Cherry bacterial burn treatment. Bacterial burn of fruit crops. New methods of treatment. Autumn pear varieties
Causes and mechanism of freezing trees
In March, the days become noticeably longer and lighter, and Sun rays already penetrate into all corners of the garden. Thanks to them, even on frosty days, the trunks and branches of fruit trees on the southern and southwestern sides are heated to +15°С.And at night, frost often strikes about 10-15 ° C, and the trees freeze again.. At the same time, the cells of the cortex that have come to life during the day do not withstand such a temperature difference and die - this is how sunburn appears. And the bright white snow cover lying in the garden reflects the sun's rays and thereby enhances the heating of the trunk and the sharp drop in temperatures. This is such an extreme situation.
The consequences of freezing trees
On the trunks and bases of the branches of burnt trees appear dark spots. Initially small, but then they increase. The bark in these places peels off or cracks and dies. Over time, it lags behind, exposing the wood.As a result, the exposed internal tissues of the tree become easily accessible to fungal diseases.
In addition, trees with burn-damaged branches and trunks have difficulty moving. nutrients and water, the normal course of physiological processes is disrupted, productivity and winter hardiness are reduced, and life span is shortened.
Which varieties are at risk
Most often in the middle lane, varieties that are valuable in taste, but not winter-hardy enough (for example, apple varieties such as Lobo, Spartan, Melba, Biforest, Klos) suffer from sunburn. Moreover, burns are observed on pears much less frequently than on apple trees, sweet cherries, cherries, apricots, plums and peaches.Also at risk are fruit trees growing in conditions of insufficient and uneven soil moisture and low air humidity.
Burns are also dangerous for young, recently planted trees. Transplanted fruit trees are even more damaged, especially those that used to grow on infertile soils.
Burns of the bark of trunks are observed even in seedlings buried for the winter. Especially if they were dug into dry soil without abundant watering. In addition, sunburn can appear when the trunk or branches are strongly pulled with wire, dense films, twine and other materials that cause banding, as well as when used to protect against rodents thin polyethylene films which worsen the thermal regime of plants.
What tree protection products to use
To reduce the damage from sunburn, you can use any of the methods that reduce the heating of the bark. For this, boles and forks of skeletal branches are whitewashed with lime ( rice. 2) or tied with some light material. White color reflects the sun's rays and prevents overheating of the bark.Whitewashing is carried out in late autumn and late winter at positive temperatures. For a 10-liter bucket, take 2-3 kg of freshly slaked lime or chalk, 50-100 g of casein glue, 400-500 g blue vitriol, previously dissolved in hot water. The solution is diluted with water to the density of sour cream.
In winter, before whitewashing, snow is raked from the stem, and then it is again sprinkled on whitewashed trees (snow will reliably protect the roots from frost). Liming at the same time serves disinfectant and a measure of the fight against pathogens living on boles and branches. But keep in mind that whitewashing trees in April-May is ineffective.
More the best remedy protection of trees than whitewash, which is washed off by rains and requires repetition, is the coating of the trunk and bases of skeletal branches with synthetic paints VS-511, "Protection", VD-K4-577. On sale you can find ready mixes: "Garden whitewash", "Gardener" and "Sunshield".
To protect against sunburn you can tie tree trunks with white parchment paper. Some gardeners nail with south side plank trunk, using two nails 35 mm long. This protection lasts up to 5 years.
And, of course, everything needs a measure. If the trunks of young trees for winter protection from rodents were tied with spruce branches, sunflower stems and other materials, then they do not need protection from sunburn.
Experienced gardeners can use another effective, but more complex way to reduce the risk of winter damage to the trunk and branches. This is the grafting of varieties suffering from burns into the crown or trunk of more hardy, although less valuable trees in other respects ( rice. 3).
In conditions middle lane the best stem and skeleton formers for apple trees are winter-hardy varieties folk selection: Sharapai, Moscow Grushovka, Cinnamon striped, Antonovka ordinary, Anise gray. For pear, these are selected seedlings (wild birds) of the local forest pear and seedlings of onion varieties: Tema, Fields, Olya, Lida, Lukashovsky early, as well as the folk variety Tonkovetka.
