How to deal with powdery and downy mildew on cucumbers. How to get rid of powdery mildew on cucumbers in a greenhouse and open ground? How to spray cucumbers against powdery mildew

One of the most common misfortunes is powdery mildew on cucumbers, which leads to rapid withering of the leaves. The bushes become unable to feed the fruits, and the harvest drops significantly. In order not to part with the result of their labors, summer residents provide the plants with optimal conditions. And if symptoms have already appeared, then treatment begins immediately.

Signs of powdery mildew damage to cucumbers

The first symptoms of powdery mildew are a white or light gray coating that resembles flour. These are the mycelium and spores of the colonized fungus. First, the plaque covers the entire surface of the leaf, then it thickens and turns black. As a result, the leaves dry out, shrinking and curling. The ends of the shoots become crooked. With extensive damage, the entire bush dies.

Powdery mildew usually attacks the lower leaves touching the ground first. If measures are not taken, the disease spreads to the upper part of the bush. While the fungus has not yet reached the fruits, they can be harvested healthy. If the cucumbers are already infected, they will not be stored - if they do not rot, they will crack.

Reasons for the spread

Fungal spores live in the soil for up to 6 years. Therefore, powdery mildew of cucumbers often develops when crop rotation is not observed. Pumpkin seeds cannot be planted on the same site for at least 6 years. But the mushroom can live in small quantities in other garden beds. If there are few spores, then the disease develops only under favorable conditions:

• Cold (below 20 degrees);
• Watering with cold water or heavy cold rain;
• Excessive air and soil humidity;
• Failure to observe the planting interval (the bushes are dense);
• Excess nitrogen in the soil.

Cucumbers are especially susceptible to powdery mildew in open ground if there is no protection from cold rains. People say that this is due to “acidic” water. But in fact, low temperatures are harmful to plants. This is why the fungus more often covers bushes in August, when it is still hot with the sun, but without it it is already very cold.

Ways to fight

The fight against powdery mildew on cucumbers includes three types of measures:

• Prevention;
• Treatment with traditional methods;
• Treatment with chemicals.

When choosing methods, not only your choice matters, but also the timing. While there is no disease, prevention is needed. If it starts, treatment. Traditional methods will help with minor damage, and chemical methods will help with extensive damage. If the fruits are already ripening, then treating cucumbers against powdery mildew with chemicals is unacceptable. Therefore, we will again have to turn to folk tricks.

Preventive measures

Prevention begins with the choice of variety. We need cucumbers that are resistant to powdery mildew:

• Aquarius (this is a variety, only hybrids are listed below);
• Farmer F1;
• Saltan F1;
• Emerald F1;
• Mazai F1;
• Moscow evenings F1;
• True friends of F1.

Other preventive measures for powdery mildew include:

• Pre-sowing seed treatment;
• Watering with settled warm water;
• Compliance with the principle of crop rotation;
• Careful use of nitrogen fertilizers;
• Avoiding temperatures below 20 degrees;
• After harvesting the last harvest, plant residues are destroyed by burning.

Attention! Even if cucumbers grow in a greenhouse, powdery mildew fungus can affect them from low temperatures at night, when it is only 1-2 degrees higher than outside. Therefore, plants are covered additionally. In Japan, growing vegetables in tunnels located inside one large greenhouse is very popular.

Folk methods of struggle

Traditional treatment of cucumbers for powdery mildew is effective at the initial stage of fungal proliferation. And this is the only acceptable method of control if fruits are already ripening on the bushes. Use any of the methods you like:

• Spraying with horsetail decoction. 1 kg of fresh grass or 10 times less dry grass, pour water over the wind and leave for a day. Then set it on fire and boil for no more than 100-120 minutes. Then cool. Can be stored for 7 days. For spraying, dilute the decoction with warm water: 1 liter of decoction per 5 liters of water;
• Spraying with marigold infusion. Grind the flowering bushes to make 5 liters of raw materials. Place them in a bucket and fill with warm water. The infusion takes 2 days to prepare. Before use, filter it and dilute 40 g of laundry soap in it;
• Spraying with mullein solution. Take 3 parts water to 1 part manure. Leave for 3 days. Before use, 1 part of the infusion is diluted in 2-3 parts of water and the resulting solution is filtered.

