Powdery mildew, also called linen or ash, is a fungal disease caused by microscopic fungi from the order of erysiphous or powdery mildew that live in the ground. Most crops are susceptible to this disease, for example: grapes, roses, gooseberries, cereals, peaches, cucurbits and sugar beets. At the same time, the signs of the disease in each plant are the same, but the pathogens are different. For example, American powdery mildew, which affects peach, gooseberry, and roses, is caused by three different spherotecs.

The first sign of damage to the plant by powdery mildew is the appearance of a whitish mycelium plaque, while drops of moisture appear on its surface. Such a plaque can form on the petioles and leaf plates, on young shoots, and also on the stalks and fruits of various crops. The stems and foliage that are closest to the soil surface are the first to be affected, after which the disease begins to gradually spread, covering the entire bush. If you look at the plaque carefully, you can see that in those places where the mycelium is attached to the plant, ulcers form. It gradually fades and loses its decorative effect, as the fungus takes away nutrients from it, moreover, the process of photosynthesis is disrupted from the foliage on which there is plaque. A culture affected by such a disease becomes less resistant to frost. On those fruits that are affected by the disease, cracks appear, pathogens of rot can penetrate through them, which leads to secondary infection.

Fungi are most active under the following conditions:

• during prolonged rains or at high humidity (from 60 to 80 percent) at a temperature of 15–27 degrees;
• often there is a sharp change in temperature;
• after radical pruning, carried out in order to rejuvenate the plant;
• the earth contains an excessively large amount of nitrogen;
• plantings are heavily thickened;
• the wrong irrigation mode is selected, or rather, if the soil often dries up or stagnation of water is regularly observed in it.

Powdery mildew treatment

If you are sure that the culture is affected by powdery mildew, you should remove all peduncles and leaf plates from it as soon as possible, which have turned yellow and wilted. Sometimes you have to cut off a significant part of the foliage, but you should not be afraid of this, since by removing the affected parts of the plant, you increase the chances of its recovery.

Next, carefully treat the diseased bush with a fungicidal preparation, the solution should moisten all its aerial parts well. In this case, the therapeutic mixture during treatment should flow down the plant as if it had just rained very heavily. If a crop growing in open ground is processed, then along with it, the surface of the soil in the garden or in the trunk circle is also necessarily treated with a solution of a fungicidal preparation.

Such a disease can also affect houseplants, what to do in this case? After the bush has been well treated with the fungicide, they should also spray the walls of the container in which it grows and the surface of the substrate. If the plant is very severely affected, then the top layer of the soil mixture, which contains a colony of mushroom mycelium, will have to be removed from the container, and a new substrate is poured in its place, which must first be disinfected.

In order to get rid of powdery mildew, an integrated approach is needed. In addition to the mandatory treatments with chemicals, special agrotechnical measures are used:

• watering is carried out only when the top layer of soil dries well;
• in autumn, the site must be cleared of plant residues, which are then destroyed;
• it is necessary to adhere to the rules of crop rotation;
• for cultivation, choose hybrids and varieties that are highly resistant to powdery mildew;
• do not apply too much nitrogen fertilizer to the soil, especially during the formation of buds;
• timely apply phosphorus-potassium fertilizers to the soil, as they help to increase the resistance of the crop to the disease;
• in the spring, it is imperative to make sanitary pruning of shrubs and trees;
• regularly spray trees and bushes with a fungicidal preparation for prevention, do this in early spring and at the end of leaf fall.

Even for the purpose of prevention, plants are also sprayed with other chemicals that are used in the fight against powdery mildew. For example, bushes are pollinated with sulfur 3 or 4 times, you can also spray them 3 times with a solution of Bordeaux mixture, copper sulphate, or another agent that has a similar effect.

Powdery mildew on vegetables

cucumbers

If cucumbers are affected by powdery mildew, then both fungicidal preparations and folk remedies can be used to treat them. However, it is impossible to get rid of powdery mildew on this vegetable crop without preventive measures. First of all, it is necessary to adhere to the rules of agricultural technology for cucumbers, and the beds must also be sprayed with a solution of Quadris (strictly follow the instructions on the package). But in some cases, the disease still affects the plant, even despite preventive measures.

What to do to cure cucumbers? For the treatment of such a vegetable crop, you can use both folk and chemical remedies. However, no matter what you choose, before proceeding with the processing, you must remove and destroy all parts of the bush affected by the disease.

Dusting the plant with sulfur powder helps quite well in the fight against powdery mildew, while 25 to 30 grams of the drug is taken per 10 square meters of plantings. Also, cucumbers can be sprayed with a solution of colloidal sulfur (25 to 30 grams per 10 liters of water). Powdery mildew on this crop is also fought with the help of mullein infusion, which also needs to process the bushes.

Of the fungicidal preparations, Topaz or Oksikhom is most often used in this case, if you decide to use them, then be sure to strictly follow the instructions attached to the product.

tomatoes

On tomatoes, powdery mildew can appear due to 2 types of fungi. One of them is Oidiopsis erysiphoides, which most often affects bushes grown in greenhouse conditions. As a rule, this happens in March, if the greenhouse was not disinfected before planting the seedlings. In the affected seedlings, the leaf plates begin to dry out from the edges, if you do not start treating it in time, then it is likely that it will die. Another causative agent of this disease is Oidiopsis taurica. In tomatoes affected by such powdery mildew, yellow spots form on the front surface of the foliage. At the beginning, a whitish coating forms only on the underside of the leaf plates, but as the disease develops, it also appears on the upper side of the foliage.