How to treat affected trees
In summer, the bark damaged by the burn is easily separated. It must be carefully removed with a garden knife, cleaning the wound to healthy wood. Then the burn site must be disinfected with a 1% solution of copper sulfate (100 g per 10 liters of water), covered with garden pitch and tied with a dark film or burlap.When the burn covers a short but wide section of the trunk, can be grafted with a bridge. With such damage, wild shoots sometimes grow from the roots. It is grafted onto the healthy part of the trunk above the injury site ( rice. 4). And if there is a top on the bole below the wound, it can also be successfully used as a bridge. If there are no tops or root shoots, some gardeners plant annual trees next to the victims. Their tops are grafted above the sunburn wound.
After the grafts grow together, the normal movement of water and nutrients is restored through them, which means that the burnt tree is saved.
Lidiya Yurina, Ph.D. Sciences
For every gardener big problem pear bacterial burn can become, which can affect young and already more mature trees. This is one of the most dangerous diseases of trees, and if appropriate measures are not taken in time, then the pear will disappear and dry out in 3-4 years.
Problems when growing pears
There are a variety of problems with fruit trees, in particular with pears. Among the main problems are the following:
- negative weather conditions;
- fungal diseases;
- bacterial diseases;
- viral diseases;
- pests.
There are a variety of pear diseases. Bacterial burn considered one of the most dangerous, since this disease literally eats the tree completely. It is very important to treat and prevent the occurrence of tree diseases in a timely manner in order to save the plant.
What is a bacterial pear burn
Bacterial burn of a young pear is considered one of the most dangerous and serious diseases that can affect a plant. Experts around the world are looking for more and more effective means to combat this disease, however, despite all this, the disease still continues to actively destroy trees.
Treatment of a pear bacterial burn should be carried out in a complex manner, since the disease completely affects all parts of the tree. Initially, inflorescences are affected, and then the disease spreads to branches and shoots. The kidneys turn black, stop growing, dry out, but do not fall off. The leaves curl, and the infection rapidly moves up the trunk.
Causes
A bacterial liquid appears on diseased plants, which, under the influence of the wind, is drawn into long strings and spreads over several kilometers. In addition, bacteria can be carried by insects and birds. When such a substance enters a healthy tree, it becomes infected.
Favorable conditions for the onset and progression of the disease are considered high humidity And normal temperature air. Bacteria initially actively develop inside the flower, and then move on to branches and other parts of the tree.
Less often, infection occurs by damaging the branches or trunk of a tree. In this case, the bacteria get on the pear with the help of rain. Bacteria survive the cold inside the trunk, and with the advent of spring they resume their activity again and appear on the surface of the bark in the form of milky white droplets.
Factors affecting the rate of spread of bacteria
Treatment of pear bacterial burn can be quite problematic, it all depends on the stage of plant damage. Recognizing the presence of a problem is quite difficult, since this disease is quite insidious and can masquerade as other diseases. Gardeners do not always take the required measures in a timely manner, and this may be due to various factors.
Since fire blight spreads from top to bottom, it happens that on adult plants the lesion is detected only when the tree is already half infected. Many consider crown wilting to be the result of insufficient moisture and increase the frequency of watering, thereby accelerating the development of the disease.
The speed of damage depends on many different factors, in particular, such as:
- tree age;
- julienne;
- the composition of the soil on the site;
- climatic conditions.
Bacteria can be carried over long distances by birds, insects, wind, and rain. Once on the branches of a plant, they begin to actively multiply, affecting all its parts.
Symptoms of a bacterial burn
The symptoms of a pear bacterial burn are quite pronounced, which is why, when the first signs appear, it is necessary to immediately treat the affected tree. Among the main signs of damage, the following should be distinguished:
- first initial stage blackening and drying of inflorescences occurs;
- darkening passes to the kidneys;
- darkens the entire tree.
