Diseases and pests of currants, methods of combating them, preventive measures

There are 4 common types of currants in Russia (white, black, yellow and red). Although they differ in color, taste and aroma of berries, the plants are unpretentious and have similar care requirements. They are affected by the same diseases and pests.

Infections and insects become the main cause of death of fruit and berry bushes. In the presence of accompanying factors, even varieties with strong immunity are affected. Without timely treatment, not only the infected plant will die, but also the crops next to it. To save the garden, it is important to promptly recognize diseases and pests and know how to combat them.

Diseases and their treatment

Healthy currants have many bright green large leaves of regular shape, produce a rich harvest of round berries with a rich taste, and easily withstand winter. An infected plant loses its frost resistance, produces meager yields, and loses its greenery. Photosynthesis deteriorates and as a result the currant dies.

Many diseases can be effectively treated in the initial stages. Later it is more difficult to fight them. Therefore, it is important to detect the infection as early as possible. The following signs should alert the gardener:

• suspicious spots on the leaves;
• plaque on greens, fruits and shoots;
• yellowing of leaves and falling earlier in the autumn;
• drying of the bush;
• fruit drop;
• the appearance of convex formations.

To understand why currants are sick and what to do, it is important to compare the existing symptoms with signs of disease.

Tuberculariosis

Tubercularosis is a fungal disease that leads to drying out of the branches and leaves of the plant. The development of the disease is facilitated by high levels of humidity and mechanical damage to the bushes.

The infection manifests itself as follows:

• red tubercles form on young shoots;
• the infection spreads to other branches and penetrates the bark, forming red seals;
• already in July the leaves dry out, curl and fall off;
• the affected branches die.

To get rid of tuberculiosis, diseased branches are removed. The cut areas are sprinkled with ash and lubricated with garden varnish. The bush is sprayed with preparations containing copper.

Anthracnose

Anthracnose is a fungal disease. The plant becomes infected with it in the spring, but the first signs appear after 1.5–2 months, in the summer. The epidemic usually occurs in July.

The affected plant quickly loses leaves and fruits. Its winter hardiness decreases and photosynthesis deteriorates.

Important! The fungus is not afraid of frost and overwinters in plant debris. Activated during prolonged rains, excessive watering, or the presence of a large number of weeds near the currants.

Signs of anthracnose:

• first red or brown spots form on currant leaves, then swelling;
• gradually the affected areas expand and merge into one large burgundy blister;
• leaves dry out and fall off.

It is easiest to treat blistering disease in the initial stages. All affected greenery is torn off. Healthy leaves are sprayed with one of the following preparations:

1. Bordeaux mixture prepared from 100 g of product and 10 liters of water.
2. Folk: dissolve 1 kg of ash and 1 piece of laundry soap in a bucket of water.
3. Chemical when other methods are powerless. One of the effective remedies is “Alirin-B” (2 tablets per 1 liter of water).

Treatment is carried out once every 7 days, in dry weather.

Anthracnose affects all types of currants, but most often the infection affects red ones.

Septoria

Septoria blight, or white spot, is considered a disease of black currants, but also affects other plants. It is caused by a fungus that becomes active in the summer.

The causes of the development of the disease include dense planting, high humidity, lack of sunlight, and poor air exchange.

White spotting is recognized by the following signs:

• angular brown spots with a diameter of 2-3 mm form on the leaves;
• over time they become white with a dark border;
• the disease spreads to the fruits;
• affected leaves and berries fall off.

Before treating the disease, all affected parts of the bushes are torn off and the weeds are carefully weeded. All collected vegetation is burned.

Effective for treating septoria:

• Bordeaux mixture (100 g of the drug per 10 liters of water);
• fungicides: phthalan, “Kuprozan”, “Kaptan”.

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Sclerotinia

Sclerotinia, or white rot, is a fungal infection that affects all parts of the plant and leads to the death of the bush. The fungus lives in the soil and is activated by high humidity and weakened plant immunity.

Signs of white rot:

• brown weeping formations appear at the base of the shoots;
• leaves fade;
• the spots begin to rot, a white coating resembling cotton wool appears;
• parts of the currant above the infected areas die.

When the first symptoms are detected, the affected parts of the bushes are removed, and the cut sites are treated with garden varnish. The entire bush is sprayed with fungicides. If signs of the disease appear again, the affected plant is dug up and burned.

Important! If you do not remove the diseased plant, the infection will spread to neighboring bushes.

