Protection of grapes from powdery mildew. Powdery mildew on grapes how to fight

Powdery mildew, or powdery mildew, is considered one of the most dangerous diseases of grapes. It is possible to detect signs of this ailment with the naked eye - infected plants give out a white powdery mushroom bloom, after some time acquiring a light grayish tint. Powdery mildew was first introduced from North America to England, where it was discovered in a greenhouse by a local gardener Tucker in 1845. And already from 1850, this attack began to spread to other European countries.

A few words about the disease

On grape leaves affected by powdery mildew, a powdery white coating is formed. As the dangerous ailment develops, the leaves curl and gradually dry out. Severely affected leaves are often necrotic and turn yellow.

The first symptoms of the ill-fated powdery mildew can be observed as early as May, when the thermometer rises to twenty-five degrees. And if the air humidity is 70% or more, then the disease can quickly spread throughout the vineyard.

Young shoots are characterized by stunted growth. They turn brown and subsequently die off, never having time to ripen by winter. Infected flowers, densely covered with a mealy bloom, turn brownish and crumble. And infected berries stop growing, dry up, crack and quickly fall off.

Powdery mildew spreads in summer by wind-blown conidia.

How to fight

Shoots and berries affected by powdery mildew should be promptly eliminated from the plots. In autumn and spring, the soil is dug under the grape bushes, and in the spring it is also mulched. Good vineyard care along with high agricultural technology can significantly increase the resistance of plantings to powdery mildew infections. Help to increase the resistance of grape bushes to ailment and phosphorus-potassium fertilizers applied in increased doses. But an excessive amount of nitrogen fertilizers, on the contrary, reduces their resistance to this scourge.

Planting grape varieties that are better resistant to powdery mildew. As a rule, varieties of American selection are considered the most resistant.

The so-called bacterial method has proven itself well in the fight against powdery mildew. Its essence lies in the fact that, first, well-rotted manure filled with three parts of water is infused for three days. Then the resulting infusion is diluted with water in a 1: 2 ratio. The strained composition is sprayed with grape plantings. This method is based on the ability of bacteria in the manure to destroy powdery mildew. If the need arises, such processing can be repeated after the berries are harvested.

Spraying with fungicides is also used against powdery mildew of grapes. Before the buds bloom, spray not only the grape bushes, but also the soil under them. The air temperature for carrying out such treatments should exceed four degrees, but at the same time it should not rise above twenty degrees.

If necessary, the use of Bordeaux liquid is also allowed, and if the vineyards are too strongly affected by powdery mildew, potassium permanganate can also be used (it is taken in 20-30 g for every ten liters of water) with further pollination of the grape plantings with colloidal sulfur (1%).

In order to protect against powdery mildew at the beginning of the growing season, preventive treatments are carried out with the contact fungicide "Tiovit Jet", and especially susceptible varieties are treated with the "Topaz" fungicide before flowering. As soon as the grapes have faded, two to four treatments with "Topaz" are carried out, and when the berries in the bunches close together, the vineyards are sprayed with the "Quadris" preparation. Well, in order to reduce the wintering stocks of the pathogen of powdery mildew, after the berries are harvested, another treatment with the Tiovit Jet fungicide is carried out.

Recently, many summer residents have been faced with a disease such as powdery mildew (powdery mildew). This disease affects almost all horticultural crops, especially grapes. The harvest that the bushes affected by fungal diseases give is unsuitable for food or for winemaking. Let's consider why powdery mildew appears on grapes, how to get rid of the disease, and what preventive measures can be taken to prevent it.

The reasons for the appearance of powdery mildew on grapes

Oidium is a fungal disease. We will not delve into the peculiarities of the reproduction of fungi that provoke the disease. It is enough for a summer resident to know that with high humidity, the disease develops at a rapid pace. An excessive amount of nitrogen fertilizers also contributes to the appearance and development of the disease.

Signs of powdery mildew

The disease can be determined both by the appearance of the plant, and by the slower rate of its growth. The grape leaves begin to curl inward. However, the same thing happens with a plant damaged by a leaf roll. But, if you unfolded the leaf and did not find any pest or cobwebs, then the matter is in powdery mildew.

Also, a sign of powdery mildew is the presence of brown spots on the shoots and leaves of the plant, slow growth of grapes. If we are talking about the flowering period, then under the influence of a fungal disease, the flowers dry out, and brown spots appear on the berries. Over time, the bunches of berries dry out, not having time to ripen.

Methods of dealing with fungal disease

Currently, there are 3 groups of methods to get rid of powdery mildew:

• biological;
• chemical;
• folk remedies.

Let's take a look at each of these methods separately.

Biological control method

For the treatment of grapes from powdery mildew, humus is most often used, which is prepared in a certain way. We take a container with a volume of 100 liters and fill it 1/3 with humus. Then, fill the container to the edge with water, the temperature of which is 250C. After that, cover it (best of all with thick burlap), and leave it warm for 6-7 days. During this time, stir the contents of the container every day. Before using the composition, filter it through cheesecloth folded in several layers. As a result, we get a concentrated saprophytic microflora that effectively fights against fungal diseases.

The resulting solution should be sprayed with grapes at the beginning of spring, when it released the first leaves and buds appeared. To process the plant, we use a sprayer, into which we pour the prepared solution. We process the grapes in the afternoon, and preferably in the evening. For processing, you should choose cloudy, but not rainy, weather.

To prevent the appearance of powdery mildew throughout the entire period of flowering and ripening of grapes, it should be processed 2 more times: a week after the first treatment and before the plant blooms.