In order to prevent the defeat of tomatoes with powdery mildew, you must adhere to the preventive measures that were described above. And even before sowing, it is recommended to immerse the tomato seed material for 42 hours in a solution of Epin or Immunocytophyte. However, if, nevertheless, the vegetable crop is affected by powdery mildew, it is necessary to start fighting it as soon as possible. Young plants are recommended to be sprayed with a solution of sodium humate, it is able to completely suppress the germination of conidia, which are the causative agents of this disease. Processing of tomatoes is carried out regularly 1 time in half a month, while you must strictly follow the instructions. Also for this purpose, you can use biological preparations that are specially designed to combat powdery mildew. For example, you can use a solution of Baktofit (1%), they should be sprayed with tomatoes 3 times with a break of 1–1.5 weeks. In this case, it is necessary to start the treatments immediately after the appearance of the first symptoms of the disease. You can also cure tomatoes with the Planriz cultural liquid, which the bushes also begin to process after the first symptoms of the disease appear.

Of the fungicidal preparations, the most effective are: Strobi, Topaz, Quadris, Thiovit Jet, Bayleton and Prevent. In order for the product to better “stick” to the sprayed plant, a small amount of laundry soap or silicate glue should be added to the solution. For those who do not want to use chemicals to treat vegetable crops, whey (10%), wood ash or skim can be used for treatment and prevention.

Zucchini

If the zucchini was struck by powdery mildew, and a white coating formed on them, it is necessary to cut and destroy all diseased leaf plates and stems, and also dig up the soil surface around these bushes. In order to cure plants, they can be treated with a solution of wood ash, soda ash or mullein. Most often, gardeners use chemicals such as Carboran, Kephalon or sodium phosphate, as they are very effective in combating this disease.

Preventive spraying is carried out at the beginning of the spring period with a solution of Nitrafen. For medicinal purposes, the treatment is carried out before the plant blooms and at the end of flowering, while using the preparations that were described above. When using fungicidal agents, at least three treatments will be needed, which are carried out with an interval of 1–1.5 weeks, while zucchini is treated with folk remedies regularly every two days. Processing is recommended to be carried out in the evening on a fine day.

eggplant

Eggplants affected by powdery mildew can be cured with a solution of soda ash, and for this you can use any fungicidal preparation, for example, Fundazol (10 grams per 1 bucket of water). In order for the plants to recover completely, they will need at least 4 or 5 sprays with a break of seven days.

Onion

Onions are susceptible to peronosporosis (downy mildew). Such a fungal disease is also very dangerous for vegetable crops. Its development is facilitated by low temperature and high humidity. The causative agents of such a disease are carried by raindrops or wind, and even with the remains of plants.

Powdery mildew control on shrubs and trees

Currant

Currant bushes affected by powdery mildew are hard to miss. And if you do not immediately start fighting this disease, then by the second half of the summer period, the entire currant may be affected. It doesn’t matter which currant is affected by powdery mildew black, white or red, this disease is equally dangerous for it.

You can try to cure diseased currant bushes with both folk remedies and chemical preparations. You need to spray the shrub on each side, while trying to get the medicine solution not only on all the leaf plates, but also on each of its surfaces: both on the top and on the bottom. You can process the plant both with a sprayer and with a brush with soft bristles. The processing of currant bushes should be done in the evening at sunset, while you need to choose a dry fine day. Processing should be carried out for at least four weeks, while the bush is sprayed at least once every seven days.

Also, for the treatment of currant bushes, folk remedies are often used, which have been tested by time. For example, they can be treated with soda ash, whey, a solution of wood ash or cow dung, a pinkish solution of potassium permanganate, powdered with sulfur, etc. As a rule, folk remedies are used only at the initial stage of the development of the disease, if the bushes are very affected , then you have to use special chemicals. In the spring, they are treated with a solution of Nitrafen or ferrous sulfate (30 grams per bucket of water), copper sulfate can also be used (10 grams of the drug per bucket of water). During the formation of buds for spraying bushes, a solution of copper oxychloride is used, for the preparation of which it combines a bucket of water with 30 grams of the drug or Bordeaux mixture (1%). When the currant fades, it is treated twice or thrice with soda ash with a break of one and a half weeks. In autumn, all plant residues must be removed from under the plants.

Gooseberry

The methods of dealing with powdery mildew on gooseberries are exactly the same as those used to treat currants. For spraying such crops, kefir, cow dung, wood ash, whey, yogurt, food or soda ash, as well as a decoction of tansy or horsetail and an infusion of onion husks or rotten hay are used. The most effective chemical agents in the fight against powdery mildew are Gaupsin, ammonium nitrate and Trichodermin. And Fitosporin in the treatment of the disease is as effective as in the treatment of phytophthora.

Grape

The powdery mildew that grapes can get sick with is called oidium. The first symptoms of such a disease are the same whitish coating that forms on shoots, fruits, foliage and stems. The most active disease develops at high humidity and temperatures from 18 to 25 degrees, but during the rains there is a slowdown in the spread of infection. In the summer, when the air temperature does not drop below 20 degrees, the grapes are treated with sulfur, so for the treatment they use a solution, for the preparation of which they combine 1 bucket of water and from 80 to 100 grams of the drug, and for prevention purposes, from 25 to 40 grams of substance per 10 liters of water. If the weather is cool, then sulfur preparations are used for processing, for example, a solution of colloidal sulfur. But during the formation of fruits, it is not recommended to use chemicals for processing. Not less than 30 days before harvesting, it is necessary to stop spraying the grapes with those drugs that are toxic to the human body.

