Content
Brown spots on apple tree leaves appear for various reasons. Most often they are associated with diseases and pests. Dark areas can also appear due to sunburn, improper care and unfavorable weather. The treatment regimen is approximately the same - remove the affected branches and burn them, and then proceed to treatment with chemical or biological preparations. It is also useful to feed the apple tree so that the tree can better resist infections.
What does it look like
Brown or dark spots may periodically appear on apple tree leaves. They look like lumpy, protruding formations of different shapes and sizes. Various colors:
- brown;
- brown (light and darker);
- olive;
- almost black.
Spots on an apple tree can increase in size, change color and shape, and merge with each other.In this case, the green (unaffected) part may become lighter, and the affected areas themselves become covered with a velvety coating.
Why are the leaves on the apple tree covered with brown spots?
If brown spots appear on the leaves of a seedling or an adult apple tree, this may be due to many reasons - unfavorable weather, fungal infection, improper care. Dark spots can also appear due to pests. They are dangerous both in themselves and because they spread pathogens of fungal and bacterial infections.
Fungal infection
Among the most dangerous fungal infections that lead to the appearance of dark spots are: scab, rust, brown spot.
These are dangerous diseases that develop especially actively in certain weather conditions:
- heavy dew;
- morning fog;
- frequent rains;
- cool, cloudy weather.
The spread of infection is provoked by improper planting and care, including a thickened crown, excessive watering, too dense placement, stagnant moisture (lowland) or close groundwater.
Dark spots affect the leaves of the apple tree gradually
Sickness and mineral deficiency
The honeyweed is also called flea beetle or psyllid. This is a small jumping insect of yellow, brown or green color. Body size up to 2.5-3.5 mm. There are transparent wings and antennae, and a conical abdomen.
Spotworm can cause dark spots to appear
Pests secrete a sugary liquid, which is gradually covered with a waxy film. The stomata become clogged, dark spots form on them, and as a result the foliage dies.
Also, dark spots on the apple tree are formed due to a lack of potassium.Regular supply of this element is especially important during the formation of shoots in the spring and at the flowering stage. Therefore, it is recommended to fertilize the tree with potassium salt or potassium sulfate.
Scab
If the young leaves of an apple tree have brown spots, the cause may also be related to scab. The main symptoms of scab are as follows:
- First, faint yellowish spots appear. Their surface seems to be oily.
- The spots become olive-brown and dark.
- Foliage is affected mainly from the upper side.
- The leaf blades gradually wither and fall off, including in the summer months.
- Young fruits become deformed and grow poorly.
- Cracks with plaque appear on the shoots of the apple tree. It is also dark, like the leaves.
As a result, the tree lags behind in development, productivity decreases, and the apple tree becomes less resistant to adverse weather conditions. The tree is also susceptible to other diseases and pests.
Weather
Brown spots on an apple tree may be due to weather conditions. If it is hot for a long time, some of the leaves get burned when sprayed or watered. As a result, yellow-brown areas of various shapes appear on the surface.
If it is not an infection, they gradually go away without additional intervention, although not always completely without a trace. There is no treatment as such - you just need to carefully water the tree and spray it in cloudy weather, preferably in the late evening or early morning.
Bacterial burn
Fire blight is considered one of the most dangerous diseases of apple trees. The main symptoms are:
- Dark (black or brown) spots on foliage.
- Darkening and falling of flowers.
- Loss of ovaries, few fruits are formed.
- The tips of the branches also begin to turn black.
- Watery spots form on the surface of the shoots.
Signs of a bacterial burn are noticeable upon visual inspection
As a rule, only the leaves of a pear turn completely black, while those of an apple tree turn brown, first at the tips, then to the base. The danger of the disease is that it spreads very quickly, and over time the tree literally withers. It has to be cut down and new seedlings grown.
Brown spot
Brown spots can appear on the leaves of a young apple tree due to brown spot (also called phyllostictosis). This is an infectious disease associated with pathogenic fungi. It manifests itself in the middle and second half of summer. The main symptoms are:
- Small spots.
- The color is brown, gray, with shades of dark.
- There may be a rim around it.
- The shape is angular.
- Diameter up to 5 mm.
- The leaf blade becomes thinner.
- Sometimes dark spots also form on fruits.
This is a dangerous pathology that leads to weakening of the tree, drying out of leaves and reduced yield.
Therefore, it is recommended to carry out regular pruning, especially if the variety is prone to intensive growth of new shoots.
