When growing blackcurrant, the gardener may encounter such a problem as terry - a viral disease of the culture. Today in the article a detailed acquaintance with the disease, treatment and prevention methods.

Description of terry in black currant

The disease is called reversion, since it manifests itself as a return to the original wild form of culture. The virus gradually affects all parts of the plant, rapidly spreading along the berry, and leads to infertility and death of currants. The danger of the disease is that it has a long incubation period - about 3 years, it can develop secretly, without distinct signs. External manifestations at the end of the incubation of the virus can be seen on different parts of the currant:

Did you know? Currant leaves are used for the production of natural food yellow dye.

a) leaves and shoots:

• the sheet changes shape, wrinkles, the plate becomes asymmetric;
• large teeth with a large interval appear along the edge of the leaf plate (in a healthy culture, the leaves are uniformly fine-toothed);
• the veins become coarse and convex, significantly brighten relative to the dark green background of the leaf;
• internodes and shoots are extended.

b) buds, flowers and fruits:

• the kidneys are deformed - from an oblong dense bud, a head is swollen, up to 1 cm in diameter;
• the affected kidneys do not bloom;
• flower buds acquire a bright red color (normal pale lilac or pink color);
• the petals of a blossoming flower are rare and elongated, the pestle is thinned;
• the flower can be covered with a scaly film, which gives it a terry appearance;
• the fruits are deformed, on many shoots they simply disappear;
• there is no aroma inherent in berries.

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Causes of the onset and spread of the disease

The causative agent of terry in currants is mycoplasma Ribes virus. The main distributor of the disease is considered a kidney tick. This microscopic insect, 2 mm in size, is transferred to the bush by wind or birds. The insect may be present on purchased seedlings or garden tools.

During the summer, a prolific parasite produces up to 3 thousand individuals. Eating the juice of the bush, the tick transmits a virus that spreads through the vessels to all parts of the bush. The parasite can overwinter in the kidneys, activating in the spring. The virus also does not freeze, it quietly hibernates in the vessels of the currant tissue.

Methods of control and treatment

When planting currants, in order to avoid future problems, they select varieties zoned and resistant to diseases and pests. Among the varieties with strong immunity, the following cultures are distinguished:

• Venus;
• Curiosity;
• Coveted;
• Kipiana;
• Mermaid;
• Success.

Mechanical

The fight against terry, in the presence of signs, begins in early spring. Swollen kidneys are cut off along with part of the shoot and disposed of.

Important! Pruning work must be done before the buds open, until the ticks migrate to neighboring plants.

After sanitary pruning, the bush can be “burned”. The treatment procedure is carried out using a blowtorch or gas burner. The device is kept at a distance of 10 cm from the shoot, carried out by flame on all branches several times. In the same way, you need to cultivate the soil in the near-stem circle. Fire will destroy ticks and their offspring, which will reduce the risk of re-infection.

If the bush is severely affected, almost all of its shoots and foliage are deformed, it makes no sense to treat . The bush needs to be dug up and destroyed, and the earth thoroughly disinfected so that the virus does not infect other plants. After the destruction of infected bushes, it is imperative to disinfect all involved garden equipment.

Biological products

The advantage of biological fungicides and insecticides in the treatment of diseases in the possibility of use at all stages of vegetation. The most effective against the virus and its carrier are:

• Fitosporin-M Resuscitator is a broad-spectrum fungicide. You need a concentrate in a ratio of 1:20 with water, for 10 m² when spraying a liter of solution is enough;
• "Haupsin" - a biological insectofungicide, a working solution for spraying in a proportion of 200 g / 10 l.

Did you know? Currant leaves are used not only for conservation, they are added when smoking meat and fish. Greens give products a special aroma, and volatile products in the composition extend the shelf life.

Biological agents include folk methods:

1. Infusion of tobacco dust 50 g / 1 liter of water, insist and strain. Then add water to a volume of 10 l and grate 40 g of laundry soap.
2. Garlic water is prepared from 200 g of chopped garlic, 8 l of boiled water. Insist 12 hours, after - sprayed.
3. Mustard infusion. 200 g of powder is poured into 10 liters of water, diseased plants are insisted and sprayed.

Chemicals

When symptoms of the disease or the presence of a tick are detected, chemicals are used. You can fight the scourge with the following methods:

1. Colloidal sulfur in a concentration of 10 g / 10 l of water will destroy both the tick and the virus. Spraying is carried out twice, with an interval of 2 weeks, the second time the concentration of the solution is halved so as not to burn the currants.
2. "Karbofos" is prepared by diluting with water in a proportion of 75 g / 10 l. The protective action period is 10 days, so if necessary, repeat the procedure after 3 weeks.
3. Agravertin is an acaricide. To destroy the tick, a working solution of 2 ml / 1 liter of water is prepared.

Important! The effectiveness of colloidal sulfur in treatment is maximally disclosed at an air temperature of + 20 ° C, Karbofos at a temperature of + 15 ° C.

Disease prevention

Terry prevention begins with seedlings. For pre-planting treatment, a mixture of 10 g of Agravertin and 40 g of colloidal sulfur in 10 l of water is prepared. In a solution, a seedling or a stalk can withstand a day, not only the roots, but all the material.

Before planting the crop, it is important to thoroughly clean the area from plant debris, shed the soil with weak pink potassium permanganate. All instruments must be sanitized.

During the care of the berry, weeds must be removed, to prevent thickening of the crown, which attracts insects. Proper and timely pruning is an important part of disease prevention . You need to remember about the processing of garden varieties or other antiseptics of all sections on the bushes.

Fig. 1. Currant pruning: a - annual seedling; b - a biennial bush; c, d - shortening of shoots. Fig. 2. Currant bush before anti-aging pruning (a), after it (b) and pruning of a neglected bush (c)

In the early spring and after harvest, preventive procedures are carried out with the fungicides and insecticides described above. Another effective way to scare away virus carriers is to plant repellents between bushes of plants, such as:

• tansy;
• sagebrush;
• garlic;
• marigold.

Growing currants can do without difficulties if you carefully read the rules of agricultural technology, methods of prevention. It is important to inspect the bushes often so as not to miss the symptoms and prevent the spread of the disease throughout the berry.