If the degree of infection is high, then after the grapes have faded, we spray it with concentrated saprophytic microflora several more times. There should be an interval of 7 days between treatments.

The use of a biological method of combating powdery mildew allows not only to get rid of the fungal disease, but also to strengthen the plant.

Chemical control methods

This method involves the use of insecticides. Despite the fact that it is the most effective, summer residents resort to it only if nothing else helps. This is due to the fact that all insecticides, without exception, contain substances that are unsafe for health, which, together with the berries, enter the human body. Each product's packaging indicates how long before harvest it can be used. These recommendations must be strictly adhered to.

When choosing how to treat grapes from powdery mildew, you should pay attention to the chemical composition of the drug. Phytosporin is most popular today. This preparation is prepared on the basis of hay sticks. Scientists to this day cannot come to a single conclusion regarding the harm of this substance. But, they unequivocally agree that this drug is the most harmless among insecticides for fungal diseases.

In addition to phytosporin, preparations such as strobe, topaz, thanos, tiovit and chorus are effective in the fight against powdery mildew on grapes. Some drugs come in powder form, some in concentrate form, and some in paste form. It is most convenient to work with concentrates that just need to be diluted with water in a certain proportion.

After the appearance of the berries, and throughout the entire fruiting period, it is impossible to use chemical methods to combat powdery mildew.

Folk recipes

Many summer residents know how to deal with powdery mildew without using insecticides. The advantage of folk remedies is their harmlessness. Consider the most popular recipes for powdery mildew.

Recipe 1

To prepare a solution that can be used to treat grape bushes from powdery mildew, we need 4 g of soda ash and laundry soap, 1 liter of water. You should use water that has stood for some time. First, dissolve the baking soda in water. Then, add soap to the resulting solution.

The resulting solution is used to treat powdery mildew on grapes. You can process the plant at any time, regardless of whether the berries have already appeared or not. To cure grapes, processing must be done 2 times with an interval of 7 days.

Recipe 2

Ash, which must be dissolved in water and green soap, will help get rid of a grape disease such as powdery mildew. For 7 liters of liquid, you need to take ½ a bucket of ash. We leave the resulting solution for 24 hours so that it is infused. Then, dilute the solution with water, in a 1: 1 ratio and add 10 g of soap. The product is ready to use.

If there is no time to wait until the ash is infused in water, it can be boiled (20-30 minutes).

Recipe 3

To prepare another remedy that can be used to treat powdery mildew, we need straw dust and water. Instead of straw dust, you can take manure. We take the ingredients in a 1: 3 ratio (for 1 part of dust or manure, 3 parts of water). We leave the resulting mixture for 72 hours. After the expiration of time, add 3 parts of water to the solution. The product is ready to use.

It is necessary to process the leaves and stems of the grapes affected by the disease in the evenings. This can be done with any frequency. If we are talking about preventive treatment, then it is enough to spray the plant 3-4 times per season. If the grapes are affected by powdery mildew, then it is advisable to spray it several times a week.

In addition to the above recipes, iodine, potassium permanganate and soda are suitable for processing grapes.

Prevention of powdery mildew on grapes

Treating grapes from powdery mildew is not an easy task. It is much easier to prevent the appearance of a fungal disease than to treat it.

Agrotechnical measures such as tying up shoots and breaking them off will help prevent the appearance of fungal diseases, one of which is powdery mildew. You should also pay attention to weed control. In the presence of a large number of harmful plants, humidity rises, which contributes to the appearance of fungus. Also, the agrotechnical measures used to combat powdery mildew include pinching.

There are video and photo tutorials describing how to properly tie up shoots and take care of bushes. But, in fact, the only thing that needs to be done is to ensure good air circulation. If the grapes are sick, then the damaged shoots and leaves must be broken off and burned or taken away from the summer cottage.

The use of sulfur for the prevention and treatment of disease

As a preventive measure, you can treat the plant with sulfur solution. To prepare it, you will need 10 liters of water and about 35 g of sulfur, which can be purchased in specialized stores. Processing is carried out in the morning or evening. If you spray grapes in bright sunny weather, burns will appear on the leaves and berries, which will negatively affect the plant's yield. This solution can also be used to combat powdery mildew. But, the concentration of sulfur will have to be increased. For 10 liters of water, an average of 90 g of sulfur is taken.

ASH A MIRACLE FOR OIDIUM. FLOURY DEW ON GRAPES vselennaya uvlesheniy

Oidium grapes. Control measures.

A sign of downy mildew is the presence of oily spots on the leaves, on top of which, when the air humidity rises, a white bloom appears. When the disease spreads, white bloom appears on the berries. With oidium, the berries and leaves are covered with brown spots.

How much work and care goes into growing a good harvest of grapes! But it is far from always possible to protect him from diseases and other dangers.

One of the most common grape diseases that can destroy a significant part of the harvest is powdery mildew, which is otherwise called powdery mildew.

Oidium affects primarily the berries, but also the leaves, stems - the entire bush, or rather, the entire aerial part of the bush.

The appearance of a grayish silvery or off-white bloom, similar in consistency to flour, is most often first noticed on the upper side of the leaves. In case of severe damage, a gray coating covers the grapes, leaves on both sides and green shoots. The grape bush looks like it has been showered with ash.

Ripening berries, if affected at an early stage of development, very often crack. At the same time, their seeds look outward.

The berry may not stop growing, but it remains very acidic, and a rough scar appears at the site of the cracking. However, the berries often stop growing and dry up after a short time.