Spraying for preventive purposes is better than treating powdery mildew on cucumbers. Therefore, herbal remedies can be used without symptoms after every cold rain and more often. Since the ingredients used in traditional methods do not have a negative effect on plants, they can be used very often.

Use of drugs

Effective preparations for powdery mildew on cucumbers:

• Topaz;
• Fundazol;
• Speed;
• Thiovit;
• Gamair;
• Fundazim;
• Bayleton.

Attention! Before treating cucumbers for powdery mildew, read the instructions for the drug chosen for this purpose: dilute and spray it according to it. And due to the fact that the fungus develops resistance to chemicals, change them regularly. Otherwise, the cucumbers will receive a dose of chemicals, but the disease will not go away.

Signs of damage to cucumbers by downy mildew

Downy mildew on cucumbers manifests itself with the following symptoms:

• A gray coating with a purple tint forms on the lower surface of the leaf;
• Oily spots of angular or round shape, light green in color with a yellow tint, form on the upper surface of the leaf;
• Over time, the spots grow larger and begin to cover the entire surface of the leaves;
• Each infected leaf becomes brown and brittle. As a result, the leaves crumble, exposing the petioles.

The difference between downy mildew and simple mildew is the color and nature of the spots formed. With simple mealiness, the leaves look as if they were sprinkled with flour. The spots are small and white. With false powdery leaves, the leaves look as if they were sunburnt from dew drops. But each of the diseases is equally dangerous for cucumbers - if left untreated, the bushes die.

Causes of the spread of downy mildew

The appearance of downy mildew is associated with the active reproduction of certain fungi living in the soil. There they can remain viable for up to 6 years. Favorable factors for fungal growth are:

• Over-humidified air;
• Frequent rains;
• Thick fogs;
• Morning dew;
• Lack of natural ventilation;
• Growing cucumbers in the shade.

A good factor for the development of downy mildew on cucumbers is a large temperature difference between day and night. A difference of more than 10 degrees leads to complete saturation of the air with water vapor. Humidity reaches 100%, and condensation – dew – collects on the leaves. Therefore, at night, cucumbers need good shelter or heating.

Control measures

While cucumbers have not yet been affected by false powdery mildew, disease prevention is carried out. This will keep the crop intact and healthy. Traditional methods of control are suitable for eliminating the first symptoms and extensive lesions if the fruit has already set. The use of chemicals is permissible only before fruiting begins.

Preventive actions

It is easier to prevent the development of downy mildew than to treat cucumbers and put up with the consequences of the disease. For this:

• Water only with warm water and only in the morning, so that the air humidity has time to decrease before the night gets cold;
• Try to keep the temperature even day and night, without sudden changes. During the day the temperature is about 25 degrees, and at night 18-21;
• Follow the principles of crop rotation;
• Ventilate the greenhouse frequently.

One of the measures to prevent downy mildew on cucumbers is the selection of varieties that are resistant to this fungus. But the hybrids that are most resistant to it are: Anyuta F1, Delpina F1 and Vicenta F1. If your choice nevertheless fell on varietal plants, then be sure to soak the collected seeds in a dark solution of potassium permanganate for disinfection before sowing.

Folk methods of struggle

Over the centuries, people have accumulated knowledge about how to deal with downy mildew. Suitable recipes:

• Garlic broth. 75 g of finely chopped garlic or arrows per bucket of water. The cooled broth is sprayed onto the bushes;
• Milk-iodine solution. Dilute 1 liter of milk with zero fat content in 9 liters of water. Add 10 to 12 drops of iodine (alcohol solution with a concentration of 5%). This composition is suitable for spraying;
• Ash “tea”. Brew 0.5-0.6 liters of ash in 3 liters of boiling water. Bring the cooled “tea” to a volume of 10 liters. Now the composition is ready for spraying cucumbers.

You can spray cucumber bushes against downy mildew at any time and at any frequency. For sick plants, the more often the better. But set aside clear weather without wind for this, so that the effect of the procedure is maximum. Can be sprayed for preventive purposes.