Powdery mildew

Powdery mildew - another fungal disease. The fungus is most active in mid-summer.

The disease poses a danger to the plant: it affects all parts of the bush, causing leaves and fruits to fall and shoots to dry out. Photosynthesis deteriorates, and the chances that the plant will survive winter frosts are reduced. Within a few years, the culture completely stops growing and dies.

The reasons for the development of powdery mildew are dry soil, high air humidity, and oversaturation of the soil with nitrogen. Currants become infected through the ground, infected planting material and weeds.

Signs of the disease:

• a dry translucent whitish coating forms on the leaves and shoots;
• Over time, it becomes denser, turns brown in places, and feels like felt;
• affected shoots become deformed, stop growing and die;
• the berries become covered with bloom, darken, and fall off without ripening.

The sooner treatment is started, the higher the likelihood of doing without serious chemicals. Before spraying plants with special preparations, cut off all diseased parts.

Treatment methods:

1. Preparations with copper. Currants are sprayed with Bordeaux mixture or copper sulfate.
2. Folk method. For a bucket of water, take 1 bottle of 5% iodine and 2 liters of milk. Plants are treated 2 times with a break of 4 days.
3. Bacterial method. Chicken manure is diluted with water in a ratio of 1:10.The resulting mixture is sprayed onto the bushes.
4. Purchased substances. If folk remedies and preparations with copper do not help, use fungicides - “Topaz” or “Fundazol”. In this case, the fruits cannot be eaten.

Rust

The causative agent of rust is a fungus. Typically, the plant becomes infected in mid-summer or autumn. As a result, leaves and berries fall off.

Important! Spores of the fungus are carried by sedge, coniferous trees, and weeds.

There are two types of currant rust - goblet and columnar. The first is expressed like this:

• orange spots appear on the inside of the leaves;
• over time, they transform into yellow bubbles filled with spores;
• the affected areas increase and lead to drying out of the entire leaf blade;
• leaves and berries fall off.

Columnar rust is no less dangerous. Its manifestations:

• the outer side of the leaves is covered with small yellow dots;
• on the reverse side, red growths with spores form;
• the growths take on the shape of hairs; the leaves feel like felt.

Before treatment, remove all affected leaves. For treatment use:

• biological product "Fitosporin";
• Bordeaux mixture diluted with water in a ratio of 1:100.

Striped mosaic

Currant mosaic is a viral disease that causes the leaves to dry out and fall off and lead to the death of the bush.

Main features:

• yellow-orange areas appear on the leaves;
• the affected areas begin to dry out, spreading over the entire surface;
• leaves fall.

Mosaic cannot be treated. Affected plants are removed from the site. To prevent the disease, bushes are treated with insecticides, since aphids and mites carry the pathogen.

Leaf curl

Curliness is caused by both a virus and a fungus. Both infections are spread by aphids.The signs are the same:

• leaves are uneven, with thicker areas;
• the leaf blade curls, bubbles and turns red;
• the leaves dry out and fall off.

To cure a plant, first get rid of aphids and remove damaged leaves. After this, the currants are sprayed with a solution of Bordeaux mixture.

Nectria drying of shoots

Nectria drying affects only red and white currants. The causative agent of the infection is a marsupial fungus. The disease leads to drying out of young shoots, and then to the death of the entire plant.

Description of the symptoms of the disease:

• orange dots appear on young shoots;
• they increase in size and look swollen;
• The fungal spores ripen and the formations turn black;
• young shoots die off.

To combat the disease, all affected branches are removed. The cutting areas are treated with garden varnish, and the plants are sprayed with a solution of Bordeaux mixture.

Reversion

Reversion, or terry, is a viral disease spread by the bud mite. The disease leads to currant mutation and infertility.

Signs of reversion:

• leaves become more elongated, asymmetrical and smooth;
• they only have 3 blades instead of 5;
• the color of the greenery changes to purple;
• flowers become longer and thinner;
• currants cease to exude their characteristic aroma;
• the ability to bear fruit is lost.

The disease has no cure. Affected bushes are removed from the area and burned. Quarantine is observed on site for 5 years.

Chlorosis

Chlorosis is a disease caused by a decrease in the quality of photosynthesis and a lack of chlorophyll in the leaves of a plant. It occurs due to nutrient deficiency and poor weather conditions. Expressed in:

• pale, yellowish green;
• premature shedding of leaves;
• crushing shoots;
• death of roots.