If the leaves and berries are already formed, they are not affected by powdery mildew, unlike the young and ripening parts of the plant.

A heavily diseased bush is densely covered with a gray bloom, many leaves curl, the berries dry out. Such a bush can emit an unpleasant specific smell, comparable to the smell of rotting fish.

Oidium is a fungal disease.

Its pathogen is called Uncinula necator Burr. (or Oidium tuckeri Berk.). In Europe, oidium has been known since the middle of the 19th century, when it was imported from North America along with plant foods.

In the form of mycelium, the culprit of the disease hibernates in the body of the plant - in tissues such as buds or annual shoots. It is also found in leaves and bunches fallen in autumn. That is why it is important to remove and destroy a variety of organic waste before wintering so that pathogens do not appear in the spring.

In the spring, the mycelium forms the so-called conidia (spores). When warm days come, short chains of conidia are picked up by the wind and carried around the area over considerable distances, affecting new vineyards.

Primary infection of plants proceeds practically without external signs. The appearance of powdery mildew on grapes is already the second stage of the disease.

The smallest spores can cause multiple waves of infection in just one season. For the development of the disease, high humidity is not necessary, and the temperature range is from + 5˚C to about + 35˚C. If the winter has been mild and the spring is warm and humid, symptoms of the disease may appear very early. And most of all, the youngest shoots will suffer.

It is important to plant the vines correctly, taking into account the prevailing wind direction.

You should carefully look after the soil, do not abuse mineral fertilizers, get rid of weeds. The bushes should not be too dense and evenly lit.

So, what to do and how to deal with powdery mildew on grapes? Chemical treatment consists of spraying with one or two percent lime-sulfur broth. You can use a 1-2% solution of DNOC (dinitroorthocresol), but you need to constantly remember about its high toxicity and observe safety measures.

Here are a few more fungicides that are effective against powdery mildew:

Another effective way: processing grapes with 1% suspension of colloidal sulfur or 0.5% suspension of 80% sulfur powder. If the weather is hot (over 20-25˚С), spraying is replaced by dusting with finely ground sulfur.

Sulfur preparations rarely last more than 10 days. After that, new viable spores of the fungus appear, within a matter of days they germinate, and the disease gives another round. Therefore, if the vineyard is heavily affected by powdery mildew, the treatment must be repeated at least two weeks later. If heavy rain passes and the chemicals are washed away, the treatment is carried out again.

Sulfur prepared for processing must be completely dry and thoroughly ground. From the day of the last treatment with sulfur until the beginning of the harvest, at least 56 days must pass.

Of the folk remedies for combating powdery mildew on grapes, treatment with a solution of baking soda (from 0.5% to 1%) with the addition of laundry soap gives the best results. For 10 liters of water, take 50 g of soda and 40 g of soap. Baking soda has no side effects and is safe for children and pets.

The main condition is access of fresh air to all parts of the grape bush, good ventilation, aeration of the soil.

Drops of water or dew do not play a special role in the spread of the disease (this dependence is much stronger in another dangerous disease - mildew). On the contrary, the rains partially wash away the spores of the fungus, and the oidium does not develop too much.

Hot and dry weather encourages the spread of the disease, and leaves dry out, curl and fall off prematurely.

Many European grape varieties suffer from this disease. Among them:

You can get acquainted with the appearance of the affected areas and methods of struggle in the video below:

Do you see inaccuracies, incomplete or incorrect information? Do you know how to make your article better?

Do you want to offer photos on a topic for publication?

Please help us make the site better! Leave a message and your contacts in the comments - we will contact you and together we will make the publication better!

We fought this disease in this way.

They took rotted manure. They poured it with warm water and set it to brew for a week, covering the barrel with old rags. To keep the temperature inside. Then foliage and stems of grapes were processed. Then the treatment was repeated at intervals of 10 days. And so on until flowering. Surprisingly, this white bloom was no longer observed.

Materials: http://selo.guru/sadovodstvo/vinograd/bolezni-v/oidium.html

Fungal infections are increasingly attacking the berries in the garden, making the fruits unusable and unfit for further processing. Powdery mildew on grapes is the most common disease known to every gardener. Its second name is oidium. The "troublemaker" - the causative agent of the disease - lives only in living culture. The spores of the fungus overwinter in the scaly structure of the vine. At an external temperature of 18-25 ° C, the heat begins to actively germinate. The higher the humidity, the more actively the mycelium grows. Symptoms of grape disease vary at different times of the year. But the end is one - the plant loses flowers, fruits, leaves. Cracked, rotting berries are not suitable for further use.

How does this disease manifest?

External signs of powdery mildew appear in different ways at different times of the year. So in the spring, the presence of a disease can be judged by the following symptoms:

• the leaves are bent at the edges;
• brown spots appear on shoots affected by plaque;
• the growth of grapes slows down, and its tissues gradually die off. If the disease manifests itself in the summer, then the following signs indicate it: excessive fragility of the leaves;
• death of young bunches and flowers due to drying;
• the appearance on the peel of young berries of dark spots with a reticular pattern and cracks.

Chemical attack on powdery mildew

Modern drugs are distinguished by a wide spectrum of action. It is worth highlighting the fungicides that destroy the mycelium: Topaz, Arobat CM, Skor, Vitaros, etc. Two-time treatment is enough. But in severe cases, you need to do this 4 times with an interval of one and a half weeks.