During the filling and ripening of fruits, grapes affected by powdery mildew can be treated with a pinkish solution of potassium permanganate, this will stop the development of the disease. And after all the fruits are harvested, chemicals can be used to treat the plants. Such a culture can be treated with fungicidal preparations, the most effective in this case will be: Thiovit Jet, Quadris and Topaz.

Apple tree

If apple trees are severely affected by powdery mildew, this can have an extremely negative impact on their yield, reducing it by half. In addition, apple trees may become less resistant to frost. Such a disease is a great danger for nurseries, as it spreads very quickly from tree to tree.

There are also effective remedies that will help cure apple trees and other fruit trees from powdery mildew. Most often, a solution of soda ash mixed with soap, colloidal sulfur or copper oxychloride is used to treat the affected plant, while spraying is carried out regularly 1 time in three or four days. It also helps very well in the fight against powdery mildew on Topaz apple trees, while in order to prevent them, they begin to be processed from the beginning of the growing season. If the plant is already affected by the disease, then it will have to be sprayed with Topaz solution 3 or 4 times with a break of 6–12 days. In order to prevent the spread of the disease, before proceeding with the treatment, all affected parts of the tree are cut and destroyed.

Strawberry

If powdery mildew affects strawberries, then this can be understood by the whitish bloom that forms on the underside of the leaf plates, because of this, they eventually become leathery to the touch, while their edges twist and turn bronze. The highest concentration of powdery coating is observed on the mustache, as well as the central leaf plates. On the fruits formed on the diseased bush, a white coating also forms, and they also have a moldy smell. For preventive purposes, do not allow thickening of plantings; for this, strawberries need to be regularly thinned out and replanted. For the treatment of diseased plants, a suspension of colloidal sulfur (1%) or TMTD is used, as well as agents such as Bayleton, Switch, Quadris or Fundazol, while spraying is carried out after the bushes have faded, and also after harvesting. When spraying, make sure that the preparation wets both surfaces of the leaf blades.

Powdery mildew on garden flowers

Phloxes

Powdery mildew affects not only vegetable, fruit and berry crops, but also garden flowers. For example, a whitish coating in the middle of the summer period can form on the foliage and shoots of phlox. As the disease progresses, it changes its color to a darker one and eventually becomes a dirty brown. Because of this, the decorativeness of plants suffers greatly.

If the first symptoms of the disease were found on the phloxes, then it is necessary to cut off all the affected leaf plates from the flowers as soon as possible and dig out the severely diseased bushes, after which they are burned. The remaining plants must be sprayed with a solution of colloidal sulfur (1%), while several treatments are carried out with a break of seven days. As a preventive measure, the surface of the soil in the flower bed is covered with a layer of mulch (peat or humus), and in early spring, after the height of the stems is 100 mm, the bushes are sprayed with a Bordeaux mixture solution, 3 treatments are needed, which are carried out 1 time in 12–14 days. In order for the flowers to be more resistant to such a disease, it is recommended to use a complete mineral fertilizer as a top dressing.

Roses

Powdery mildew affects a variety of flowering plants, it does not bypass roses. If the bushes are hit very hard, then all the foliage on them will curl up, dry out and fly around ahead of time, while a felt coating forms on the surface of the bare stems and shoots, which will prevent the flowers from growing and developing further. In order to prevent the development of this disease, the surface of the area near the roses should always be clean, while trying to remove weeds almost immediately after they appear. In autumn, when the leaf fall ends and sanitary pruning is carried out, the site must be cleared of all plant residues that should be destroyed. And the surface of the soil under the bushes needs to be dug up.

As soon as the first signs of disease damage are found on the bushes, you need to start processing them immediately. To do this, use a solution of Fundazol, Maxim, colloidal sulfur or Fitosporin-M. In early spring or in autumn, it is recommended to spray roses from powdery mildew with the following mixture: 0.3 kilograms of green soap, 15 grams of copper oxychloride, and another 50 grams of soda ash are taken for 1 bucket of water.

Petunia

Petunia is also susceptible to powdery mildew. A whitish coating appears on the surface of the bushes, which eventually spreads to all above-ground parts of the plant. Due to this disease, rot forms on the flowers, and they die. In order to save them, you should cut out all the affected areas of petunias and destroy the ear, after which the flowers are treated with a fungicidal agent, for example, Fast, Previkur, Topaz or Fundazol. In the case when the flowers are not grown in open ground, but in a container or pot, it will be necessary to remove the top layer of the substrate and pour fresh soil mixture instead, which is pre-treated with Fitosporin-M.

Of all the folk remedies used to combat this disease on petunias, treatment with an ash or soap-soda solution shows the greatest effectiveness, and potassium permanganate, whey, mustard or garlic infusion can also be used for this purpose.

violets

In garden violet, which is also called viola, foliage, buds and shoots suffer from powdery mildew. The most common causes of the development of the disease are: an excessive amount of nitrogen in the soil or heavy morning dew on a dry, fine day. Diseased bushes become less spectacular, and they also bloom much less than the due date. In this case, to cure the flowers, chemicals such as Topsin-M, Fundazol, Morestan, Ftalan, Kuprozan, Tsineb are used, and the bushes can also be sprayed with a solution of soda ash, to which a little soap is added.