As a result, the tree is completely covered with blackness and dies after the trunk darkens. When the final stage of the development of the disease comes, it is almost impossible to save the tree, it is completely covered with brown stains and white drops form on its surface.
The timeliness of the treatment of a bacterial pear burn largely depends on the correctness of the diagnosis. To determine the pathogen in the laboratory, a bacteriological culture of the tissues of an infected plant is carried out.
Methods for treating pear
Having found a bacterial pear burn, treatment should be carried out immediately so that the infection does not spread to nearby trees. With a significant infection, the plant only needs to be uprooted and burned.
If the infection is small, then you need to remove the affected branches, and then burn them. For processing the cut point, copper sulfate is well suited, the concentration of the solution of which is 1%. To do this, 100 grams of vitriol is taken for 10 liters of water.
Pear treatment from a bacterial burn is also carried out by using special antibiotics. The garden should be sprayed with a solution of antibiotics 3 times with an interval of 5 days. Be sure to use in the complex preparations to combat insect pests.
chemical method
At the initial stage of infection, the fight against a bacterial burn on a pear is carried out by a chemical method, by using copper-containing preparations. You can use special products containing copper, in particular, such as "Rovral", "Oxyhom", "Skor". In addition, you can prepare the remedy yourself, since the recipe for the drug against bacterial pear burn is very simple.
To do this, you need to take 1% copper sulfate, mix with lime milk and add water. The most important thing is that the solution is not very concentrated, as it can cause leaf burns. Spraying the tree is carried out 5 times, from early spring until the end of flowering. And then additionally you need to carry out processing after harvesting. If there is no improvement, then antibiotic treatment is carried out, and radical methods of combating the disease are used.
radical method
The radical method is applicable if several bacterial burn infections are found in one area, or the tree is more than half affected. It is desirable to destroy the infected plant in order to prevent infection of other trees. If the area of infection is insignificant, then only infected areas of the tree can be removed, cutting out even healthy tissues 0.4 m below the affected one. All sections must be immediately treated with a solution of copper sulphate.
After each cut, it is necessary to disinfect the working tool. by special means, since firing does not give full protection. All pruned branches should be burned immediately to prevent the spread of infection.
Use of antibiotics
Most good result can be obtained during the treatment of a bacterial pear burn with antibiotics. For this, Streptomycin is used. One ampoule of the drug should be diluted in 5 liters of water and sprayed with the resulting solution on infected trees. The first treatment is carried out in June, and then every 3 weeks. If there was rain or very hot weather between treatments, it is advisable to treat the garden again.
When the first signs of the disease occur, it is necessary to immediately treat the bacterial pear burn. It is advisable to change the preparations every year. You can use tools such as:
- "Tetracycline";
- "Ofloxacin";
- "Fitosporin";
- "Gentamicin".
"Fitosporin" helps to resist many pear diseases and is used if the plant is badly damaged. However, you should not use this remedy often, and even more so every year, since plants develop strong immunity to it.
"Tetracycline" can be used every 1-2 years. To process a pear, you need to dilute 2 tablets in 3 liters of water. Treatment of a bacterial pear burn with antibiotics involves the use of "Gentamicin". This is very good remedy. To prepare the solution, you need to take 1 ampoule and dissolve its contents in 1 liter of water, and then spray the pear. This procedure should be carried out 2-3 times per season.
The antibiotic "Ofloxacin" from a bacterial pear burn is considered a fairly powerful tool, which is also used to control pests. When processing Special attention should be given to the branches and trunk of the tree. The stem is treated from top to bottom to prevent the transmission of bacteria.
Carrying out preventive work
It is best to prevent the occurrence of a disease than to treat for a long time or destroy half the garden. There are certain rules for prevention. For prevention, it is necessary to pull out nearby wild plants. This is especially true of the hawthorn, since this small tree is considered one of the main carriers of the infection that provokes a bacterial burn.
Plants should be periodically sprayed with drugs designed to combat pests and diseases that weaken their immunity. Be sure to show the fight against insect pests that spread the infection between the trees. It is best to grow pears that are resistant to bacterial burn. It is necessary to purchase seedlings only in proven nurseries, and when pruning, it is necessary to disinfect the tools.