Attention! During the ripening period of grape bunches, chemicals cannot be used to combat powdery mildew. You can get out of the situation by using complex preparations that are acceptable for processing during the entire ripening period.

But the most effective remedy for powdery mildew on grapes is sulfur. In the form of a suspension, it is actively absorbed by the fungus. Turning into hydrogen sulfide in it, the sulfur compound destroys and destroys the mycelium. Processing is done before sunrise or after sunset. Spraying frequency: every 15-20 days. Moreover, the compositions for prophylactic and therapeutic purposes differ. In the first case, the proportions are as follows: 10 liters of water to dissolve 30-40 g of the substance.

Getting rid of powdery mildew on grapes

In the second, 100 g of sulfur is taken for the same amount of water.

Biological methods of protection

The treatment of grapes is also carried out using biological methods. The easiest way is to prepare humus from saprophytic microflora in the spring. He prepares as follows:

• humus is placed in a one-liter barrel. Moreover, it must occupy at least a third of its volume;
• the container is carefully covered with dense burlap;
• the mass must be thoroughly mixed every day.

After six days, the substance will reach the desired condition. But immediately before use, it should be filtered through cheesecloth. The resulting liquid is poured into spray guns and sprayed in order to prevent fungal diseases on young leaves and shoots of grapes. The procedure is recommended to be carried out on cloudy days or in the evening after sunset.

The frequency of processing depends on the degree of damage to the grapes. It is advisable to spray the microflora twice during the ripening period with an interval of seven days. It is also recommended to process the plants just before flowering. And if the dew still spreads strongly, then you need to spray the microflora several more times after the end of flowering with an interval of one week.

The effect of this method is based on the penetration of beneficial microflora into the kidneys and the use of fungal spores as a nutrient. Thus, in the process of applying the biological method, a double effect is achieved: the grapes receive the nutrients necessary for it and harmful spores are destroyed.

Oidium grapes - treatment of the disease

Alas, the time of vineyards, completely free from diseases, has passed, fungal diseases have reached the northerners. And the most common disease is powdery mildew.

ODIUM: REFERENCE INFORMATION

OIDIUM (synonyms - powdery mildew, ashtray) is the most common grape disease.

the pathogen affects all green parts of the plant and lives only on living tissues, making the berries unsuitable for winemaking.

It causes the greatest damage in hot summers, especially after winter with temperatures not lower than -30 ° C. The spores of the fungus overwinter under the scales of the eyes and on infected shoots and germinate at a temperature of + 18 ... + 25 ° C.

It actively develops at high air humidity on a dry tissue surface. Powdery does not need drip-liquid moisture to germinate spores, so rains can stop the spread of the disease.

Choose varieties with high resistance, break out excess shoots, remove diseased parts and burn plant debris. Apply balanced fertilizers without excess nitrogen.

Signs of infection with powdery mildew

Spring: young leaves and shoots from buds infected since last year turn yellow, become covered with an off-white powdery bloom, mainly on the upper side. Separate spots merge, the edges of the leaves bend up and dry out. A bloom also appears on green shoots, and brown spots under it. When trying to erase it, a specific smell of spoiled fish is felt. With a strong lesion, the tissues of the shoots darken and die off, growth is impaired.

Summer: young bunches, flowers dry up, ridges become fragile. Young berries, the sugar content of which is not higher than 8%, become covered with dark spots during filling, then with the coloring of the berries, a mesh pattern appears on the surface of the skin and its corking. The berries crack, rot, and the seeds "look" out. The development of the fungus on the berries may continue until harvest.

The use of sulfur preparations for treatment

In a fine dispersed form, sulfur is absorbed by the cells of the fungus and, turning into hydrogen sulfide, acts on the spores of the fungus as a toxin.

In the south, treatments are started during the budding period, which prevents the appearance of powdery mildew on green shoots. Sulfur pollination is effective only at air temperatures above +20 ° C, and in cold weather it does not.

Treat bushes with sulfur-containing preparations in the morning or evening - in hot weather, burns may occur on the leaves and berries of grapes.

Consumption for prophylaxis - 25-40 g / 10 l, during treatment - 80-100 g / 10 l, waiting period - 56 days. If the air temperature is below +20 ° C, it is better to spray the vineyard with colloidal sulfur or sulfur preparations "Tiovit Jet" or "Cumulus DF".

The treatment is repeated after 10-20 days, during the season 3-6 treatments are carried out. It is convenient to apply complex fertilizer Plantafol 5:15:45 on the leaf, which already contains 12% sulfur.

Systemic and contact drugs to combat powdery mildew

Do not use chemicals during the ripening period. Potassium permanganate (5 g per 10 liters of water) will briefly stop powdery mildew.

"Topaz", "Horus", "Skor" are the most famous preparations for oidium. If you have oidium since last year, then in the spring, spray on the vine and young greenery with "Horus".

It is one of the few systemic drugs that "work" in cold weather. If these funds do not help, use the drug "Strobi".

There are reviews that a mixture of "Strobi" and "Tiovit Jet" can be used even while pouring berries, but "Strobi" no more than three times per season.

Good for the prevention of oidium "Talendo" and "Karatan", the latter - only after flowering.

For powdery mildew with associated rot, the combined fungicide "Switch", a new complex preparation (from powdery mildew and anthracnose) "CabrioTop" is effective.

