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Chestnut is a very beautiful majestic tree that will decorate any summer cottage. However, many plant growers are stopped from buying seedlings by the well-known chestnut disease - rust, which disfigures the curly leaves with scatterings of unpleasant brown spots. But you should not give up the decision to plant a plant on your estate, because this and other diseases of this crop are quite treatable.
Chestnut diseases and their treatment
Although chestnut is considered a rather unpretentious plant, its cultivation is associated with various diseases that affect different parts of the tree. Most often, the leaves serve as an indicator of chestnut health, since the symptoms of the disease appear first on them. If the leaf blades turn yellow in the middle of summer, curl or acquire an unhealthy color, it means that the chestnut is affected by a certain disease.
Rust
Of all the chestnut diseases, rust or spotting can be called the most common ailment.It not only spoils the aesthetic appearance of the plant, but also poses a serious threat to the health of the chestnut, often causing developmental anomalies and even the death of the tree. There are several types of the disease:
- rust holey;
- black rust;
- brown rust;
- rust is red-brown.
Each type of rust has its own symptoms and causes. Accordingly, methods of combating these chestnut diseases also differ.
Rust is black.
A characteristic feature of this disease is that the chestnut leaves begin to quickly turn black and soon fall off. In the long term, rust causes various disturbances in the development of the plant, and it gradually weakens. Flowers on chestnut appear much later and in much smaller quantities. Some flowers do not open at all or fly away after just a few hours. Flowering itself becomes shorter-term and scarcer.
There are 2 causes of this disease:
- excess moisture due to frequent watering or heavy rainfall;
- lack of sufficient potassium in the soil.
Based on the existing reasons, choose the appropriate method of treating chestnut for black rust.
In the first case, it is necessary to reduce the number of waterings of the chestnut and water the plant as the earthen clod dries out. In regions where summers are often humid, watering can be done even less often or not at all - the chestnut tree will have enough water received from precipitation.
The second case requires adding mineral fertilizer to the soil.As a rule, a lack of potassium in the soil can be avoided if you regularly fertilize the soil: in the fall - nitroammophos at the rate of 15 g per 10 liters of water, in the spring - 1 kg of mullein and 15 g of urea per the same amount of water.
Red-brown rust
As the name suggests, this disease causes reddish-brown spots to appear on chestnut leaves. Most often, rust makes itself felt at the end of July or in August. If you do not interfere with the development of the disease, very soon the rust spots will grow and cover the chestnut leaves almost completely.
A large amount of moisture can provoke red-brown rust, so you should pay close attention to the watering regime of the chestnut tree.
The occurrence of disease on a plant can also be affected by sudden temperature changes. If the plant grows in regions with an unstable climate, care should be taken to insulate the chestnut tree trunk, especially in autumn. This can be done using mulch, such as wood chips, peat or a mixture of peat and compost. Such a measure will not only protect the roots of the plant from freezing, but will also serve as an additional fertilizer for the chestnut.
Brown rust
Based on the symptoms, this disease is very similar to red-brown rust, and therefore even experienced plant growers often confuse these 2 types of chestnut disease. Brown rust also appears closer to the middle of the summer season, however, in the first days of the disease, brown formations affect not only the front, but also the back side of the plant leaf.
Brown rust can occur for the same reasons as the red-brown variety of the disease, namely due to excessive watering or sudden temperature changes.In addition to mulch, you can soften the impact of the latter by making a shelter of wood stakes and cling film around the chestnut trunk.
Rust control measures
In addition to using the measures described above, rust, regardless of type, can be cured in the following ways:
- With the onset of spring, you should spray the chestnut crown with a weak solution of Bordeaux mixture once every 10 days. This must be done regularly until the beginning of the flowering period. As soon as the chestnut finishes blooming, it should be treated again with the composition or its substitutes - Azophos or Bayleton.
- If the rust has developed too much, from the beginning of the plant’s budding period until the end of its flowering, the chestnut is treated with Bordeaux mixture - once with an interval of 30 days during the season. To consolidate the effect obtained, the crown of the plant is sprayed with a 5% urea solution for the winter, observing a dosage of 5 g of the composition per 1 liter of water. The soil around the chestnut is treated with a 7% solution, using 7 g of the substance per 1 liter of water.
Powdery mildew
In addition to rust, another disease that affects chestnut is powdery mildew. This disease is caused by a special type of fungus. As soon as optimal conditions of temperature and humidity arise for this, it begins to actively reproduce. Also, its development can be caused by an imbalance of nitrogen and potassium fertilizers in the soil. As a result of the lesion, a characteristic gray-white coating forms on the leaves of the plant. In addition, dark brown spherical formations can be observed on chestnut leaf blades - these are fungal spores. Without treatment for a long time, the leaves of the plant eventually turn brown and die.
Powdery mildew is infectious in nature; chestnut can become infected with this disease through air and water or through contact with infected plants. Therefore, if a disease is detected in one plant, you should immediately isolate it from healthy chestnuts and begin urgent treatment.
First of all, you need to remove all damaged leaves from the infected plant and burn them. If the cause of the appearance of fungus lies in a lack of minerals, their reserves should be replenished with potassium-phosphorus fertilizer. It will be useful to treat chestnut with various fungicides such as Fitosporin-M, Topsin, Fundazol or Skor. Fans of environmentally friendly preparations are recommended to use a composition based on wood ash:
- 500 g of ash is poured into 1 liter of water and left for 48 hours.
- A mixture of 5 g of laundry soap and water is added to the solution.
- The resulting composition is treated with the chestnut trunk, branches and leaves 2 times with an interval of 1 week.