Some house flowers are also susceptible to powdery mildew, for example: begonia, cissus, saintpaulia, gerbera, rose and kalanchoe. As a rule, the disease begins to develop due to stale air with high humidity, sharp temperature fluctuations day and night and dry soil mixture. The causative agents of such a disease can be transferred from the affected bush to a healthy one by airflow, pests, or during contact with each other (the containers with flowers are very close). You can understand that the flower is sick by the whitish spots that have formed, which can be found on both surfaces of the leaf plates, as well as on the buds. Immediately after the discovery of such symptoms, you need to start the fight against the disease. If the treatment is started too late, then the flower may lose its decorative effect, and rot will appear on it. At the very beginning of the development of the disease, the bushes can be treated with garlic infusion or a solution of potassium permanganate or soda ash. If the plant is very sick, then chemicals cannot be dispensed with, in this case Skor, Hom, Vectra, Bayleton, Fundazol, Vitaros, Topaz or Thiovit Jet are used. Before preparing the solution, you must carefully study the instructions attached to the preparation.

As preventive measures, you should properly water the flowers, feed them with phosphorus-potassium fertilizers, systematically ventilate the room, and also remember to observe plant hygiene.

Preparations and folk remedies for powdery mildew

chemicals

The most commonly used chemicals in the fight against powdery mildew are: Skor, Quadris, Hom, Vectra, Thiovit Jet, Fundazim, Fundazol, Vitaros, Bayleton, Ftalan, Cineb, Kuprozan, Topsin-M, Fitosporin-M, Previkur, Switch, Bordeaux liquid, copper sulfate, copper oxychloride, colloidal sulfur, etc. These funds can be purchased at a specialized store, while they must be used strictly following the instructions attached to the preparation, and in no case should the dosage be increased independently.

If fungicides were chosen for spraying powdery mildew-affected home flowers, then the procedure will need to be carried out on the street, and safety precautions must be observed. Fruit bushes and trees, as well as berry and vegetable crops, are recommended to be sprayed with such chemicals only if they are very severely affected, however, during the active growth of fruits, all chemical treatments must be suspended.

Folk remedies

At the initial stage of the development of the disease, as a rule, folk remedies are used to treat plants. There are many time-tested folk remedies that are absolutely not dangerous for both humans and cultures. For example:

1. Soda and soap solution. To prepare it, it is necessary to dissolve 20 grams of liquid or grated laundry soap in one bucket of water, as well as 50 grams of baking soda or soda ash. Spray the plant should be at least two times with a break of 7 days.
2. Whey solution. In order to prepare such a remedy, you need to combine 1 liter of whey with 1 bucket of water. A well-mixed mixture is sprayed on a dry fine day, there should be at least three such procedures with intervals of three days.
3. Kefir solution. To prepare the product, you will need a liter of fermented yogurt or kefir, it is diluted with water in a ratio of 1:10. It will take three treatments with an interval of three days.
4. horsetail. A decoction is prepared from field horsetail, for this, 100 grams of grass are mixed with a liter of water. The mixture is allowed to brew for 24 hours, and then brought to a boil and kept on low heat for a couple of hours. When the broth has cooled, it is filtered and mixed with water in a ratio of 1:5. For a complete cure of the plant, at least 3 or 4 sprays will be required, which are carried out with an interval of five days. Undiluted decoction, placed in a cool and dark place, retains its properties for seven days.
5. Mustard. In one bucket of tepid water, you need to dissolve 2 large tablespoons of dry mustard powder. With the resulting solution, the diseased plant is either watered or treated.
6. Potassium permanganate. To make such a solution, you need to mix a bucket of water with 5 grams of potassium permanganate. Such a mixture helps to stop the development of the disease, and it also removes the fungus from the surface of the fruit.
7. wood ash. For 1 bucket of water, 1 kilogram of ash is taken. The infusion will be ready in a week. It is carefully drained and 20 grams of grated laundry or liquid soap are added to it. Plants are sprayed regularly every two days.
8. Cow dung (mullein). Combine water and manure in a 3:1 ratio and mix everything well. The infusion will be ready after 3 days. It must be carefully drained and diluted with the same amount of water. This means of culture is sprayed before they bloom, after flowering, and also shortly before the start of leaf fall.
9. Garlic. To prepare the infusion, pour 50 grams of garlic pulp into a couple of liters of water (cloves crushed together with garlic shoots). After a couple of days, the agent is filtered and used for treatments in undiluted form.
10. onion peel. 1 bucket of boiling water is combined with 200 grams of onion peel. The infusion will be ready after 2 days, it remains only to strain. The processing of crops is carried out before flowering, after the bushes have faded, and even before the start of leaf fall.

A dangerous fungal disease that can harm plants and completely destroy the crop.

How to protect plants from it?

Powdery mildew is caused by various types of microscopic powdery mildew fungi. It usually affects plants in warm, humid weather at + 18 ... + 25 degrees. The fungus actively develops at high humidity on a dry surface of tissues in dry weather, without precipitation.

At high average daily temperatures, it also develops in conditions of low air humidity.

Spores do not need liquid moisture to germinate, so rain, watering, and washing the leaves can stop the spread of the disease.

Powdery mildew affects many crops. The symptoms of the disease (as the principles of dealing with it) are the same in each case. Each of the pathogens specializes in only one or a few plant species. Therefore, you should not be afraid that powdery mildew of oak will migrate to phloxes, gooseberries and cucumbers.