Regular inspection of trees will allow timely detection of the disease and take the necessary measures to prevent its spread. In autumn, a comprehensive cleaning and processing of the garden from fallen leaves, fruits, and other debris is carried out. After all, it is in them that pests and bacteria overwinter. Helps eliminate bacterial spores and digging the ground in late autumn.
Summer pear varieties
The Carmen variety is considered resistant to diseases and pests. Fruit ripening occurs in mid-August, they are stored for 2 weeks after picking. The fruits are burgundy in color, juicy pulp is sweet and sour, medium density with pleasant aroma duchess. This variety is hardy, picky, frost-resistant and practically not affected by infections.
Autumn pear varieties
Among the autumn varieties resistant to diseases and pests is the pear Autumn of Bukovina. The color of the fruit is golden yellow, with a delicate, pink blush. The pear bears fruit quite plentifully, has soft and juicy pulp, which literally melts in the mouth, sweet and sour taste. The fruits are harvested from September to October. The variety is frost-resistant, practically not affected by scab and bacterial burn.
Pear Tavricheskaya belongs to the autumn-winter variety, characterized by high fruiting, good transportability and frost resistance. The fruits are quite large, oval or egg-shaped. At maturity, the color of the fruit is bright yellow with a slight pinkish blush. The pulp is juicy, very tasty with a spicy aroma. The tree is medium-sized, characterized by high resistance to scab and leaf blight.
Winter pear varieties
Pear variety Zest of Crimea refers to winter varieties, as it ripens only at the end of October. The fruits are large, golden above and below, and the rest of the bright pink. The pulp has a cream color, medium density, slightly crunchy. The main advantages of this variety is that its fruits are very well preserved for a long time, and the tree is resistant to various kinds of bacteria and pests.
Late varieties resistant to bacterial burn include the Noyabrskaya pear. It is very popular due to its excellent long-term storage properties. The fruits are harvested in the first half of October, and they can be consumed only in early December. This pear variety has excellent taste qualities, thanks to the juicy and fragrant pulp.
A good variety is the pear Kucheryanka, which is resistant to scab, frost and bacterial leaf burn. This variety is characterized by precocity.
When you see dying plants in your garden, it becomes bitter and annoying. Pity the plants and their labor invested in them. It's a shame, because timely preventive actions could prevent diseases.
It happens that in order to save a tree or a bush, it is already too late to fight pathogenic bacteria, but healthy crops grow nearby, you need to think about them and act correctly. Until recently, gardeners in Russia knew about bacterial burns only by hearsay, but now they are faced with crops scorched by bacteria in their gardens. The most common bacterial pear burn.
If it is recognized and treated in time, measures are taken to prevent the spread of bacteria, then the garden will be saved.
Bacterial burn of fruit trees: causes and symptoms
Bacterial tree burn is caused by a severe infectious disease. disease fruit crops cause microorganisms of the Enterobacteria group, with which mankind is already familiar from diseases gastrointestinal tract due to E. coli and salmonellosis.
The first warning signs of a fruit tree disease are gradual wilting and then drying of individual inflorescences or groups of flowers. As the infection spreads, the leaves are affected by bacteria - they wither, and then dry, curl. At first they remain green, over time they darken and become Brown color. And they continue to hang on the tree.
Microorganisms continue to attack healthy plant tissues and infect the buds, they dry out, darken, but remain in place. Branches and leaves, fruits acquire brown color, brown spots appear on the bark of trees.
Numerous cracks go along it, on the dried bark there are drops of milky color - exudate, and around them - reddish-brown stains. The bark affected by the infection exfoliates, becomes covered with blisters.
During the rampant infection, the tree stands with leaves, fruits - they do not fall off, but the fact that the tree is sick is clear even to non-specialists. The plant is all brown, and it is scorched by an ailment, which is popularly called anton's fire.
