Sooty mold on apple trees: causes and measures to combat the black plaque

In the second half of summer, a thick black coating, resembling soot, can be found on the leaves and branches of apple trees. Not everyone knows that this is the main symptom of sooty mold, a disease that seriously damages the health of fruit crops and the ripening harvest.

Information about the disease

Sooty fungus (black mold) is a type of mold fungus. Its spores overwinter in tree bark and are also constantly present in the soil, activating in large accumulations of nectar and the natural excretions of pests.

That is why, when fighting sooty mold, it is first necessary to completely get rid of harmful insects: aphids, scale insects, larch, etc.

Causes of occurrence

In addition to the awareness of the pests of the nutrient medium, the appearance of the fungus is caused by the following factors:

• insufficient sunlight;
• excessive thickening of the bark;
• improper care, which contributes to a decrease in immunity.

Symptoms and development

The appearance and development of sooty mold occurs quite quickly: a black coating is visible within a few weeks of the tree's infestation. The disease progresses at high temperatures, which is especially noticeable in July and August.

In addition, its presence is indicated by the following:

• premature leaf fall;
• loss of fruit's original appearance and size, this usually occurs before harvesting.

The fungus feeds on tree sap and insect excrement, especially aphids. As the fungus clogs the microscopic holes in the bark, it disrupts air circulation, negatively impacting the health of the garden plant.

The black plaque can be easily wiped off or washed away with water, but without proper treatment, the infection can recur. Only a properly implemented set of measures can completely eliminate this problem.

Methods of treating the disease

Once established, sooty mold immediately penetrates the tree's tissue and begins to multiply rapidly. Several methods are available to eliminate the disease and provide reliable protection for fruit trees.

Mechanical method

This treatment option involves pruning overgrown trees and removing infected bark. Once the first signs of plaque are detected, it is removed with a suitable tool and then treated with specialized products. Severely affected areas are cut off.

Pest control

Efforts to eliminate sooty mold begin with the complete elimination of the insects parasitizing apple trees. For this purpose, store-bought products or homemade solutions can be used. Folk remedies can be obtained in the following ways:

1. Soap solution. Grate 72% laundry soap using a coarse grater and add slightly warm water, maintaining the ratio: 150 g / 10 l.
2. Ammonia. Dissolve half a medicine bottle in 10 liters of water and mix with 100 g of crushed tar or laundry soap. Let the mixture sit until the soap dissolves completely.
3. Tobacco decoction. Pour 400 g of tobacco dust into 10 l of water and let it steep for 3–4 hours. Then bring to a boil and add 50 g of soap shavings or the same amount of liquid dish soap.
4. Ash infusion. Pour boiling water over wood ash (400 g/1 l), then dilute with 9 l of cold water and add 1 tbsp of liquid soap.
5. Pepper infusion. Pour 1.5 kg of hot pepper into cold water and leave in a dark place for 24 hours. To prepare the working solution, add 40 g of laundry soap shavings.
6. Garlic infusion. Peel the garlic cloves and press them through a garlic press, then add cold water in a 1:1 ratio. Pour the mixture into a glass container, seal it tightly, and leave it in a dark place to steep for about 10 days. Before use, dilute the infusion with the prepared glaze water in the proportion of 250 ml: 10 l.

The most effective of them are the following:

To spray the garden with chemicals and folk remedies, choose a dry, windless day. Each apple tree will require 2 to 5 liters of the spray solution, depending on the tree's age.

When starting to fight pests, it is worth paying attention to several nuances:

1. The bug overwinters in the soil, and in the spring it primarily attacks young shoots. Therefore, apple trees are sprayed with special preparations during this time, and preventative measures are carried out in the fall, such as clearing the tree trunks of fallen fruit, etc.
2. Bark beetles disrupt sap flow by boring holes in the trunk. To eliminate this pest, treat with fungicides, clean, and prune the affected tree sections.

Eliminating garden ants

Many gardeners consider ants to be garden cleaners, but this is far from true. Ants create favorable conditions for colonization in a garden plot. caterpillars, psyllids, and scale insects. To obtain the sugary secretions, these hard-working insects take every precaution to protect the aphids.

