotten, the roots eventually die, and a white-pink coating from the sporulation organs of the fungus appears in the area of the bottom. The bulbs soften (they are watery when cut through the tissue), and the leaves die off, starting from the tops. The development of the disease is facilitated by increased soil moisture in the presence of warm weather. Harmfulness is expressed in the death of plants, thinning of plantings and the death of bulbs during storage.

floralworld.ru

Cucumber diseases, melon aphids, powdery mildew, control agents

When growing crops in greenhouses, it is important to avoid sudden temperature changes in them. Peronosporosis affects cucumbers, melon, pumpkin, watermelon, as well as plants of the goosefoot family. More often than other plants, parsley, parsnips, celery, dill, as well as cucumbers, zucchini, cabbage, peas, onions, and beets are infected with this disease.

When growing vegetables in a greenhouse, it is recommended to maintain the microclimate in it as much as possible. This will help prevent dripping moisture from appearing on the foliage. If you notice that spots appear on the leaves, they should be removed immediately, without leaving stumps.

watermelons.Cucumber hybrids that are not infected with powdery mildew, however, suffer from downy mildew. We are talking about varieties, for example, about

Melon aphid on cucumbers

After the last harvest, the bed must be treated with a solution of copper sulfate (3 tablespoons per 10 liters of water). After a day, pull out the plants by the roots and burn them. When melon aphids appear on cucumbers.

Widespread disease. Damages gooseberries and currants. It affects ovaries, fruits, and young shoots, causing them to dry out. It overwinters in the form of fruiting bodies on damaged parts of the plant. In spring, spores are released from the fruiting bodies, causing further infection. A white powdery coating appears on the affected areas; later the spots increase in size and become covered with felt-like formations. The leaves curl, dry out, the berries do not develop and fall off, the upper parts of the shoots turn black and dry out. To prevent powdery mildew, pollination with sulfur is carried out 3-4 times during the summer. Overfeeding plants with nitrogenous fertilizers, especially during budding, increases the risk of powdery mildew. On the contrary, fertilizing with phosphorus and potassium fertilizers increases resistance to the powdery mildew pathogen. Ventilate the room more often, avoiding cold drafts, maintain humidity levels.

How to deal with melon aphids

Erysiphe communisProtection of onions from bottom rot consists of observing crop rotation (returning onions to their original place no earlier than after 5 years), careful culling of planting material, and treating the sets with a 3% TMTD suspension for at least 20 minutes.

High air humidity is also harmful to plants under the film.As you can see in the photo, powdery mildew is a white coating on the leaves and causes plants to dry out. With severe damage, white spots also appear on the stem and fruit.

Downy mildew on cucumbers

It is very important to increase the resistance of plants to possible diseases by fertilizing with mineral and organic substances.

This disease does not affect the fruits of the plant. But dried and fallen leaves, which are a source of nutrition for the fruit with useful substances, become a consequence of the drying of the entire vine. And this already leads to underdevelopment of the fruit, or to a decrease in yield. Therefore, marketable fruits are dull in color and tasteless. Canned F1, Baby mini F1, Veselchak F1,

Safe and environmentally friendly methods of control.Aphids appear in open ground in early summer, and in film tunnels and greenhouses in spring. At first it is yellowish, then dark green, winged and wingless, occupying the entire underside of the leaves. They wrinkle and curl, and the ovaries and flowers fall off.

How to deal with downy mildew

Measures to combat American powdery mildew.In the prevention of downy mildew, spraying (3 times) with Bordeaux mixture or fungicides that replace it helps

on sugar beets,

Disease pathogens Onion diseases include several diseases that can manifest themselves with various characteristic symptoms. Measures to combat onion diseases depend on the pathogens. Specific chemicals can be found on sale in specialized stores.

Powdery mildew on cucumbers

The rapid spread of powdery mildew in protected soil conditions is facilitated by sharp temperature fluctuations, drafts, and watering plants with cold water. In open ground, powdery mildew spreads quickly with the onset of persistent hot weather and the appearance of dew. A fairly effective method of control is to treat the seeds with biological substances before planting. The drug Trichomerdin is ideal in this case. The main thing is not to overdo it with the dosage, which can lead to deformation of the seeds and subsequently to inhibition of plant growth. Trichomerdin paste containing 40% of the main drug is also well used. Its application is carried out in places where the affected leaves and stems of the plant are cut. Since downy mildew is a fungal disease, its reproduction occurs through the spread of spores, or more precisely, zoospores. Their unique shape with a flagellum allows them to move through liquids. And each watering of the plant contributes to their favorable reproduction and infection of more and more new plants.

and about many others.Early ripening cucumbers are sown in a warm bed with biofuel under double cover as early as possible: from May 25 with dry seeds or from June 1 - germinated, or seedlings are planted. Then you can have time to harvest before the peak of downy mildew.

How to deal with powdery mildew

Reliable methods of struggle. In early spring, before the leaves bloom, they are treated with fungicidal preparations. After the gooseberries bloom, repeat spraying is carried out; in the future, it is repeated every 10-15 days, the number of treatments is no more than recommended in the instructions for the drug. Excess nitrogen and too active pruning provoke the development of infection. You should regularly remove diseased parts of the plant and dig up the soil around the bushes.

If several leaves or buds are affected, they must be removed. Spraying every 5-7 days with special biological preparations to combat powdery mildew, as well as potassium permanganate (2.5 g per 10 liters of water), 0.5% copper oxychloride, 1% colloidal sulfur, a mixture of soda ash and soap (per 10 liters water 50g soda and 40g soap).