Ukraine is one of the largest producers and exporters of nuts. According to the Center for Industrial Growing, the annual walnut harvest in the country is 75-85 thousand tons (according to some sources - up to 100 thousand), approximately two-thirds of this amount is exported to other countries. The current needs of the Ukrainian population for nuts are satisfied only by 40%. One of the priorities is environmentally friendly cultivation. It is believed that nuts can be grown as organic culture, that is, without the use of protective equipment and fertilizers. But the realities of life dictate their conditions. Now in different countries More than 100 walnut pests have been registered worldwide.
Walnut is one of the most unpretentious plants in terms of soil conditions and agricultural technology. It is grown on carbonate soils, constantly loosening and fertilizing the surface. Young trees suffer from frost, so they need to be earthed up for the winter. With proper care, nuts grow quite quickly, giving 1-1.5 m of growth per year. Walnut trees mercilessly exploit the soil: level groundwater underneath them it drops sharply, the soil turns to stone, even grasses cannot withstand such proximity. The leaves of the walnut contain a toxic substance - juglandin. Rain washes it out of fallen leaves into the soil and suppresses the development of other plants.
In the south of Ukraine, in a region of potential industrial cultivation, walnut leaves, branches, fruits and trunks damage and affect about 50 types of walnut diseases and pests.
Nut gall mite- a pest that damages only walnut plantings. Distributed in the right-bank regions of the Forest-steppe and Steppe, in Podolia. Low numbers are still observed in Polesie and Central Ukraine.
By feeding on leaves, mites cause profound pathological changes. Young and medieval trees suffer the most: leaves fall prematurely, their general depression is observed, productivity decreases in subsequent years, and the decorative appearance of the trees deteriorates. Some experts believe that the nut gall mite is a carrier of bacterial diseases, including bacterial nut spot. It is quite difficult to fight this walnut pest, because in places of damage it forms galls - large round swellings, the leaves below are covered with thick yellowish felt. In this felt covering (erenium), the ticks are well protected - even most acaricidal drugs do not have a pronounced systemic effect. The optimal period for control is May - early June, that is, the period when migration and reproduction of ticks occurs in galls.
Apple codling moth(Laspeyresia pomonella L., series Lepidoptera, family Tortricidae) is a polyphagous pest. Distributed everywhere in Ukraine, it damages apple, pear, quince, apricot, plum, hawthorn, chestnut, and the form L. putaminana Strg - walnut fruits.
In the conditions of southern Ukraine, the pest develops in two generations: the first in May - June, and the second in July - September. The first generation caterpillars appear in early June and damage young fruits, causing them to fall off. One caterpillar can spoil up to 10 fruits.
The codling moth butterfly is dark gray in color with dark transverse stripes and a large oval yellow-brown spot, with a golden-copper sheen at the top of the wing, wingspan - 18-20, body length - about 10 mm. Butterflies fly in May - June, in the evening twilight and at night, and during the day they sit motionless on the branches and trunk, merging in color with the bark. When the night air temperature exceeds 15 °C, butterflies begin to lay eggs, placing them one at a time on the smooth surface of leaves or fruits. One female is capable of laying from 40 to 220 eggs.
The eggs are round, flat, whitish-transparent, with a diameter of 0.9-1.3 mm. The embryonic development of the egg, depending on the temperature, lasts up to 10 days. The revived caterpillars are whitish-pink, about 2 mm long, with a dark head. As they feed, which lasts up to 38 days, and grow, the caterpillars become intensely pink. After feeding, they pupate in places where branches branch, under the bark, at the root collar, under clods of earth, in weeds. The second generation butterflies appear in July, and the caterpillars are reborn within eight to ten days of the butterflies' flight.
The most harmful pests of walnuts are second-generation caterpillars, which are reborn during August. Penetrating inside the walnut through the base of the fruit, they eat away its kernel. Some of the damaged fruits may fall off prematurely, and those that remain on the trees lose their marketability. The walnut pest overwinters in the pupal phase in the cocoon web under the bark and in the soil.
To protect the crop from the codling moth, it is necessary to constantly carry out phytosanitary monitoring of the walnut pest using pheromone traps. Because butterflies fly high, traps should be placed at the top of the canopy. In small plantings, traps are hung at the rate of 1 piece/100 m2, in large areas - 1 piece/2 ha. Traps are checked every three days. When catching more than five butterflies per week, it is recommended to treat with pesticides after 7-14 days (they are used during the rebirth of the caterpillars, before they have time to get into the fruit). If the number of butterflies caught in a trap is less than the harmful threshold, the use of pesticides is not advisable.
