Blackcurrant terry (curl, reversion): description with photographs of leaves, methods of treatment and preventive measures to combat the disease, resistant varieties

What is blackcurrant terry?

Blackcurrant terry (reversion, curl) is a viral disease that affects all parts of the bush: shoots, leaves, fruits.

If terry disease is not detected at an early stage and treatment is not started, the plant will stop bearing fruit and die.

Description of the disease

Terry is caused by a virus. It develops only in the cells of living organisms and enters the site through planting material or insects.

During the growing season, the causative agents of terry disease spread throughout the plant, primarily attacking the leaves and branches, and later move on to the fruits and root system. Sometimes viruses appear after pruning and penetrate open wounds.

Often the terry disease is disguised - there are no external signs of the disease. The virus can only be recognized by a sharp decrease in yield.

Damage caused

The damage from terry disease is significant: if plantings of fruit bushes are not treated, the plants will die. If a viral disease is detected at an early stage, the crop can be saved.

The disease is dangerous because it spreads quickly and affects neighboring plants. The disease is especially common in the Central and Northwestern regions.

Methods to combat the defect

Terry disease is a very dangerous disease of berry plantations. You won't be able to get rid of it completely. Even if the plant is destroyed at the roots, the virus is still present in it. Therefore, it is impossible to graft young shoots onto a stump where a diseased bush grew.

Important! The virus can only be destroyed together with the bush.

Then how to deal with terry? The main thing is to protect your lands from the attack of the “enemy”, or to prevent an existing pathogen from spreading. First of all, this concerns the kidney mite:

Treatment of viral terry black currant occurs by pruning shoots affected by the bud mite and removing diseased buds. In spring, mite settlements on the kidneys become especially noticeable. Before they have time to open, they become swollen and not dense. These buds should be cut off and destroyed. If there are a lot of buds, then the entire shoot is removed. The procedure must be completed before the buds open.
Hot water is very effective in the fight against ticks. Infected shoots are cut back to healthy wood. The remaining branches are tied together and scalded with water, the temperature of which should be up to 80 degrees. Cuttings from diseased branches are always destroyed; in the spring you can burn them with last year’s foliage.
To combat currant terry and spider mites, you can use special preparations that have insecticidal properties. These include: colloidal sulfur, Lepidocid solution, Bitoxibacillin, Fufanon, Akarin and others, which are sold in specialized stores. It is important to dose the product according to the instructions.

Causes of terry

Currant bud mite

The most common carrier of the disease is the kidney mite. It appears on the site due to infected seedlings. At the moment of flowering of the currant, the affected buds wither, and the female mites get out.

Infection occurs at the end of spring or beginning of summer, depending on the timing of ripening. In addition to the bud mite, aphids, plant bugs and spider mites can carry the virus. They actively develop in hot and humid summer conditions and love weakened plants.

The virus also occurs because the currant seedlings were already infected at the time of planting. The peculiarity is that the planting material is externally healthy - there are no signs of damage. And only after 2-3 years, summer residents observe a decrease in yield and delayed flowering.

Attention! The virus prefers plants with weak immunity. It occurs due to improper care: due to lack of watering and fertilizing, irregular pruning, and weeds on the site. Therefore, it is important to care for the currant bush, monitor its appearance and conduct inspections.

Causes of the appearance and spread of the disease

The causative agent of currant blight is mycoplasma Ribes virus. The main spreader of the disease is considered to be the kidney mite. This microscopic insect, 2 mm in size, is carried to the bush by the wind or birds. The insect may be present on purchased seedlings or garden tools.

Over the summer, the prolific parasite produces up to 3 thousand individuals. By feeding on the sap of the bush, the tick transmits the virus, which spreads through the vessels to all parts of the bush. The parasite can overwinter in the buds, becoming active in the spring. The virus also does not freeze out; it quietly overwinters in the vessels of currant tissue.

