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Currants grow in almost every garden. Gardeners appreciate it for its unpretentiousness and delicious fruits. But even with proper care, the plant is susceptible to some diseases that can cause irreparable harm to the shrub. To avoid unpleasant consequences, you should carefully monitor any changes and be able to stop them in time. Below you will learn in detail what to do if red spots appear on the leaves of the currant.
What diseases provoke red spots on the leaves of black and red currants
Noticing reddish spots on the berry bush, the first step is to identify the cause. There can be three of them:
Let's take a closer look at each one.
Fungal disease anthracnose: symptoms and cause
Anthracnose is a fungal disease. It slows down the growth of the plant, reduces its viability, especially in the cold season, significantly reduces fertility and worsens the quality of the crop. Begins to develop in late spring, early summer. The ideal weather is warm and humid. Insects and animals can carry the disease. Rain and wind also spread spores, and if any damage is present, anthracnose immediately infects the plant.
Important! Most often, the fungus develops on shrubs that are deficient in potassium and phosphorus, as well as growing in acidic soil.
The main symptoms of anthracnose are:
- the appearance of small dark red spots with a dark rim, which increase over time, accompanied by swelling;
- shiny black tubercles form on the spots;
- infected greenery dries up and falls off;
- if the disease has spread to the branches, brown deep ulcers are noticeable on them;
- in an advanced case, the fungus also affects the fruits, covering them with black spots, after which the berries fall off.
Red-gall aphid: signs of parasitism
Gall aphid is a parasitic insect, no more than a couple of millimeters in size. Due to its amazing fertility, it causes irreparable harm to the plant. It starts an attack with young shoots at the stage of inception, so new leaves appear already deformed and incapable of active growth and regeneration. Because of this, the condition of the bush worsens the next year.
The insect settles on the inside of the leaf and feeds on its juices, which is why reddish, dense, swollen growths - galls - appear on the greens. This is how the bush tries to heal itself. Generations of aphids live on the plant until it dries up completely. But even after that, the aphid does not fly far away - it settles on the nearest weed grass.
Important! Aphids attract ants, which in turn also feed on leaf juices. In addition, the pest is a carrier of dangerous diseases, and in addition to currants, it can attack other garden crops.
Rust: how is it manifested and how dangerous?
Another reason for the appearance of red spots on currants is frost-resistant fungal rust. Carriers are sedge and conifers. The wind instantly spreads the spores of the fungus. It is almost impossible to notice rust in the early stages. It begins to show itself in the spring.
There are two types of rust:
- goblet. On the back of the leaf, bright yellow convex pads appear, which subsequently join together and turn red. Unripe berries and ovaries are affected;
- columnar. Covers the outside of the leaf with yellow spots. On the inside, dots appear with spores that look like hairs.
The consequences of the fungus are sad - during the illness, the bush loses a quarter of its leaves, and by autumn it is completely bald. Currants do not give new shoots and crops, and in winter they die.
Important! With delayed treatment, the disease can spread to other plants.
How to treat currant bushes
Having found that the leaves of the currant turn red, and having identified the cause, it is necessary to proceed with immediate treatment.
Fungal control methods
Before starting chemical treatment, a number of agrotechnical measures should be taken to destroy fungal spores:
- collect all the fallen leaves and burn. Do this as far from the garden as possible so that the disease does not affect other plants;
- destroy all weeds around the currant bushes;
- loosen and dig up the ground by at least 5 centimeters;
- carry out timely pruning;
- drain the planting holes.
After taking the measures, it is necessary to proceed directly to the treatment. Chemicals are suitable for killing anthracnose spores:
- DNOC 1%. Solution: dilute 50 grams in 2 liters of water, and then add another 8 liters. Treat the bush when digging, soil and fallen leaves. Important! It should be applied no more than 1 time in two seasons.
- Copper sulfate 1%. Dissolve 100 grams of copper in 10 liters of water. One bush - 1.5 liters. Treat in the spring, before the buds swell, and in the fall, after the foliage has fallen off.
- Gamair. Dilute 1 tablet in a little water, and then bring the volume to 10 liters. Important! Do not use hot water for the solution, as the product will lose its effect.
- Ridomil Gold. It is used exclusively for the treatment, not the prevention of the disease. Solution: 25 grams per 10 liters of water.
- Fundazol. Suitable for both treatment and prevention. 10-15 grams of powder per 10 liters of water.
- Fitosporin. Can be used at any stage of bush development. For a solution, 5 grams of powder should be diluted in 10 liters of water.
- Bordeaux liquid 1%, 3%. Suitable for the prevention and treatment of reddened plants. Can be used up to 5 times per season.
For rust treatment, use Fitosporin and Bordeaux liquid.
To get rid of aphids, first of all, it is necessary to cut off and burn all branches with damaged leaves.
Important! It is necessary to destroy branches, even with minor damage, where eggs can be laid, in order to avoid recurrence of infection.
Before starting the fight with chemicals, it is worth trying to destroy the pest with natural insecticides:
- Tobacco solution. Pour boiling water over 300 grams of tobacco dust and leave for 2-3 days. Strain the infusion and add 100 grams of soap dissolved in water.
- A decoction of marigolds. Pour 10 liters of boiling water over half a bucket of chopped flowers. Insist 2 days. Strain and add 50 grams of soap.
In a more advanced case, you should turn to chemicals: Confido Maxi, Vofatox, Proteus, Calypso, Actellik (they should be used before the berries appear and after they are picked). Softer means: Bitoxibacillin, Aktofit, Avertin.
Timing and frequency of treatment
Healing activities are carried out throughout the season.
Frequency of treatments against fungal diseases:
- in the spring, when the leaves are blooming (the most important treatment);
- after flowering;
- after harvest.
If the disease progresses, the frequency of treatment should be increased.
Treatment of currants against aphids:
- on bushes with dormant buds and on the soil;
- when blooming buds.
Additional spraying - depending on the infestation.
What to do to prevent currant leaves from turning red
Currant treatment is a troublesome and long-term business. Therefore, it is much easier to suppress the appearance of the disease by carrying out regular prevention.
Begins after picking berries. You can also start it at the end of August. In autumn prevention, infection should be fought with strong chemicals. More attention should be paid to pruning leaves and dry branches, and then burning them, because it is in the fallen leaves that the largest number of fungal spores and insects are found.
You can remove leaves on black currants manually. On red, they must fall off on their own.
It begins before the leaves open and before the snow melts and is considered the most important. At this time, in addition to plants, diseases are also awakened. It is necessary to do the treatment with boiling water, watering the plant and the soil around. In addition, regardless of the presence of the disease, treatment with chemicals or copper solutions should be carried out.