Content
Bacterial burn of an apple tree (also called bacteriosis) is a dangerous infectious disease that manifests itself by blackening of leaves, ovaries, discharge on the bark, as well as mummification of fruits. Often leads to the complete death of the tree and spreads to neighboring plantings. Treatable only in the early stages. For treatment, chemicals belonging to the group of antibiotics are used.
Reasons for appearance
The disease is infectious in nature. It is caused by bacteria from the genus Erwinia amylovora. They are distributed in different ways:
- with raindrops;
- by the wind;
- with irrigation water;
- aphids;
- bees;
- gall midges;
- birds.
The pests overwinter in the plant tissue of an infected tree. With the onset of spring, they become more active and again parasitize the apple tree, and can spread to neighboring plantings. The disease develops in relatively warm (temperature from 18 degrees) and humid weather (from 70%).
Signs and symptoms
Bacterial burn affects the entire above-ground part of the apple tree. The main symptoms of the disease are the following:
- The leaves become deformed and begin to curl. Then they turn black, but do not fall off.
- The trees look like they've been burned.
- The bark on young branches swells due to the large influx of liquid.
- Then the liquid begins to flow down the bark.
- At first, the discharge is colorless, then it darkens and solidifies in the form of droplets of yellow or brown color.
- Apple tree flowers quickly fade and become dark.
- The shoots dry out and die.
An apple tree affected by fire blight can be identified by blackened foliage
The disease is widespread. Bacterial burn affects not only apple trees, but also pears, as well as quince, rowan, rose, raspberry, strawberry and other crops. Exacerbation of the disease is observed up to three times per season:
- In the second half of spring, when flowering occurs.
- At the beginning of summer (June), during the period of intensive shoot growth.
- At the end of August - beginning of September, when secondary growth of annual shoots is observed.
What can a bacterial burn be confused with?
Diagnosing bacterial burn of an apple tree is quite simple. But it can be confused with bacterial cancer, i.e. necrosis of the cortex. This is also a bacterial disease caused by Pseudomonas syringae.
The main signs of this pathology:
- Sudden wilting of young leaves that appear in the spring.
- Dark spots without plaque form along the edge of the leaf blade.
- The leaves do not fall and continue to remain on the tree.
- Flowers and buds that do not bloom also darken and remain on the apple tree.
- Cracks in the form of wedges form on the bark. They separate diseased tissues from healthy ones.
Apple tree cancer is diagnosed visually
Fire blight symptoms resemble damage caused by drought. The comparison is presented in the table.
Sign | Bacterial burn | Drought damage |
Condition of the leaves | Red areas between veins | Brownish areas on the edges of leaves. Damage does not affect veins |
State of shoots | Fade like a "shepherd's crook" or "whip" | Branches remain straight when withered |
Development of lesions | Top down | |
Condition of the cortex | Damp, sticky. White discharge gradually turns brown | Dried bark. No allocations |
Flowers, ovaries | The buds acquire a dark brown tint and die off, remaining on the branches. The ovaries darken and do not grow | Do not change color, do not fall off |
Condition of the fruits | Covered with secretions, then mummified. Remain on branches and overwinter | They may become wrinkled, but do not mummify. Fall to the ground |
This is a fungal disease that affects the leaves (they do not fall off even in winter) and bark (longitudinal cracks, ulcers). At the same time, the bark on skeletal branches noticeably lags behind, while on young branches it only peels off.
Treating an apple tree for fire blight
Treatment is carried out using complex methods - chemical and biological drugs are used simultaneously. As an additional measure, you can use folk remedies.
Chemical preparations for fire blight on apple trees
To treat pathology, gardeners use chemicals - antibiotics:
- “Ampicillin” - 1 ampoule is diluted in 1 liter and sprayed on the tree throughout the season.
- “Fitolavin” – 20 ml per 10 l. The apple tree and tree trunk are treated.
- “Streptomycin” (1 ampoule) and “Tetracycline (3 tablets) – dissolve in 5 liters and treat the bacterial burn before, during and after flowering.
- “Gentamicin” – 1 ampoule per 1 liter. Moisten the gauze and tie the damaged areas (clean them first).