Use of chemicals

You can use chemicals and biochemical preparations even at the stage of preparing seed material for sowing. This is better than treating downy mildew on cucumbers, which always causes yield losses:

• Gamair;
• Adirin-B;
• Fitosporin-M.

To prevent downy mildew, cucumber seeds should be kept in a fungicide solution for 100-120 minutes. After the procedure, the seeds are rinsed under running water and dried. Then you can sow them as seedlings or in open ground. Liquid consumption is 1.5 liters per 1 kg of seed material.

During the period of stem growth, to combat downy mildew on cucumbers, you need to spray the bushes with one of the following preparations:

• Vitaplan (consumption – 2-3 liters per are, frequency – 2-3 weeks);
• Fitosporin-M (consumption – 10 liters per are, frequency – 1.5-2 weeks);
• Proton Extra (consumption – 10 liters per hundred square meters, frequency – 1-1.5 weeks);
• Profit Gold (consumption – 5 liters per hundred square meters, frequency – 1-2 weeks);
• Gamair (consumption – 10 liters per ar, frequency – 2 weeks).

After using chemicals to treat cucumbers for downy mildew, the condition of the plants may worsen. To keep them viable, test the solution on a few bushes first. If they don’t get worse within a day, feel free to spray the product throughout the plantation.

If your cucumbers do not produce fruit every year due to damage to the garden by simple or downy mildew, do not neglect chemicals even during the period of ovaries and fruiting. You won't be able to harvest for at least a week because it will be inedible. But this way you will be able to enjoy the fruits for the rest of the season.

Cucumbers. Their climbing two- and three-meter vines with large leaves, which are akin to maple, are strewn with more than a dozen treasured greens with pretty yellow flowers. With the exception of the latter, each puzzle with such a wonderful plot is presented in turquoise and light green colors. And it also happens that you have to “ring the bells.” The reason for this is powdery mildew on cucumbers. Well, she knows how to bring gray into the colorful days of a summer resident. In addition to it, there is also the so-called. downy mildew (peronosporosis), due to which the leaves of cucumbers are first covered with colorless pigments on the underside. Quickly corroding the tops layer, fungal spores emerge in the form of small brown inclusions. It’s good that the measures to combat powdery mildew and downy mildew are the same.

Shaking will not help - “surgery” is needed

Downy mildew on cucumbers

• Firstly, it is better to use scissors or pruning shears to remove diseased cucumber foliage, because It is difficult to tear the thick stalks by hand;
• Secondly, the stalk should be cut at a distance of 2-3 cm from the main stem, so that in the future the cucumber will spend less energy on the problem area, while receiving contaminated liquid in return;
• Thirdly, the remaining tip immediately releases juice, and this is stress for the plant. To stop the “bleeding”, the branch must be smeared with garden varnish or pollinated with wood ash;
• Fourthly, it is advisable to burn the cut “tops” or at least take them away from the beds.

In general, pruning of cucumber leaves should be done in cases of mosaic disease, fusarium, etc. But spores of harmful fungi, flying through the air, can easily cover the entire plant. Accordingly, in the fight against dew, it is better to focus on the growing conditions than to treat the symptoms themselves, which is precisely the disease.

On a note! When neglected, common and downy mildew on cucumbers enters an acute phase, making the affected parts yellow and dry. Powdery mildew and peronosporosis also affect grapes, gooseberries, peaches, tomatoes, beets, garden roses, and pumpkin crops.

Video “Downy mildew on cucumbers, control measures”

Moisture and moisture are different

Just as mushrooms grow throughout the forest after a long rainfall, so spores of the harmful mycelium of powdery mildew cover vegetable and garden crops after regular spraying and even watering. The culprit has been identified - excessive humidity.

Moreover, we are talking about high humidity of the air and the ground at the same time: the soil evaporates moisture upward, making the atmosphere “bathhouse”. Therefore, powdery mildew on cucumbers in a greenhouse is less common than on cucumbers growing in the open air: in the unstable climate of Russia, temperatures of +20-25 °C sometimes alternate +15-18 °C, which contributes to the formation of “frost” on the top and large leaves. The corresponding fluctuation often occurs in May and August, when cucumbers are young or ripe. But the retention of moisture inside the soil provokes excessive evaporation, which is why the lower leaves of the cucumber “rust”, because suffer from peronosporosis.

