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Treatment of a pear bacterial blight requires a gardener to have certain knowledge about the disease itself and its development. To cope with the problem, you have to use different methods. If you skip the initial stage of the disease or leave the trees untreated, the result can be very disastrous. A bacterial burn in a short time will lead to the death of the garden.
What is pear blight
This is the name of a dangerous disease of fruit trees caused by the penetration of infection. The causative agent of pear blight is Erwinia Amilovora, a bacterium of the genus Erwinium. The disease spreads very quickly from diseased trees to healthy ones.
There are pear varieties that are most susceptible to infection, and some are resistant to damage. The most vulnerable varieties are Bere Garley, Conference, Lukashovka, Favorite. If you do not take measures to save the pear in time, the tree will die in 2-3 years. A bacterial burn affects all parts of the plant, from flowers and leaves to the root system. The degree of danger of injury depends on the age, pear variety, climatic conditions in spring, the juiciness of the wood tissue. Trees of any age are affected. Photo of a bacterial blight of a pear:
Reasons for the development of infection and provoking factors
The causes of bacterial blight 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. Today, 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 intensification of the disease occurs from the end of 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 a decrease in temperature; in winter, the spread of bacterial burns among pear varieties is not observed. The question of how the pathogen gets from a diseased tree to a healthy one is still relevant.
Scientists studying methods of treating the disease have noted the following processes of the spread of bacterial burns in the garden. At a certain stage of the development of the disease, amber drops are formed on the pear.
They can be found on fruits, bark or leaves. This is a released exudate containing whole colonies of bacteria. Any insect or bird, touching an infected droplet, becomes a carrier of the disease.
The cycle of development of an infectious disease
The most susceptible parts of a pear to pathogenic bacteria are flower buds and inflorescences. The infection process begins 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 instance:
- Budding period... Affected buds turn black, dry out, but remain on the branches.
- Pear flowering period... Flowers darken, wither, then blackening goes to leaves and branches.
The last stage of a fire blight is characterized by a softening of the bark, the release of a white exudate. Then, under the influence of air, it acquires a brown hue. The tissues affected by a bacterial burn begin to peel off and become covered with blisters, the bark acquires a "marble" hue.
Pear death occurs very quickly if pathogenic bacteria invade the roots. The root system turns black, which causes the tree to dry out.
Features of parts of a pear with a bacterial burn:
- The set fruits darken after infection, dry, and remain on the tree until autumn.
- The bark on the branches and trunk of the pear becomes covered with droplets of white exudate, similar to mold, and becomes soft. Then it cracks and takes the form of marble.
- The branches are covered with sores that move to the trunk.
If you do not start the fight against bacterial burns in time, you can lose the entire pear garden in a couple of seasons.
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 buds, then on flowers. It doesn't matter how many parts are affected. First, wilting is observed, then drying out, the flowers turn black. Further, the bactericidal burn moves to the rosettes of leaves and young twigs.
- Leaves... Turn black and curl, often looking burnt.
- Branches... Their tips turn black as from fire and bend, the bark becomes covered with dark watery spots.
The complexity of the definition of the disease lies in the similarity of symptoms with other processes. For example, moisture deficiency. Gardeners believe that the pear dries up from lack of water and begin to flood the tree. Also, the state of the cortex resembles the necrosis that occurs with bacterial cancer.
How to treat a pear bacterial 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 fire blight.
The first option involves the use of special means for treating the tree. In the second, a radical method is used - the removal of the affected specimens in general or their parts. Gardeners get rid of pears, which are more burned than other trees.
If the disease has captured less than 30% of the pear area, then partial removal is recommended. Only sore spots are excised, capturing part of healthy tissue. At the same time, instruments must be disinfected.
If the lesion is not extensive, gardeners use copper-containing preparations. Most often, however, antibiotics have to be used.
Antibiotic treatment for pear blight
This method is considered the most effective. Various antibiotics are recommended for treating pears for bacterial burns. The preparation of the solution depends on the concentration in which the drug contains the active substance. Among the popular ones:
- Streptomycin... The choice of a drug is dictated by its availability and low cost. The disadvantage is that it quickly collapses and ceases to work. Dosage - 1 ampoule per 5 liters of water.
- Gentamicin... Enough 1 ampoule of the drug for 1 liter of water. It is a powerful antibiotic.
- Ofloxacin... The drug has a more severe action on the site of infection. It is used for medical dressings (1 tablet per 1 liter of water) and spraying (2 tablets per 10 liters of water). The dosage must not be violated.
- Tetracycline... In terms of cost and availability, it is in the same place with Streptomycin. Often used in duets. Tetracycline prevents the emergence of streptomycin resistance in Erwinia.To treat pears for bacterial burns, dissolve 2 tablets of Tetracycline in 3 liters of water.
A bacterial burn on pear seedlings can be quickly treated with antibiotics. During the season, it is necessary to spray the trees, alternating a solution of streptomycin and the drug Skor. The procedure is carried out once every 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 composition of the solution do not die under the influence of sunlight.
Treatment of bacteriological pear burns with copper-containing preparations
Copper sulfate, copper oxychloride, and other copper preparations are used among copper-containing preparations in the treatment of Antonov's fire. A mixture of copper sulfate with a lime mortar is popular, but it is important to observe proportions here. If you add more vitriol than the norm, it scorches 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 efficiently, besides, it is less toxic to pears than vitriol. Deep penetration into the tissues of the tree will not occur, but insects will not transfer bacteria on their limbs.
The main action that copper preparations produce is to stop the development of bacteria. However, the destruction of the infection does not occur. Therefore, gardeners are more likely to use antibiotics or other remedies.
Other drugs for the treatment of pear blight
This category includes biological products or some fungicides. The most famous are:
- Gamair... Low toxic to humans, but effective in the fight against pathogenic bacteria. When treating a bactericidal burn, a solution of 2 Gamair tablets per 1 liter of water is used. Spraying is carried out with a weekly interval from the moment of budding 2-3 times. If signs of the onset of the disease are noticed, spraying is continued many times. Doesn't work in cool weather.
- Phytoflavin... It can also be used during a cold snap. Dilute 20 ml in 10 l of water, process the pear several times. Consumption of working solution 3 liters per tree.
- Fitosporin... A drug that significantly reduces the course of putrefactive processes. It is used for severe lesions of the pear.
According to gardeners' reviews, the best effect is obtained when combining bactericidal agents with fungicides Skor, Energi 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 thoroughly disinfect all tools.
Preventive measures
Measures to prevent bacterial burn:
- Mandatory inspection of the garden, starting from the very first days of spring.
- Treating the garden with insecticides to kill pests - vectors of infection.
- Weeding the garden area from weeds.
- Selection of disease resistant pear varieties.
- Carrying out winter sanitary pruning with obligatory disinfection of the instrument. Burning cut branches.
- Pre-winter treatment with copper-containing preparations.
There is no point in treating a bacterial burn in the fall - ervinia does not multiply during this period, but goes into the stage of encapsulation. Antibiotics are powerless, and treatments will remove other pathogenic bacteria that weaken the tree's immunity.
Conclusion
Treating a pear blight 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 the measures are taken, the more chances for a complete victory and salvation of your favorite pear varieties.
