Bacterial cancer (black leaves and trunks): how to protect trees
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BACTERIAL CANCER OF TREES - HOW TO TREAT?
For the third year in a row, we have been observing abnormal weather changes that have hit plant immunity hard. As a result, bacterial diseases actively spread on weakened fruit trees. Is it possible to help green pets in such a situation? Listen to the recommendations of the candidate of agricultural sciences Yulia KONDRATENOK.
Yulia Georgievna, for starters, how do you assess the results of the outgoing season? — This year was very difficult for gardens: abnormally cold May, rainy June, sharp July temperature drops during the day from +5 to +25 degrees, then heat up to +35 degrees, against the backdrop of lack of precipitation, a sharp cooling in September with night frosts - all this is a shock both for people and animals, and for plants. But the latter, unlike animals, get out of such stress more slowly.
And since weather anomalies have been repeated for the past few years in a row, plants do not have time to recover. Therefore, we are seeing a worsening situation with diseases in gardens. This year, more than ever, bacterial cancer is raging on fruit trees, and not only on the pear, which is especially sensitive to this in the mouth, but also on the apple tree, as well as on stone fruits (cherries, plums, cherries).
Bacterial pear cancer: leaf edge affected
Bacterial pear cancer: affected flowers
What is the nature of the disease?
- The main causative agent of all bacterioses is the bacterium Pseudomonas syringae. She lives on the surface of the plant, but as long as the tree is healthy, the bacterium cannot harm it. But as soon as the plant
immunity falls, the protective barrier decreases, the bacterium penetrates inside, causing the death of young shoots, leaves, flowers with its toxins (they become brown or black). Dark depressed spots, necrosis, and then ulcers form on the bark.
Reference by topic: Treating a pear bacterial burn - my tips and remedies
And how should the gardener act in this situation?
- Help the plants. Right now, it is necessary to properly prepare for wintering and then support them in the new season, timely eliminating possible problems, and sometimes acting ahead of the curve.
In October, water-charging irrigation was important (for each square meter of the crown projection, about 5 buckets of water), and at the end of leaf fall, eradication treatment. As for the latter, the classic version is a solution of urea (700-800 g per 10 liters of water). But if you notice signs of bacteriosis on the tree (dying off of the tips of the shoots and their characteristic bend in the shape of a shepherd's crook, browning of the apple tree or blackening of the pear leaves), only copper can cope with the problem. And not the usual Bordeaux liquid or blue vitriol - alas, the bacterium has already developed resistance to them. And preparations based on copper oxychloride or hydroxide of copper - Abiga-Peak, Koside.
Surely many gardeners - amateurs will now be outraged, they say, copper is a heavy metal
We need to choose the lesser of two evils. And it is important to eradicate the infection now in order to use less drugs next year.
Do not put off sanitary pruning for spring: it is not too late to remove all diseased, broken, dead branches. Clean necrosis or ulcers on the trunk with a sharp knife to healthy wood and disinfect with Azo-phos, a solution of copper sulfate or Bordeaux liquid (30 g per 1 liter of water). Then, be sure to paint over the wounds, including after pruning, with garden paint with the addition of fungicides (Azophos, Tridex, Tersel - 4-5 g per 1 kg of putty). Sick branches, plant debris immediately burn.
And one more thing: for the winter, all trees must be whitewashed!
How to start a new season in the spring for the prevention of bacterial cancer?
- Again, from copper preparations - Kosida, Abiga-Pika, Medex-sa. They will also contain the spread of fungal infection. Plan the first treatment during the period of swelling and bud break. And then monitor the condition of the plant: if it does not lack nutrition and moisture, there are no affected fallen leaves in the garden, cut branches do not roll, protective treatments are carried out, then the tree may well cope with the bacteria itself. But if the weather in the spring again does not correspond to the climatic norm, the plants will inevitably be stressed. In this case, as with the first signs of bacterial cancer, preventive spraying with copper preparations or Ditan NeoTek contact fungicide is mandatory. At + 18 + 25 degrees, the biological product Fitolavin is effective.
FIGHTING BACTERIAL CANCER IN FRUIT TREES - ADVICE AND FEEDBACK FROM SDA
PEAR, BACTERIAL CANCER AND ANTIBIOTIC
At the beginning of summer, leaves began to turn black on my four-year-old pear, as if they had been scorched by fire. The same fate befell the ends of the branches themselves. A neighbor determined it was cancer and advised antibiotic treatment. True, he did not remember in what ratio the medicine should be diluted. I decided to trust my intuition. I found a package of Cefotaxime in the first-aid kit: the contents of two vials of the drug (1 g of powder each) were diluted in 3 liters of water. With the resulting solution, I carefully processed the entire tree from the sprayer, after cutting off the affected branches, capturing 10-15 cm of healthy wood. In addition, she injected the composition directly into the branches through fresh sections through a syringe, which she then smeared with garden pitch. The procedure was repeated 2 more times with an interval of a week. There were no more black leaves on the tree.
© Author: Irina KUDRINA, Voronezh
According to the description, the pear does indeed have a bacterial cancer (and possibly a bacterial burn, which is now quite widespread). But the use of antibiotics in fruit growing in Russia and Belarus is prohibited! For the prevention and protection against bacterial cancer and burns, experts recommend using copper preparations (Abiga-Peak, Kuproksat), as well as the Fitolavin biological product.
The uncontrolled use of antibiotics in agriculture has already led to disturbances in ecosystems, because antibiotics do not care who they kill - both good and bad microorganisms suffer. Antibiotics accumulate in fruits, berries, animal meat, and then end up on our table. Abroad, their use is allowed only on young (non-fruiting) trees and under strict supervision.