To reduce the risk of diseases, growing young cucumbers through seedlings, as well as their prevention, makes sense by default. In this case, you will have to pay a lot of attention to watering. It must be carried out strictly according to schedule, guided by growing conditions:

How to water cucumbers correctly

Powdery mildew on cucumbers, how to water

The question is, how to get rid of powdery mildew, which is caused by excessive moisture, if you have to water the cucumbers quite often? It’s simple – you need to use an integrated approach:

• Firstly, the watering regime implies not only a schedule, but also water consumption. This indicator varies depending on the age of the cucumbers (the larger the bush, the greater the consumption), but in any case, the volume of water consumed should be such that by the time of the next watering the land where the crop grows has time to dry out a little;
• Secondly, cucumbers do not tolerate cool and especially cold water. It sits in the ground for a long time and causes stress in the plant, causing the leaves and greens to curl;
• Thirdly, the prevention of powdery mildew necessarily involves enriching the soil with phosphorus and potassium. Wood ash is rich in the last element, which is why it is so often recommended to pollinate the ground and leaves of cucumbers. Phosphorus is produced by superphosphate, as well as complex fertilizers. But root feeding with nitrogen fertilizers like saltpeter or urea should be completely abandoned, because they increase the acidity of the soil, after which the latter becomes heavy, which impairs the ventilation of the root system;
• Fourthly, downy mildew first covers the lower leaves, which indicates waterlogging of the soil. To ensure that the latter evaporates less moisture, it is recommended to cover it with mulch in the form of straw, tree leaves or agrofibre. By the way, with a mulched layer, the soil stores more moisture, so the watering schedule can be reduced;
• Fifthly, cucumbers need to be provided with good lighting. Shade reduces air temperature and promotes humidity, so green vegetable beds must be cleared of weeds and thinned. This is especially true for seedlings, which some gardeners often plant densely;
• Sixth, small but constant watering is better than abundant watering. Accordingly, it is more beneficial to moisten the soil with a drip tape than with a watering can. The use of the latter is a tradition for many, but because of it, water often gets on the stems and foliage of the vegetable, which only contributes to powdery mildew on cucumbers.

On a note

The soil can be of different types - sandy loam, loamy, peat, turf. The latter is a good option for growing cucumbers, but to get it, you need to go to a forest planting. Sandy loam soil does not store moisture well, loamy soil is viscous, peat soil is nutritious but “sour.” Therefore, to prevent various diseases, including powdery mildew, cucumbers should be grown in mixed peat-turf substrates.

But how to fight for the future health of cucumbers if there is no way to prepare universal soil? It’s simple: when choosing a site, it makes sense to at least be guided by the vegetable crop that grew the previous season. The fact is that the soil can be contaminated, so the best predecessors for cucumber are legumes and root vegetables; acceptable - tomato, cabbage and bulbous; the worst are potatoes and pumpkins, especially cucumbers themselves.”

Cucumber variety resistant to powdery mildew

Choosing a cucumber variety that is resistant to powdery mildew

The fight against powdery mildew on cucumbers can be completely eliminated if you use resistant cucumber hybrids. They are bred by breeders by crossing several varieties in humid conditions. The mark “F1” indicates hybridity. Among the relevant representatives, the most well-proven ones are:

• Anyuta F1;
• Voyage F1;
• Darling F1;
• Pasadena F1;
• Octopus F1;
• Murashka F1;
• Boy with Thumb F1;
• Darling F1;
• Crane F1;
• Fontana F1;
• Phoenix plus F1;
• Benefit F1;
• Sir F1;
• Princess F1;
• Ibn Sina F1;
• Julian F1 et al.

Moreover, some hybrids have complex resistance to common diseases of cucumbers - ascochyta blight, mosaic blight, fusarium blight, tobacco mosaic. Adequate immunity is not a guaranteed panacea. Moreover, when choosing cucumber seeds, you must also pay attention to their ability to self-pollinate, early ripening, taste, suitability for preservation, etc.