Biological methods of combating powdery mildew

The most accessible and interesting technique was tested by Professor Gunvaldis Vesmins from Latvia. In the spring, a concentrate of saprophytic microflora is prepared from humus: a 100-liter barrel is covered by one third with sifted humus, poured with warm (+ 20 ... + 25 ° C) water, covered with burlap and kept warm for 5-6 days, stirring constantly. After 5-6 days, the microflora multiplies, competition for food begins.

The concentrate is filtered through cheesecloth and poured into a sprayer. For prophylaxis, freshly blossomed leaves and vines of grapes are treated.

The kidney scales are open, the saprophytic microflora goes directly to the awakened mycelium of the fungus. This is the nutrient substrate for our microflora. They are processed only on cloudy days or in the evening.

The second treatment is after a week, another one is before flowering. More often the team of Vesmins carried out only the first treatments when the leaves were blooming, not allowing the oidium to “bloom”. But if you have a lot of infection, especially if the autumn was without rain, then after flowering, at an interval of a week, you need to carry out a couple more treatments. So in Latvia they have been successfully fighting against powdery mildew for over 15 years.

Peter Crisp of the University of Adelaide discovered that milk fat and possibly whey protein feed the microorganisms living on the skin of berries, which compete with powdery mildew for space and eat its spores. Spraying with a 10% aqueous solution of milk or whey once a week helps control the spread of powdery mildew.

I hope now you, colleagues, have enough information to overcome this disease. Well, I personally "bet" on the Vesmins' method. Good luck to all of us.

FOLK MEANS OF PROTECTION AGAINST OIDIUM

1. Daily infusion: half a bucket of ash in 7 liters of water. Before spraying, dilute with water (1: 1) and add 100 g of green soap as an adhesive. Ash can not be insisted, but boiled for 20 minutes.

2. Pour fresh manure or straw dust with water (1: 3), leave for three days for fermentation. Process in the evening at any time, filtering and diluting 3 times more.

Fighting powdery mildew on grapes

One of the main problems that summer residents who grow grapes face almost every year is powdery mildew or powdery mildew. This harmful disease of grapes is widespread in all countries with developed viticulture, usually in areas with dry and hot summers. However, grapes can be saved. You will learn how to completely suppress powdery mildew in early spring so that in the fall the annual vine is free of infection even in the most susceptible grape varieties, you will learn from our article.

Signs of powdery mildew: how powdery mildew manifests itself on grapes

Powdery mildew (powdery mildew) - its causative agent is the erysiphoid mushroom (Uncinula necator = Oidium tuckeri ) that lives on the surface of shoots, leaves and berries.

Oidium on grapes usually begins to appear first. on leaves and young shoots(where he actually hibernates) with top (front or outside) side of the sheet as powdery gray-white bloom(as if sprinkled with flour) that can be easily wiped off with your fingers.

In the photo: oidium on grape leaves

By the way! But it always appears on the underside of the leaves.

Photo: oidium on grapes

And already after flowering, when the fruits set and they begin to ripen, a characteristic sign of the presence of powdery mildew on grapes is the fact that green berries crack (previously they also covered with a white bloom), thereby outward all their insides are turned inside out (seeds) that almost instantly start rot or dry out (depending on the weather), being affected by various bacteria and fungi, and highlighting the characteristic the smell of missing fish (rusty or rotten herring).

Dark, very quickly blackening spots appear on the shoots. Such a vine does not ripen for a long time and freezes very easily in winter.

The main danger of this fungal disease is that, appearing on grapes, it strikes it suddenly, and you can lose the entire crop in a couple of weeks, which will simply be lost.

Important! All affected brushes must be cut off and thrown away (buried), and not in a compost pit, otherwise the fungus will return again.

The main reason provoking grape disease oidium(powdery mildew) is dry and hot weather without rain, as well as constant temperature drops (it is quite cold at night, very hot during the day).

It is worth distinguishing! But, on the contrary, wet weather- this is the main reason for development.

Video: description of the disease and measures to combat powdery mildew on grapes

Prevention of oidium on grapes: when andhow to process grapes from powdery mildew

In order not to fight the powdery mildew directly, it is necessary to take timely preventive measures to protect the grapes from this fungal disease.

It is important to note that for the prevention of various diseases of grapes in early spring, it is best to use various systemic or complex preparations.

Important! Be sure to pay attention to the waiting time for the drugs used, for example, for "Quadris" - 25 days, and for "Falcon" - from 30-40 days. It is extremely important to process your vineyards on time.

The main processing of grapes from oidium must be carried out before flowering:

1. The first treatment is carried out when 3-5 leaves appear on the grape bush (or with a flag shoot of 5-7 cm). At this moment, it is optimal to use systemic drugs (Topaz, Talendo, Impact, Skor, Raek, Falcon, Ordan, Topsin-M, Strobi).
2. The second treatment is a week and a half before flowering. Repeat spraying with systemic fungicide.

As a rule, such spraying should be enough to protect the grapes, and this will be the guarantee that the powder will not manifest.

By the way! Some gardeners somewhat erroneously advise in early spring to spray grapes on a bare vine against the appearance of powdery mildew (1-3% solution), dissolving 300 grams of the product in 10 liters of water. However, it is best to deal with copper-containing preparations not with powdery mildew, but with

If for some reason you did not carry out the spring processing of the grapes before flowering, or it did not help you, and the grape bushes and bunches still became infected and turned white, then already during the period of fruit formation (grape bunches) this process should be approached more carefully and carefully. The point is that at this time undesirable use of systemic fungicides due to their rather long waiting period, it is better to use contact and sulfur-containing drugs that have a minimum waiting time and are well washed off by rain.

