The main task when growing any fruit or berry culture is to obtain a high yield and high-quality fruits. These indicators primarily depend on the state of the whole plant: its growth and development, on its "health". It is impossible to imagine that a sick and stunted bush of currant gives a harvest of beautiful and juicy berries. That is, to obtain a good harvest, it is necessary that all parts of the plant function normally.
If the currant leaves curl and dry, then it is hardly worth waiting for a full collection of berries from it. What to do? First of all, you need to find the cause of the plight of the bush and why currant leaves are curled, then find out how to process it.
Why currant leaves curl
What needs to be done to find out the cause of the disease state of the bush? It is necessary to determine the nature of leaf damage. The causes of the disease can be varied, but mainly pests and fungal infections.
Pests
Spider mite
Settled by wind and with cuttings. Braids the bottom of the sheet with a network of the finest web. Damaged areas are light specks that gradually grow into faded areas. The leaves become "marble", darken and dry. Currant suffers. Its winter hardiness and productivity are reduced.
Fallen leaves and topsoil are the wintering grounds for females. In spring, they climb the currant and lay their eggs on the blossoming leaves. Hatched larvae can be seen in a magnifying glass. They are yellow-green in color. In the heat in the south, up to ten generations develop. The mass exit of the tick occurs in June - July. By autumn, the larvae become orange-red and go for wintering.
Currant Glass
Butterfly with narrow transparent wings, on the abdomen of a female there are three transverse yellow stripes. Butterflies fly out ten to fifteen days after the flowering of black currant. They lay up to 50 eggs in cracks in the bark. Caterpillars bite into the core of the branches, making moves up to 40 cm. Next spring and summer, they damage the branches, sliding down. In autumn, they re-winter inside the branches and in the youngster of spring - the beginning of summer, having made a hole, they go outside. First pupate, and then turn into butterflies.
Branches affected by a glass-case wither and dry at the beginning of ripening of blackcurrant berries.
Currant leaf gall midge
Small mosquito brownish-yellow in color, with one pair of wings. Lays eggs on young leaves of blackcurrant, on top of shoots. Young leaves, damaged by larvae, are deformed, acquire a "torn" appearance, blacken and dry. Shoots stop growing or begin to branch unnaturally. Young bushes and seedlings are especially affected. Up to four generations of gall midges are displayed in one summer. Winter is spent in cocoons in the soil. Years begin when the flowers of currant bloom. Lays eggs on open leaves. Hatching larvae live in groups in unfolded leaves, causing them to curl and dry out. The tops of the shoots often die. The pest causes especially great damage in nurseries.
Currant shoot gall midge
Yellow-orange mosquito with two brown stripes on the back; the wings are covered with thick dark hairs. Lays eggs in cracks in the currant bark. Larvae inhabit colonies under the bark. They feed on the juice of branches, which makes the bark get a brown hue, gradually darkens. In infected areas, depressed, gradually growing spots and cracks appear. Branches break and dry.
During the summer, 2-3 generations of gall midges hatch. The annual death of branches reduces the shoot-regenerative ability of plants and productivity.
Gall leaf aphid
It settles on the leaves of white and red currants. In the spring-summer period, aphids do not have wings; later, winged females fly over long distances. The pest hibernates in the stage of eggs, which it lays in autumn on the bark of shoots near the kidneys. Larvae hatch in the phenophase of bud blooming. Aphid colonies settle on the lower surface of the leaves. Red or yellow "blisters" - galls - form on the upper side of the leaves. The leaves are dying.
When currant growth stops, aphids migrate to grassy and weedy plants. In September, the pest goes back to the currant to lay eggs.
Gooseberry shoot aphid
Larvae hatch from eggs during kidney swelling. They feed on leaves, causing them to curl. Shoots are deformed, grow poorly. Leaves are compressed into a lump. At the end of flowering, the larvae mature, turning into females. In the fall, they lay eggs on shoots, which then winter.