Along with this remedy, experienced plant growers advise treating chestnuts with an infusion of weeds and water in a 1:2 ratio.
Necrosis
Chestnuts often undergo various forms of necrosis:
- stem;
- Phomopsis;
- septomyx;
- Cryphonectria.
The symptoms of these diseases are largely similar. All three forms of necrosis imply the gradual death of the chestnut bark: it begins to crack and become covered with black or brown seals with a diameter of 2 - 3 mm, which can be seen with the naked eye. In the case of stem necrosis, the seals may also be pale pink. Septomyx necrosis of the plant can be recognized by the way the bark takes on a gray-white hue.
Although such a disease is not dangerous for adult chestnuts, it greatly harms the decorative appearance of the plant. Young trees can die if the disease is ignored for a long time.
To get rid of the disease, you first need to thoroughly clean the affected area of the trunk with a well-sharpened garden knife. Then the infected area is treated with bactericidal preparations and covered with garden pitch. It will also be useful to spray the chestnut with Bordeaux mixture or antifungal medications.
Chestnut pests and their control
In addition to diseases, improper care of chestnuts can provoke the appearance of pests. Among them, plant growers rightly consider the mining moth to be the most dangerous.
Mining moth
The leaf miner, or chestnut moth, resembles a butterfly and reaches a length of 4 mm. The first mention of this pest dates back to the 80s of the last century, but today it is not known for certain where it came from. In recent years, this seemingly harmless insect, causing damage to millions of plants, has become a real punishment for gardeners around the world. The fact is that the chestnut moth lays eggs on chestnut leaves. As soon as the caterpillars hatch from the eggs, they begin to eat the leaf blade from the inside, gnawing tunnels in it. This damages the structure of the leaves, causing them to wither and quickly fall off. The situation is further complicated by the fact that the leafminer moth is very prolific and is capable of producing hundreds of larvae several times a season. In addition, it is unpretentious to conditions, which allows it to expand its habitat from year to year and cause damage to more and more farms.
At the moment there is no way to get rid of this pest once and for all.Researchers are looking for drugs against it, but the only option available now is internal injections. Despite their high price, such injections are very effective, and often even single sessions lead to the recovery of the plant.
However, this method of treatment has a significant drawback - the drug for administration is very toxic not only to moths, but also to the environment as a whole. Therefore, when choosing a medicine for injection, you should give preference to compounds of the 1st and 2nd classes, because they do not have such a harsh impact on the environment. It is strictly not recommended to use injections in populated areas.
As an alternative, you can use hormonal agents, for example, Insegar. This composition should be sprayed on chestnut leaves before the moth has time to lay eggs on them.
Chafer
May beetles are classified as root pests, although in reality the root system of chestnut trees is attacked by the larvae of these insects. Adults feed mainly on the leaves of the plant. May beetles do not pose such a large-scale danger as the chestnut moth, but they can significantly weaken the plant.
These pests can be controlled with the help of chemical insecticides and folk remedies. Thus, a week-long infusion of onion in water in a 1:2 ratio has proven itself to be effective. It is diluted half and half with water and watered around the trunk of the chestnut tree instead of ordinary water.
Shchitovka
Scale insects are a representative of sucking pests that feed on the sap of leaves and shoots. The size of the scale insect is very small - about 5 mm. It has a strong wax shield on its body, from which it gets its name. Young individuals of this pest are born without it. The layer is formed after the insects attach themselves to the leaf and begin to eat intensively.
In addition to insecticides such as Fitoverm and Metaphos, you can control these pests by using an infusion of onions, garlic and pepper or a weak vinegar solution. A powdered preparation against Colorado potato beetles, diluted with water, is also suitable.
Elm leaf beetle
The elm leaf beetle is one of the many species of the genus of leaf beetles. This insect has two wings with hard elytra and a bright yellow color with black longitudinal stripes. The pest feeds on chestnut leaves, and mature individuals gnaw holes in them, and the larvae eat the entire leaf blade, leaving only the skeleton.
As a rule, leaf beetles are sensitive to any insecticides, so periodic treatment of chestnut will soon help rid the plant of the problem. Spraying it with infusions of tomato tops or chamomile will not harm it.
Mealybugs
Mealybugs are also classified as sucking insects, since they, like scale insects, feed on leaf juices. These small pests are white or light pink in color and have transverse stripes on the surface of the body.During their life, they secrete a slimy substance that glues insect eggs to the leaf plate. Because of scale insects, the leaves and other parts of the chestnut grow much slower and quickly turn yellow, and the mucus of the pests serves as a breeding ground for dangerous fungi.
Good means of combating scale insects are chemicals - Actellik, Aktara and others. Connoisseurs of folk compositions use garlic infusion.
Prevention of chestnut diseases and pests
Prevention has been and remains the best remedy for chestnut diseases and pests. Proper care and timely actions will help prevent illness and facilitate further treatment of the plant:
- You should regularly inspect the chestnut, noting the slightest changes in its condition.
- It is necessary to prune on time and get rid of dry and damaged branches of the plant.
- Wounds and splits that appear on the bark of the plant must be immediately examined and treated.
- It is necessary to follow the recommendations for feeding and watering chestnut trees.
- It is strictly not recommended to use leaves of even a healthy plant for mulching, as they may contain pathogens. Fallen chestnut leaves should be burned immediately.
Conclusion
Although the most common disease of chestnut is rust, there are many other diseases and pests that affect this plant. To get rid of some of them, you will need to make significant efforts, so it is important not to bring the chestnut to a deplorable state, but to recognize the threat in time and eliminate it.
