Methods for combating diseases and pests of red currant
Redcurrant is a tasty berry loved by many, which, along with its black and white counterparts, is widely grown by gardeners on their land plots. The berries of this culture are not only very tasty, they are also rich in many useful substances and trace elements that strengthen the human immune system and have a positive effect on overall health. Redcurrant is also widely used in cooking - it is served as an independent dessert, jam, marmalade or jam is made, and the leaves are used in all kinds of marinades.
Unfortunately, currant bushes face a number of dangers throughout their life cycle - they can be attacked by diseases and pests. If the disease is not recognized in time, then the bush can not only give a small crop, but simply die. Pest and disease control can take a lot of time and resources, but knowing your “enemy in the face” and following a number of rules and recommendations can make your life much easier, save currant bushes and harvest a large crop of delicious red currant berries.
Common diseases
Thanks to the efforts of breeders, currant varieties with very good disease resistance are now becoming more common.Unfortunately, the same cannot be said about old varieties, which are most widely represented on the land plots of summer residents and gardeners. Despite the fact that the red currant is somewhat less susceptible to disease than its black relative, it also has its weak points.
First of all, you need to remember that red currants are extremely vulnerable to all kinds of viruses. But in addition to viral diseases, there are a number of diseases typical of this culture that affect it most often.
The first in the list of the most common redcurrant diseases will be anthracosis. The causative agent of this disease is a fungus - it is because of it that over time the leaves fall off. This fungus spreads especially quickly in conditions of high humidity and can quickly move from one bush to another. The disease first attacks those leaves that are too low or in the shade - small dark spots begin to appear on them in large numbers, which then turn into small tubercles.
In subsequent stages of anthracosis development, these tubercles burst and fungal spores come out to move to other plants with rain and wind. In those places where spots on the leaves, bumps or sores of anthracosis have already appeared, the currant berries will fall off.
This disease is extremely dangerous for red currant bushes. It quickly spreads through the bush itself and moves to other plantings with great speed, while even with relatively small lesions, the currant sheds absolutely all the leaves.
Terry, which is also found under the name reversion, is also a dangerous disease for red currants.Until now, the causative agent of terry has not been definitely established, since some agricultural technicians consider this disease to be viral, while others insist that microplasmosis causes it.
It should be noted that terry infects red currants less often than black currants, but the bush can still get sick through low-quality planting material or through pests such as mites.
Terry entails a rapid change in the appearance of the currant bush. The leaves on the bush have only three lobes instead of the prescribed five, they decrease in size and their color turns pale, at the same time cloves appear on them, and the veins become stiffer and coarser. The easiest way to notice terry during the flowering of currants, because instead of flowers, specific purple scales appear, and the shoots are severely deformed. The disease shows itself most actively in conditions of high humidity, to the point that during a drought it can be in a latent stage, and with a large amount of precipitation it will manifest itself again.
Goblet rust is also a danger to currants. It can usually be seen on bushes that grow near marshy areas. The causative agent of the disease is a fungus that needs sedge for its development, and cold and wet weather favorably affects the development of the disease. Goblet rust can cause the loss of a large part of the berry crop, and in some cases even all.
With some knowledge, recognizing rust is not difficult. It appears on the reverse side of young leaves, where growths of an orange hue form. The ovary and leaves fall off with the development of the disease.
The disease has a cyclical nature, because of it the bush withers, and if preventive measures and treatment of plants are not carried out, it will repeat next spring.
Columnar rust is a pathogenic fungus that most often affects currant bushes growing in areas with some coniferous trees - the main carrier of this fungal disease. The main symptom of this disease is yellow spots that appear on the upper part of the sheet with a reddish pile below.
Columnar rust most actively affects bushes in conditions of high temperature and high humidity. This disease slows down the normal growth of shoots and causes early leaf shedding, which weakens the green bushes and reduces the yield.
White spot is called septoria among professional farmers. It is spread by a fungus, appearing first as small spots on foliage that is bright red with a brown tint. Then the spots change shape and increase significantly, the color also changes - the formations darken and turn brown, with a white area in the middle. The development of the disease leads to falling leaves, drying out of the kidneys and stopping the growth of shoots.
Septoria begins to manifest itself in late spring and early summer, and the most intense impact occurs in the second half of summer. Due to the fact that the leaves fall off the bushes, the red currant will endure cold worse, it will have incomplete brushes, and its yield will decrease significantly. This disease rarely affects redcurrant bushes growing in our latitudes, however, so far it has not been possible to breed varieties that would be resistant to white spot.
American variety of powdery mildew - sphere library. This is another disease caused by a fungus. First of all, young leaves, shoots and newly born buds affect the sphere library. At the first stages of the development of this disease, a white coating appears in the lesions, which then turns into brown. At the next stage, the leaves may change their shape, and the berries may fall off.
The disease greatly suppresses the immune system of the bush, its branches dry, and if it is strongly launched, the plant will most likely simply die.
