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Treatment of pear bacterial burn requires the gardener to have certain knowledge about the disease itself and its development. To deal with the problem, you have to use different methods. If you skip the initial stage of the disease or leave the trees without treatment, the result can be very deplorable. A bacterial burn in a short time will lead to the death of the garden.
What is bacterial pear blight
This is the name of a dangerous disease of fruit trees caused by infection. The causative agent of pear blight is Erwinia Amilovora, a bacterium of the genus Erwinia. The disease spreads very quickly from diseased trees to healthy ones.
There are varieties of pears that are most susceptible to infection, and some are resistant to damage. The most vulnerable varieties are Bere Garli, Conference, Lukashovka, Favoritka. If measures are not taken in time to save the pear, then the tree will die in 2-3 years. Bacterial burn affects all parts of the plant, from flowers and leaves to the root system. The degree of danger of damage depends on the age, variety of pear, climatic conditions in spring, juiciness of tree tissues. Trees of any age are affected. Photo of a bacterial pear burn:
Causes of infection and provoking factors
The causes of the bacterial burn of pears in the garden are being studied quite actively. Scientists are trying to find a complete list of factors that lead to the appearance of the disease. To date, the main ones are:
- the presence of carriers of a bacterial burn – insects or birds;
- minor injuries or damage to pear trunks;
- excess nitrogen in the soil.
Also, bacteria are easily transferred from one tree to another in windy weather. Most often, the activation of the disease occurs in the period from late May to June. Favorable conditions for the emergence and spread of infection are an increase in air temperature above the usual rate, humidity and rain.
The activity of the pathogen decreases with decreasing temperature; in winter, there is no spread of bacterial fire among pear varieties. The question of how a pathogen gets from a diseased tree to a healthy one is still relevant.
Scientists studying ways to treat the disease have noted the following processes for the spread of fire blight in the garden. At a certain stage in the development of the disease, amber-colored drops form on the pear.
They can be located on fruits, bark or leaves. This is a released exudate containing whole colonies of bacteria. Any insect or bird, touching an infected drop, becomes a carrier of the disease.
Development cycle of an infectious disease
The most susceptible part of the pear to the effects of pathogenic bacteria are flower buds and inflorescences. The infection process starts with them and then spreads to the rest of the tree. The rate and course of the disease is directly dependent on the growth phase of the pear in which the initial infection occurred. For example:
- Kidney bloom period. Affected buds turn black, dry up, but remain on the branches.
- pear blossom period. The flowers darken, fade, then the blackening passes to the leaves and branches.
The last stage of a bacterial burn is characterized by softening of the bark, the release of white exudate. Then, under the influence of air, it acquires a brown tint. The tissues affected by a bacterial burn begin to exfoliate and become covered with blisters, the bark acquires a “marble” hue.
The death of a pear occurs very quickly if pathogenic bacteria invade the roots. The root system turns black, which leads to the drying of the tree.
Features of parts of a pear that has become ill with a bacterial burn:
- The set fruits darken after infection, dry, remain on the tree until autumn.
- The bark on the branches and trunk of the pear is covered with drops of white exudate, similar to mold, and becomes soft. Then it cracks and takes on the appearance of marble.
- The branches are covered with sores that move onto the trunk.
If you do not start the fight against a bacterial burn in time, after a couple of seasons you can lose the entire pear orchard.
Signs of a bactericidal pear burn
The spread of bacterial burn occurs on the tree from top to bottom. In order not to miss the onset of the disease, the gardener needs to know the signs of the disease:
- The first appears in the spring on the kidneys, then on flowers. It does not matter how many parts are affected. First, wilting is observed, then drying out, the flowers turn black. Further, the bactericidal burn moves to rosettes of leaves and young twigs.
- Leaves. They turn black and curl, often looking like burnt.
- Branches. Their tips turn black as if from fire and bend, the bark is covered with dark watery spots.
The complexity of determining the disease lies in the similarity of symptoms with other processes. For example, moisture deficiency. Gardeners believe that the pear dries from lack of water and begin to flood the tree. Also, the state of the cortex resembles necrosis, which occurs with bacterial cancer.
How to treat a bacterial pear burn
There is a conditional division of treatment methods into chemical and mechanical. In any case, success will depend on the degree of damage to the pear by a bacterial burn.
The first option involves the use of special tools for the treatment of wood. In the second, a radical method is used – the removal of affected specimens as a whole or parts thereof. Gardeners get rid of pears, more than other trees affected by burns.
