Fungal and viral diseases of apple trees
- Part 1. Fungal and viral diseases of apple trees
- Part 2. Protecting an apple tree from a bacterial infection
- Part 3. Apple pests - control methods
Apple trees bloom - what a miracle. Indeed, it is better that there is no color when the apple trees bloom and it is insulting to tears if the garden literally becomes empty during the summer. Sickened by disease fruits rot under the crowns of trees. In years with epiphytotic lesions of trees, up to 90% of the crop dies.
Apple trees, like other garden crops, are affected by 3 types of diseases: fungal, bacterial and viral. In addition, every year an increasing number of trees in the gardens suffer from violations of the agricultural technology of fertilizer use, water and temperature conditions, and the use of protection from diseases and pests. The enemy must be known in person, only then the struggle for the crop will be crowned with victory without harming the health of the family and animals. A common enemy for gardening is a violation of agricultural care practices.
General agrotechnical measures for the care of horticultural crops
The garden must be kept under steam or tinned. Systematically destroy weeds in which diseases and pests accumulate.
Every year during the growing season and autumn, it is necessary to clean the near-trunk areas from fallen leaves, fruits and other garbage. Sick fruits destroy. The leaves of healthy trees are usually laid in compost pits or used for mulching.
Apple trees are infected with rust from common juniper. Therefore, planting juniper should not be placed close to the garden.
In the autumn, after falling of leaves, it is necessary to systematically inspect the stem and skeletal branches. Sanitary pruning, freeing the crown from diseased, dry, growing inward branches. To clear the stem and skeletal branches of the old lagging bark.
It is necessary to close up hollows, cracks with special compounds with the addition of medical preparations. Large saw cuts paint over or other protective compounds.
Pruning is carried out from February to March, when the plants are at rest (there is no sap flow).
Several times a year (not only in spring and autumn) whiten the trunk and skeletal branches with a freshly prepared solution of freshly slaked lime mixed with clay, copper sulfate, glue, fungicidal and bactericidal preparations.
In the fall, before digging, apply phosphorus-potassium fertilizers and disinfect the soil using copper sulfate, ammonium nitrate, and biological products. If the garden is tinned (not digable), then drill 5-10 wells along the edge of the crown, fill in a mixture of fertilizers, cover with turf and water.
During the growing season in the spring, feed the apple trees with nitroammophos, at the rate of 50-100 g per crown. Fertilize microfertilizers annually.
Over the summer (especially dry) watering is required at least 2 times. After watering, mulch or superficially hoe the soil.
Fungal Disease Control
The defeat of the apple tree is caused by pathogenic fungi. The mycelium and its spores winter in fallen leaves, diseased fruits, in cracks and hollows. Overwintered spores, parts of the mycelium in warm spring weather begin to multiply actively, capturing healthy areas of the vegetative and generative organs of plants. The most common and harmful fungal diseases are fruit rot, powdery mildew, black and other types of cancer, scab, rust, brown spotting cytosporosis.
Symptoms of a disease
Each type of fungus has its own distinctive signs and properties that can be combined according to the manifestation of external symptoms. Fungal infection is manifested in the form of separate oily translucent or round red, yellowish, dry spots, grayish-white deposits, various velvety to the touch, round formations on the leaves. They turn yellow, curl, stop growing. Separate rounded spots appear on the fruits, which grow. The tissue of the fruit begins to rot or becomes woody, covered with cracks. The fruits are mummified on branches and fall off. The most favorable conditions for the spread of fungal diseases are warm, humid weather.
At home, you always want to grow an environmentally healthy crop, so some gardeners believe that it is best not to use any drugs at all. But this approach is fundamentally wrong, because after a few years nothing will remain from the garden except dried or absolutely diseased plants. Protective measures in the garden are required. Nowadays, biological preparations made on a natural basis - useful microflora that destroy pathogenic fungi are used for garden treatments. These drugs are completely harmless and can be used literally the day before the harvest.
Biological product protection technology
In autumn, on the bare crown of the apple tree and in the spring before waking up from winter rest, we carry out blue spraying with a 2-3% solution of copper sulfate.
In the spring, before buds open, we disinfect the soil with 7% urea solution or 10% ammonium nitrate solution. Thoroughly spray the soil with trunks and after 2-3 days we dig 10-15 cm.
In the pink bud phase and subsequently every 7-10 days, we process apple trees according to the recommendations of one of the biological products Fitosporin-M, Gamair, Integral, Mikosan, Haupsin, Agat-25, Planriz . They can be used to cultivate the garden until the harvest, and the use of Planriz helps to extend the shelf life of products. In order not to cause addiction of negative microflora to the preparations, a biological product is constantly being replaced during the processing of plants.