What is dangerous powdery mildew

Powdery mildew always appears on young plant tissues - leaves, green shoots, petioles, green berries. Further development of the disease leads to a deterioration in decorativeness, poor winter hardiness, and in berry bushes - loss of yield.

The mycelium, which looks like a thick cobweb, grows rapidly, the spores easily scatter in the form of a white powder, similar to flour. With the development of powdery mildew during flowering, normal pollination does not occur, so the berries are formed ugly, covered with bloom, acquire a mushroom taste and smell.

The concentration of spores in the air and the risk of infection of plants from spring to mid-years is constantly increasing. However, in most plants, by this time the leaves are covered with a protective wax coating - cuticola, and it becomes difficult for fungi to infiltrate living tissue. If timely measures are taken, the disease can be stopped. The infection persists in plant debris and in the root of the affected shoots.

Powdery mildew prevention

• Mixed planting of unstable crops (phlox, roses, delphinium), refusal to grow monoculture in one place.
• Creating conditions for plants for free air circulation. Be sure to break out the extra shoots, garter.
• Timely removal of shoots with signs of disease, plant debris, fallen leaves.
• Deep tillage for annual flower and horticultural crops, as well as between rows.
• Balanced supplements. From the second half of summer - a decrease in the dose of nitrogen fertilizers. During an outbreak of powdery mildew activity (as a rule, the end of June - the beginning of July), it is better to feed the plants with phosphorus-potassium fertilizers, foliar microelements, and add wood ash.
• Regular watering, sprinkling of leaves and crowns can weaken and even stop the disease. The resistance of the leaves decreases in drought or due to lack of watering (for example, caragana, common barberry, maple get sick faster on sandy soil with a lack of moisture).
• Preventive autumn and early spring tillage in near-stem circles with copper-containing preparations.
• Selection of resistant varieties.
• Before flowering and immediately after harvesting, spraying plantings with a soap-copper emulsion (20 g of soap and copper sulfate per 10 liters of water).
• At the initial stage of defeat by powdery mildew on shrubs and roses, ash helps a lot: the bush is sprayed with water, dusted with ash, after a couple of hours the plant is again thoroughly washed with water.
• ! During the ripening period of berries, do not use chemicals. Potassium permanganate (5g per 10 liters of water) - let it be for a couple of days, but stop the disease just before ripening.

Control measures

To combat powdery mildew, sulfur preparations have been very effective and have long been used. In a fine dispersed form, sulfur is absorbed by the cells of the fungus and, turning into hydrogen sulfide, acts on them as a toxin. Before the leaves open, treat the plant with Thiovit Jet or Cumulus DF. Treat bushes with sulfur-containing preparations in the morning or evening hours, as hot weather can cause burns on leaves and berries. Good for the prevention of "Talendo" and "Karatan".

The development of powdery mildew can be suppressed by spraying plants with special preparations based on triazoles (Topaz, Horus, Skor), before treatment, diseased leaves are preliminarily removed.

The easiest way to deal with powdery mildew- a weak solution of urea. You need to spray in the evening after sunset on the lower and upper sides of the leaves.

Repeated spraying with fungicides is carried out after 10-14 days. For greater effectiveness, it is recommended to alternate drugs. Pay special attention to clipped hedges and plants at risk.

Folk remedies for the fight against powdery mildew

1. 10% aqueous solution of milk or (to save) whey - spray grapes and fruit bushes once a week. Milk fat, or possibly whey protein, then serves as food for microorganisms that compete with powdery mildew for space and eat its spores.

2. Daily infusion of ash(half a bucket of ash per 7 liters of water). Before spraying, dilute with water (1:1) and add 100 g of "green soap" as an adhesive. Pour the bushes from a watering can, wetting the leaves and clusters well. Some colleagues do not insist on ashes, but boil for 20 minutes.

3. Concentrate of saprophytic microflora. In the spring, pour 1/3 of the sown humus into a 100 l barrel, fill it with warm (+20 ... + 25 degrees) water, cover with burlap and keep warm for 5-6 days, constantly stirring. After 5-6 days, the concentrate is filtered through cheesecloth and poured into a sprayer. For prevention plants are treated in the "green cone" stage on cloudy days or in the evening. The second processing - in a week, one more - before flowering.

Introducing powdery mildew with descriptions and photos. We list the causative agents of the disease on different plants, shrubs and trees and consider the signs of infection with a fungus. We will also consider downy mildew (peronosporosis) and its features.

Powdery mildew: description

This is a widespread fungal disease that affects a large number of plant species, shrubs and trees. It is also called bel or ashtray.

The infection is often transmitted by sucking - especially often tolerates. Also, spores of the fungus can get with water during irrigation, from infected specimens through the air, or be transferred by humans through contact with them.

The development of a fungal disease is promoted by high humidity (60-85%), moderate air (16-28 ° C), an excess of nitrogen and excessive planting density. In open ground conditions, the disease appears from the end of May and develops until late autumn. The peak of ashpel development is in June-July.

The causative agent of the disease

Microscopic fungi act as pathogens - the order Powdery mildew or Erysiphales (Erysiphales). In this case, the symptoms of the disease are similar when affected by different genera of fungi.

Common species of pathogenic fungi belong to the genera: Erysiphe, Microsphaera, Phyllactinia, Podosphaera (formerly Sphaerotheca) and Uncinula. Some species of them infect certain plants, shrubs or trees.