To correct the situation, complex mineral fertilizer is applied and care is adjusted.

Necrosis

Marginal necrosis is caused by excess chlorine in the soil. As a result, the edges of the leaves dry out and the greenery becomes ash-gray.

If signs of necrosis are detected, ammonium nitrate is added to the soil. This is done before and after currants bloom.

Pests and their control

Pests are no less dangerous than diseases. They feed on juices, leaves and fruits, leading to the death of the bush. Insects often carry viruses and fungi.

Currant pests:

1. Kidney mite. It settles in the buds of the plant and feeds on them. Affected kidneys appear swollen and round. The next year, small, thin, light-colored leaves of irregular shape grow from them. The affected parts of the bush are torn off and burned. Currants are sprayed with preparations containing sulfur.
2. Spider mite. Small light-colored insects feed on the sap of the plant, covering the underside of the leaves with cobwebs. The pest causes premature death and shedding of greenery. To get rid of spider mites, they use not only insecticides, but also folk remedies, for example, a decoction of wormwood with grated laundry soap. Currants are sprayed until the problem disappears completely.
3. Sawfly. The larvae eat the pulp of the leaves, leaving only the veins. The pest resembles a green caterpillar with a black head and spots on its back, and has 10 pairs of legs. It overwinters in a brown glossy cocoon underground, and in the spring it turns into a butterfly that lays eggs on the inside of the leaves. The caterpillars that hatch from the eggs devour the greens. The cycle is constantly repeating itself. To get rid of pests, an oilcloth is spread under the bush, onto which the larvae are shaken off.If this does not help, use insecticides (“Iskra”).
4. Ognevka - a butterfly whose caterpillars feed on berries. The pests are green with black legs, heads and stripes on the back. They envelop the ovaries in a web and then eat the berries, leading to their premature ripening and drying out. To get rid of the problem, nests with pests are removed. Currants are treated with Karbofos before flowering.
5. Moth. Another butterfly whose caterpillars devour leaves, leaving only the veins. To get rid of the pest, spread an oilcloth or cloth under the bush and shake off insects onto it. If this does not help, use insecticides.
6. Glassware resembles a wasp with a thickening at the end of the abdomen. The insect lays larvae under the bark. The caterpillars gnaw on the branches, causing them to die. The affected areas are removed by covering the cut areas with garden pitch. Additionally, insecticides are used.
7. Aphid. Small black insects feed on the sap of shoots and leaves. Because of this, the latter fall off prematurely, the shoots stop developing, and the bush dies. To get rid of the pest, the bush is sprayed with an infusion of onion and garlic with laundry soap.
8. Zlatka. Small shiny bugs settle in the shoots and eat them. The branches of diseased currants die. To save the plant, all affected parts are removed and insecticides are applied.
9. Mol. Caterpillars eat currant buds, then turn into butterflies and lay eggs in the berries. The larvae eat the fruits from the inside. The pest overwinters in the lagging bark. Insecticides are used for control.
10. Shield. The larvae crawl along the tree and become overgrown with a shield, under which they remain for the rest of their lives and lay eggs.Scale insects feed on the sap of the plant, leading to the gradual drying out of the branches and the death of the entire bush. To destroy the pest, currants are sprayed with the preparation “Rogor-S”.

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Prevention of diseases and pests

Fighting insects, treating diseases and aftercare for beginners is not as simple as it might seem. Therefore, it is much easier to prevent problems:

1. Compliance with the rules of care (watering, loosening, mulching) is the basis of prevention. It is improper irrigation and lack of loosening that become the main cause of fungal infections.
2. All old and diseased branches must be removed.
3. When the snow melts, experienced gardeners “burn” the currants. To do this, the bush itself and the soil around it are watered with boiling water.
4. Leaves and other vegetation around the bush are removed and burned in the fall. As the crop grows, the land around it is weeded.
5. In spring, currants, gooseberries and other fruit and berry bushes are treated with copper sulfate.
6. It is advisable to choose varieties that are resistant to viral and fungal diseases.
7. When planting currants, it is important not to thicken the plantings.
8. The soil, planting material and garden tools must be disinfected.

Conclusion

Diseases and pests are the most common cause of currant death. They affect all parts of the plant, leading to shedding of leaves, shedding of inflorescences and fruits, and drying out of shoots. You can get rid of the problem by promptly recognizing the symptoms and choosing the right treatment.Recovered plants take a long time to recover and require increased care, so diseases are easier to prevent than to treat.