- “Ofloxacin” – 1 tablet per 1 liter.Moisten the bandage and also tie the damaged areas. You can also dissolve 2 tablets in 10 liters and treat the apple tree against bacterial burn before and after flowering.
Ampicillin and other antibiotics are used to treat burns.
But this is only an additional, and not the main means of treatment.
Biological products
Biological agents are not used to treat fire blight. They are used only to enhance immunity simultaneously with the chemicals described above. Among the most effective medications are the following:
- “Stimix Concentrate” – dilute 100 ml in 10 liters. Water the tree after harvesting.
- “Stimix Standard” – 50 ml per 10 l. The leaves are treated seven times during the summer with a break of two weeks.
- “Stimix Phytostim” – 50 ml per 10 l. Treatment is carried out once a month.
- “Baikal EM-1” – 10 ml per 10 l. Three sprayings are carried out per season.
- “Siyanie-1” – 10 ml per 110 l, treatment is carried out in the spring (watering the apple tree).
Folk remedies
Folk remedies will not help cure a bacterial burn. But they can be used as an additional means of treatment, as well as for prevention. By treating with solutions, an acidic environment is created - in such conditions the spread of infection is difficult. Also, home remedies can be used as additional feeding for the apple tree to increase its resistance to diseases.
Basic recipes (for 10 liters of water):
- Boric acid – 10 g.
- Succinic acid – 10 tablets.
- Wood ash – 200 g.
- Dry yeast – 10 g.
- Sugar – 2 tablespoons (dissolve in warm water).
All solutions are used to treat apple trees against fire blight in the late evening or early morning. They can be alternated with the main drugs (interval 3-5 days).
It is placed in a circle around the trunk as mulch (layer 5-7 cm). It destroys bacteria and also helps saturate the soil with valuable nutrients (phosphorus and potassium).
Boric acid and other folk remedies can only be used as an auxiliary measure
Preventive measures
Bacterial burn is a very dangerous disease that often leads to the death of a tree. Therefore, gardeners need to know not only about treatment methods, but also about preventive measures:
- Always follow the watering norm - a young apple tree is given no more than three buckets of water, an adult - no more than eight. It is better to take water from the tap, previously settled at room temperature.
- To facilitate the treatment of bacterial burn of an apple tree, in the fall all plant debris is carefully removed and burned. If the tree is already damaged, you need to remove all affected parts, including mummified fruits.
- Do not neglect potassium and phosphorus fertilizing, especially during flowering and formation of ovaries, as well as during the period of treatment of the tree for bacterial burn.
- Carefully inspect seedlings when purchasing. Purchase them only from trusted suppliers and nurseries.
- Plant apple trees at a distance of at least 4 m from each other.
- Regularly prune the crown, especially if the variety is prone to active shoot formation.
- During pruning, disinfect garden tools with potassium permanganate or other preparations.
- Carry out preventative treatment against pests every spring.In summer you also need to monitor the appearance of aphids and other insects. If necessary, treat with an insecticide, for example, Aktara or Fitoverm.
Frequent errors in treatment
Beginners and even experienced gardeners often make mistakes in treating fire blight on apple trees. They are associated both with incorrect diagnosis and with the procedures themselves. The main inaccuracies are:
- If the diagnosis is incorrect, then the treatment will be incorrect. For example, a gardener may believe that an apple tree has suffered from drought and will begin to water it abundantly, which will cause an even greater spread of the disease.
- Treatment using fungicides. These drugs are used to destroy fungi, and bacteriosis is treated with other means, including those described above.
- Gardeners can also leave mummified apples on the branches, especially if they grow at a height that is difficult to reach. And they need to be completely removed and burned, since it is in such parts that pathogens overwinter.
- Another common mistake is that summer residents avoid using chemicals and use folk remedies for a long time. This measure will not help - the disease will continue to develop. Therefore, it is better to immediately use chemical and biological agents.
For successful treatment it is necessary to learn how to accurately diagnose the disease.
Conclusion
Bacterial burn of an apple tree is quite dangerous, and coping with it is not always easy. Therefore, it is recommended to follow general preventive measures and learn to diagnose the disease by external signs. Antibiotics are mainly used for treatment. Biological drugs and folk remedies can only be considered as an additional measure.