In the photographs, you can see dried brown orchards, the bacterial burn of fruit crops did not leave anything healthy in them, and the treatment of affected trees is sometimes useless. Dead trees are uprooted and burned, and the territory within a radius of the source of infection is cleared.
To protect neighboring trees and gardens from infection, an infected plant should not be moved around the garden. So the spread of the infection can be localized. But with early recognition of the disease, the plants could be saved. The fatal disease is caused by enterobacteria Erwinia amylovora. For them, the age of the plant is not important, microorganisms affect both young and old crops.
How does the pathogen get to healthy plants? At the peak of the development of the disease, when the bark had already begun to become covered with ulcers, exudate drops that appeared on the bark become a breeding ground for harmful bacteria. They are carried by the wind, they are carried by insects - bees, flies, wasps, and birds perching on a tree. Less commonly, bacteria enter the plant with raindrops. In isolated cases, a pruning tool can become a source of infection. Infection is also possible during vaccination.
Your destructive path healthy plant enterobacteria begin by penetrating the bark through microcracks, getting into the flower. During abundant flowering the risk of infection of the plant with infection is especially high.
If the disease is not treated, the bacteria will spend the winter in the plant, and in the spring they will continue the destructive infection and destruction. Scientists who dealt with the issue of bacterial burn of fruit trees found patterns. Thus, soil abundantly saturated with nitrogen-containing fertilizers and organic top dressing contributes to the onset and progression of infection. The soil with a minimum amount of fertilizer has a deterrent effect on the development of the disease.
Treatment and prevention of bacterial lesions of the pear
Several methods have been developed for the treatment of bacterial burn of fruit crops, including pears. Each of them has its own disadvantages and advantages. The gardener's choice. Ways to deal with burns are as follows:
For spraying, you should choose a day when the weather is cloudy, it is impossible to spray the plant in the heat due to the high risk of death of beneficial microorganisms under the influence of the drug and sunlight. To improve the micro- and bioclimate of the plant and promote the development of beneficial microorganisms, rotting grass can be placed under the tree.
Antibacterial drugs are effective and effective. But their frequent use leads to addiction (even in plants) and mutations of the infectious agent. And this is a new round in the treatment of bacterial burns.
Compliance with proven rules will help protect the fruit tree from a bacterial burn, namely:
At the slightest suspicion of an infection, measures should be taken to localize the infection and treat the plants to eliminate the disease.
A century and a half has passed since the first mention of a bacterial burn. The disease has moved from the category of rare to the category of common. You can blame the environment or look for other reasons for the spread of a bacterial infection, but this will not affect the actions to save your garden.
An insidious and destructive disease for plants must be identified in time. Careful inspections of trees will help you see fading leaves and inflorescences, and the fact that they have dried up and left hanging on a tree should be the first bell. When the leaves and fruits begin to turn black, and the buds darken, it is not too late to take emergency measures.
One of the dangerous diseases of fruit trees, caused by Erwinia Amilovora bacteria, is called fire blight.
For the first time, outbreaks of this disease were recorded in the 18th century in North America.
During the sale and transportation of seedlings of fruit plants, fire blight was spread throughout the world.
This disease is insidious in that often inexperienced gardeners often mistake its symptoms for manifestations of other infections and do not take appropriate measures in time:
Due to the fact that the burn develops on the plant from top to bottom, it happens that on adults tall trees it is discovered when the tree is already half struck;
The initial wilting of the tree crown is considered a consequence of a lack of moisture and watering is increased, accelerating the development of the disease;
Bacterial burn is often confused with bacterial cancer(You can distinguish between these diseases by spending clinical researches infected tissue samples).
All parts of the fruit tree are affected by this infection, but flowers, young shoots of the current year, and ovaries are most affected.
How does the disease develop?
The rate of damage to a pear by a bacterial burn depends on the following factors:
The age of the tree (young seedlings are more often affected);
Pear varieties;
Soils on the site (increased nitrogen content in the earth enhances the development of the burn);
Climatic conditions(high humidity and air temperature are most favorable for the progression of the disease).