We use drugs

Despite the abundance of techniques and means to prevent “whiteness” and “rust”, many vegetable growers, hoping for chance, are faced with thematic scourge “head-on”, and only then take up the treatment of powdery mildew on cucumbers. Well, better late than never. The following table suggests considering the most effective drugs in the fight against powdery mildew.

Table “Preparations for powdery mildew”

• On a note!

To prevent downy mildew, control measures are kept to a minimum, it is better to spray cucumbers with biofungicides and fungicides in advance - 2-3 times during the entire growing season, i.e. every 2.5 weeks.

Although biofungicides can be used during fruiting, vegetables treated with them are allowed to be consumed 2-3 days after treatment. Also pleasing is the presence of useful micro- and macroelements in the composition of biofungicides.

Folk remedies

In addition to industrial preparations, powdery mildew can be combated with folk remedies. They are less effective, but economical and natural, which makes them suitable for use even during the period of active formation of ovaries.

• Soap and soda solution.

When you mix a teaspoon of soda and soap in 10 liters of water, you get a good antifungal solution, which should be sprayed on cucumbers once a week for 2-3 weeks.

• Horsetail solution.

To prepare this remedy, you must first boil “tea” from 100 grams of field grass and a liter of water for 2 hours. Next, one part of the solution should be diluted with 5 parts of water, after which the solution is ready for spraying. Treatment is carried out 4 times every 3-4 days.

• Garlic infusion.

To the question “there is powdery mildew on cucumbers, what should I do?” was solved in a week, you can infuse medium garlic in water at room temperature. The resulting tincture remains to be strained so that it does not clog the spray bottle.

On a note! To prepare a soap-soda solution, it is better to use tar soap instead of regular soap. The dissolution process of soap is accelerated if it is liquid. Also, powdery mildew mycelium does not tolerate wood ash: natural soot absorbs moisture and generally serves as an excellent disinfectant for a septic tank. Accordingly, it is very beneficial to use it in conjunction with folk remedies.

Video “Powdery mildew on cucumbers, what to do”

Prevention of powdery mildew infection of cucumbers

Although cucumber is a moisture-loving vegetable, you should not overdo it with watering. Otherwise, powdery mildew on cucumber will not be long in coming; measures to eliminate it are as follows:

• sustainable hybrid “F1”;
• Planting in well-lit and high-quality soil, where a foreign crop previously grew;
• Laying a mulch layer on top of the topsoil;
• Optimal watering regime;
• Fertilizing with phosphorus-potassium fertilizers;
• Thinning and loosening of beds;
• Preventive spraying.

It turns out that powdery mildew is easier to prevent than to treat. An integrated preventative approach seems difficult, but it is better to apply it in a timely manner than to lose 50-100% of the harvest due to disorganization.

Video “A word from the agronomist about cucumbers”

When summer becomes cool and rainy, many summer residents are worried about the problem: how to protect their own beds with cucumbers from a disease such as powdery mildew. This is a fairly popular virus, which, unfortunately, many gardeners need to fight. In our article, we will look in detail at what powdery mildew means, why it occurs on cucumbers, and what measures are available to combat it. So, how to save cucumbers from powdery mildew?

Powdery mildew on cucumbers is one of the well-known diseases that brings a lot of trouble. If no action is taken against it, the affected cucumber plantings will disappear and there will be no harvest. In addition, in places where plants suffered from powdery mildew, new plantings may become infected the following year.

Downy mildew of cucumber

This disease easily destroys entire fields of cucumbers if you do not pay attention and help the crop in a timely manner:

1. Downy mildew is expressed by yellow-green spots with a light green coating, which instantly attack the upper lobes of the cucumber leaf.
2. The spots can be of various shapes; they quickly spread to all plants, forming a purple coating on the bottom of the leaves.
3. More often, the disease manifests itself in mid-July (in greenhouses and in June), and rapidly affects not only the plant itself, but also all surrounding plantings.

Downy mildew of cucumbers expands due to condensation, significant environmental moisture, temperature differences at night and during the day, due to cold watering, cold morning dew and fog. It spreads very quickly, as it is also carried by the wind.