© Author: Julia KONDRATENOK, Cand. agricultural sciences
See also: How to deal with bacterial vine cancer
BACTERIAL CANCER OF TREES - HOW TO TREAT? VIDEO
© Author: Victoria GULKO. Photo by Yulia KONDRATENOK
Below other entries on the topic "Dacha and garden - with their own hands"
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- How to deal with strawberry leaf beetle on strawberries and raspberries
- Milk whey as a means of combating aphids on cucumbers
- Ampelopsis econitolisty (Parthenocissus) as a remedy for pests!
- What do pumpkins get sick with - pumpkin, zucchini, squash, etc.: and how to deal with it?
- Top rot in potted tomatoes - how to treat?
- Processing strawberries from pests without chemicals
- Diseases of tubers and bulbs of ornamental plants - description from agricultural sciences
- Apple bark diseases
- 5 working folk recipes and remedies for phytophthora
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FROM BLACK AND ORDINARY CANCER
Wounds are cleaned with a sharp knife to a living bark. Live callus ridges, if they are around the ulcer, are not cut off. Then they are disinfected, usually closing after that with garden pitch or paint. The cut affected tissues and branches are burned.
Treatment in early spring and autumn with a 3% Bordeaux mixture, copper or iron sulfate, or "Abiga Peak" (HOM).
Starting from the green cone phase, they are sprayed with copper-containing and other chemical and biological products, combining them with immunostimulants.
The number of treatments depends on the weather, the resistance of the variety, the intensity of the development of diseases.
The applied fungicides are rotated to prevent the emergence of resistant populations of pathogens.
PREVENTION AGAINST CANCER DISEASES
Compliance with agricultural technology, diet, watering,
regulation of fruiting, Z regular cutting of affected branches,
cleaning of wounds and hollows with subsequent disinfection, putty of wounds and cuts (garden balsam, pitch),
filling hollows (by layer-by-layer cementing),
attention when buying to identify diseases of the bark and roots,
in autumn and early spring, cleaning the trunk and skeletal branches from dead bark, mosses, lichens, cutting drying branches, whitewashing, cleaning the litter. Burn all waste.
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Ordinary cancer, NECTRIOSIS
WHAT PLANTS AFFECT
Apple, pear, cherry, sweet cherry.
Pathogen: Nectria mushrooms. Trunks, forks of skeletal branches and branches of the first order of various hardwoods are affected. Dispersed by rain, wind and pruning.
Symptoms
Small yellowish sunken spots form on the bark; then the bark in these places dies off with the formation of large nodules or outgrowths and deep cracks, sometimes reaching the core of the tree. In spring, reddish tubercles form around the wounds - spore-carrying of the fungus, which leads in summer to re-infection of other trees, penetrating through various mechanical damage to the bark. On thin dead branches, rounded pink-red pads from the mycelium of the pathogen are clearly visible - a characteristic sign of this disease.
Causative agents of necrosis-cancer diseases overwinter in the affected parts of the plant.
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Black Cancer
WHAT PLANTS AFFECT
Pathogen: Sphaeropsis malorum fungus. It affects the bark of the trunk and branches, penetrating through wounds, often manifests itself on leaves and fruits.
Apple, pear, quince, cherry, peach, apricot.
Symptoms
A dent appears on a branch or trunk, the bark in this place fades, acquires a brownish-violet color, which then turns into black, as if charred. Later, the bark cracks in different directions, even exposing the wood, its surface is covered with small tubercles. The bark is separated. The development of the disease depends on the condition of the tree. If optimal conditions are created for it and if only certain parts of the bark are affected, then the development of the fungus stops. If the wounds are well scarred, the spread is also limited.
Signs of damage also appear on the leaves - in the spring during their blooming. Initially, they appear as small purple spots on the upper side of the leaves, which then increase to 3-6 mm in diameter. The edge of the spots remains purple.
Areas of rot on fruits are brown to black, of indeterminate shape, surrounded by a reddish border, increase with time, forming concentric rings with black pycnidia. The fruits are mummified and often remain hanging on the tree, as in moniliosis.
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Bacterial cancer of the bark (gommosis)
Pathogen: Pseudomonas syringae bacteria. They remain in the affected plants, penetrate through mechanical damage to the bark, especially often when pruning trees and when grafting.
Symptoms
Shoots, flowers, fruit ovaries turn brown and dry. Watery blurry spots first appear on the leaves, the veins turn red, the leaves turn yellow, curl up and fall off.
Slightly depressed spots and ulcers form on the bark. Drying up, the ulcer deepens even more; along the edges there are influxes of callus and dried gum. In humid weather, the areas of the affected bark become moist, swell and emit a sour smell. Drops of a whitish or brownish liquid form on the affected organs, which quickly dry out in dry weather and remain on the surface in the form of a film.
PROTECTION MEASURES
It is obligatory to cull diseased plants.
As a preventive measure - the use of healthy planting material.
Protection against insect vectors.
Disinfection of cutting tools.
WHAT PLANTS AFFECT
Apricots and cherries are especially affected.
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Is it possible to cure black cancer in a fruit tree for an ordinary summer resident?
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- If the cancer does not progress, then it can be stopped. Take a closer look at the tree: if there are few affected areas, branches of the second, third order are sick, then carefully remove them to the nearest healthy lateral branch or cut out dead areas, disinfect (with a solution of copper sulfate or Bordeaux liquid - 50 g per 1 liter of water) and cover with garden pitch or quality garden paint with a fungicide. Give the tree good care and timely watering.
If there are many ulcers, the cancer has affected a large area of the cortex, covered the skeletal branches, more than half the circumference of the bole, moved to the forks - even professionals will not be able to cope here. It is better to remove such a tree.