Brown spot appears on various plants; apple trees are also at risk. Compared to late blight, the disease is not as serious. If all conditions are created for the development of brown spot, half the crop will die.
What is apple phyllosticosis?
Phyllosticosis or brown spot is a disease that is fungal in nature.Microorganisms in the process of activity create brown spots on the leaves of the apple tree. The likelihood of developing phyllostictosis on apple trees increases in mid-summer. In regions with a warm climate, you can notice the appearance of brown spot at the end of May; in such places, fruit trees suffer most from the disease.
Causes of brown spots on tree leaves
They are divided into two groups:
- internal;
- external.
In the first case, the disease occurs as a result of weakening of the body. External factors for the development of brown spot include various fungi from the genus Phyllosticta. Moreover, brown spot occurs not only on apples, but also on pears and quinces.
The pathogen begins to develop when suitable weather conditions occur. The weather outside should be warm and high humidity.
Winter is not terrible for fungi, since they can calmly wait out the cold season in order to infect as many plantings as possible next season with renewed vigor. Late blight and brown spot cannot exist together on the same plant.
Signs and symptoms
In mid-May, the leaves of the apple tree become covered with small spots. Over time, they become blurry and acquire a brown tint. The spots have a brown rim. At the end of summer, the middle of the spot becomes lighter. The leaf blade becomes thin and covered with black pycnidia. In regions with cold climates, the development of symptoms is observed later. Despite the fact that the disease is not as active, the infection does not leave the trees.
Drugs for protection
Spraying with fungicides or antibiotics will help solve the problem. There are many drugs that fight not only phyllosticosis.
"Raek"
The drug contains the active ingredient difenoconazole. Benefits of the fungicide:
- effect after the first use;
- rapid penetration into the plant;
- providing protection over a long period of time;
- slows down the formation of spores, making their germination impossible.
Raek is presented in the form of a liquid. 2 cubes of the drug are diluted in 10 liters of water. Spray an apple tree suffering from brown spot at the moment the buds open. The treatment procedure is repeated during the budding period.
"Fitolavin"
You can fight phyllostictosis with the help of another equally effective medicine - Fitolavina. It is an antibacterial drug with fungicidal properties. The active substance is phytobacteriomycin.
The main advantage of Fitolavin is its wide spectrum of action, but there is also a drawback. As a result of use, the drug accumulates in plants and trees. Therefore, it is recommended to use if infestation has reached a large scale. Spraying is carried out long before harvest.
"Strobe"
The drug to combat phyllosticosis is part of the group of strobilurins. Benefits of the fungicide:
- acts systematically;
- distributed evenly over the entire sheet;
- the liquid on the leaves is not washed off by rain;
- continues to operate during temperature changes;
- destroys fungi and other pathogens.
Treatment of brown spot on apple trees with this drug can result in negative consequences for humans. Direct contact with skin and inhalation of vapors leads to the development of allergic reactions. If it is necessary to cure apple trees from brown spot, it is recommended to alternate Strobi with other drugs. This will prevent the development of fungal resistance.
Fungicide "Zato"
“But” for spraying deprives microorganisms of the opportunity to breathe. This causes the fungi to stop growing and die.It is used in rainy weather, as it is not washed off by wet streams.
This drug is recommended in cases where it is urgently necessary to take measures to combat fungi, especially if it is cold outside.
“But” is suitable for treating affected apple trees if the weather is constantly changing.
Folk remedies
In addition to chemicals, it is worth paying attention to the products that are at hand. Common and most popular recipes for combating brown spot:
- A solution containing 20 drops of iodine, 5 liters of water and 500 ml of milk.
- 1 liter of serum per bucket of water.
- Decoction of coal ash - 10 liters of water and 500 g of ash. The mixture is boiled for 25 minutes.
- Potassium permanganate solution. Potassium permanganate is added to a bucket of water in such an amount that the liquid becomes light pink.
- 500 g of crushed cloves of garlic and arrows of a green plant, infused in 10 liters of water.
All recipes should result in liquid. Infected apple trees are sprayed with the prepared solution. To prepare them you will need simple ingredients.
Disease prevention
Consists of many activities. Gardeners sometimes underestimate the importance of tree pruning. Sanitary removal of branches is necessary, since the affected ones are also destroyed along with the dry ones. Healthy branches should also be pruned to thin them out to provide more space.
Pruning for the purpose of thinning has a beneficial effect on the processes of photosynthesis in apple tree leaves, increasing them. This is also useful, as the ventilation of the crown branches increases. The sparse structure of the apple tree guarantees that much fewer foci of infection will form. Direct access of sunlight to the branches kills the remaining fungus.
To protect apple trees from brown spot, be sure to destroy fallen leaves. There are several ways to do this. Fallen leaves are used to make compost or simply buried in a trench. To make them easier to work with, they are burned.
Chemical treatment
The drugs that are used to control apple trees are also used as prophylaxis. The only difference is the dilution of smaller doses. Treating healthy leaves will eliminate the likelihood of disease development.
It is advisable to spray with chemicals after harvesting - in the fall. There is no need to postpone the procedure until spring. If the apple trees feel healthy before the onset of cold weather, this will help avoid the development of the disease in the new season. The leaves of the tree will not become stained, and the person will be able to harvest.
Fertilizers and pests
Feeding apple trees plays an important role. But even during such an event, a person can make a mistake. It is necessary to observe the dosage of the components of the fertilizer that is introduced. To increase the resistance of fruit trees to brown spot, the presence of nitrogen in fertilizers is mandatory.
Another preventive measure against brown spot is the destruction of insects. Pests suck the sap from the tree, thus transmitting the infection. Thrips and aphids are especially dangerous.
What to do with the harvest
At an advanced stage of the disease, the most aggressive fungicides are used. If treatment with solutions occurs shortly before harvest, it is better to refrain from eating the fruits. Spraying is not abandoned even in the fall, as this will ensure fruiting of the apple tree next year.
Apples can be eaten if treated with fungicides long before they were harvested.Over time, they get rid of accumulated harmful substances. That is why apple trees are sprayed during the budding period.
If no measures are taken, a person may lose half of his garden harvest. Fallen apples, as well as leaves, are disposed of. Fruits can carry a source of infection, which will cause the disease to appear next year.
Conclusion
Brown spot or phyllostictosis is one of the diseases that affects not only the appearance of fruit trees, but also apples. To preserve the harvest and the ability of trees to bear fruit, it is recommended to carry out regular processing. Chemicals and traditional medicine products are used as spraying agents.