Symptoms

On young plants, doubleness most often develops hidden. Symptoms appear on shrubs older than 3-4 years. Signs of damage become clear when the incubation period ends.

External signs of damage to black currant by terry

A characteristic symptom of terry growth is the absence of berries on the bushes. Gardeners also notice that the leaf plates are deformed, and the shape and color of the flowers change. Many lateral shoots and green shoots appear, and the strong currant aroma of the plant disappears.

On some shrubs, gardeners notice that the leaves become asymmetrical, with rare coarse veins appearing on one side. Such signs can be detected visually during examination and prevent the development of the disease.

When terry blossoms are detected in the spring, gardeners notice deformed flowers - they seem to be covered with scales and take on a reddish-lilac hue. The petals of the flower are separated, the stamens are elongated. Complete destruction of the bush is accompanied by the fact that the plant becomes dense - a large number of shoots grow.

Currant hybrids

Today, only 2 currant hybrids are popular.

Yoshta

This is a hybrid of common gooseberry, black currant and protruding gooseberry. It was born in 1970. It took specialists about 40 years to create it. This is a very strong spreading shrub, reaching a height of approximately 150 cm, its diameter can also be 150 cm. There are no thorns on the plant. The fruits are covered with a thick skin and weigh about 5 grams. They are painted black with a purple tint. The berries are collected in a cluster of 3–5 pieces. They have a nutmeg flavor that is quite pleasant. The bush is frost-resistant and resistant to certain pests and diseases. Life expectancy is from 20 to 30 years. Very popular in Western Europe.

Kroma

This hybrid of gooseberries and currants was created in Sweden. Large smooth fruits are painted black and reach 20 millimeters in diameter. They are 3-5 pieces collected in a brush. The plant does not have the characteristic smell of currants. The fruits have the taste of both currants and gooseberries. In Sweden, fruit ripening occurs in mid-July.

How to treat shrubs

There are several ways to treat shrubs. Chemicals are used when the virus has already been detected on the plantings. Agrotechnical techniques and traditional methods act as additional methods of protection; to be effective, they are combined with chemicals.

Chemicals

Chemicals are highly aggressive, so they are used with precautions. An effective chemical for treating terry hair is Fufanon. The active components of the drug are malathion. It blocks pathogens within 1-2 hours. Working fluid consumption is 1.5 liters per 1 bush. Spray the solution in dry, windless weather, wetting the currant leaves on all sides. Leftovers cannot be stored; they are disposed of immediately.

Gardeners use the drug “Topaz”. It has a preventive, curative and eradicative effect. The Topaz solution is quickly absorbed by currants, which reduces the risk of being washed off by rain or evaporation due to sunlight. To make a solution, 2 ml are diluted in 10 liters of water, the consumption rate is 1 liter per 10 square meters. m. It is not recommended to mix Topaz with other pesticides. During the season, currants are processed 4 times with an interval of 2 weeks.

Agrotechnical techniques

Agrotechnical techniques are not able to completely cure black currants from terry disease, but they help strengthen the bush’s immunity and slow down the spread of the disease.

Summer residents pay attention to the following recommendations:

If a source of infection is detected, the affected bushes are removed and burned away from the site. The remaining plants are treated with Fufanon, a solution of Bordeaux mixture or copper sulfate. And the soil under the bush is watered with a solution of wood ash.
In early spring and the first half of summer, shrubs are sprayed with a solution of colloidal sulfur. The treatment destroys pathogens, protects currants from aphids and bud mites, and prevents the appearance of fungi. During the season, the event is held 2 times with an interval of 1 month.
To strengthen the immunity of currants, mineral and organic fertilizers are applied. In April, the bush is watered with mullein solution, in mid-June it is fertilized with double superphosphate, and in August it is watered with a herbal infusion of chamomile, tansy and sage. Comprehensive care not only protects against viruses, but also increases productivity.

Traditional methods

Folk remedies are used only in conjunction with professional treatment methods.