Lack or excess of fertilizers
Dark formations can appear due to a lack or excess of various fertilizers - nitrogen, potassium, phosphorus. The general rule works: it is better to underfeed a little than to overfeed. The composition of fertilizers must be balanced. You can prepare the mixture yourself or purchase it in a store, for example, Factorial, Pospeta and other preparations.
Other
There are other causes of dark spots, such as rust.This is an infectious disease caused by fungal pests. Characteristic signs appear in the second half of summer and September:
- The spots on the leaves are round in shape and orange-yellow in color.
- Brown or dark (almost black) dots form on the surface.
- Very rarely, small warts may appear on the leaf blades, and spotting may appear on the fruits themselves.
Rust also develops mainly in cool and damp weather; its appearance is provoked by heavy rains and violation of watering norms.
Characteristic signs of rust are easy to notice during visual inspection.
How and what to treat brown spots on apple leaves
It is not always possible to cure apple foliage affected by dark spots, since they can affect a significant part of the plate. But it is quite possible to stop the spread, as well as prevent the emergence of new defective areas. To do this, it is necessary to apply fertilizers, as well as treat them against diseases and pests.
Fertilizer application
Often the appearance of dark fragments is associated with potassium deficiency. Therefore, at the stage of flowering, as well as the formation of ovaries, it is necessary to water the tree with a solution of potassium sulfate. Standard consumption: 30-50 g per 10 l per 1 m2. You can give two buckets for one tree, and if the seedling is young (up to 3 years old), 10 liters is enough.
Disease Control
If dark swellings, dots and other signs of damage are detected, be sure to carry out 1-2 treatments using fungicides:
- "Ridomil Gold";
- "Maksim";
- "Fitosporin";
- "Skor";
- “Respect 25%” and others.
Spraying begins in the late evening or early morning, trying to completely cover the leaves and shoots. Moreover, it is necessary to treat not only sick trees, but also healthy ones, in order to prevent the spread of infection.
It is also important to consider that each drug has its own waiting period, i.e. minimum period between the last treatment and harvest. For chemicals, the terms are maximum and can be up to 30 days. For biological agents they are much shorter – up to 10 days. This is important to consider when planning the procedure.
Preparations containing copper
To treat apple trees against scab, rust and other fungal diseases, fungicides containing copper are very helpful. The most commonly used are Bordeaux mixture, HOM, and Abiga-Peak.
Compositions containing sulfur
Sulfur-containing preparations emit sulfur vapors, which enter fungal cells and combine with hydrogen. The resulting hydrogen sulfide disrupts metabolic processes, causing pests to die. The main sulfur-containing fungicides: “Colloidal sulfur”, “Tiovit Jet”, “Cumulus”.
"Tiovit Jet" is one of the best sulfur-containing fungicides
Biological products
Biological preparations are used during the fruiting period, when there is not much time left before harvesting. Among the most effective biofungicides are:
- "Fitosporin";
- "Strekar";
- “Phytolavin. VRK";
- "Abacus Ultra, SE";
- "Bellis, VDG";
- "Piktor, KS" and others.
Preventive measures
Preventing the appearance of apple tree diseases and pests that cause dark spots to form is easier than dealing with the consequences. Experienced gardeners recommend following these rules:
- Do not exceed the watering norm.As a general rule, a young seedling is given 2-3 buckets of water, a 3-5 year old apple tree - 5-8, and older trees - 6-10 liters. Moreover, it is enough to do this 3-4 times per season, taking into account the rains.
- Carry out sanitary and formative pruning regularly. This should be done every spring, before the buds begin to swell, and also in late autumn on the eve of the first frost.
- In the fall, dig up the tree trunk and remove all fallen leaves, branches and other plant debris. They are taken away and burned to destroy insect eggs and fungal spores.
- In early spring, after pruning, preventive treatment with fungicides is carried out, then spraying is repeated one more time - in May. For these purposes, you can use not only chemicals, but also folk remedies.
- Periodically loosen the tree trunk circle. This is especially important to do after watering or heavy rain, otherwise the soil may become compressed and the roots will not receive enough oxygen. It is recommended to do weeding at the same time as loosening.
Conclusion
Brown spots on apple tree leaves are most often associated with care errors and fungal infections, such as rust, scab, and brown spot. Pests are especially active in conditions of high humidity. Excessive watering, as well as failure to comply with preventive measures, can also cause stains to appear. Therefore, it is important to regularly thin out the crown, feed the tree and carry out treatments against diseases and pests.