Primary infection occurs in the spring during pear flowering. Bacteria from infected plants are carried over long distances by insects, birds, wind, and rainwater. Once on the flowers, the bacteria begin to actively multiply and spread inside the plant, affecting young shoots, branches, trunk.
Also, infection can occur through damaged tree bark, wounds on the leaves.
Secondary infection occurs in summer period when a whitish viscous exudate containing a large number of bacteria begins to stand out from cracks in the trunk and branches of a tree. On outdoors it stretches out in the form of thin threads and is easily carried by the wind. Less commonly, infection occurs through gardening tools or during grafting.
Symptoms of a bacterial pear burn (photo)
The disease has the following symptoms:
Slow opening of the buds, and then their blackening (while they do not fall off, but remain on the branches);
Blackening, wilting and drying of flowers (if infection occurred during flowering);
Blackening and twisting of shoots, leaves.
Red-brown stains on the bark, a viscous milky exudate is released from the cracks;
Affected wood tissues swell and flake off (this last stage the tree is dead).
As a result, the pear tree looks charred (hence the name of the disease).
Signs of a bacterial pear burn
Diagnosis of a bacterial burn
The ability to save the pear tree and the garden as a whole depends on the timely diagnosis of the disease. To determine the pathogen in the laboratory, bakposev is carried out on the tissues of an infected tree (tip of shoots, tree bark, fruits).
Treatment Methods
In the treatment of bacterial burns, timely detection of the disease is important. There are several methods to fight this infection, each with its own pros and cons.
In the initial stage, the disease can be treated with copper-containing drugs. A mixture of 1% solution of copper sulphate with milk of lime has a pronounced antibacterial effect. At the same time, it is important not to overdo it with the amount of vitriol - its excess causes leaf burns. You can also use such preparations with copper content as Abiga-Peak, Rovral, Skor, Oxyhom and others. Spraying of affected trees is carried out five times:
1. the period of swelling of the kidneys;
2. leaf blooming;
3. after the end of flowering;
4. 2 weeks after the last treatment;
5. after harvest.
If there is no improvement, therefore, the bacteria have developed resistance to this fungicide. In this case, it is advisable to cut and burn the affected parts of the tree and treat with antibiotics.
radical method
This method is applicable if symptoms of a bacterial burn are found on one of the fruit trees in the area. It is better to destroy the infected plant in order to protect the remaining plantings from infection. It is better to sacrifice one tree than to lose an entire orchard. If the affected area is small (less than 30%), then diseased areas can be removed, cutting out even healthy tissue 0.2-0.4 m below the affected tissue. All sections are treated with a solution of copper sulfate (1% -100 g of powder per 10 liters of water) or iron sulfate (70 g per bucket of water). To disinfect the instruments used after each cut, solutions such as copper sulphate (5%), inkstone(8%), dichloramine (1%), potassium permanganate (1%). Burning the blades in the fire does not completely destroy the infection.
All cut parts of the tree should be burned immediately, preventing the leaves from scattering. Harvesting and storing firewood from infected pear branches and trunks is not allowed, otherwise the infection will quickly spread to all plantations.
Antibiotics
The use of antibiotics is the most effective method in the treatment of bacterial burns in pears. For this, Streptomycin is used. An ampoule (500 thousand units) is diluted in 5 liters of water and the affected trees are sprayed. The first treatment is carried out in June (during the active growth of shoots), then every three weeks. If in the period between treatments it rained or the weather was hot, then the trees were sprayed again. Additionally for boosting immunity pear trees stimulants are used (Zircon, Immunocytophyte, etc.).
Bacteria tend to mutate and develop resistance to the antibiotic used, so every year you need to change the drugs. Well proven in the fight against bacterial burns:
Tetracycline (2 tablets per 3 liters of water);
Ofloxacin;
Gentamicin (2 mg (1 ampoule) diluted in 1 liter of water).
On a note! When using any drug, it is necessary to process the entire tree from the top to the very bottom of the trunk, since the disease "descends" down the table to the root system.