To prevent and treat terry, use an infusion of tomato tops . It contains solanine, a poisonous compound that fights diseases and pests. To prepare, take 4 kg of fresh tomato leaves, chop them and pour 10 liters of warm water. Leave for 4 hours and put on the stove for half an hour to boil. Afterwards, the broth is filtered, diluted with water in a ratio of 1:4 and 40 g of grated soap is added so that the solution sticks to the bushes. Damaged plants are sprayed early in the morning.

To prepare a green medicinal infusion, chamomile, dandelion, sage, calendula and other medicinal herbs are used in equal parts. They are soaked in boiling water for a day, filtered and diluted in a ratio of 100 ml of herbs per 1 liter of water. Currants are sprayed 2 times a month; pesticides are used in between such treatments.

How to deal with the disease?

Terry is very insidious not only because of the harm and difficulty of diagnosis. Until now, no remedy has been found that can cure viral and mycoplasma plant diseases. No chemical or biological drugs can even weaken the effect of reversion. If obvious signs of terry disease are detected on the currant, the diseased bush must be immediately destroyed. Even drastic pruning of the stump will not save a plant in which the virus has already settled. It is better to direct all efforts to protect against potential carriers of infection and take other measures to protect currant plantings from infection.

To protect yourself and your garden from encountering currant blight, we can recommend the following preventive measures:

Purchasing and planting healthy planting material. You need to be careful when choosing seedlings so as not to bring the disease to your site with them. Buy young seedlings and currant cuttings only from reliable garden centers and nurseries.
Compliance with quarantine measures. Due to the fact that during the first years the virus may not manifest itself in any way outwardly, and no one guarantees that the purchased seedlings were obtained from healthy plants, take them under special control during the first 4 years. It is better to place new currant plantings at a distance from the main plantation.
Competent organization of queen cells. When creating queen cells, be sure to leave at least one fruiting branch on each donor to be able to make sure there are no signs of disease.
Proper preparation of cuttings . Take cuttings only from healthy currant specimens that have not shown symptoms of doubleness over the previous 3-4 years. Never use cuttings cut from fattening annual shoots for propagation. And under no circumstances should you take cuttings from suspicious plants. If there is any doubt, it is recommended to subject lignified cuttings to thermal disinfection by immersing them in water at a temperature of 45-47 °C for 15 minutes.
Selection of resistant currant varieties. There are no varieties that are completely resistant to the terry virus. Of the old varieties that are relatively not susceptible to the pathogen, the most often called Pamyat Michurin, Zhelannaya, Podmoskovnaya, Uspeh, Neapolitanskaya. You can try to find currant varieties in your area that are resistant to bud mite damage.
Regular inspection of existing plantings and destruction of diseased bushes. At the end of flowering, when the manifestations of doubleness are most reliable, you need to carefully inspect all the plantings, paying special attention to the flower clusters. If at least a few double flowers are found, the entire bush must be immediately destroyed. Such inspections should be repeated throughout the season. It is a mistake to think that cutting out individual branches will help stop the spread of infection. If the virus has penetrated the tissue, the bush cannot be saved; it should be immediately uprooted and burned before the disease spreads to neighboring bushes. It is not recommended to resume planting currants in the same place over the next 5 years. The virus can survive only in living tissues, so there is no need to disinfect the soil at the site of the affected plantings.
Proper pruning. Do not get carried away with too much pruning of currants, otherwise you can provoke the appearance of a large number of basal shoots and tops. Such shoots are of greatest interest to pests who carry the infection. In early spring, it is enough to carry out moderate sanitary pruning, not forgetting to disinfect the pruning shears after handling each bush.

Preventive measures

The causative agents of the disease are viruses; the fight against them is long and not always fruitful.