Scab also often worries the owners of plots where red currants grow. In bushes affected by it, brown or gray dots with a dense structure form on leaves, shoots and berries. As the scab develops, the surface of these spots begins to crack, the areas where the currant is covered with scab rot, and the flowers and ovary fall off. As a result, the currant simply loses a significant percentage of its green mass and, as a result, the yield of berries.
parasites
Parasites and pests that usually attack currant bushes also affect all other members of the gooseberry family, which dictates special conditions for planting these crops - professional farmers plant them far from each other. The vast majority of harmful insects can be found on any currant bush, regardless of its variety and variety.
The main representative of the animal world, which often attacks currant bushes, is the currant glass. It is the larvae of this insect that cause the greatest damage to plants - they feed on the tissues of the shoots of the bush, eating through peculiar tunnels in them.In most cases, this pest can be found on old plants - if the branches are too fragile and break without any effort, and their cut is black, then there was a currant glass case.
The shoot aphid is found in almost any garden, since its diet is the juice of various crops, and not just currants. This parasite massively infects plant bushes, aphid colonies attack young leaves, shoots, flowers and ovaries, forming a sticky coating and spreading soot fungus. The leaves rapidly change their shape and color, their color becomes reddish, they twist and inflate, and then completely dry out.
Aphids are a symbiotic that lives with ants, and therefore it will be necessary to get rid of both it and ants.
Currant bud moth is a dangerous parasite that can cause a lot of trouble. The embryos of this insect feed on the kidneys, attacking them from the inside. This leads to the fact that the currant bush stops developing, begins to tolerate frosts worse and bring much less yield. In the future, the bugs can also attack the leaves of the plant, which is why they shrivel and fade.
The currant variety of the kidney mite causes many problems when growing red currants. You cannot see this parasite with the naked eye, but the buds of the plant will serve as a visual marker, since this is where the tick lays its eggs. The kidneys are deformed and inflated, significantly adding in size. In a bush attacked by a bud mite, the leaves will either not bloom at all, or will have a non-standard shape and color. The currant becomes disheveled in appearance, with deformed shoots and practically no buds.
Another common parasite is the spider mite. Finding out if a redcurrant bush is affected by this pest is quite simple by the kind of web that forms around the top of the shoots, flowers and berry brushes. Ticks primarily attack the leaves that have not yet blossomed and feed on the juices of the plant. When a tick eats currants, you can see dots of a beige or yellow hue on it, as well as deformed ovaries and dried leaves, which will fall off in the future. In hot and dry weather, the spider mite is most active.
The berry sawfly is a pest with which you need to be as careful as possible. The caterpillars of this parasite are able to destroy the currant bush as soon as possible. This pest gnaws the leaves so hard that only veins remain from them. The sawfly lays its eggs in the ovary of the berries, which causes them to puff up, darken their color, and become ribbed in shape.
The gooseberry moth is also considered a very dangerous insect for this crop. Its larvae eat the buds and ovaries from the inside, as a result of which the seeds of the plant are destroyed. When the caterpillar comes out, it creates a kind of web, due to which the currant berries dry up - often this causes the loss of at least half of the currant crop. In some cases, with a massive defeat of the bushes with moth, the crop is completely lost.
The gooseberry moth may seem like a very beautiful butterfly, but it can cause great damage to currant bushes. Caterpillars of this insect, after wintering and emerging from the cocoon, begin to actively devour the buds on the bush.She also eats the leaves themselves, which causes huge holes to form in them, to the point that only veins remain from the leaf.
Methods of treatment
Treatment of anthracnose includes several basic measures. In the fall, currant bushes should be sprayed with a one percent solution of Bordeaux mixture and all parts of the plant affected by the disease should be destroyed - they are burned along with dry leaves. In the spring, the treatment of this disease is carried out with the help of vitriol and digging up the land where currants grow. Even before the bush blooms, you can use special chemicals like Epin or Zircon.
However, during the period of active fruiting, such preparations cannot be used and the bushes should be treated only with the help of biological solutions.
Redcurrant goblet rust is treated primarily by pruning all the branches that the fungus has attacked. Then you need to collect and burn all the fallen leaves - such material is not suitable for compost or fertilizer, as it is infected. In the autumn and early spring, the bushes can be sprayed with special antifungal drugs, and if necessary, if the plant is still sick, this procedure can be repeated two more times.
When treating currant bushes with potent chemicals, it is important to strictly follow safety rules and use personal protective equipment - glasses, a hat and overalls. You also need to remember that such preparations cannot be used when the bush blooms and bears fruit. Powdery mildew is also treated by regularly spraying the bushes with antifungal drugs. While the disease is at an early stage of development, experts recommend removing leaves and currant berries affected by powdery mildew.
You can also try to cure this disease with such an affordable remedy as soda - just dissolve fifty grams in ten liters of water and treat the bushes with this solution.
Special antifungal agents and antibacterial drugs will save you from septoria, which can be easily found today on sale in specialized stores. It is important to properly process redcurrant bushes with these compounds, for which you need to strictly follow the instructions. The main point is not to exceed the concentration of the active substance, otherwise the prepared solution will cause even more harm to the bush.
