Content
Hazelnut or hazel is a popular shrub that can be found in Russian gardens. Despite timely care, often under unfavorable climatic conditions, various hazelnut diseases may appear. Diseases and pests are very similar to those often found on other plants. If you follow preventive measures, you can avoid troubles and reap a rich harvest.
Hazel diseases and treatment methods
The plant is immune to many diseases, but after a cold winter and during the rainy season, fungal, infectious and bacterial diseases can appear. Hazelnut diseases without timely care and treatment can lead to the death of the bush. Therefore, when the first symptoms appear, it is necessary to begin timely treatment.
Bacterial burn
The most dangerous disease of hazelnuts is bacterial burn. The fungal disease damages the entire above-ground part: leaves, shoots, flowers and fruits. The disease appears due to high temperature and humidity. In hot and dry weather, the disease occurs extremely rarely.
The main signs of the disease are numerous black spots.
- When the disease affects a flower, it withers, turns dark brown and falls off.
- Young branches are covered with dark spots, the tips are bent and painted black.
- The leaves take on a charred, drooping appearance and turn brown.
- Affected unripe nuts turn black and remain on the branch until the end of autumn.
- When the disease appears, the bark becomes covered with cracks, and an extensive burn with clear boundaries appears on the trunk.
The disease develops in the spring, when the active growing season begins. The disease on hazelnuts appears with pollen. Carriers are birds, insects, and rainwater. When air temperature and humidity increase by 80% or more, the disease begins to actively progress.
Branches become infected from damaged bark and leaves. The source is unsterile instruments, diseased bushes, fruits and rooting cuttings. A year after infection, a thick, viscous exudate flows from the sores, which is easily carried by the wind, infecting neighboring plantings.
Treatment of the disease is carried out as follows:
- Trimming damaged shoots to healthy tissue.
- Spraying hazelnuts in the bud swelling phase with 3% zinc sulfate.
- Treatment of hazel with copper-containing preparations.
- Autumn fertilizing with potassium fertilizers.
White rot
White rot or sclerotinia is a dangerous fungal disease that leads to rotting of the root system. The main signs of the disease are:
- wilting of the aboveground part;
- the formation of white plaque on the leaf plate, fruits, stem;
- the root system is covered with a snow-white mucus-like mass;
- black sclerotic formations are visible on the cut of the shoot;
- the leaf blade becomes watery and discolored, sometimes covered with a white coating.
The pathogen infects walnut bushes through the soil. The disease affects hazelnuts when the temperature drops sharply and the air humidity is high.
The disease primarily affects walnut wood. It loses its elasticity, acquires a fibrous state and a snow-white color, becomes less durable and breaks easily.
To get rid of the disease, it is necessary to carry out comprehensive treatment. At the initial stage of the disease, damaged shoots are cut back to healthy tissue, and the cut site is treated with potassium permanganate or crushed chalk. Next, the hazelnuts are treated with fungicides, changing them once a season to prevent addiction. If the disease has affected a large part of the bush, it is better to get rid of it so that the disease does not spread throughout the garden.
Brown spot
Brown spot or phyllosticosis is a fungal disease that often affects hazelnuts. The disease spreads through soil and water. The disease quickly spreads from one hazelnut bush to another by wind, insects and birds. It progresses quickly at high humidity and air temperature.
To recognize the disease, you need to carefully examine the nut bush. When infected, dark red spots of irregular shape form on the leaf blade. At the initial stage of the disease, the central part of the spot is much lighter than the periphery. Over time, the outer side of the leaf becomes covered with small swellings.
The disease often affects old, weakened leaves during the fruiting period.The peak of the disease occurs in early July, especially in rainy weather. The massive development of the disease leads to early leaf fall, which significantly reduces the nut yield in the next season.
Since brown spot is a fungal disease, it must be treated with fungicides. These may be purchased drugs, or they may be folk remedies. When using chemicals, treatment is completed a month before hazelnut harvest. When treating the disease with folk remedies, the following are used:
- Spraying the bush and trunk circle with iodine chloride (30 g of potassium chloride, 40 drops of iodine per bucket of water).
- Treatment of the bush with diluted whey.
- Spraying the bush with garlic infusion.
Powdery mildew
Powdery mildew is a fungal disease that affects leaves and young shoots. The affected foliage becomes covered with a white coating, turns yellow, curls and falls off. New leaves appear deformed and weakened. When infected, young shoots do not ripen, do not become woody, and as a result die from the first autumn frosts.
When the first symptoms of the disease appear, it is necessary to begin timely treatment, otherwise the disease will quickly spread to neighboring bushes. Without timely removal of white plaque, photosynthesis fails, which further aggravates the condition of the hazelnut.
Powdery mildew often appears at moderate humidity and high air temperatures. Insects, wind and rainwater are considered carriers of the disease. The fungus overwinters on the affected leaves, so if the fallen leaves are not removed, in the spring powdery mildew attacks the walnut bush with renewed vigor.
When the disease appears, it is necessary to begin treatment immediately:
- Trim all affected shoots back to living tissue.
- Treat the shrub with soda ash and soap or garlic infusion once every 7 days.
- Spray the nut with an antibacterial mixture. Terramycin 100 units, penicillin 100 units, streptomycin 250 units. diluted in warm water in a 1:1 ratio.
- Treating shrubs with slurry gives good results. 1 part of manure is diluted with 3 parts of water and left to infuse for 3 days. The finished solution is diluted 1:3.
