White bloom on currant leaves: how to process and what to do for treatment

During the summer, the activity of the fungus that causes powdery mildew is often increased. The disease affects fruit bushes, and its first sign is the appearance of a white coating. On currants, it forms on the inside of the leaves, covers young shoots, and over time, the infection spreads to the berries, which is fraught with a complete loss of the crop. In the absence of a fight against the pathogen, the affected bushes freeze in winter.

Causes of white bloom

Some gardeners often do not understand why mold appeared on the currant, they do not know that it is very dangerous for the loss of berries. The development of powdery mildew is promoted by:

1. Combination of high humidity with high temperatures.
2. Thickened planting bushes.
3. Lack of light for currants.
4. Applying large amounts of nitrogen fertilizers.

The disease develops when the cuts are not processed during the shortening of the shoots, spores easily get into them. The plant becomes infected with powdery mildew if planted next to a diseased bush.

White plaque often occurs on blackcurrants, which, unlike red ones, are not resistant to fungal infection. Powdery mildew spreads rapidly, passes from the leaves to the fruits, the berries turn gray, the plaque acquires a brown tint.

Who is the causative agent

The spheroteka fungus, which waits the cold season on the stems and in the apical buds of fruit bushes, begins to multiply under favorable conditions, spores are carried by insects and wind to the leaves and ovaries of pumpkin crops, grapes, gooseberries.

The pathogen reproduces with the help of conidia that fall on other shrubs, and sexually, when the spores of the parasite are released from its body in spring.

Symptoms of defeat

The first sign indicating a currant infection with a fungal infection is that a whitish coating has appeared on the bushes. When powdery mildew spreads, the leaves curl and wither. Due to a violation of photosynthesis, they lose their green color, and then fall off, the ovary crumbles. If the disease has affected ripening berries, a brown coating forms on the fruits.

What is the danger for the currant garden

Spores of the fungus do not die even in severe frost, in spring, microorganisms begin to multiply. The infection is spread from one bush to another by wind, birds, and insects. Sick plants weaken, withstand the winter very poorly. If the currant is covered with bloom, the berries disappear.

Drugs and treatments for powdery mildew

Infection of shrubs occurs at a tremendous rate. You can save the plant if, when a plaque appears, you immediately start fighting the fungus. With belated treatment, problematic shoots are cut, the leaves are burned and they are selected with what to process the crop.

Folk ways to deal with white plaque

Not everyone wants to use chemicals to deal with currant disease. At the beginning of its appearance, gardeners 2 tsp. rapeseed oil is poured into a bucket of water. The result of treating the shrub with such a tool is noticeable after 10-14 days, the plaque disappears as the spores die.

Wood ash is used in the fight against fungal infection. A kilogram of this organic matter is infused in 10 liters of water. After a week, the solution is filtered and mixed with crushed or liquid laundry soap and the affected bush is sprayed.The sediment is again combined with water and poured under the root of the currant.

When the first signs of infection with a fungus appear, a soda solution is used to literally wash the plant. The composition is prepared from 2 tablespoons of the substance, the same amount of grated soap and 10 liters of water.

If the weather is dry and rain is not expected in the near future, currants are treated with whey or kefir, but not with a concentrated solution, but half diluted in water.

Spray the bushes with a composition that is prepared from 10 ml of iodine and 10 liters of liquid. Fungi do not multiply in an acidic environment, and alcohol disinfects the leaves from spores. Pathogens do not like the infusion of arrows or garlic cloves.

Chemicals

With a significant damage to the shrub by powdery mildew, using only folk methods, it is impossible to cure the plant, and chemical preparations have to be used.Such products contain poison, they must be combined with water strictly following the instructions. It is necessary to spray currants with a spray gun so that the composition is distributed evenly and hits all parts of the plant.

Processing is performed not once, but several times:

• during snowmelt;
• before bud break;
• before and after flowering;
• late autumn.

Preparations containing sulfur are less toxic than other chemicals used to eliminate powdery mildew. Berries can be consumed after spraying, but it is better to wait at least a week.

The optimum temperature for treating currants with Thiovit Jet and colloidal sulfur is 20-30°, at 35 the shrub can get burned.

Bordeaux liquid helps to cope with fungi, which is prepared by dissolving 10 grams of copper sulfate in a bucket of water.The first time the currants are sprayed, wetting the ground near it, until the buds awaken. The treatment is carried out three times a season, constantly changing the preparations, since the fungi quickly get used to the composition.

Effectively cope with the infection systemic fungicides that penetrate into the tissues of the bush and stop the development of the disease.

When using Topaz, Skor, Agrolekar, Fitosporin-M, Raek, berries can be consumed no earlier than 2 weeks after spraying.

Mechanical Methods

When a small amount of plaque appears, when only a few sheets are affected by the infection, it is possible to do without chemical treatment.

Contribute to the development and spread of powdery mildew thickened plantings. If the bushes are located close to each other, the diseased plant is dug up. Shoots infected with spores are cut off, leaves are cut off and all this is burned.

Before breaking up a plot for currants, the ground is disinfected with fungicides.

How to handle properly

Beginner gardeners, having bought the drug, may not know what to do before spraying the bush. The plant needs to be prepared for the procedure.

Berry plaque

Fungal spores are not only spread by wind and birds, the infection passes from currant leaves to fruits, when infected, they turn white, but eventually turn brown and disappear. Affected berries must be plucked, and he althy ones are sprayed along with the bush.

On shoots and branches

In currants affected by powdery mildew, plaque eventually forms on the stems and trunk. Such a bush is cut to the ground, cold water is directed to the plant under pressure. After that, they are sprayed with fungicides along with the ground.

In case of significant damage to the shoots, the currants are dug up and all branches are burned. Under diseased bushes, the top layer of soil is removed, mummified fruits are removed, in which harmful microorganisms like to spend the winter .

On foliage

Powdery mildew quickly affects entire plantings of blackcurrant, if you do not immediately notice the first signs. First, the fungus attacks the inside of the leaf plate, so not every gardener who recently grows a shrub can detect a problem.

Even experienced gardeners sometimes pay attention to the presence of plaque when the outer parts of the leaf plate are covered with it. In this case, folk remedies are not always effective, you have to use fungicides. Before spraying the bush with drugs, cut off and burn all the white leaves.

Prevention Methods

To reduce the risk of currant infection, seedlings for cultivation should be purchased from a nursery, it is worth choosing varieties bred recently, as they are highly resistant to fungal infection.

To prevent powdery mildew, you need to:

1. Before planting, dip young bushes in boiled water or Bordeaux liquid.
2. Comply with the requirements of agricultural technology.
3. Don't leave weeds near currants.
4. Timely get rid of weakened shoots.

Branches on which plaque has formed must be cut off. You should not grow currants in the same place for more than 10 years. In the spring, it is desirable to treat the bushes with a solution that is prepared from water and humus. Plants are sprayed with this compound when leaves and flowers appear.

Disease resistant varieties

Fruit bushes have been suffering from powdery mildew for a very long time. In Russia, they have been fighting the disease since the beginning of the last century. Recently, breeders have bred currant varieties that are immune to fungal infection. Gardeners are advised to purchase:

• Riddle - productive shrub resistant to frost;
• Vernissage - with large dark purple berries;
• Agate is a compact plant with straight shoots, created in Siberia.

The self-fertile hybrid Black Pearl is rarely affected by powdery mildew. This currant grows in different regions - from the North Caucasus to the Urals, pleases with fruits weighing up to 6 grams.

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