Causes of powdery mildew

Causes of powdery mildew disease in cucumbers and conditions if the fungus expands the most:

• sudden change in air temperature; frequent rains; moisturizing with cold water;
• dense plantings, in which cucumbers are not ventilated and do not dry out for a long time after rain;
• dried parts of last year's plants were not removed from the garden in the autumn;
• an untidy area overgrown with weeds;
• little sun illumination of the beds;
• there is an excess of nitrogen in the soil, and a deficiency of phosphorus or potassium.

Signs of defeat

Infection usually occurs at the beginning of summer, when the heat is replaced by rain and a sudden cold snap. The initial indicator of cucumbers being affected by this disease will be the appearance of a white or yellow coating on the body leaves and on the bases of the plant shoots. In addition, small brown balls (spores) can be noted on the greenery.

Have you confused powdery mildew with downy mildew?

YesNo

After these spores have matured, droplets of moisture appear on the surface of the plaque - this explains the name “powdery mildew.” In advanced cases, the plaque becomes very dense and takes on a brown tint. It rises from below and attacks the entire plant - its stems, cuttings, flowers, leaves, stalks and fruits. The plant becomes lethargic and unhealthy.

Ways to fight

How to fight powdery mildew on cucumbers? At the initial stage of the disease, it is recommended to use biological substances (preparations for powdery mildew on cucumbers):

• "Albit" - the drug effectively functions against the fungus regardless of atmospheric conditions and temperature changes. In addition to its medicinal and protective properties, it exhibits an immunostimulating effect, can help the plant regenerate after exposure to chemical pesticides, and promotes the development of additional stems and the formation of the root system.

• "Alirin-B" - treats powdery mildew and other fungal diseases, restores microflora in the soil, reduces the essence of nitrates in fruits. Treatment of cucumbers against powdery mildew occurs as follows: soap is added to the solution for better adhesion to the leaves and sprayed.

• "Gamair" - inhibits the influence of pathogens of fungal diseases, renews the soil, reduces its toxicity, activates plant growth and increases immunity. Biological substances are used repeatedly, including when the first signs of powdery mildew occur, and until the disease completely stops.

Chemical fungicides

How to spray cucumbers against powdery mildew? If the spores have covered a significant part of the plant, it is necessary to use chemical fungicides:

• "Bayleton" - the protective effect lasts up to 4 weeks, depending on atmospheric conditions.
• “Raek” - the effect occurs 2 minutes after treatment, the protection lasts approximately 7 days. Doesn't wash off in the rain.
• "Tiovit-Jet" - the protective effect lasts up to 7 days, it can also be used to eliminate ticks.
• “Topaz” - the effect lasts for 1-2 weeks, is used for prevention and treatment. So it has eradicating qualities.

Expert opinion

Filatov Ivan Yurievich, private farmer for more than 30 years

In order to cure powdery mildew on cucumbers, it is possible to combine the use of biological and chemical substances. Chemical agents are the most effective, while biological ones reduce their toxicity and restore plants from stress after a disease.

Folk remedies for combating powdery mildew on cucumbers

Folk remedies are used for prevention or at the first signs of the appearance of fungus. In a difficult situation, when the disease covers large cucumber plantations, and in addition to the leaves, the stems and ovaries are infected, the fight against powdery mildew on cucumbers has little chance. Of absolutely all the products, fermented milk products performed best:

• curdled milk;

• serum;

• kefir.

The ratio of substances is approximately this:

1. 1 part to 10 parts water at room temperature.
2. The whole plant is thoroughly mixed and cultivated.
3. Soda ash - 1/3 teaspoon diluted in 1 liter of water and add a little soap solution.
4. Wood ash - 1 liter jar of ash per 5 liters of boiling water. Leave for about a day, strain, and add liquid soap.

It is best to start using all these resources in this case if the weather begins to be damp, or dew lingers for a long time in the morning, and fog rises in the evening. Cultivate once a week, moistening all cucumber plantings and the ground near them with the substance. The disease may occur, but it will not develop.

