Bacterial pear blight: treatment with antibiotics and drugs, resistant varieties

A microscopic gram-negative bacterium, having got to Europe together with seedlings of fruit crops or flowers, began to spread rapidly through the environment, moving with the help of flagella. Ervinia does not form spores, whole colonies appear when it divides. The pathogen multiplies rapidly during warm, humid weather, which hastens the onset of fire blight on pears and many fruit crops. Gardeners do not immediately notice the problem, and often it is not possible to save the tree.

What is fire blight?

Ervinia, having made its way into the bark, goes to the cambium, where it begins to divide. During winter frosts, most bacteria die. In the spring, along with the juice, the surviving microbes appear on the surface of the shoots in the form of a white liquid. The exudate contains rods that, with the help of insects, settle on the pistils of flowers and infect the tree again. In wet and dry weather, the bacterium multiplies every 20 or 30 minutes. Microorganisms are sent to the vessels, where they produce toxins that reduce the immunity of the plant. Ervinia penetrates to the flowers and ovary, which leads to their death. The most dangerous bacteriosis for seedlings.

Reasons for appearance

Exudate, stretching into long threads, is transferred to other trees when pollinated by insects, wind, birds and gets into cadmium through wounds and cracks. In humid and warm weather, bacteria become active, and, developing inside the flower, infect the branches, and then the trunk.

Sometimes microbes get on the shoots or leaves along with splashes of water, and hide in a bole for the winter, appear on the shoots in the form of a milky liquid in the spring and begin to divide.

Factors affecting the rate of spread of bacteria

The presence of ervinia during the primary infection of a pear is difficult to recognize. And even when the disease progresses to the next stage, it is very difficult to determine that it is a bacterial burn.

The rate at which anaerobic microorganisms attack a tree is affected by:

• type of soil in the garden;
• climate and weather;
• pear varieties;
• age of culture.

The disease starts at the top of the tree, causing growers to find the problem when most of the shoots and trunk are infected. When the leaves wither, people begin to water the tree much more often than before. Excess moisture promotes the growth of bacteria, the spread of the disease.

First signs of illness

When infected with ervinia in the spring, the buds on a pear do not open for a long time and gradually turn black, but do not crumble from the branches. On an infected tree:

1. Flowers wither and wither.
2. Leaves are curling.
3. The bark is streaked.

As the bacterial burn progresses, a viscous white liquid begins to flow out of cracks and wounds. When the wood peels off, the pear can no longer be saved. She looks like she's been on fire.

Ways to deal with bacterial burn

To identify the causative agent of the disease and begin treatment, the tips of the branches and bark of a withering tree are taken to a special laboratory, where they begin bacteriological seeding. To deal with an infection caused by ervinia, not one, but several methods of eliminating it are used, each of which has its own advantages, but is not without its drawbacks.

Before using any of the methods, infected shoots are removed, lubricating the cut area with copper sulphate. With extensive damage, the tree is dug up and burned.

Chemical method

If signs of a bacterial burn are found, when it appears, pears are treated with fungicides, which contain copper, - Oksihom, Skor, Rovral, or sprayed with vitriol, adding to a 1% percent solution of the drug in milk made from quicklime.

The procedure is started:

1. Before bud swelling.
2. When leaves appear.
3. After flowering.
4. When forming the ovary.

The last treatment is done in the fall, after collecting all the fruits. It is not always possible to cure a pear using this method, since Ervinia quickly gets used to drugs.

Radical method

When a fire blight is found on one plant, it is destroyed to save the garden. When only a branch or 1/3 of a tree is infected, the infected shoots are removed, capturing up to 40 cm of he althy tissue.Sections are treated with copper sulphate, stirring half a glass of the substance in a bucket of water. Ferrous sulfate is suitable for this purpose, 70 g of the product is enough for 10 liters.

The infected parts of the pear are burned, they cannot be stored and used as firewood. Tools after the procedure are disinfected in potassium permanganate or dichloramine.

Use of antibiotics

Very often, fungicide treatment in the fight against the disease caused by anaerobic microorganism is ineffective, and it is necessary to apply antibacterial drugs that are sprayed all over the tree, not missing he althy areas.

Fitolavin

This product is a waste product of actinomycetes and combines the functions of a biological fungicide with the action of an antibacterial drug. Penetrating into the tissues of the tree, Fitolavin spreads through their vessels, but does not accumulate in the ground, and helps to strengthen the root system of the pear.After treatment of the plant with the drug, beneficial microorganisms also die.