To prevent the development of the disease, summer residents take simple measures as preventive measures:

buy two-year-old seedlings from trusted sellers;
before planting, treat the soil with Bordeaux mixture and dig it thoroughly;
plant currants next to gooseberries, avoid proximity to raspberries;
at the end of February or beginning of March, water the bushes with boiling water - it destroys viruses and pest larvae overwintering in the soil;
water the currants once every 2 weeks with water at room temperature;
regularly inspect the plants and monitor the amount of harvest;
remove and burn all weeds and debris from the plantings.

Prevention measures

Experienced gardeners believe that it is better to prevent a disease in advance than to fight it later. They recommend the following actions:

When buying seedlings, inspect them carefully.
After planting, the young bush must be constantly inspected. Terry is insidious in that it can slowly develop over four years, changing its activity from time to time.
Only healthy currant bushes are chosen for cuttings.
It is better to plant varieties on the site that are resistant to many diseases and pests.
Carry out preventive pruning.

Feeding

To increase the stress resistance of currant crops to the effects of terry, it is proposed to use phosphorus-potassium liquid fertilizer.
For foliar application of fertilizer, it is recommended to use a manganese composition.
It is a good idea to feed plants outside the root system with elements such as boron and molybdenum.

The use of increased amounts of nitrogen fertilizer in the fight against terry is categorically not indicated. Such feeding can only have the opposite effect.

As soon as the currant crop is harvested, it is advisable to spray the bushes with colloidal sulfur.

Increasing the immunity of shrubs

If you carefully observe garden crops or berry plants, you will see that diseases and pests primarily affect weakened specimens. Therefore, when growing currants, you need to take care of the bush’s immunity. This is the most effective technique in the fight against terry and bud mites.

To increase the resistance of currants to diseases, it is necessary to apply complex fertilizers to the bush, including the necessary microelements. According to gardeners, spraying with immunostimulating agents would not be amiss. This link will tell you about glass rust on currants.

Terry-resistant blackcurrant varieties

Choosing a resistant variety is one of the preventative measures that helps prevent the appearance of terry. Summer residents from central Russia are advised to pay attention to the varieties Ilya Muromets and Titania. In addition to strong immunity, they are distinguished by their ease of care, large and juicy berries, and balanced taste.

For the northern regions, the Sakharnaya or Sokrovische varieties are chosen . They can withstand temperatures down to -40°C and rarely suffer from rot, powdery mildew, or rot. The varieties are resistant to drought and can easily tolerate long-term lack of watering.

In the south, Gamma or Sevchanka currants are grown . Plants are not afraid of bud mites and are rarely damaged by other pests. The berries are sweet and sour, the taste is refreshing.

Attention! Even when planting terry-resistant varieties, we must not forget about preventive and agrotechnical measures. There is no plant that is 100% immune to leaf blight. It is also recommended to study reviews from experienced gardeners when choosing a variety.

Features of currants

Currant is a perennial shrub that can be spreading or compact. Its height varies from 100 to 200 centimeters. The greenish fluffy stems turn brown with age. Young shoots grow from dormant buds every year. The plant's root system is powerful, and it penetrates the soil to a depth of about 0.6 m. Three-lobed or five-lobed leaf plates with a serrated edge have a diameter of 3–12 centimeters. The front surface of the leaves has a dark green color, and the back surface has pubescence along the veins. Racemose drooping inflorescences consist of light pink or lavender bell-shaped flowers. The fruit is a fragrant berry. The color and size of the fruit is influenced by the type and variety of the plant. Flowering occurs in May and June, and fruiting occurs in July and August. The plant begins to bear fruit in the second year after planting in open soil. Currants are considered a popular crop, as are, for example, strawberries, blackberries, strawberries, raspberries and blueberries. It is cultivated by gardeners on their plots, and currants are also grown on an industrial scale. Currants are a relative of another popular crop - gooseberries.

