Why red spots appear on currant leaves and how to deal with them

The yield of currants depends not only on favorable climatic conditions, but also on compliance with the rules of agricultural technology and preventive measures to combat diseases and pests. The appearance of red spots on the leaves of a plant means that it is affected by the fungal disease anthracnose or has been attacked by gall aphids. When the first signs are detected, it is important to immediately take appropriate measures, since both problems lead to crop loss and increase the risk of currant death.

Red raised spots caused by gall aphids on currants

What to do if red spots appear on the leaves of red currants? First, it is important to inspect the plant and determine whether the problem is caused by anthracnose or gall aphids.

Symptoms

The fact that the bush is affected by gall aphids is indicated by tubercles. brown and red in irregular shape. On the underside of the leaf you can see small pale green insects about 2 mm long. The larvae are yellow-white. Aphids suck the juice from the leaves of the bush. To heal wounds, the plant produces red growths.

Most often, the pest settles on red and white currants, since their leaves are more delicate, they are easier to pierce. Insects are rare on black and golden species.

During the winter, aphids lay black eggs, which remain on the branches of the plant.. With the onset of spring, larvae hatch and suck the juice from the leaves.Scattering throughout the area, they give rise to 6 to 7 new generations. Insects live on currants until mid-July. As soon as the foliage becomes coarse, they move to oregano, lavender or sage. If measures are not taken to combat gall aphids, the yield is reduced, the bush becomes sick and may die completely.

What to treat in spring

If red raised spots appear on currant leaves, what means of control should be used? To get rid of aphids, it is recommended to use traditional methods at an early stage. If they do not produce results, chemicals are used.

In spring, many gardeners scald a plant with unopened buds with boiling water. To do this, water is boiled and allowed to cool to +70°C. Then fill a container with a sprayer and treat the bushes.

Spraying currants with iodine solution is effective (1 drop per 1 liter of water). The plant is treated with liquid at room temperature.

A solution of laundry soap helps get rid of aphids. Use half a piece for 10 liters of water. It is grated on a fine grater and dissolved. The entire bush is sprayed with the product.

To deal with aphids, make various infusions that are used to treat the affected plant:

1. 3 kg of raw celandine or 1 kg of dried celandine is poured into 10 liters of water, left for 24 hours, and filtered.
2. 300 g of tobacco dust is poured into 10 liters of boiling water and allowed to brew for 3 days. The product is filtered, 100 g of soap solution is added (it is made from laundry or tar soap).
3. 25 g of mustard is poured into 1 liter of boiling water and left for 2 days. Add water to 10 liters, add 100 g of soap solution.
4. 5 liters of crushed marigold flowers are poured into 10 liters of water. Keep for 22 days. Strain and add 100 g of soap solution.

Effective fumigation of currants with smoke. It gets into hard-to-reach places where infusions do not penetrate when sprayed. Burnt rubber is used for this. This procedure is carried out only until the buds open. When the leaves bloom, cut off the tops of the shoots affected by aphids, repeat 2 times, after 10 days.

Reference! Chemical treatment agents are used only in extreme cases: with an extensive lesion and a completely depressed state of the plant.

If the leaves of a bush begin to swell due to aphids, biological preparations that are safe for humans are used., created on the basis of fungi, viruses and spore bacteria (“Aktofit”, “Avertin”, “Bitoxibacillin”). Chemicals that are effective in controlling insects are: “Aktelik”, “Vofatox”, “Proteus”, “Calypso”. Since toxic substances are retained in plant tissues, currants are treated with insecticides before buds appear and after harvest. When using chemicals, it is important to observe safety precautions and strictly follow the instructions.

Spotted bumps on leaves due to anthracnose

Symptoms of the disease and treatment of spotted bulges on leaves due to anthracnose have their own characteristics. All types of crops are susceptible to fungal disease. The causative agent of anthracnose is able to survive the winter under bushes. The infection is spread by various insects. Moisture promotes increased growth of pathogenic microorganisms, so currants are most often affected by the disease during the rainy season.

Symptoms

A fungal disease occurs on the leaves of the bush. First, small brown spots form on the upper side of the leaf blade. with a brown edging and a dark tubercle in the center. Then they grow and merge.The entire leaf is damaged, which impedes the movement of nutritious juices. It dries out prematurely and falls off.

Reference! Red currant bushes survive this disease worse than others. Their stalks, petioles and berries are affected.

Fallen diseased leaves are a source of infection in May and June. Later, conidiospores are formed, which spread the infection in July and August. The annual infection of the bush by anthracnose leads to the death of the branches and the entire plant.

Basic reasons for the spread of fungal spores:

• lack of potassium and phosphorus;
• strong thickening of the bush;
• insufficient lighting;
• increased humidity and temperature;
• windy weather;
• remnants of the affected parts of the plant.