Remember! Biological products do not relieve the disease with a single treatment. Mandatory systematic processing of trees. The greatest effect is achieved for 2-3 years.
Chemical measures to protect the apple tree from fungal diseases
Sometimes gardens are so affected by diseases that the use of biological products does not have an effective effect on the affected trees. In this case, chemical protective measures are applied.
When using chemicals, be sure to follow health measures (bathrobe, gloves, glasses, headgear). After work, wash your face and hands with soap or take a shower.
We begin protective measures in the fall. After harvesting weeds, fallen leaves and fruits, we use blue spraying of apple trees with 3% solution of copper sulfate.
In the spring, before the buds open for processing the crown, you can repeat the blue spraying or use a 1% solution of DNOC.
Instead of copper sulfate and DNOC, it is possible to sprinkle the crown, as well as the stem and the soil of the trunks with a solution of mineral fertilizers for preventive purposes. We carefully treat the crown with a 5% urea solution, and the soil with a solution of 7% concentration. You can use a 10% solution of ammonium nitrate or a 15% solution of ammonium sulfate to treat the trunk and skeletal branches. After a few days, the treated soil must be dug up with a depth of 10-15 cm.
In the phase of the green cone of leaf buds, before and after flowering, the crown is treated with 1% Bordeaux liquid. Bordeaux fluid effectively protects trees from scab, moniliosis, powdery mildew and other fungal diseases. It does not belong to poisonous preparations, therefore it is allowed to treat trees with its solution after flowering.
Starting from the phase of pink buds, apple trees are treated every 2-3 weeks according to the instructions with the preparations “Chorus”, “Flint”, “Skor”, “Strobi”, “Raek”. During flowering, spraying is stopped. The last treatment is carried out a month before the harvest or in the fruit setting phase.
To reduce the load on the number of treatments, it is possible to switch to the treatment of trees with tank mixtures in the protection system, having previously checked the compatibility of the preparations.
Viral diseases and protection technology
Viruses - the smallest particles of protein matter, invisible in an ordinary microscope, but harmful enough for living plants. They are carried by pests when working on open plant tissues (vaccinations), water, and wind.
External symptoms of the disease
At the beginning of the introduction of the virus, its destructive work is not visible and the plant continues to function as healthy. The manifestation of the disease by external symptoms is much like a fungal infection. Spots appear on the leaves, the fruits are deformed. Over time, the differences become more pronounced. Separate spots on the leaves merge into a mosaic pattern of green-yellow colors and shades. Deschlorinated sections of leaf blades become necrotic, affected leaves fall off. Flattening, flattening of shoots, softening of wood are observed. Branches become unusually soft, gutta-perched, easily break under the load of the crop. Individual flowers and inflorescences are strongly deformed, acquire ugly forms. During spring development, at the ends of young shoots, bundles of dwarf shoots are formed with leaves or only leaves of an unusual shape and unusual color. Bunches of fatliquoring shoots (witch rings) are formed on old branches. The fruits crack, form crust-like spots and growths, lose their palatability, and also fall off.
External manifestations of viral diseases identified their names. The most common viral diseases of the apple tree: mosaic, star cracking of the fruit, panicle (witch's broom), rosette, proliferation or growth of vegetative and generative organs (ugliness), chlorotic ring blotch, wood dimple.
Technological methods of protection against viral diseases
There are no drugs destroying the virus as a source of infection yet. Therefore, the main control measures are agricultural technology of culture.
Agrotechnical measures are the same as those used to combat fungal diseases. Be especially careful when carrying out the following work.
Pruning should only be done when plants are deeply dormant (February).
When pruning, all diseased parts of the plant and the tree as a whole must be destroyed. In no case should compost waste be used.
With the manifestation of the most common diseases of rosette and paniculata of apple trees, it is necessary to reduce the dose when using simple forms of phosphorus and nitrogen fertilizers. Switch to fertilizer in complex forms, in which the elements are in the optimal ratio for cultivated crops.
Introduce micronutrients, including zinc sulfate, into the dressings, especially with a clear manifestation of rosette.
Use for spraying phytohormones Epin or Zircon, which increase the immunity of plants to viruses. The drugs are effective in preventive measures. They do not stop the developing disease.
Note! The main defense against viral diseases is the destruction of sucking pests, which are the main carriers of viruses.
Bacterial diseases will be discussed in a separate article.
- Part 1. Apple pests - control methods