Worldwide, the most common causative agents of powdery mildew are the fungi Erysiphe cichoracearum and Podosphaera fuliginea.

• Blumeria graminis – cereals (cereals), lawn grasses
• Erysiphe alphitoides – oak
• Erysiphe cichoracearum - family Asteraceae. Aster, marigold, dahlia, calendula (marigold), daisy, sunflower and zinnia.
• Erysiphe cichoracearum, Podosphaera fuliginea, Podosphaera fusca - gourd family (watermelon, melon, squash, lagenaria, pumpkin and zucchini)
• Erysiphe cruciferarum – swede, cabbage, turnip, sugar beet
• Leveillula taurica – onion
• Microsphaera diffusa – soybean
• Moniliniafructigena, Podosphaerapannosa - rose family. Plum subfamily: apricot, quince, cherry plum, hawthorn, cherry, pear, peach, mountain ash, plum, cherry and apple tree. Rose family: strawberry, strawberry, raspberry, rose and rosehip.
• Podosphaera clandestina – apricot and peach
• Podosphaera leucotricha – pear, apple
• Podosphaeramacularis - hops
• Podosphaeramors-uvae – gooseberries, black and red currants
• Uncinulanecator - grapes (oidium - powdery mildew on the vine)

Signs of defeat

On the surface of the aerial part of the plant (usually leaves, young shoots and stem), white powdery spots with fungal spores are visible, they ripen and secrete liquid drops resembling dew.

In most cases, the disease occurs on leaves closest to the soil in the same way that fungi live in the soil. As the infection develops, the spots become larger and denser, a large number of spores are formed and the ashtray can move up or down the plant.

The fruits infected with the fungus crack and rot, and the flowers and buds fall off, and the plant stops growing.

Powdery mildew on a pumpkin leaf

Features of the lesion in various plants, shrubs and trees

Vegetables

Powdery mildew on cucumbers in greenhouses spreads with drafts and insufficient lighting against the background of a weakening plant. Most often, cucumbers near doors and vents are the first to become infected. A fungal disease can destroy vegetables very quickly. Vegetables from the Pumpkin family due to ashtray lose 40-60% of the crop, and the quality of the fruit also deteriorates.

Strawberry, strawberry, raspberry, rosehip and rose

In these species, the entire aerial part is affected, especially the leaves. Their edges are deformed, and the leaves become rough with a bronze tint on the inside. Powdery mildew-infected leaves stand out especially in August-September. On top of the berries and fruits, a powdery coating is visible and a specific aroma of the fungus is heard.

flowering species

In ornamental plants, the leaves darken and fall off from whites.

Gooseberry and currant

In the early 60s, powdery mildew pathogens from gooseberries moved to blackcurrants and since then gardeners have been fighting the disease on both shrubs. The infection bends the shoots and slows down growth, and the leaves become smaller and wither. Gooseberries still suffer from fruits - white spots appear on them, darkening with time.

To treat infection on gooseberries and currants, it is important to cut off the infected tips of the shoots in the spring. Before the flowering of the bushes and after picking the fruits, it is advised to spray them with preparations or folk remedies.

Pear, peach, plum, apple tree

On trees, a fungal disease attacks young shoots, leaves, flowers and fruits. Shoots and buds die in winter, and infection reduces the winter hardiness of the specimen. The leaves stop growing, deform and crumble.

The infection is especially active on old trees. Trees growing on the southern and southwestern sides of the hill suffer more from powdery mildew. It is important to prune the affected parts and spray with fungicides during the isolation of the buds.

Affected plants

Powdery mildew can infect a large number of plant species, bushes and trees. We list the species that the fungus affects most often.

• Greens: lettuce, dill, spinach.
• Cereal crops (cereals): wheat, barley.
• Ornamental crops (flowers): aster, marigolds (tagetis), dahlia, gerbera, hydrangea, delphinium, daisy, petunia, rose, september, phlox and chrysanthemum.
• Trees: apricot, quince, cherry, pear, oak, maple, peach, rowan, plum, cherry and apple.
• Other crops: watermelon, lawn grasses, peas, melon, calendula (marigold), mint, sunflower, rosemary, soybeans, tobacco, hops.
• Shrubs: barberry, hawthorn, grapes, honeysuckle, gooseberry, almond, lilac, currant, hazelnut (hazelnut, hazel) and dog rose.
• Vegetable crops: zucchini, cabbage, potatoes, onions, cucumbers, peppers, turnips, beets, tomatoes, pumpkins and garlic.
• Berry crops: strawberries, strawberries, raspberries.
• Indoor plants: balsam, gloxinia, potted gerbera, dracaena, kalanchoe, indoor rose, laurel, orchid, pedilanthus, violets (saintpaulia), ficus, yucca.

Powdery mildew on grapes

Downy mildew (Peronosporosis)

Mycoses of the disease outwardly resemble powdery mildew, but its causative agent is mushroom-like organisms from the Oomycetes class - the Peronosporaceae family.

Signs of defeat and where it comes from

The infection affects the leaves. At first, yellow spots of various forms are visible on their upper side, and on the lower side there is a gray coating of spores. With the development of downy mildew, the spots turn brown and brown (tissue necrosis) and increase in size, and the light coating of spores becomes dark.

Infected leaves shrivel, turn yellow and wilt. The disease destroys leaf tissue and rarely affects the stem or petioles.

1. Downy mildew 2. Powdery mildew

Downy mildew comes from unsterilized soil (especially with high levels of acidity and low air permeability) and undisinfected seeds.

