Powdery mildew on currants - control measures and treatment

Powdery mildew is the main enemy of currants, the causative agent of this disease are microscopic parasitic fungi sferoteka (Sphaerotheca mors-uvae), which are dangerous for gooseberries. The development of a large number of spores can even lead to the death of bushes. Therefore, prevention and control measures become paramount for gardeners who want to preserve the crop and are looking for a non-toxic remedy for treating the plant. It should be borne in mind that preparations that are well suited for other crops and flowers, such as roses, may not cope with powdery mildew on currants.

Causes and signs of powdery mildew on currants

This disease is caused by fungi, which, having spent the winter in the soil, in the spring with the establishment of warm weather, affect parts of the plant close to the root, gradually spreading higher. The spores and ulcers formed on the leaves cause the greens to dry and die.

If you do not take measures to save the plant, then by mid-summer the infection will spread throughout the bush, reaching fruits that will begin to dry out and crack.

The causes of powdery mildew can be considered:

• lack of sufficient sunlight;
• high level of humidity from 60%, sometimes this value may be slightly lower;
• excess nitrogen in the soil more than 600 g per 100 m2;
• lack of potassium and phosphorus;
• dense bushes;
• incorrect irrigation: the amount of liquid is exceeded or severe waterlogging following a long drought;
• plants are most vulnerable in the first 16-21 days after the appearance of foliage;
• infected water.

All these factors significantly reduce the immunity of currants, which leads to the development of the disease. Also, the gardener himself can transfer spores to healthy bushes by simply touching a diseased plant.

This also applies to tools, gloves and other used equipment.

It is possible to understand that currants are affected by powdery mildew by the following signs:

• On the front side of the leaves, a white coating of mycelium is formed.
• Violation of photosynthesis of the bush. Damaged greens become hard, with a strong defeat curls and crumbles. A new crown growing out of the kidneys appears twisted and develops incorrectly.
• The growth of shoots stops, they begin to bend, deform and the upper parts dry out. With the maturation of spores, droplets of liquid form, and the spots acquire a brown hue, small ulcers invisible to the eye appear.
• Frost resistance decreases.
• The berries are covered with flour and inedible.

The main symptoms of the disease are similar for both red and black currants. Powdery mildew is dangerous for both species. However, there are some differences that need to be understood and, based on this, find the right solution.

On black

Blackcurrant is more susceptible to the disease. If you do not take proper measures and do not deal with powdery mildew, then most of the crop will have to be disposed of. The main signs that you should pay attention to:

• the appearance of a thin white layer on leaf blades, shoots and emerging fruits;
• with the progression of the disease, the spots will begin to change their color and become gray;
• greens lose their shape, bend and crumble;
• saturated berries disappear in the berries, become faded or brown-brown.

On red

Red currants are less likely to become infected with the disease than black currants. However, it is on it that you can see the characteristic signs, because of which powdery mildew got its name:

• at an early stage it is a flour-like coating, it is easy to erase it with your fingers, but after a while it appears in a larger volume, and it is already impossible to remove it mechanically;
• with severe infection and an increase in the colonies of fungi, leaf plates become wet, covered with drops of liquid.

Powdery Mildew Treatment

To date, powdery mildew is a dangerous ailment, but it has been well studied, which allows you to quickly find the right medicine. For the best effect, you need to combine different drugs with the prevention of the disease.

Many remedies act as follows: at first, they stop the development of a fungal colony, and already at the second stage they locally neutralize spores.

Folk ways to deal with powdery mildew

Many gardeners, in the fight against powdery mildew, prefer folk remedies rather than chemicals, considering them safer for themselves, as well as plants. However, this only helps in the initial stages of infection and as a preventive measure. You can choose the right recipe using the table:

Biological products for the control of powdery mildew

This group of drugs contains bacteria and viruses that interact with pathogenic fungi and inhibit their microflora. They are not harmful to processed plants, domestic animals and humans. The main representatives can be found in the table:

Powdery Mildew Chemicals

When home-made infusions and biological products do not have the proper effect or currants are badly affected by powdery mildew, this is a signal to use chemicals. The table will help you choose the right medicine:

When using fungicides, it is important to remember their alternation, because the disease with prolonged use of a particular drug gets used to it. However, drugs are ineffective if the gardener does not follow a number of simple rules:

• identified affected areas must be cut and removed;
• wash the remaining parts from the hose;
• remove the top layer of the substrate under each affected plant;
• when spraying, clearly follow the instructions for use;
• if necessary, perform 2 more treatments.

Strong drugs should be used carefully, especially in the period before the formation of the ovaries.

Powdery Mildew Prevention

So that currant disease and the fight against it do not cause problems for the gardener, preventive measures are very important:

• if necessary, clean the area from last year's residues and weeds;
• to process plants with a solution containing soap and ash, another remedy is copper sulfate;
• regularly inspect for the first signs of the disease;
• to disinfect newly purchased seedlings and soil.

You can also adjust the growing conditions of the plant:

• water only after the substrate is completely dry;
• pruning thick bushes in the spring, plant copies located too close to each other;
• make top dressing containing phosphorus and potassium or completely exclude it;
• tear off leaf plates located very close to the ground;
• observe crop rotation;
• give preference to varieties resistant to powdery mildew.

These actions will help prevent the disease and provide the plant with protection for the whole season.

Powdery mildew on currants

For the entire growing season, currants need to be sprayed three times. It is important to do this correctly and in a timely manner and in the following order:

• In the spring, the most successful moment for processing plants: drugs cause minimal harm and actively fight against fungal spores and prevent them from forming.
• In the summer, during the period of abundant flower formation and berry development. One must be careful not to use strong chemicals that can be deposited in the fruit and enter the human body, causing poisoning.
• In the fall, after harvesting and removing cut parts of the plant, to prevent infection in a future season.

It is necessary to carry out the treatment by abundantly wetting all the surfaces of the sheet with a spray gun or a wide brush. It is better to do this in the evening hours in clear, not wet weather according to the scheme: at least 1 time per week, for a month.

Mr. Dachnik recommends: mildew resistant currant varieties

Often gardeners look for varieties that suffer from this disease less often than others. Good immunity will reduce the time spent on treatment and allow you to get a plentiful and full-fledged crop. Thanks to the work of breeders, a sufficient number of varieties of currants resistant to powdery mildew have been bred. The main characteristics of the best representatives can be found in the table:

If the first signs are found, the gardener should take measures to reduce the number of spores of fungi and protect bushes and berries.

Powdery mildew is a serious disease of currant, which appears in the absence of proper care and attention. However, having studied information about the manifestations of the first signs of the disease and choosing an effective method of controlling the fungus, you can not only cure the plant, but also save most of the crop.

Watch the video: How to Cure Gerbera Daisy Fungus (November 2024).