Watch this video on YouTube

Advice from experienced gardeners

To protect the bush from terry, gardeners make sure that the soil is nutritious and balanced. When planting, the pit is fertilized with organic matter, a distance between seedlings of 1-1.5 m is maintained. Every year in early spring, pruning is carried out - dry and weakened branches are removed, thereby reducing the likelihood of pests and diseases. Every year, shrubs are treated with a solution of Bordeaux mixture - a simple and powerful remedy that protects against viruses and fungi.

It is recommended to remove currants from the area if currants have affected more than 40% of the bush. In this case, it is useless to save the plant - it is better to remove it immediately so as not to infect nearby bushes and save the remaining harvest.

Currant diseases: spread of rust

The fungus itself cannot be completely eradicated. Therefore, if you are fighting a disease on one bush, all others must be urgently prevented. There is no way without this. Otherwise, the fungus will easily spread to neighboring plantings. And the problem could triple. And even grow. It all depends on the number of currant bushes on your site.

Treated bushes are able to fight the disease. Therefore, closer to autumn, the fungus quietly moves on to simple grass. As well as neighboring plants that have nothing to do with currants. For example, sedge is an excellent place for rust to overwinter. And have a safe winter there.

Anthracnose

Among summer residents and gardeners, the name fly-catcher is more common. The disease is relevant for all types of currants. But the pathogen has the greatest selectivity for red currants.

How to recognize the disease?

The pathogen is highly resistant and thrives in last year’s currant leaves, overwintering under bushes. Its spread is facilitated by water and numerous bugs and insects. A fungal infection affects bushes during the rainy season. High humidity stimulates the rapid growth of pathogenic fungus. It spreads throughout the bush, leading to its death. Main signs of the disease:

the appearance of small brown spots. Their diameter is up to 1 mm. There are dark tubercles in the center;
the spots grow and merge, involving the entire leaf blade in the inflammatory process;
as a result, the leaves dry out and fall off;
the bush is dying.

Red currants tolerate the disease much worse than black currants. A few small spots are enough and the leaves will begin to fall off.

Fungal spores can persist in contaminated plant material for many years, perfectly tolerating any frost.

Prevention

Dead bushes are dug up and burned.
Old and diseased leaves must be completely destroyed.
Mandatory digging of the earth along the periphery of the bushes is carried out. The depth of the top layer is 10 cm.
In the infected area, it is necessary to carry out a special autumn treatment with a fungicide. You can generously spill the soil around the bushes with a solution of copper sulfate.
New bushes should not be planted on contaminated soil. You need to choose a new place at least 5 m from the fungal outbreak.
All weeds must be carefully weeded. It is better not to leave them on the site. The infection persists in them.

Treatment

Timely treatment is the key to saving the bushes in time. What you can use for this:

Bordeaux mixture is the highlight of all gardeners for many pathologies. It kills fungi and stops the disease. Therefore, when spots with tubercles are detected, immediate treatment should be started. The drug is diluted as follows - 100 g of product per 10 liters of water;
Nitrafen. A 3% solution is an effective remedy against fungi. Therapeutic dose is 300g per 10 liters of liquid. Plants are sprayed in the spring before the buds swell. At the end of October - after the leaves have completely fallen off;
Cuprosan;
Colloidal sulfur.

Choosing a resistant variety ensures success when growing currant bushes.

Signs of bush infection

How to identify terry on currants? As a rule, the first signs of attack by such a defect appear on the foliage and buds. You can identify doubleness on currant bushes by the following signs:

first, the gardener observes the deformation of the inflorescences;
further, diseased flowers acquire a purple color;
there is practically no ovary on diseased flowers;
Well, if the fruits are present, then after ripening they acquire a deformed appearance;
sometimes a gardener can see a flower cluster that is not completely deformed, on which part of the buds is affected, and the other part is absolutely healthy;
currant leaves also change their shape, the segments become small and narrow.

If a currant bush is completely damaged, then additional shoots will begin to appear on it at the ends of the branches, making the crop several times thicker.