Diseases and pests of hazelnuts: causes and signs of what to do to combat them

Growing any horticultural crop does not go smoothly. Pathogenic fungi, harmful insects affect plantings of fruit trees as a result of inept care, weather and climatic anomalies. The specificity of hazelnut diseases is such that it is necessary to deal with them, based on the symptoms of the pathology. Some of the diseases are characteristic only for walnut crops, so few summer residents know about them.

Because of what happens

The causes of hazelnut ailments include:

• care the plant incorrectly;
• no growing conditions for crop;
• soils are swampy, saline;
• little light.

During periods of humid and hot summers, the activity of pathogenic fungi increases, hence the high threshold of disease in hazel trees. The inattention of the gardener allows you not to notice white spots on the leaves or yellow, brown. And this is the first sign of a fungal infection. It is easier to deal with a disease detected in a timely manner. Advanced pathological conditions lead to the death of the walnut plantation.

Diseases and pests of hazelnuts

It is typical that the causative agent of the main hazelnut diseases causes infections in other fruit crops. Hazel plantations often suffer from powdery mildew. Aphids can also live on tree leaves. But there are specific diseases that are found only in plantings of walnut crops.

Diseases

Hazel suffers from many fungal infections. Viral diseases are rare for the plant.

Powdery mildew

According to scientists, this disease is more common on crops than various types of spotting. The yellow aphid provokes the development of the disease. Leaving its excrement on the surface of the leaves, it attracts pathogenic fungi to the plant. With further development, powdery mildew grows into whitish spots containing mycelial spores.

They are visible to the naked eye on the surface of the leaves. The main factors provoking the disease are high humidity, temperatures above 28 degrees Celsius.

Conidia, having overwintered in hazel buds, infect plants. Although many varieties of hazelnuts are resistant to the fungus, regular spraying is needed to stop the spread of the pathological process.

Phyllostictosis

The disease caused by the fungus is called yellow-brown leaf spot for a reason. Necrosis of plant tissues is manifested by large spots of irregular shape. A border is visible along their edges, and dark dots form inside. Over time, the affected part of the leaf cracks, falling out. In neglected states, the leaves begin to turn yellow and fall off.

The consequence of infection with phyllostictosis will be the weakening of the shoots, their poor ripening. A sick hazel tree may not survive the winter. To prevent the infection from spreading to neighboring trees, it is necessary to collect and burn the fallen leaves.

Ocher-brown spotting

Leaves on hazelnuts are covered with brown spots. Then they turn white, and black dots are scattered on top, the so-called flattened pycnidia. The consequence of fungal pathology will be drying, falling leaves. But fungi retain their activity in fallen leaves affected by infection.

The development of the disease is favored by rainy warm weather. Pycnidia swell, releasing pycnospores. Winding mucous masses are carried by the wind to neighboring plants. Insects help fungi reproduce.

Red-brown spotting

The spots on the leaves are reddish at first, gradually turning into yellow pillows. They contain spores of a pathogenic microorganism. The result of the action of the fungus is a delay in the growth and development of hazelnut shoots. The shrub is weakening and bearing little fruit.

The disease is more common in the southern areas of hazelnut cultivation. In the gardens of Siberia, the Chernozem region, the fungus rarely spreads, although it can be registered on a hazel tree.

Cylindrosporium spotting

Cylindrosporium fungi cause numerous spots on the surface of the leaves. They are either round or with corners. Spores are collected on the upper side of the leaf with brown pads. In humid-hot weather, the pads burst, allowing the spores to spread to other crops.

Cercospora Spot

The disease is different:

• lots of spots;
• red-brown dots;
• merging spots into one grayish area;
• an inconspicuous bloom of mycelium with spores around the edges.

If the brown dots are 1-3 mm in diameter, then the spot into which they combine can capture the entire surface of the plate.

Black spotting

Another name for Phomopsis disease. It is dangerous because it affects all parts of the plant. Pathology is determined by:

• discoloration of lignified shoots;
• dark spots on the bark;
• the dying off of branches;
• brown spots with a brighter middle on the leaves.

Plaque on the surface of the leaf plate indicates the spread of the disease by spores. From a diseased tree, neighboring ones become infected, as spores are carried by precipitation, wind, and insects. The nut stops developing, blooming, bearing fruit.

Pests

There are also a lot of insects that infect hazelnuts and hazelnuts. Some of the pests parasitize, feeding on the juices of the leaves, others regale on the delicious fruits of the tree, their pulp.

Birch pillowcase

The pest belongs to small-sucking insects. It has a convex body up to 8 millimeters long and 3-4 mm wide. Adult insects are immobile, but their offspring, larvae, cause great harm to the hazel. They feed on the juice of the hazelnut bark. Wintering under it, in the spring they continue to harm the nut. In females, a mealy egg sac is formed up to 1 centimeter in size, outwardly similar to a pillow. In the middle of summer, the female lays up to 600 eggs in it. They are less than 1 mm in size, red.

The pest is most often found in the European part of Russia, in southern Siberia, in the Far East.

Green garden bug

Every summer resident met with a garden bug. Very mobile insect with a green shiny body and leathery front wings. The bug belongs to sucking pests. The larvae are similar in appearance to adults, but light brown in color. They affect all parts of the plants of the garden and vegetable garden. Due to the action of adult insects and larvae, hazelnut leaves become wrinkled, turn yellow, and inflorescences fall off.

Hazel weevil

You can recognize the pest by its long proboscis. The black bug has a body 6-8 millimeters long, and a nose - 4. Yellow-gray scales give the insect a light shade. For wintering, weevil larvae burrow into the ground, where they pupate. In the spring, the beetles find their food on the hazel. And the female lays her eggs in the pulp of the set nuts. Parasites live there, eating the inside of hazelnut fruits. The larvae live for 25 days.

