Anthracnose on currants: control measures, pathogen

Currant bushes are susceptible to fungal diseases that affect the entire plant, reduce its immunity and winter hardiness. Without timely treatment, plantings may die. In spring and early summer, the development of black and red currant bushes is closely monitored to prevent such an insidious disease as anthracnose.

How is the disease manifested

The onset of currant infection with anthracnose begins in the spring. The causative agents of currant anthracnose, having overwintered on fallen leaves, are also spread by insects during rain. Plants with the smallest mechanical damage are often affected.

Causes of the disease

This fungal disease is caused by marsupial fungi of several genera. The disease affects the leaves and shoots of many plants, especially currants – red, white and black. The smallest spores, conidia, having hit the plant, form a mycelium in the tissues between the cells. The incubation period after being hit by spores that cause anthracnose on blackcurrants is approximately 2 weeks. Red currants get sick after a week. Having developed, the mycelium produces two generations of conidia – in May and July.

Favorable for the development of the disease is the summer season with frequent rains, when the humidity reaches 90%, and the air temperature is 22 ⁰C. In such years, the disease is most widespread. In dry years, cases of damage are much less common. It has been noticed that plants located on acidic soils, as well as with a lack of potassium and phosphorus, often suffer.

Ways of infection

Anthracnose spores from diseased currant plants to healthy ones are transmitted in several ways:

• Spread by insects and mites;
• Air currents;
• The thickening of plantings of currant bushes and the remaining last year’s leaves contribute to the disease.

Signs of infection

With anthracnose, leaves, petioles, young branches, stalks and less often berries suffer.

• A symptom of the onset of the disease are dark or light brown spots of a rounded shape, with a darker border, ranging in size from 1 mm. Over time, the spots increase, merge into a large affected area on the leaf plate, which becomes dry and falls off;
• Later, from the middle of summer, a second sporulation develops, noticeable by black tubercles. When they ripen and rupture, they become white. The disease through new pathogens captures a large area of ​​uXNUMXbuXNUMXbthe plant, can continue until September;
• Shoots, as well as petioles and stalks on red currants, are covered with dark sunken spots that prevent the free flow of nutrients;
• Later, cracks form in place of the spots on the shoots. When wet weather returns, the shoots rot;
• If the disease is transferred to the berries, it is recognized by small glossy black or brown dots with red edges;
• In the stage of leaf fall, young shoots wither;
• In July, only new leaves can remain on the bush.

Consequences of the disease

You can assess the condition of a diseased blackcurrant bush in the middle of summer, especially if the temperature stays below 19 degrees. On red currants, the disease manifests itself earlier – at the end of May, early June, if the temperature ranges from 5 to 25 degrees. Leaves from bushes of red and white currant fall almost immediately after the defeat. On blackcurrant, brown and dried, twisted leaves sometimes remain until autumn. With unhindered development, up to 60% of the leaves fall off, the plant does not receive enough nutrients. The yield on the diseased bush is lost by 75%, the sugar content of the berries decreases, young shoots do not form, up to 50% of the branches can die during the winter.

Anthracnose fungi overwinter on fallen leaves. If they are not removed from under the currant bushes, in the spring they produce new spores, and the bush becomes infected again. It happens that the disease goes away, but the plant weakens and may not recover without treatment and support.

Control measures

Knowing about the symptoms of the disease, gardeners apply preventive measures to combat anthracnose on currants, carefully removing fallen leaves in autumn and digging up the soil under the bushes. Treatment with chemicals helps to destroy currant pathogens. Each gardener chooses his own option from the range of drugs for the treatment of currant anthracnose. Bushes are sprayed in dry weather, when there is no wind, carefully processing each leaf.

Processing options

• Before bud break, 1% copper sulphate is used, cultivating the bushes and the soil under them;
• Kaptan, Ftalan (0,5%), Cuprozan (0,4%) or 3-4% Bordeaux mixture is applied to unopened buds, before flowering or 10-20 days after harvest;
• Before flowering, Topsin-M fungicide is also used mixed with drugs that stimulate immunity: Epin, Zircon;
• Currants are sprayed with Cineb or 1% Bordeaux liquid after flowering;
• In case of detection of anthracnose on currants during the ripening period of berries, they are treated with microbiological preparations: Fitosporin-M, Gamair;
• After picking the berries, currant bushes are re-treated with fungicides Fundazol, Previkur, Ridomil Gold or others.

Prevention

Proper spacious planting and pruning of currant bushes, soil care, weed removal, moderate watering, careful inspection and regular preventive spraying will save plants from treatment for anthracnose disease.

Preventive treatments are carried out with drugs that protect plants from a wide range of fungal diseases and pests. Fungicides Cumulus DF, Thiovit Jet, Tsineb, Kaptan, solution 1% Bordeaux liquid is used after flowering and 15 days after picking berries.

Having noticed the first signs of anthracnose, the affected parts are removed so that the disease does not spread. In autumn, fallen leaves are collected, and the soil is dug up.

From the experience of summer residents

Not all gardeners like to use chemicals, but they treat currant anthracnose with folk remedies weekly.

• In March or February, depending on the region, bushes are scalded with hot water over dormant buds, the temperature of which is not higher than 70 ⁰C;
• Used to treat currant anthracnose by spraying the bushes with a solution of laundry soap. Half of the bar is rubbed on a grater and diluted in a bucket of water, with a temperature of at least 22 ⁰C;
• Currant bushes are treated with an infusion of 150 g of chopped garlic and 10 liters of warm water: a pungent smell repels pests, and one of the distribution routes of currant anthracnose is interrupted;
• A solution of iodine is used in the treatment of currant bushes. Its antiseptic property is equated to the action of a fungicide. Iodine destroys microorganisms and provides preventive support to plants. For a working solution, 10 drops of iodine are diluted in 10 liters of water.

Additional fertilizing

Plants with developed immunity are easier to treat. Currants are supported by complex feeds.

• For a 10-liter bucket of water, take 1 tbsp. a spoonful of potassium sulfate and ammonium nitrate, half a teaspoon of boric acid and 3 g of iron sulfate. Top dressing restores an exhausted currant bush, helps to grow greenery and prevents leaf chlorosis;
• In the ovary formation phase, a top dressing with wood ash is prepared to improve the quality of the crop and increase the endurance of currants. In a bucket of water, dissolve 200 g of ash, 1 sachet of sodium humate, 2 tbsp. spoons of potassium sulfate and 1 tbsp. a spoonful of superphosphate;
• The use of Immunocytophyte has a good effect: 1 tablet of the drug is diluted in a bucket of water, a solution of 1 tbsp is added. spoons of superphosphate and 2 tbsp. spoons of potassium sulfate.

When buying currants, you can choose varieties with high resistance to anthracnose:

• Blackcurrant: Stakhanovka, Katun, Altai, Exhibition, Siberian daughter, Zoya, Belarusian sweet, Dove, Elegant;
• Redcurrant: Faya fertile, Firstborn, Victoria, Chulkovskaya, Red Dutch, London Market.

The disease brought by fungi can be defeated. Increased attention to the garden will bring a quality harvest.

Reviews