Advice! In the fall, after the grape harvest, powdery mildew treatment should also be carried out in order to try to get rid of the fungus, so that it does not stay overwintering on the bush and in the ground.

Video: causes of infection and ways to combat powdery mildew on grapes

Proper grape care is the best pprophylaxis

So that the grapes do not get sick and do not have to be treated for oidium, the plant should not suffer from a lack of moisture (that is, the grapes need to be watered correctly), it is also recommended to regularly and abundantly feed it with potassium and calcium.

Can't be allowed in order to grape bushes especially after cold rains, in the heat of the day they stood damp. They should be well ventilated, that is, the plantings should not be thickened, in other words, regular summer pruning should be carried out, namely pinching (pinching), while unnecessary leaves in the cluster area should be removed.

Note! It is best to tie the grapes to the trellis. How to do it correctly, read

But the most effective way to prevent powdery mildew on grapes is to grow varieties that are not susceptible to this disease.

So grape varieties are considered the most resistant to powdery mildew: Red, Ainset, Rylines, Friendship, Bianca, Ruby Magaracha, Saperavi Dediani, Zhgia, Ruby, Frumoasa Albe, Srebrostruy, Liana, Delight.

Advice! You can try (unlikely, but you can try) to protect the grapes from powdery mildew simply by planting calendula, sorrel, onions or garlic under the bush.

Video: calendula under a vine that protects it from powdery mildew

How and what to treat oidium on grapes

It is very good if you notice white bloom on the leaves even before flowering. But if you were not lucky, and you found powdery mildew on the grapes already during its fruiting period, that is, after flowering, when the berries began to ripen, then you need to take the most urgent measures to combat it.

Advice! In the prevention and control of any diseases and pests, preparations should be alternated (that is, use agents with different active ingredients) so that addiction does not arise and the effect of use is maximized.

What drugs to use

To combat this fungal disease of grapes, it is necessary to use the following drugs against powdery mildew:

Interesting! Some sources recommend using a fungicidal contact agent such as .

Recently have become quite popular biological products (Trichophyte, Liposam or Guapsin).

Advice! Very important properly handle vines... Spray leaves and berries enough profusely so that the solution reaches the maximum area. Concerning grape bunches, then it is better to process them from all sides.

Colloidal sulfur

Colloidal sulfur is one of the safest preparations for fighting the first signs of powdery mildew on grapes. Its waiting period is only 2-3 days.

Important! Processing sulfur-containing drugs (including Cumulus, Tiovit Jet, Abiga-Peak) must be carried out at temperatures above + 18-20 degrees... The bottom line is that sulfur fights powdery mildew on grapes using the method fumes, therefore, there is a mandatory need for warm weather.

Also worth knowing that spraying should be carried out either early in the morning, or late in the evening, or in cloudy weather so that the bunches do not get burned in the scorching daytime sun.

It is also worth considering that the protection period of a grape bush treated with colloidal sulfur is about 1-2 weeks. And since this is a contact preparation that is easily washed off, therefore, spraying should be repeated at least every 2 weeks, or earlier if it has rained.

It is not difficult to prepare a working solution of colloidal sulfur, and it must be done correctly:

1. First, pour colloidal sulfur into a jar (consumption - 30-40 grams per 10 liters).
2. Gradually pouring water into the container, stir until a homogeneous mass (gruel) is obtained.
3. Then the resulting concentrated solution is poured into a bucket and stirred again.
4. Strain, pour into a sprayer, and then carry out a thorough treatment on the leaf and bunches.

Video: colloidal sulfur - a simple and reliable remedy for oidium on grapes

Folk remedies

In order to remove powdery mildew and at the same time not particularly think about the negative consequences during the fruiting period of grapes, it makes sense, first of all, to turn to folk remedies.

However, it should be understood that the effectiveness of such funds is extremely low.

Baking soda, iodine, and potassium permanganate

A truly folk remedy in the fight against powdery mildew on grapes is to prepare a spray solution with baking soda, iodine and potassium permanganate, which can be used without fear. in the stage of ripening berries.

Important! Also, this mixture of funds will help protect the grapes from anthracnose and anthracnose.

So, the recipe for preparing a solution from oidium is as follows:

1. Have to take 4-5 st. tablespoons of baking soda or soda ash and dissolve in hot water (40-45 degrees).
2. Then drip 15-20 drops of iodine.
3. Pour the resulting solution into a bucket of water to end up with 10 liters.
4. Dissolve in a separate container manganese and pour into a bucket to end up with light pink solution.
5. Add 40 ml. liquid laundry soap so that the solution adheres well.
6. Spray the resulting solution over the leaf and berries.

By the way! After this treatment, the berries can be eaten on the second day.

Video: baking soda, iodine and manganese from oidium on grapes

Wood ash

Another natural folk remedy for treating grapes from powdery mildew is wood ash.

To prepare an ash solution for processing grape bushes, you will need:

1. Pour 2 liter cans of ash (1 kg) into a bucket of water and stir well.
2. Let it brew for 1-3 days so that the ash extract is the most effective.
3. Dissolve 1 liter of the resulting extract in a bucket of water.
4. Add 3 tbsp. tablespoons (40 grams) of liquid laundry soap (for better adhesion).
5. Strain, pour into a sprayer and process.

By the way! Wood ash is also an excellent potash fertilizer, that is, it is an excellent foliar feeding.

Video: wood ash - a miracle remedy for powdery mildew on grapes

Milk serum

Spraying it with milk whey is another safe way to combat powdery mildew on grapes.