Prevention

The first step in preventing powdery mildew on cucumbers in your beds is maintaining crop rotation. It is necessary to constantly change the places for sowing the same crops, since over time in one place there is a great possibility of the proliferation of microbes and diseases typical of a particular plant. Also, to get a healthy harvest, you need to follow some more rules:

1. Fertilizing with potassium and phosphorus fertilizers increases the resistance of cucumbers to this disease.
2. Every autumn you need to thoroughly dig up the beds, removing absolutely all residues and weeds.
3. To prevent powdery mildew on cucumbers in greenhouses, it is necessary to carefully monitor the maintenance of suitable moisture and a temperature of 23-25 ​​degrees.
4. The first stems and leaves treated with plaque must be immediately destroyed and burned.
5. Sowing hybrids that are resistant and invulnerable to this virus will reduce your chances of “getting to know” it.

Video

In this video you can see ways to combat powdery mildew on cucumbers.

Diseases of cucumbers are especially active in the second part of the summer period, which is associated with the occurrence of cold pre-dawn dew. Some of them attack plantings at the very beginning of the growing season. One of the most dangerous fungal diseases, which can provoke a large loss of yield, is called powdery mildew on cucumbers. How to recognize the disease and begin to take measures, what effective methods of prevention exist, read our article.

What is this

Warm and damp weather conditions are favorable factors for the spread of the virus. 3-4 days after heavy rainfall, outbreaks of powdery mildew can already be observed on cucumbers. She prefers temperatures between 16–22 degrees and a high degree of humidity. Spore formation also requires plenty of light. A decrease in the immunity of vegetable crops to pathogenic effects is facilitated by sharp changes in day and night air temperatures.

The causative agents of the virus often remain living in last year’s plant debris that overwintered on the site.

Signs

Certain plant conditions contribute to the infection of plantings by ashtray:

• cool and damp weather;
• plantings thickened beyond the norm;
• high nitrogen content in the soil structure;
• excessive drying and subsequent flooding of the soil;
• watering the area at a time when the top layer of soil is still quite wet.

The hallmark of the disease is a white fluffy coating on the surface of the foliage. The first signs of damage to cucumbers by a spore-bearing fungus are round whitish spots or light reddish spots. First they can be seen on the top of the leaf, and later on the bottom. Over time, they colonize all green areas, right down to the shoots and roots. Some lashes, in case of severe damage, can dry out. The leaves become curled and have a loose surface. Plants are weakened, there is an acute lack of oxygen, which often provokes their death.

Very favorable conditions for the appearance of ashtrays exist inside the greenhouse. There, air humidity can go off scale up to 80% and there is droplet moisture. The first signs of the disease can be observed near open windows. Often the disease can be seen on the foliage of cucumbers, less often it is located on the cotyledons. The infection spreads from leaves and shoots located close to the soil surface. Fruits infected with the virus are prone to cracking and rotting.

Video “Signs of powdery mildew on greenhouse cucumbers”

See what greenhouse cucumbers look like with leaves affected by powdery mildew.

How to fight

As soon as you notice the first signs of the disease, you should take immediate action. Before starting treatment of plants, you need to exclude any types of spraying, stop fertilizing, improve the level of illumination of the plantings, thin them out and remove old and weakened leaves, and cut off flower stalks. After such manipulations, it will be possible to effectively fight not only the mycelium, but also fungal spores.

Modern gardeners and gardeners often use chemicals to combat fungal infections:

• Topaz, which is used by many to fight the virus, is a popular systemic drug whose active ingredient is penconazole. It is used for treatment at the rate of 1 ampoule of the product per 10 liters of water. Spray with the freshly prepared solution. Treatment frequency: every 2 weeks. The drug in the process of treating plantings is moderately dangerous to human and animal health.
• Tilt CE for the treatment of plants with the active ingredient propiconazole is offered in a convenient emulsion form. It tends to suppress the formation of spores. The effectiveness of the drug is enhanced by high ambient temperatures. The product quickly penetrates the plant tissue. A solution to combat the disease is prepared at the rate of 0.4 - 0.5 ml of the drug per 1 liter of water. The protective effect appears a few hours after treatment and lasts for more than 2 weeks. The product is dangerous for bees and fish.