Prevention of bacterial burn
Infections orchard A bacterial burn can be prevented if prophylaxis is carried out in time:
Observe the cleanliness of plantings - weeding (many wild plants are incubators of the causative agent of this disease) and the destruction of wild fruit trees (especially hawthorn);
Spraying plantings with drugs against various diseases that weaken the immunity of trees;
Control of insect pests that carry infections between plants;
Cultivation of varieties resistant to bacterial fire;
Acquisition of seedlings in proven nurseries;
Disinfection garden tools when pruning trees;
Regular inspection of garden plantings will detect the disease on early stage and take timely action.
Winter control of suspicious seedlings: twigs are cut from marked specimens, put into water in room conditions and waiting for the buds to open. Conclusions about the presence or absence of infection are made according to the state of emerging leaves.
Today there are many various diseases fruit trees that motivate gardeners to enter into a desperate struggle to keep the splendor of their garden in integrity and harmony. One of the most common, especially insidious and dangerous diseases is a bacterial burn. This disease has such a detrimental effect on the tree that if it is not identified in time and decisive action is not taken to save the tree, then in the coming years the gardener may lose the plant.
Bacterial burn on pear fruit
Favorable environment for the development of the disease
Unfortunately, various representatives of the flora, ranging from flowers to fruits of trees, are susceptible to the above ailment.
Many gardeners are constantly faced with this disease, but only a small part is able to detect it in a timely manner and correctly diagnose it.
There are many tales, fairy tales and legends about the disease, and even more advice on getting rid of it. If you take a quick look at the entire information block dedicated to this disease, you can note a wide range of recommendations, starting from the fact that the affected tree should be uprooted and burned, ending with the use of various chemicals.
Garden that died from a bacterial fire
Until recently, there was an opinion that fire blight is a disease common in Canada, the USA and Australia, but in our latitudes it has not been identified as such.
But more and more often, all kinds of photographs began to appear on the forums of gardeners, which depict trees with clearly expressed symptoms of this disease. The occurrence of this disease has a clear dependence on a number of factors, among which the age of the tree, its belonging to a particular species or subspecies, as well as the conditions external environment. For example, spring, torrential warm rains are the most favorable, one might even say a concomitant factor for the spread of the disease on the branches and inflorescences of plants. A dry and hot summer, according to the observation of many gardeners, helps to slow down the development of the disease. For some reason, it is the pear among all fruit trees that is much more often and more exposed to this destructive virus than others.
Features of the development of the disease in a pear
Bacterial pear burn is a severe infection fruit tree, caused by a microorganism belonging to the group of enterobacteria (such as salmonella). On wet days, especially during the rainy season, which mainly occurs in early June, favorable conditions arise for the development of the disease. Today, every year this disease affects everyone more trees not only somewhere there, in Canada or Australia, but already in our open spaces.
The first stage is monilial wilt.
The first signs of a tree infection infection appear on pear inflorescences in the form of individual or group clusters.
Flowers on a fruit tree gradually wither and dry out over time. Gradually, the infection covers new areas, heading down the tree trunk to the pedicel, which first changes color to green and then to amber. Over time, the infection covers the buds of the tree, which also darken, but do not fall off.
Twigs, with leaves turning dark brown, for a long time retain their positions on the tree, hanging in dead clusters and acquiring the appearance of wilted.
From the bark, the infection penetrates into the internal structure of the pear, the tree trunk begins to become covered with brown spots with a clearly defined dying zone, where the bark shrinks significantly and is dotted with numerous cracks. Very often, the appearance of drops of a milky color, dense consistency on the dried areas of the bark is noted. The phenomenon of cortical necrosis is typical for the later stages of the disease, when the likelihood of a positive outcome of the disease is minimal.
The second stage is the drying of the leaves
If the infection is not recognized in a timely manner or the efforts to cure the tree are not effective enough, the plant dies.
Causes of a bacterial burn
In the early 1980s, pear blight became the object of detailed research by scientists and gardeners. As previously mentioned, the causative agent of this disease is a bacterium from the Enterobacteriaceae family (among which Salmonella and Escherichia coli are especially dangerous for human health). The next fundamental question to be answered is how, having infected one tree in the garden, this disease spreads unhindered to other healthy plants?