The working solution is prepared in the following proportion: 1.5 liters of whey is dissolved in 10 liters of water.

It is advisable to carry out such processing at least 1 time per week.

Also, in the fight against powdery mildew on grapes, some summer residents advise using garlic infusion (250 grams of chopped cloves per 10 liters of water, 24 hours).

Important! It should be understood that folk remedies are relatively weak remedies for the treatment of oidium, which are not suitable for the fight if the disease is raging in full force in the vineyard.

If you want to have a luxurious and high-quality grape harvest at the exit, you need to make every effort to protect it from powdery mildew. To do this, it is imperative to use both folk methods and more effective chemical and biological ones. The main thing is not to miss the onset of the disease, and if you have not noticed an outbreak, continue to fight systematically and regularly.

Video: how to deal with powdery mildew (powdery mildew) on grapes

In contact with

Oidium grapes - how to treat? For novice gardeners, it is important to determine the first signs of the disease, see a photo and only then start treatment. Using prevention, combined with the treatment of bushes with drugs, you can achieve a complete victory over the disease.

Oidium grapes - how to treat and photos of plants affected by the disease

From such, at first glance, a harmless spot, this disease, which is terrible for a plant, begins.

The late treatment of the bush leads to such a consequence.

Description of the disease

The second name for the most common vineyard disease is powdery mildew or ashtray... The causative agent of the disease lurks in the living green tissue of the plant. When a bush is damaged, not only foliage and young shoots are destroyed, the disease affects the berries. The harvest is not even good for making wine and juices.

Oddly enough, strong winter frosts give impetus to the emergence of colonies of fungi. Experience shows that a major epidemic on bushes will certainly occur at a long-term temperature of at least -30 °. The fungus remains in the shoot eyes and is protected by scales. The temperature in spring reached 18 °, during this period the rapid growth of spores begins.

At this time, it is necessary to especially carefully monitor the condition of the bush, especially in wet weather. At the same time, prolonged rains can not only slow down the development of myceliums, but also completely destroy them, preventing the spread of spores through the vineyard.

For beginners, it is important to understand why grapes are affected by powdery mildew and the main ways to deal with it.

Causative agent of the disease

Oidium on the site is populated on a bush with the help of a marsupial fungus, which easily tolerates subzero temperatures and in the process of its development, cells and plant tissues are affected. During growth, the thin hyphae of the fungus allow the conidia to develop and spread through the bushes, infecting trees and shrubs.

In addition to vineyards, powdery mildew is scary for several types of horticultural crops and grains. This disease gradually kills the plant. It is simple to determine the affected foliage at an early stage - plaque appears on the leaves, spots of a grayish-whitish color. The fungus is attached to the plant using suction cups.

The spores of the fungus grow into the cells of the leaf covering and begin to actively feed. The cell is gradually destroyed and dies off. Acting on the berries, powdery mildew destroys the structure, and they simply explode. Spores remain on the surface of foliage and berries and are spread by the wind. At high air temperatures and humid conditions, the spread of powdery mildew increases, the spores quickly become fixed in the eyes of the plant and are prepared for wintering.

For the growing season of the fungus, depending on weather conditions, a week is enough. With the development of the mycelium, the disease spreads to the entire bush, affecting the shoots and vines. All areas are covered with a grayish bloom, consisting of mycelium, as well as pathogenic.

It is important to start using effective control measures at the first signs of the appearance of grape powdery on your bushes.

Signs of defeat

The first signs of damage to the bushes appear on the foliage and vine of grapes only at the beginning of the next season. Spring warm days give impetus to the development of mycelium. At the end of the season, spore activity decreases, and they prepare for wintering. Symptoms of the disease in grapes, manifested at different periods, are different:

1. Spring.
   At the first warming, the development of powdery mildew spores is activated. During this period, you can find young foliage, which hatch from the buds, covered with a dirty yellow bloom. On the outside of the foliage, a white fungal bloom appears, which gave the name to the disease - "powdery mildew". With the development of the disease, the foliage on the bushes or trees dries out along the edge, then dies off. Oidium affects young shoots of the plant, which become brownish. When cleansing the foliage from the fungus, an unpleasant odor appears, as if you touched the rot.
2. Summer.
   On neglected bushes, the developing powdery mildew begins to infect the inflorescences, then passes to the berries. The disease progresses throughout the season, destroying the crop. It is possible to distinguish oidium from other plant diseases by distinctive features:

• berries lose weight, do not develop and burst;
• the pulp does not become sweet, this is to blame for the lowering of sugars in the berry;
• grapes are colored unevenly;
• on the hands there are many berries affected by ulcers and scars.

In the case of a late start to the fight against powdery mildew, the grower runs the risk of losing the harvest. For novice gardeners, it is important to know how to remove fungus from the site.

Control measures

Among them, there are 2 stages:

1. it is easier to prevent disease on the site by carrying out agrotechnical measures and preventive spraying of the vineyard;
2. if treatments are started late, you will need to move on to spraying the bushes with chemicals or solutions made according to folk recipes.

Preparations made on the basis of colloidal sulfur kill the fungus on the bush. But first, let's take a closer look at preventive ways to combat powdery mildew.