The disease develops rapidly in natural conditions - cold nights with periods of long dew, and in a greenhouse with high humidity and poor ventilation.

This disease is more common in greenhouses, and in open ground conditions is much less common than powdery mildew.

ADDITIONS TO THE ARTICLE:

This concludes the presentation of fungal diseases. We hope that the above information will help you in determining the disease.

We wish that this disease does not disturb you either at home or in the garden / vegetable garden or greenhouse!

Powdery mildew is a rapidly spreading fungal disease of plants. At first, a white powdery coating appears on the leaves, similar to flour or powder. It can be easily erased with a finger and even mistaken for ordinary dust. But it was not there! Before you have time to look back, this infection will reappear, and even in greater numbers, capturing more and more new areas of habitat. Not only leaves become white, but also stems, peduncles. Gradually, the old leaves turn yellow and lose turgor. New - grow ugly and twisted. If measures are not taken to cure powdery mildew, the plant will die.

This is what powdery mildew looks like when magnified
Ulcers at the site of mycelium formation

Powdery mildew disease: where does it come from?

• the weather outside is cool (15.5-26.5°C), damp (humidity 60-80%), cloudy weather (for example, during the rainy season). Weather conditions have a particularly great influence on outdoor and balcony plants; when grown in rooms, they are not so noticeable;
• there is a large amount of nitrogen in the soil;
• plantings are thickened;
• irrigation regime is not observed. For example, a plant is often watered without waiting for the top layer of the earth to dry out. Or, on the contrary, they regularly dry out an earthen lump, and later they fill it. All this leads to a violation of immunity and, as a result, the appearance of powdery mildew.

In addition to these external conditions, already “awakened” spores can get on flowers:

• by air (from infected trees or plants);
• through irrigation water (if spores got there);
• through your hands (if you touched an infected plant, and then touched a healthy one).

Powdery mildew can completely destroy a plant in a short time

Proper agricultural technology is an important condition in the fight against powdery mildew

The fight against powdery mildew is an integrated approach. First, you need to put in order the agricultural technology of growing the affected plant. This means:

• watering only after the top layer of the soil has dried;
• at the time of the fight against powdery mildew - completely abandon spraying;
• if possible, take the affected specimen to a brighter, sunny place until the powdery mildew is cured;
• thin out thickened plantings, cut off old leaves that touch the ground;
• for the period of remission - less nitrogen fertilizers, more phosphorus-potassium fertilizers (in case of illness - no fertilizers at all).

All care errors must be corrected, otherwise powdery mildew will appear regularly. Now let's talk about direct treatment.

How to deal with powdery mildew: therapeutic spraying and watering

To get rid of powdery mildew, do the following:

1. Cut off the affected (yellow, devoid of turgor) leaves and all flower stalks. If powdery mildew has appeared on roses, petunias, chrysanthemums and similar bushy plants, it is advisable to carry out a cardinal pruning. The more damaged branches are destroyed, the greater the chance of a cure;
2. replace the top layer of soil in a container, pot or under a plant in a flower bed - whole colonies of mushroom mycelium hide there;
3. carry out therapeutic spraying and watering the plant with one of the medicinal preparations. When spraying, you need to strive so that all leaves and shoots are abundantly wetted. It should pour from the plant, as after a spring shower. There is a more effective way: pour the healing solution into the basin and dip the bush there. The soil is abundantly wetted with a solution, by spraying from a spray bottle or watering. The walls of pots and pallets are also processed.

Powdery mildew: folk remedies

Let's make a reservation right away: folk remedies for powdery mildew are effective as a preventive measure or at the initial stages of the spread of the disease. If the destructive process has been launched for a long time, more than 5-7 days ago, it is already useless to fight in this way. It may be possible to stop the development of the disease, but not completely eliminate it.

The most famous and effective folk remedies for powdery mildew are prepared as follows:

1. From soda ash and soap

25 g of soda ash are dissolved in 5 liters of hot water, 5 g of liquid soap are added. Spray the plants and topsoil with a cooled solution 2-3 times at weekly intervals.

A protective drug against powdery mildew is prepared from soda ash and liquid soap (best household)

2. From baking soda and soap

In 4 liters of water dissolve 1 tbsp. l. baking soda and 1/2 tsp. liquid soap. Spraying is performed 2-3 times with an interval of 6-7 days.

3. Potassium permanganate solution

2.5 g of potassium permanganate are dissolved in 10 liters of water, used 2-3 times with an interval of 5 days.

4. Serum solution

Serum is diluted with water 1:10. The resulting solution forms a film on the leaves and stems, which makes it difficult for the mycelium to breathe. At the same time, the plant itself receives additional nutrition with useful substances and improves health, which affects the improvement of its appearance. Treatment with a serum solution is carried out in dry weather, at least 3 times, with an interval of 3 days.

5. Decoction of horsetail

100 g of horsetail (fresh) is poured into 1 liter of water, kept for a day. Put on fire and boil for 1-2 hours. Filter, cool, dilute with water at a concentration of 1:5 and spray the bushes. The concentrate can be stored in a dark, cool place for no more than a week. Spraying with horsetail can be carried out regularly to prevent powdery mildew in the spring and summer. In the fight against an existing disease (in the initial stage), 3-4 times spraying with a frequency of once every 5 days is effective.