The answer was soon found. The fact is that at a certain stage of the disease, peculiar drops of amber color appear on the affected areas of the tree (bark, leaves or pear fruits). They contain huge colonies of harmful bacteria. Insects such as wasps, bees, flies and even birds visiting affected inflorescences and fruits become an unwitting mechanism for transporting these harmful microorganisms to healthy trees. Through various microcracks in the bark resulting from mechanical damage, bacteria penetrate the internal structure of the tree, thereby causing inflammatory process in a healthy plant.
Drying of whole branches - the third stage
Atmospheric phenomena such as rain, wind or fog also contribute to the movement of pathogens from the affected areas of the pear to healthy ones.
In addition, scientists have established some relationship between the development of the disease and chemical composition the soil in which the tree grows. The fact is that the soil, abundantly saturated with nitrogen-containing approvals or organic matter, is favorable factor contributing to the emergence and further spread of the disease. Whereas soil with a minimum content of fertilizers prevents the development of the disease.
Affected pear ovaries
Prevention of bacterial pear burn
Bacterial pear burn is a very serious disease. The priority task of the gardener is timely diagnosis and comprehensive, comprehensive treatment.
Preventing the development of the disease is much easier than dealing with the consequences of this insidious disease.
Processing trees in the spring - a preventive measure
Most effective methods prevention is the following activities:
The most well-known way to combat "Anton fire" is the use of copper sulphate in combination with lime mortar.
With the right dosage and proportion of the components, such a mixture is very effective. Very often, too much vitriol leads to singeing of the leaves, and not enough leads to the loss of medicinal properties.
Copper sulfate stops the disease in the early stages
If the efforts made have not led to positive changes, then it is recommended to apply the wood treatment method using fungicidal preparations.
Some gardeners are inclined to use radical methods of eradicating the disease - uproot the affected tree and burn it. It is strictly forbidden to move the plant to other parts of the garden, as there is a high probability of the spread of pathogens in areas where healthy plants grow.
Some gardeners consider it appropriate to destroy all fruit trees in the nearest radius from the source of infection.
Tools used when working with an infected plant should be further disinfected with carbolic acid or formalin. The use of this method is justified only if the treatment has not led to positive result- sometimes it is better to sacrifice one tree in order to save the whole garden in the future.
Oflosaktsin drug is effective in the second stage
Science does not stand still and today there is a whole range of drugs that effectively destroy bacterial burns. Among the huge number of medicines, it is worth highlighting:
- Streptomycin is the most common antibiotic, its indisputable advantage is its general availability and absolute cheapness.
- Tetracycline - not inferior in popularity to streptomycin, an inexpensive and widespread drug.
- Fitosporin - medicine It is recommended to use only with severe damage to the pear. Reduces the rate and degree of putrefactive processes in the tree structure.
- Ofloxacin is a medicine of a qualitatively new level. His hallmark is a powerful and aggressive effect on the source of infection. It should be used strictly adhering to the indicated dosages.
In the process of getting rid of the disease, it is important to spray not only the leaves, shoots and inflorescences, but also the tree trunk itself.
Signs of a burn on a tree trunk
It is strictly forbidden to spray a pear on hot days, preference should be given to cloudy weather, for the simple reason that if a pear is treated with a solution of this drug in the sun, beneficial microorganisms will die under direct sunlight.
The above antibiotics are modern means to get rid of bacterial burns in fruit trees, including pears.
It is important to remember that antibiotic treatment is not a panacea for this disease. The fact is that the regular use of all the substances noted above leads to the fact that the causative agent of the disease at the genetic level can undergo mutation and develop resistance to their effects. In order to improve the micro- and bioclimate, it is recommended to lay rotting grass around the pear trunk.
Such actions create a favorable environment for the development of beneficial microorganisms that will kill pathogenic bacteria.
As a result, it is worth noting that this disease is quite dangerous for a variety of fruit trees, but with the timely detection of the disease, the tree can still be cured.