Prophylaxis

The whole cycle of work is divided into several stages:

• vineyard care begins with the planting of the bushes. It is better to buy varieties that are not susceptible to the development of the disease, but if you like a vulnerable variety, be prepared to start processing on time, carefully examining each young leaf;
• when planting bushes and trees, pay attention to the wind rose in the place of your summer cottage. The wind should ventilate the bushes, so it is better to place the rows along the movement of seasonal winds;
  shoots and vines are tied up immediately after opening the bush, in this case there will be constant and sufficient ventilation of the grapes;
• it is better to break off branches without brushes, and leave only 1 bunch on the shoot;
• constantly remove weeds in the beds. Spores of the fungus can hibernate on weeds;
• diseased growth and foliage should be immediately removed from the bushes and the site;
• before covering the grapes for the winter, be sure to treat the vine and the left shoots, as well as the soil around the row with a solution of iron sulfate;
• do not get carried away with fertilizing the vineyard with nitrogen-containing fertilizers, especially fresh manure;
• run a drip irrigation system. In this case, water will flow to the roots, and not spill over the aisles, increasing humidity and the possibility of spreading powdery mildew spores;
• Rows of garlic, radishes, dill or calendula planted in row spacing reduce the risk of marsupial fungus.

Preparations from oidium

Preparations for powdery mildew on grapes can be divided into 3 types:

1. Spraying bushes and trees with sulfur-based preparations. In this case, sulfur is absorbed by the marsupial fungus, turns into hydrogen sulfide and affects powdery mildew as a toxic substance. During bud break, the first treatments are carried out with drugs of this group, which prevents the appearance of fungi and spores on green shoots. Processing must be carried out at a temperature of 200, spraying at a low temperature will not affect the disease, you will only waste the solution. Do not spray plants in the scorching sun, such "care" will cause burns to the foliage and infect the plants no worse than the disease. Only work at sunset or sunrise.

It's important to know! Preventive treatment - for this, add up to 40 g of the substance to a bucket of water. When treating bushes, increase the rate to 80-100 g.

For such spraying use a solution of colloidal sulfur or "Tiovit", "Kumulus DF". Repeat the application of the solution no earlier than a decade, the total number of treatments is 3-6 times. It is possible for preventive purposes to apply protection on the leaf with a solution of the complex fertilizer "Plantafol".

The disadvantage of such drugs is that they are washed off by the rain, therefore, in the rainy period and before flowering, it is better to treat the bushes with improved drugs of the next group.

2. Systemic and contact type of substances. Treatments with "Topaz", "Skor" or "Horus" are known to many gardeners. In the spring, you can spray the affected bushes using the "Horus", it works at low temperatures. An effective and reliable preparation is "Strobi", some growers advise to process flowering plants with it.
It is not recommended to use Strobe more than 3 times a season. Preventive treatments can be done with "Karatan", but after the flowering of the grapes. If the grapes are affected by powdery mildew and gray rot, the systemic fungicides "Cabrio Top" or "Switch" can be used to combat.

3. Biological protection measures. Here we can single out a simple but effective method of Professor Vesminsh. It is carried out in 2 stages:

• spring - sifted humus is poured into the barrel by a third. Then water is poured so that it covers the humus. The barrel is closed with a lid and after a week, the resulting microflora begins to actively multiply and feed. For preventive purposes, young shoots and vines are processed.
  At this time, the controversy had already been freed from winter clothing. Saprophytes, getting on the mycelium layer, begin to actively eat it. Processing should be carried out on a cloudy day or at sunset;
• the two remaining treatments are carried out: one - a week after the first and the second - immediately after flowering. But in humid weather, biological solutions can be used 2-3 more times.

Folk remedies

Such "drugs" against powdery mildew on grapes are more likely for prevention. It is better to protect heavily infested bushes with effective contact or systemic fungicides. Here are a few "recipes for traditional plant medicine":

• stir 50 g of soda ash and 40 g of laundry soap in a bucket of water. Such a solution is harmless to humans and animals, but according to experienced winegrowers, it gives a good prophylactic effect;
• cover and let the solution brew for a day - pour 0.5 buckets of wood ash with 7 liters of water. Add 100 g of soap for better adhesion of the solution to the foliage and strain through cheesecloth, spray the plants. Spraying preparation can be accelerated. To do this, it is enough to boil the solution for 20-25 minutes;
• mix 3 parts of water and 1 part of manure, close the container tightly and set aside for 3 days. Then strain the prepared mixture and add 3 more parts of water. After mixing, process the leaves from 2 sides, the vine and shoots, as well as the ground around the bush with the prepared mixture.

On a note! A good result in the fight against powdery mildew is given by spraying with a mixture of 1 part milk and 8 parts water. Such processing attracts and promotes the reproduction of microorganisms on berries, natural enemies of the spores of the marsupial fungus.

In conclusion, we present lists of grapes that are not susceptible to the influence of oidium and a list of varieties that are undesirable for planting.

Resistant varieties

• "Bianki";
• "Dachny";
• "Friendship";
• "Pearls of the Hall";
• "Crystal";
• Marshall Foch;
• Platovsky;
• "Regent";
• "Dublyansky";
• "Jubilee Zhuravel".

Disease susceptible varieties

• wine varieties "Rkatsiteli", "Cabernet";
• late variety "Moldova";
• "Cardinal";
• Merlot.

In conclusion, it remains to be noted.

Oidium in the garden and in the vineyard is one of the most insidious diseases and the enemy of gardeners. At an early stage of the development of spores, it is impossible to detect the disease; it is shown and affects young growth in the 2nd year. At the same time, it is important to detect the disease in time and begin to fight it. But it is better to pay more attention to grapes, to carry out preventive measures.In this case, you will get a good harvest of sweet berries and you will be able to please your loved ones with grape juice and young wine.