If the disease has captured less than 30% of the pear area, then partial removal is recommended. Cut out only sore spots, capturing part of the healthy tissue. At the same time, instruments must be disinfected.
If the lesion is not extensive, gardeners use treatments with copper-containing preparations. However, antibiotics are most commonly used.
Treatment of bacterial pear burn with antibiotics
This method is considered the most effective. Various antibiotics are recommended for the treatment of a pear from a bacterial burn. The preparation of the solution depends on the concentration in which the drug contains the active substance. Among the popular:
- Streptomycin. The choice of the drug is determined by its availability and low cost. The disadvantage is that it quickly collapses and ceases to act. Dosage – 1 ampoule per 5 liters of water.
- Gentamicin. Enough 1 ampoule of the drug per 1 liter of water. It is a strong antibiotic.
- Ofloxacin. The drug has a more severe effect on the focus of infection. It is used for medical dressings (1 tablet per 1 liter of water) and sprays (2 tablets per 10 liters of water). The dosage must not be changed.
- Tetracycline. In terms of cost and availability, it is in the same place with Streptomycin. Often used in duet. Tetracycline prevents the development of Ervinia resistance to streptomycin. To treat a pear from a bacterial burn, dissolve 2 Tetracycline tablets in 3 liters of water.
A bacterial burn on pear seedlings responds quickly enough to antibiotic treatment. During the season, it is necessary to spray the trees, alternating the solution of streptomycin and the preparation Skor. The procedure is carried out 1 time in 2 weeks.
Antibiotic treatments are carried out 2-3 times per season. It is strongly not recommended to spray pears during a period of intense heat, so that microorganisms in the solution do not die under the action of sunlight.
Treatment of bacteriological pear burns with copper-containing preparations
Among the copper-containing drugs in the treatment of “Anton fire” use copper sulfate, copper oxychloride, and other copper preparations. A mixture of copper sulphate with lime mortar is popular, but it is important to observe the proportions here. If you add vitriol more than the norm, it will singe the leaves. If not enough, then the composition will lose its medicinal properties. Therefore, it is best to take ready-made Bordeaux liquid.
Copper oxychloride works most effectively, and besides, it is less toxic to pears than vitriol. Deep penetration into the tissues of the tree will not occur, but insects will not carry bacteria on their limbs.
The main effect that copper preparations produce is to stop the development of bacteria. However, the destruction of the infection does not occur. Therefore, gardeners often use antibiotics or other means.
Other drugs for the treatment of bacterial pear burn
This category includes biological products or some fungicides. The most famous:
- Gamair. Low toxicity to humans, but effective in the fight against pathogenic bacteria. In the treatment of a bactericidal burn, a solution of 2 tablets of Gamair per 1 liter of water is used. Spraying is carried out at weekly intervals from the moment of bud break 2-3 times. If signs of the onset of the disease are noticed, spraying is continued many times. Doesn’t work in cold weather.
- Phytoflavin. Can also be used in cold weather. Dilute 20 ml in 10 liters of water, process the pear several times. The consumption of the working solution is 3 liters per tree.
- Phytosporin. A drug that significantly reduces the course of putrefactive processes. It is used for severe lesions of the pear.
According to gardeners, the best effect is obtained by combining bactericidal agents with fungicides Skor, Energy or Previkur. Some remain supporters of radical methods – tree uprooting. At the same time, it is important not to move the tree around the garden and to thoroughly disinfect all tools.
preventive measures
Measures to prevent a bacterial burn:
- Mandatory inspection of the garden, starting from the very first days of spring.
- Treatment of the garden with insecticides to destroy pests – carriers of infection.
- Weeding the garden area from weeds.
- Selection of pear varieties resistant to the disease.
- Conducting winter sanitary pruning with mandatory disinfection of the instrument. Burning cut branches.
- Pre-winter treatment with copper-containing preparations.
It makes no sense to treat a bacterial burn in the fall – ervinia does not multiply during this period, but goes into the encapsulation stage. Antibiotics are powerless, and treatments will remove other pathogenic bacteria that weaken the tree’s immunity.
Conclusion
Treatment of a bacterial pear burn can take a lot of time and effort. However, this does not mean that it is impossible to save the garden. The sooner the symptoms are noticed and measures taken, the greater the chances of a complete victory and the salvation of your favorite pear varieties.