Rust
Rust is a common and dangerous disease. The fungus affects the entire above-ground part of the walnut bush. As a result, cold resistance, yield and quality of fruits decrease. When infected, the nut begins to quickly lose moisture, the process of photosynthesis and metabolism deteriorates, and shoot growth sharply decreases. If timely measures are not taken, the hazelnut may die.
The disease can be identified by the outside of the leaf blade. In the initial stage of the disease, small dark brown spots appear on it, which over time spread throughout the entire leaf blade.
If treatment is not started immediately, then in mid-summer large growths appear on the inside of the foliage. With further development of the disease, the foliage dries out and falls off. Untimely leaf fall weakens hazelnuts and reduces cold resistance.
Rust removal is carried out in several ways:
- Spraying hazelnuts with copper and sulfur containing preparations. Treatment is carried out before and during flowering.
- In early spring, the affected shoots are stripped back to healthy wood, followed by treatment with disinfectant solutions.
- Pruning the affected shoots by 5 cm and skeletal branches by 10 cm below the lesion. Pruning is carried out until the sap flows.
- After pruning, the bush is treated with fungicides at intervals of 10-13 days.
Black spot
Black spot or Phomopsis is a dangerous fungal disease that affects the entire above-ground part of the hazel tree. The disease develops intensively in humid weather, affecting the leaves and woody part of the nut.
The disease can be recognized by careful examination of the bush. Woody shoots become discolored and dark spots appear on the bark. If treatment is not started, the fungus penetrates deeply into the wood, forming rotten areas. Over time, hazelnuts stop growing and developing, and infected shoots die off. If the disease affects the foliage, it becomes covered with dark brown spots with a lightened center. Over time, the leaf blade dries out and falls off. Without treatment, the plant refuses to flower and bear fruit.
Black spot is spread by wind, rainwater and insects, through mechanical damage to shoots.
The disease tolerates cold winters well on plant debris. Experienced gardeners have noticed that if fallen leaves are removed in a timely manner, the fungus will not have enough food and will die in 5 days.
To get rid of the disease you need to:
- treat hazelnuts with copper-containing preparations;
- apply herbal solution.
To do this, the mown grass is poured with water in a 1:1 ratio and left to infuse for 1 week. The resulting solution is filtered and the bush is treated after sunset.
Hazelnut pests and their control
Hazelnuts are loved not only by gardeners, but also by pests. Insects feed on shoots, leaves and nuts. The greatest damage is caused by insects that destroy crops. If you do not fight them, they can destroy up to half the crop.
Fruited nut
The fruiting nut or nut weevil is common in all regions of Russia where hazelnuts are grown. This insect easily destroys up to 50% of the crop. The beetle overwinters in the ground and lays larvae in early spring, which hatch at a temperature of + 15 °C. The beetle begins to attack the plant at the end of May, beginning of June.
Insects are located in the crown, where they destroy leaves and young shoots. Females gnaw through unripe fruits and lay eggs in them. The revived larvae feed on the nut, completely eating away the kernel. After destroying the crop, the larvae leave the nut and burrow into the ground.
To get rid of beetles, you need to:
- treat the soil with insecticides in early spring;
- in early May, the crown is treated with acaricides;
- collect and destroy fallen fruits in a timely manner;
- in spring and autumn, the tree trunk circle is loosened;
- early in the morning, a wide cloth is spread around the bush, the bush is shaken, and the fallen beetles are immediately disposed of.
Walnut longhorned beetle
The walnut longhorn beetle is the most dangerous pest that can destroy a bush in a short time. Adult beetles begin flying around orchards from early May to mid-June. In mid-June, the adult lays eggs under the bark of young branches. The larvae appear at the end of June. In the first days, the larvae gnaw through the core of the branches, as a result of which the shoots begin to dry out, the upper leaves turn yellow, curl and crumble.
Without treatment, the larvae hide in the bark for the winter and, when warm days arrive, begin to destroy 3-year-old shoots.
Treatment is carried out immediately after the first signs of the disease are detected:
- dried shoots are removed and burned;
- in mid-June the nut is sprayed with insecticides.
Hickory pipe gun
The hazel beetleworm is a small beetle that feeds on young foliage. It can often be found at the end of May when the leaves are blooming. Females gnaw the leaf plate to half its length, wait for it to dry and roll it into a tube where they lay eggs. The hatched larvae feed on dry leaves and burrow into the soil around the tree trunk for the winter.
The beetle, according to gardeners, does not cause severe damage to the tree. But in order for the plant to look healthy and develop well in early spring, before the buds open, the crown and soil are treated with insecticides.
Aphid
Aphid larvae appear on nuts in late spring. Pests suck the sap from the plant, which leads to slower growth and rapid death. Also, an aphid colony is a good spreader of fungal diseases.
Premature leaf fall reduces the taste of fruits and yield. If left untreated, aphids can quickly spread throughout the garden.
You can get rid of insects in 2 ways: removing them from the foliage or treating the bush with soapy water. In case of mass infection, the nut is treated with insecticides a month before harvest.
Prevention of pests and diseases of hazelnuts
Hazelnut yield depends on timely prevention. To protect the nut from diseases and pests, you must follow simple rules:
- carry out timely watering and fertilizing;
- remove damaged, dried branches;
- in autumn, cut out shoots that thicken the crown;
- in early spring, treat the nut and the soil around the tree trunk with copper-containing preparations;
- When the first signs of disease appear, remove damaged leaves and fruits;
- in the fall, get rid of fallen vegetation;
- destroy adult insects before oviposition begins.
Conclusion
Hazelnut diseases are better prevented than treated. If you follow the rules of care and carry out timely prevention, the nut bush will delight you with a rich harvest of tasty, healthy fruits.