After the first signs of the disease appear, it is important to remove the damaged parts of the plant. and disinfect it. When the leaves fall, a second disinfection is carried out.

How to fight

As soon as the leaves of the bush begin to turn red, treatment begins immediately to save the harvest and the plant itself. Various chemicals are used to treat the disease. Fungicides interfere with the biochemical reactions that occur in fungal cells. They stop reproducing fully and die. To combat the disease, Previkur, Kuproxat, Ridomil, Fundazol, Acrobat MC are used. Before using them, it is important to carefully study the instructions, since all drugs differ in their hazard class and the way they affect the plant.

As with gall aphids, a solution of laundry soap is used to combat anthracnose. To do this, grind half of the bar on a fine grater, add 10 liters of water and stir until completely dissolved. The resulting liquid is sprayed onto the affected currants.

Before the leaves appear, the bush is treated with a 1% solution of copper sulfate. Before flowering, “Topsin-M” is used. When the ovaries begin to appear, the crop is fed with ash. To develop stable immunity in the plant, complex fertilizers containing nitrogen and boric acid are used.

After harvesting, the bush is treated with Bordeaux mixture. To prepare a 1% solution, take 100 g of copper sulfate and 150 g of lime. They are dissolved separately in 1 liter of hot water. Each solution is brought to a volume of 5 liters by adding cold water. Lime milk is filtered through thick gauze, and then a solution of copper sulfate is poured into it in a thin stream, stirring frequently.

Important! Bordeaux liquid can be stored for no longer than a day, so it is used immediately after preparation.

In autumn, fallen leaves from an infected plant are collected and burned.to destroy fungal spores. The soil is dug up and the bush is sprayed with fungicides, for example, Nitrophen.

Disease Prevention Measures

Preventative measures help reduce the likelihood of diseases that cause leaves to turn red and swell. So, for landing select varietiesresistant to anthracnose (for example, Victoria, Dutch Red, Firstborn).

The site should not be protected from direct sunlight. It is undesirable to flood it with spring meltwater. It is important to prune the plant on time, both sanitary and rejuvenating.. Particular attention is paid to watering and fertilizing the bushes, which should contain a sufficient amount of phosphorus and potassium.

in autumn

After the harvest, when the currant leaves begin to acquire a reddish tint, autumn prevention beginsto prepare the shrub for winter and prevent re-infestation. First, fallen leaves are collected and burned.

The earth is dug up with the formation turned away so that pests, their larvae and pathogenic microorganisms die. Deep digging is carried out within 20 cm. To consolidate the result, the soil is treated with fungicides. When stable cold weather sets in, it is fertilized with manure.

Produces sanitary and anti-aging pruning, cutting off dry and old branches, shoots with cracks and lichen with pruning shears. All cuts are treated with garden varnish to avoid the laying of aphid eggs. If pruning is done correctly, this will lead to an increase in yield; after rain or watering, the plant will dry out faster, and the spores that fall on it will not ripen.

in spring

After the snow melts they rake up all the garbage around the bushes and burn it. Removing organic residues helps get rid of fungal spores and harmful insects. The soil around the currant is loosened to increase oxygen access to the roots and ensure adequate nutrition for the plant. This increases the shrub's resistance to various pests. The soil is treated with a solution of copper sulfate.

If the snow has melted and there is not enough precipitation, it is important not to forget about watering the plant. It is done once a week, pouring 3-4 buckets of water under each bush.

In the spring, before the buds swell, to avoid infection with infectious diseases diseases and pest attacks, the bushes are sprayed. A simple and effective way is to scald plants with hot water. This procedure gets rid of aphid larvae and fungal spores. Treatment with chemicals is carried out after the leaves appear, but before the flowers form.

Additional care tips

Before planting currants carefully choose the plant variety, study their strengths and weaknesses, resistance and sensitivity to specific diseases.

You can’t plant bushes close to each other: They will create shade and quickly transmit infections. If the plant is initially planted in a damp lowland or shade, it is moved to open space in the fall. It is important to periodically thin out shrubs.

To get rid of aphids, garlic, onions, calendula, chamomile and marigolds are planted nearby: insects cannot tolerate their pungent odor. There should be no herbs near the currants that aphids can transfer to, especially nettles and plants of the Lamiaceae family (sage, oregano, mint, lemon balm, thyme, etc.).

To attract insects that feed on aphids (bees, ladybugs, lacewings), meadow grasses are sown near the bushes. At the same time, there should be no anthills near the currants, since it is the ants that carry, or rather, breed aphids.

Conclusion

Gall aphids and anthracnose are among the most common causes of currant leaves becoming covered with red spots. When the first signs appear, it is important to immediately proceed to treatment of the bush in order to save the harvest and the plant itself. There are many folk remedies and chemicals for this.

To avoid the occurrence of diseases, it is important to carry out preventive measures in time and properly care for the bush.