You can also treat vegetable plantings to combat fungal infections with the drugs Sulfarid, Bayleton, Fundazol, Previkur, Skor, Vitaros, Acrobat MC. In the initial stages of the disease, it is permissible to fight the disease with sulfur-containing drugs, such as Tiovit Jet or VDG. Copper-containing ones are also effective - oxychloride, Bordeaux mixture in the proportion of 1 teaspoon per 10 liters of water.

There are quite a variety of folk methods of control, which have proven themselves well among gardeners over many years.

A soap and soda solution has always helped get rid of a fungal infection. To prepare it, take 5 grams of liquid soap, 25 grams of soda ash per 5 liters of boiling water. The plants will need to be treated several times, after a break of 7–10 days.

A solution of whey at the rate of 1 part to 10 parts of water is also used to combat the disease. Treatment is done 3 times with an interval of 3 days.

Horsetail decoction – 100 grams of horsetail per 1 liter of liquid. It's not difficult to prepare. Horsetail is filled with water and kept for 24 hours. Cools and strains. Before spraying, dilute with water in a ratio of 1:5. Plants are sprayed with it 3 times every 5 days.

Copper sulfate in an amount of 5 grams is combined with 50 grams of soap and 5 liters of water. The resulting emulsion should be used to treat the plantings at least 2 times, taking a break of 1 week.

Mustard solution will also help in treatment. To prepare it, 2 tablespoons of mustard powder are stirred in 10 liters of warm water. Next, the vegetables are watered.

Among folk methods of struggle, treating cucumbers with a solution of soap and ash is popular. It will require 1 kg of ash per 1 bucket of water. The solution should be infused for about 1 week. Before treatment, which will be carried out every day or every other day, add a little soap.

A solution of rotted mullein will also come to the aid of cucumber plantings - 1 part to 3 parts water. It is infused for about 3 days. Before use, dilute with water, increasing the volume by 2 times.

Garlic infusion – 50 grams per 2 liters of water. The garlic is crushed, placed in cold water for 1 day, then filtered.

Another recipe for fighting the disease is 80 grams of copper sulfate, 50 grams of soda ash, 10 liters of water.

You can try treatment with a solution of colloidal sulfur. To prepare it you will need 40 grams of sulfur per 10 liters of liquid.

In addition to powdery mildew, there is also downy mildew, called penosporosis. It is distinguished from powdery mildew by the presence of yellow spots on the surface of the leaves, not white ones. Since it is even more difficult to fight with it than with ashtray, it is better to take preventive measures: you should not sow the seeds too thickly, you need to adhere to the rules of crop rotation, you should not water the crops with cold water, you need to harvest on time.

If the appearance of downy mildew cannot be avoided, measures must be taken to treat it. Such drugs as Kuprosat, Ridomil, Oxychrome will help with this. Traditional recipes are effective against the false form of the virus, for example, spraying with whey in combination with copper sulfate (1 teaspoon per 3 liters of whey and 1 bucket of water).

How to warn

Experts advise growing cucumber varieties that have lasting immunity to the disease. These are Ofix, Swallow, Phoenix, Golubchik, Octopus, Pasadeno, Pasamonte.

Sanitary cleaning of the area (removal of plant debris and weeds) and adherence to crop rotation rules (returning pumpkin crops to their usual place no earlier than 3 years) are used as preventive measures. Preventive measures include isolating crops to prevent the virus from being affected by the virus at a distance of more than 20 meters from similar crops. It is also necessary to regularly thin out the plantings and remove old leaves from the cucumbers that touch the surface of the ground. It is important not to apply a lot of nitrogenous fertilizers and to feed the crops with phosphorus-potassium fertilizers in a timely manner.

There is a type of disease prevention tested by many gardeners.

Even before the leaves bloom, namely in early spring, the bushes on the site are scalded with boiling water. This is done quickly using a watering can with a diffuser.

This effect does not harm plants waking up after hibernation, but it leads to the death of fungal infections. It is permissible to resort to the help of a household steam cleaner - a jet of steam, which is supplied under high pressure, has a similar effect.

Video “Ways to counteract powdery mildew”

In this video, an experienced gardener will tell you what needs to be done to prevent and treat one of the most common fungal diseases that affects gardens and vegetable gardens.