Resistant varieties of hazelnuts to the weevil have not been bred, so the pest has to be fought everywhere.

Halnut tube runner

A beetle 6-7 millimeters long is distinguished by a black body, a red back. The structure of the insect's head is interesting: it is elongated by a tube with an expansion at the top, as if constricted from the sides. The white thick larvae of the tubeworm are inactive, they feed on the green parts of the plant. The eggs are laid by the female in a rolled hazel leaf. The leaves begin to dry and fall off.

Halnut barbel

One of the dangerous pests that can destroy walnut plantations begins its activity in early May. Making a flight around its possessions, an insect with long black antennae lays its eggs under the hazelnut bark. Already in June, the appeared larvae begin to gnaw on the branches of the bush. The shoots dry up, and the foliage turns yellow and falls off. You can identify the pest by twisting the foliage in the upper parts of the shrub. Although the root remains alive, the plant cannot be reborn.

After wintering, the larvae infect 2-3-year-old shoots. Gnawing through the branches, they lead to the drying out of most of the shoot.

Alder leaf beetle

This bug is dangerous for industrial hazelnut plantations. You can identify it by the black paws and antennae, the elytra of a purple tint. In April, beetles appear on hazelnuts when they wake up after wintering. Hazel leaves are attacked by the parasite, which it eats with lightning speed. The larvae are born from eggs laid on the plant. Their life span is 25 days.

Northern birch sawfly

Hymenoptera larvae hatch from eggs laid on the underside of a leaf. False caterpillars of a dirty green color are so voracious that they can completely eat the whole hazel. Moreover, they appear twice during the summer: in May and from July to September.

An adult insect with a shiny black body and transparent wings feeds mainly on birch leaves. You can see sawflies at the beginning of summer when they fly around the garden. Females incise the underside of the leaf and lay 1 egg in them. Caterpillars pupate in the ground where they hibernate.

Hazel moth

If a small butterfly with narrow silvery wings flies around a tree, then this is a moth. Its larvae harm hazel leaves, biting into the thickness of the leaf. Eating out a significant mine visible from the bottom of the leaf, the larva moves to the top. In this case, the leaves become marble-spotted color. Larvae live in mines, turn into pupae, being in this stage for only 8-9 days. In July-August, a butterfly flies out of a fragile cocoon.

Moth-baby hazel serpentine

A butterfly with beautiful fringed hind wings is not itself dangerous.But its larvae, having appeared on hazelnut leaves, make passages inside plant tissues that look like a snake's track. From this picture, decorated with parasite excrement, the pest can be identified. After 3 weeks, the caterpillar gets out of the leaf, falling to the ground. She pupates and overwinters safely in the ground until spring.

Moth hazel pocket

Distinguish small, a little more than 1 centimeter, silver butterfly wings and a fringe behind them. The larvae hide in curled leaves like pockets, feeding on their juices. They fasten parts of the shelter with sticky cobwebs. Inside the leaf, tissues that are skeletonized are eaten away. During the period of its development, the caterpillar makes up to 4-5 pockets. In dry and hot summers, moths cause significant damage to hazel.

Insect and disease control methods

Walnut plantation pest control needs time to save the crop:

1. As soon as the hazel leaves begin to bloom, they are sprayed with Fufanon or Kemifos preparations.
2. Suitable for the destruction of pests "Karbofos", "Fozalon".
3. Processing is carried out twice more of those trees on which pests are found.
4. Rolled leaves are harvested by hand.
5. Shake off the weevils, bugs on the ground, pre-laying a sheet of cellophane or non-woven material. Then they are destroyed.
6. It is necessary to burn plant residues in autumn, as well as to dig up the soil in order to destroy the pupae and larvae of parasites.
7. Pruned after the snow melts shrunken branches 10-15 centimeters below the drying level.
8. Continue pruning in July-August, capturing 2-3 he althy leaves.
9. In the spring, before the release of insects, it is necessary to till the soil with 10% Bazudin, planting the granules into the ground.

The way to deal with hazelnut diseases is the same: the treatment of affected plants with fungicides. In the spring, when the buds swell, they are sprayed with Bordeaux liquid with a concentration of 1%. Walnut bushes damaged by fungi can be treated with Abiga-Peak three times.

To combat many fungal infections, preparations containing copper are used. From folk remedies, the use of herbal infusion is effective. To prepare it, take dry grass, pour warm water in a ratio of 1: 1. It is necessary to keep the solution for a week, then it is filtered and walnut bushes are sprayed with it. Best done in the evening.

If hazelnuts drop fruits, then you need to collect them and destroy them. They are damaged by pests that can kill all trees. Of the methods of combating diseases, loosening of the soil between rows in spring and autumn can be distinguished.Digging the site will save you from diseases and pests.

Prevention measures

It is easier to prevent diseases than to find a way to get rid of them later. Prevention activities include:

• carrying out timely watering and feeding of hazel, hazelnuts;
• removal of damaged shoots;
• cutting branches that thicken the crown of a hazel tree;
• regular inspection of plants;
• protecting them from frost, heat, high humidity;
• digging the soil in spring and autumn.

The walnut plantation can only be saved by competent agrotechnical measures. To ensure the he alth of hazelnut plantings, do not plant birch or alder nearby. The pests of these trees can move to the hazel and destroy it. If the infection has occurred, then it is necessary to get rid of the plant where the pests settled, as from the source of the disease.Or you can pick up another place for the hazel on the site.

Recommended