Terryness or reversion of red currants is unfortunately not currently cured. Now there is only one way to get rid of this disease - the complete destruction of the diseased plant, since there are no drugs for this disease yet. Fortunately, in places where currants do not grow too densely, terry is not very common on ordinary summer cottages and land plots. Usually, foci of this disease break out at large agricultural enterprises, where the technology of planting bushes is violated and they grow too densely.
To fight pests and parasites, in addition to various specialized chemicals, folk remedies and methods proven by many years of experience are also widely used. They do a good job of killing insects, and the likelihood of harming plants will be much lower than when using chemicals.
So, you can prepare a special herbal infusion - such a liquid will be completely harmless to the human body, but it effectively shows itself in the fight against aphids.Summer residents and gardeners are advised to make such an infusion based on celandine, but in addition to it, you can use garlic, dandelion, potato tops or onion peel. To prepare an infusion of celandine, you need to take three kilograms of this plant and soak in ten liters of water for a day.
Good results in the fight against red currant pests are shown by a solution made from tobacco dust. It is prepared simply: 300 g of tobacco dust is poured with ten liters of boiling water, after which the liquid should stand for three days. The resulting solution is filtered, after which 100 ml of a solution based on laundry soap is added to it.
A powder-based mustard solution is considered a good remedy. 20 g of dry mustard should be poured with a liter of boiling water and insisted for two days. After that, 10 liters of water and 100 g of ordinary laundry soap must be added to the solution.
Another good folk remedy is an infusion of marigolds. To prepare it, you need to take 0.5 kg of the flowers of this plant, pour 10 liters of boiling water and let stand for a couple of days. Then the solution is filtered, and laundry soap is added in the same way.
If such methods cannot get rid of insects and pests and the fight against them does not give the desired result, then the treatment can be done with the help of insecticides.
It should be borne in mind that most of these agents pose a danger to human health and tend to be deposited in plant tissues for a certain period.
Prevention
As you know, the best way to deal with diseases is their prevention, and therefore in the spring and after flowering, a number of measures can be taken that can effectively protect plants from damage by fungus, viruses or pests in the future.This is not very difficult, but such measures will help to greatly protect the bushes and, as a result, get a good harvest of delicious berries.
First of all, experienced farmers recommend analyzing what diseases and pests can attack currants in a particular area, and in accordance with this, select crop varieties that are as resistant to them as possible. It is equally important to plant red currants in the right place: the site should be well lit, without excess moisture and with reliable protection from the wind.
Another point that can prevent a number of diseases is regular sanitary pruning of red currant bushes.
It is known that diseases develop faster not only due to specific weather conditions, but also due to a lack of a number of nutrients. Most of all, the immune system of this culture is strengthened by such microelements as potassium and phosphorus, and therefore proper feeding effectively shows itself in the prevention of diseases.
Before the bush blooms or after harvesting, it can be sprayed with a weak solution of potassium permanganate, which greatly strengthens the leaves of the plant. Also, a solution of potassium salt is used to treat currants after harvesting - this top dressing protects the currant bush well from future fungus damage. A good feed will also be a solution based on iodine and warm water.
As an effective preventive measure against insects and other pests, planting crops with a characteristic pungent odor can be recommended. For example, aphids do not tolerate proximity to plants such as onions, garlic, chamomile, as well as marigold or calendula.
It is very important to destroy weeds that can grow near the currant bush in time, since pests can live on them for a long time.
In the spring, it is necessary to carry out a sanitary inspection of currants in order to timely trim deformed shoots and leaves. It is also recommended to treat the bush with special complex fertilizers, since many of them not only serve as nourishment, but also additionally strengthen and protect currants from diseases and parasites.
resistant varieties
Despite the fact that redcurrant is a very popular crop, breeders have not yet developed a variety that would be as resistant as possible to the vast majority of known diseases, pests and parasites. However, there are varieties that do well with a fairly large number of diseases that usually affect members of the gooseberry family.
First of all, it is the redcurrant "Victoria". This is a European variety capable of producing a bountiful harvest of tasty medium sized berries. This is primarily a dessert currant, but it is sometimes grown for the purpose of further processing. "Victoria" is able to effectively resist diseases such as anthracosis and goblet rust.
Another variety that is quite resistant to many diseases is "Faya fertile". This variety was bred in America, has medium winter hardiness and produces a good yield of medium-sized berries. The redcurrant of this variety is quite resistant not only to anthracosis, but also to the American variety of powdery mildew and goblet rust.
Folk breeders also bred a variety that copes well with many diseases - this is the "Chulkovskaya" red currant.This is an early maturing variety that bears medium-sized berries with a standard flavor. It tolerates winter well and is extremely resistant to dry weather. It tolerates many diseases well, but is vulnerable to reversion, that is, terry.
For information on how to deal with certain types of pests, see below.