To prepare a solution, add 20 ml of Fitolavin to a bucket of settled water, spray the leaves with the composition, water the near-trunk circle. The tool quickly loses its properties, it is necessary to process the pears within 2-3 hours.

"Tetracycline"

When the first signs of infection with a bacterial burn appear, a tablet of this antibiotic containing 100 g of the active ingredient is mixed with water. Spray the tree once.

Gentamicin

A drug from the group of aminoglycosides destroys gram-negative bacteria, is active against Erwinia amylovora. To prepare a composition for processing pears, 2 ampoules of "Gentamicin" are combined with 1 liter of water. The tree is sprayed three times, the interval after the procedure is 5 days.

"Streptomycin"

This antibiotic is used to treat industrial plants because it is inexpensive. In order to spray 10 plants, 5 liters of a composition prepared from water and an ampoule of Streptomycin is enough.

The tool can not be used 2 or 3 years in a row, it is better to alternate it with "Gentamicin", because Ervinia gets used to the active ingredient, and it stops helping. How to dilute the drug for spraying pears is indicated in the annotation if you buy such antibacterial agents not in a pharmacy, but in specialized gardening centers.

About folk and alternative methods

Infection of a tree with a bacterial burn is fraught with its death. It is impossible to destroy the causative agent of the disease by spraying the plant with decoctions of celandine or infusion of garlic and other folk remedies.Agronomists advise first destroying harmful microorganisms, and then restoring beneficial microflora in the garden.

For the prevention and treatment of bacterial and fungal diseases is used:

1. "Trichodermin". The spores of the mycelium present in it germinate into the soil. Releasing toxic substances in the course of their life, they destroy pathogenic microorganisms.
2. "Pseudobacterin", which is produced on the basis of a living culture of the microbe, has a negative effect on the harmful flora, accelerates the growth of trees.
3. "Mikoplant" acts as a fungicide, improves the formation of vermicompost in the ground.

Some gardeners water pears with Previkur Energy in spring, although the product is intended to protect vegetable crops from diseases, it strengthens the immune system of trees, prevents the reproduction of microbes.

Resistant varieties

Among the hundreds of types of pears, there are those that are less likely to become infected with a bacterial burn. In regions where the disease has begun to spread actively, it is advised to plant the autumn early-growing Potomac variety, bred in the USA.

The pear of Ukrainian selection Yablunivska is resistant to fungal diseases, it is practically not affected by scab and bacterial burn.

The late varieties of Maria and Noyabrskaya have good immunity to Erwinia amylovora infection.

Prevention measures

It is very difficult to cure a pear from a bacterial burn, and it turns out only in the early stages. If the whole tree turns black, the fight does not guarantee a positive result.

Reducing the risk of Ervinia infection can be prevented by:

• uprooting wild shrubs in the garden;
• weed removal;
• spraying pears with copper preparations.

Blackened trees should be disposed of immediately so that the infection does not spread to other crops. Do not get carried away with watering, bacteria and fungi love damp soil. You can not overfeed pears with organic matter, mineral complexes. Reduce the likelihood of infection with the disease regular sanitary pruning.

Competent choice of seedling

A tree for growing in a suburban area or cottage must be purchased at a nursery. It is advisable to find out from which region it was brought, and find out if there are cases of infection with a bacterial burn. You should not risk buying seedlings from Belarus, Tambov and Saratov regions. A he althy young tree has no scratches on the stem, no damage to the roots, and the pear itself has an even light brown color.

When choosing seedlings, it is worth giving preference to varieties that are resistant to bacterial burn infection:

• Maria;
• Potomac;
• Williams;
• Carmen.

We must not forget that when trees are treated with the same compounds, pathogenic microorganisms can get used to them, and even worse, mutate. Fungicides need to be changed more often.

In early spring, pears are sprayed with Bordeaux liquid, dried and diseased shoots are removed, lubricating the cuts with garden pitch. In summer, in order to stimulate the plant's defenses, biologics such as "Zircon" are used. In areas where fire blight occurs, pears are sprayed with antibiotics for prevention.

Pest control

Caterpillars, butterflies, beetles carry the infection, affecting leaves and branches, help reduce the defenses of trees. When aphids, codling sprouts, and spider mites appear, both pears and the soil on which they grow are treated with insecticides, since some pests lay eggs in the near-stem circle, larvae are planted in the ground.

Disinfection of garden tools

When shortening the shoots, a pruner or a sharp knife is used; when uprooting diseased pears, one cannot do without a saw. Mycelial spores and bacteria remain on the tools and are then transferred to he althy trees. To prevent this from happening, the cutting parts are disinfected in a solution of potassium permanganate, alcohol, kerosene.

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