Boosting immunity

Any healthy garden crop is fairly resistant to various diseases and pests. Therefore, it's important to regularly feed apple trees with immunity-boosting compounds. For this purpose, we recommend the following fertilizers:

• ammonium nitrate – used in early spring;
• ammonium sulfate;
• potassium chloride;
• potassium salt - application in late autumn;
• potassium sulfate;
• nitrophoska;
• urea.

Choice of drug

Today, manufacturers offer a variety of products designed to combat sooty mold. In addition to their therapeutic properties, these compounds also protect plants from dangerous diseases. The choice of a specific product depends on a number of factors:

• age of apple tree;
• type of disease;
• form of progression;
• garden area;
• presence of pets nearby.

It's not recommended to purchase a product based solely on advertising, as it may not produce the desired results. Furthermore, using unfamiliar products can seriously harm crops.

Use of fungicides

There are several types of fungicidal preparations that can be used to combat sooty mold:

1. Therapeutic – block the development of the disease and eliminate its pathogen.
2. Protective (inorganic or organic) – relevant for the prevention of fungal diseases.
3. Complex – used during the treatment process and increase its effectiveness.
4. Immunizing agents – normalize metabolic processes in garden crops, increasing their resistance to fungal damage.

Furthermore, these products differ in their mode of action. For example, contact fungicides protect only the parts of the tree where they are applied. Recently, experienced gardeners have begun to prefer organic liquid products that move freely through the tree's vascular system. Such formulations can protect healthy shoots from a tree already infected with fungus.

Different types of fungicides can have a wide variety of effects on parasites:

• interfere with growth and reproduction;
• block cellular respiration and enzymes;
• stop the synthesis of lipids and proteins for cell membranes;
• They draw fluid from fungal organisms, thereby killing them.

Comparison of organic and inorganic fungicides

Fungicides can be inorganic or organic. The latter are environmentally friendly, with respect to human health and the environment. Their advantage lies in the absence of hazardous metals, which are detrimental not only to parasites but also to earthworms and animals.

Natural preparations decompose on their own in the soil within a short period of time, but at the same time, this reduces the duration of their therapeutic effect.

Popular remedies

To treat apple trees against sooty mold, it is recommended to use the following fungicides:

• "Horus" - 2 g;
• "Strobi" - 2 g;
• "Oxychom" - 20 g;
• Topaz – 3 ml;
• "Skor" - 2 ml;
• "Kuproksat" – 50 ml.

When preparing the working solution, each of the preparations in the specified dosage is diluted in 10 liters of water.

Windless and dry weather is chosen for carrying out the treatment procedure.

Application of Fitoverm

Fitoverm is an insectoacaricide. Its main component, when applied to the skin of harmful insects, negatively impacts their nervous system and intestines. As a result, the paralyzed insect dies. Fitoverm's main advantage is its ability to kill almost all types of pests. Just two treatments are sufficient to completely eliminate the problem.

Other possible means

In addition to the listed methods of combating sooty mold, the following are used in gardening:

1. Spraying apple trees with 1% Bordeaux mixture. A standard sprayer is sufficient for small areas. For larger infestations, professional high-capacity sprayers are recommended.
2. Processing copper sulfate (1%), blocking the development of fungus.

Many gardeners prefer varieties that are highly resistant to fungi and diseases, for example:

• Lungwort;
• Antonovka;
• Cypress;
• Sun;
• Aphrodite.

Preventive measures

With a competent and comprehensive approach, completely eradicating sooty mold is not difficult. However, it's much easier to prevent this problem from occurring by implementing timely preventative measures and strictly adhering to agricultural practices. This comprehensive approach includes:

• collection and destruction of plant waste: fallen fruit, branches, leaves, weeds and last year’s mulch;
• regular feeding;
• digging and loosening the soil in the tree trunk circle;
• timely pruning: rejuvenating and sanitary;
• pest control;
• preventive treatment;
• autumn and spring whitewash trunks with lime solution.

Sooty mold is a rather dangerous disease that hinders the trees' normal growth. When detected, immediate action is required; otherwise, the fungus will spread to healthy apple trees, significantly complicating the problem.