6. Copper soap solution

This remedy for powdery mildew is highly effective due to the inclusion of a well-known fungicidal preparation - copper sulfate. In a glass (250 ml) of hot water, dilute 5 g of copper sulfate. Separately, 50 g of soap are dissolved in 5 liters of warm water. After that, carefully, in a thin stream and with constant stirring, pour the solution with vitriol into the soap solution. Plants are sprayed with the resulting emulsion 2-3 times with an interval of 6-7 days.

7. Mustard solution

In 10 liters of hot water, 1-2 tablespoons are mixed. dry mustard. The cooled solution is good for both spraying and watering.

8. Ash + soap

In 10 liters of heated (30-40 ° C) water, stir 1 kg of ash. The solution is insisted, stirring regularly, for about 3-7 days. After that, the liquid component is poured (without ash suspension) into a clean bucket, a little liquid soap is added, poured into a spray bottle and processed. Spray the plants every day or every other day 3 times. Add 10 liters of water to a bucket with ash particles that have sunk to the bottom, stir and use it for irrigation.

9. Infusion of decayed manure (better than cow's)

Pour rotted manure with water in a ratio of 1: 3, insist 3 days. Then dilute the concentrate twice with water and spray the bushes.

10. Infusion of garlic

25 g of garlic (chopped) pour 1 liter of water, stand for 1 day, filter and spray the collection.

Powdery mildew: treatment with chemicals

If powdery mildew has appeared on your flowers, the fight against it is most effective with the help of modern fungicides. They have a detrimental effect on the fungus, stop the harmful processes in the cells of the plant, protect and treat it. Spraying is carried out 1-4 times with an interval of 7-10 days (depending on the chosen preparation).

Powdery mildew chemicals act quickly and effectively

The most effective preparations for powdery mildew:

• Fundazol;
• Topaz;
• Acrobat MC;
• Previcour;
• Speed;
• Vitaros;
• Amistar extra.

A well-known fungicidal preparation is phytosporin, the active ingredient in which is a concentrate of bacteria Bacillus subtilis in powder of chalk and humates. Despite the fact that phytosporin is considered a remedy, it is practically useless against existing powdery mildew. However, as a preventive measure, it will work flawlessly.

One of my acquaintances recently said with regret: this year all the oaks were white, and all the plants in the garden were infected from them. But if the leaves are covered with a white bloom, then the oaks are just not to blame.

Symptoms on all plants are classic: at first, individual spots of white plaque appear, consisting of mycelium with spores, gradually the plaque grows and occupies the entire leaf blade, turns gray, and numerous black dotted fruit bodies of the wintering stage form in it. The leaves are deformed and dry out prematurely.

On herbaceous plants, the fungus overwinters in plant debris, on ornamental shrubs also in the bark of affected shoots. This explains the fact that powdery mildew appears immediately at the beginning of summer on growing leaves. In rainy years, powdery mildew appears in gardens especially often, and one must always be prepared for this misfortune.

And yet, can oak "infect" other plants? Definitely - no. In different types and forms of plants, powdery mildew pathogens are different.. Often the genus of the fungus is one, and the species or form is different, confined to a particular genus of the plant. So, the causative agent of the disease on oak is a fungus Microsphaera alphitoides; on a rose Sphaerotheca pannosa Lev. var rosae; on barberry - 2 mushrooms: Phyllactinia berberidis and Microsphaera berberidis; at the delphinium Erysiphe communis Grev.f.delphinii; on the lilac - two mushrooms: Microsphaera syringae and Phyllactinia suffulta; on phlox - Erysiphe cichoracearum DC. f. phlogis etc.

The disease is one, and its causative agents–different

I understand that readers are more concerned not with the names of mushrooms, but with a very practical question - how to prevent the spread of powdery mildew in our gardens. I answer: first of all, it is necessary to create all the conditions for normal growth and development for plants, since the weaker the plants, the more susceptible they are to diseases. In addition, mushrooms develop especially intensively with dense plantings and with an abundance of moisture.

As already mentioned, powdery mildew fungi always develop on young growing tissues. Therefore, if you make a large amount of organic matter, then you risk having powdery mildew all the time, since large doses of nitrogen cause active growth of shoots and leaves. This is especially true for varieties and plant species susceptible to this disease. Plants need nitrogen at the very beginning of the growing season, and potassium and phosphorus are important during budding and flowering. Therefore, in order to prevent the nutrition of flower and ornamental crops should be balanced.

Now about protective measures. To use drugs against powdery mildew or not, everyone decides for himself. However, I must warn you - if you fundamentally refuse to spray plants, then every year the infection accumulates, plants, especially shrubs, completely lose their decorative effect. In addition, if you spray the plants during the mass manifestation of the disease, when the leaves and shoots are already all white, you will not restore the decorative effect and beauty of the leaves, but only suppress the development and spread of spores to other plants.

All preparations that are approved for use on ornamental crops are recommended for spraying at the first symptoms of the disease, i.e. when single white raids appear. With the mass spread of the disease, repeated, eradicating spraying with the same drugs is carried out.

For ornamental crops, the following preparations can be used: colloidal sulfur, Cumulus, Vectra, Speed, soda ash solution(0.4%+ 0.4%). A drug Topaz recommended for roses, carnations, potted crops and berries. As the best prevention, I would recommend collecting plant debris and pruning heavily affected ends of the shoots. And when sheltering heat-loving crops, you can safely use fallen oak leaves - it really is not contagious for roses and phloxes.

Love Treivas,
Main Botanical Garden

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