Disease
Sphere library
It affects young leaves, shoots, fruits. It manifests itself as a powdery coating, which gradually becomes brown, felt. The shoots dry out, the leaves become deformed and fall off, the berries lose their commercial quality. Infection of plants occurs in the first warm days, when the buds open, leaves bloom, or after tying berries. The most favorable conditions for the development of the disease are a temperature of 17-28 ° C and an air humidity of 90-100%. In dry weather, the process stops.
Anthracnose
Acts on petioles of leaves and young shoots, less often - on berries. It is expressed in small brown spots on the leaves. During the disease, the spots grow together, the leaves turn brown, dry, and fall off prematurely.
On petioles, stalks and green shoots, the spots are small, black, slightly depressed. As a result, the growth and winter hardiness of plants decrease, the shoots die off.
Signs of it appear on the leaves in June. Infection quickly grows under favorable conditions and lasts until the end of September. Intensive development of the disease occurs in years with strong hydration.
Septoria
The fungus infects leaves and berries. It manifests itself in the formation of brown spots of various shapes from below. With the development of the disease, the spots become white with a brown border.
On berries, the disease appears before ripening with brown spots, dented or cracked. Disputes also form on them. Leaves fall ahead of time, growth slows down, the quality of berries deteriorates.
Column rust
Chlorotic spots appear on top of the leaves, below the pustules of the fungus, orange and powder. They gradually turn into tan columns from spores in the form of hairs, like felt. By the fall, it turns brown. Leaves fall in a month - one and a half to natural leaf fall, which affects the winter hardiness of plants and productivity. Spores hibernate on fallen leaves, mycelium on coniferous trees. Blackcurrant of European and Scandinavian subspecies is severely damaged. Rust of this type is found in all areas of industrial cultivation of currants.
Ball rust
Blackcurrant becomes infected during the budding phase. Yellow spots appear on the leaves of young shoots. Later they swell and crack, cup-shaped dimples filled with orange spores become visible.
Leaves turn brown and dry. Berries showered. Spores infect sedge; a fungus develops on it in the second half of summer and hibernates. The most severe disease develops in rainy spring. Currants should not be cultivated in places favorable for sedge growth.
Currant leaves curl than to process? Measures to combat diseases and pests of currant.
In autumn or early spring, they are removed under the root and dry damaged shoots are destroyed. In such shoots, there may be larvae of a glass-case, goldfish, stem gall midge, currant bud moth and other pests, pathogens of various diseases (anthracnose, powdery mildew, etc.). They burn fallen leaves, dig up the soil in order to reduce the number of pests and destroy the sources of diseases.
How to treat currants from curling leaves?
Sample calendar of protective measures:
• In the phase of bud blooming against the main fungal diseases in the stands, spraying with 1% Bordeaux mixture is carried out.
• Before flowering, the bushes are treated against aphids, ticks, and other pests with one of the insecticides: fufanone (10 ml / 10l of water), or kemifos (10 ml / 10l of water), or a spark (10 ml / 10l of water).
• Before the appearance of flower brushes against anthracnose and other fungal diseases, another treatment with Bordeaux mixture is carried out (100 g of copper sulfate + 100 g of lime / 10 l of water).
• To contain American powdery mildew (sferoteka), Tiovit Jetom (20-30g / 10l water) is treated.
• After flowering, cut below the level of the soil and burn shoots damaged by the glasshouse.
• After harvesting when pests and diseases appear, the plantations are sprayed with the same preparations as before flowering.
On commodity plantations of berry crops, chemical treatments after flowering are not carried out. In the case of pests after flowering, plants are protected by biological treatments:
• bitoxibacillin - 80-100 g / 10l of water;
• lepidocide - 20-30g / 10l of water;
• fitovermom - 4 ml / 10 water.
Spraying is carried out against each generation of the pest (caterpillars 1-3 age) with an interval of about a week.
These measures help eliminate the various causes of curling currant leaves.