One of the ways to regulate the number of codling moths in small gardens walnut - mass capture of males using pheromone traps. To catch butterflies you need to use one trap per mature tree or two or three young ones. As the adhesive pad in the trap becomes full, it is either cleaned or replaced. It should be borne in mind that positive results can be expected by carrying out mass catching of butterflies for several years in a row. In any case, the use of pheromone traps will ensure the destruction of some males and thereby significantly weaken the pest population. When some plantings are infested with codling moth, food traps (fermented sweet solutions of syrups, jams, kvass) and fishing belts are used, and the mandatory collection and destruction of carrion is also carried out. By the beginning of butterfly summer (around April), you should carefully examine the tree bark and its crevices, especially in the lower part of the trunk, and destroy overwintering cocoons with pupae.
Chemical protection of walnut plantations from the pest is very problematic. This is explained by the fact that the fruits of the nut contain oils in which organophosphorus and some other insecticides can dissolve and remain suspended. As an option, trees are protected with biological products based on avermectins produced by Streptomices avermitilis, Pseudomonas aureofaciens and Bacillus thuringiensis.
Unfortunately, there are no pesticides yet approved to protect walnut plants from pests. Therefore, business owners should make a lot of effort to prevent the infestation of walnuts by pests, using the agrotechnical and mechanical protection measures given above. To destroy pests that have grown en masse in plantations, we recommend using chemicals, in particular from the groups lambda-cyhalothrin, thiamethoxam, thiacloprids, chlorantraniliproles, approved for the protection of fruit crops. Despite the fact that the standards and methods of processing these drugs may differ depending on the manufacturer, you should follow the appropriate instructions.
In 2015 at walnut trees The American white butterfly (Hyphantria cunea Dr., order Lepidoptera, Ursa family (Arctidae)) developed quite actively, which is classified as an object of internal quarantine.
The American white moth (ABM) is a polyphagous pest that damages (according to various sources) 250-300 plant species. Most often these are fruit trees, walnuts, elderberries, hops, and grapes.
The pest develops in two generations. Pupae overwinter under loose bark of trees, in branches and crevices, plant debris, and other protected places. Under natural conditions, they can withstand frosts down to -30 °C, but are very sensitive to sudden temperature changes in the spring.
Butterflies fly out at the end of April - the first ten days of May and lead a twilight lifestyle. At this stage, the pest is snow-white, with a wingspan of 25-35 mm, in some specimens even up to 40-50 mm, and a body length of 9-15 mm. Feeds on nectar flowering plants and does no harm. Females lay eggs in groups of 200-350 eggs, mainly on the underside of leaves. One female can lay up to 1500 eggs. The eggs laid are spherical, smooth, bluish or yellowish, with a diameter of 0.5-0.6 mm. The revival of caterpillars occurs after 14-25 days. Younger caterpillars are greenish-yellow in color; with age, they become brownish in color with black warts on the back and orange warts on the sides. The pectoral shield and abdominal legs are black.
In 2015, the American white butterfly (Hyphantria cunea Dr., series Lepidoptera, Ursa family (Arctidae)), which belongs to the objects of internal quarantine, quite actively developed on walnut trees.
American White Butterfly (ABM) is a polyphagous pest that damages (according to various sources) 250-300 plant species. Most often these are fruit trees, walnuts, elderberries, hops, and grapes.
The high harmfulness of ABM lies in the ability of the caterpillars to completely eat leaves on plants, which they envelop in cobwebs, forming nests. Due to damage leaf surface The photosynthetic activity of plants decreases, metabolic processes are disrupted, which, in turn, affects productivity, winter hardiness, protective functions and often causes the death of plantings.
This walnut pest develops in two generations. Pupae overwinter under loose bark of trees, in branches and crevices, plant debris, and other protected places. Under natural conditions, they can withstand frosts down to -30 ° C, but are very sensitive to sudden temperature changes in the spring.
Butterflies fly out at the end of April - the first ten days of May and lead a twilight lifestyle. At this stage, the walnut pest is snow-white, with a wingspan of 25-35 mm, in some specimens even up to 40-50 mm, and a body length of 9-15 mm. It feeds on the nectar of flowering plants and does no harm. Females lay eggs in groups of 200-350 eggs, mainly on the underside of leaves. One female can lay up to 1500 eggs. The eggs laid are spherical, smooth, bluish or yellowish, with a diameter of 0.5-0.6 mm. The revival of caterpillars occurs after 14-25 days. Younger caterpillars are greenish-yellow in color; with age they become brownish in color with black warts on the back and orange warts on the sides. The pectoral shield and abdominal legs are black.
After finishing feeding, the caterpillars pupate. The pupa is lemon yellow, becomes dark brown over time, 8-15 mm long, located in a loose, dirty gray cocoon. The pupal stage lasts up to 20 days. In July, butterflies of the second generation appear, which are highly fertile - the female lays up to 2500 eggs. Having finished feeding, the caterpillars of this generation pupate in September - October and hibernate at this stage.
Plant protection system - quarantine, agrotechnical, chemical and biological measures aimed at limiting the number of the pest and preventing its spread throughout the country.
Quarantine measures include: introduction of quarantine in areas where the pest is found; constant inspection of plantings and its destruction in areas of detection. Agrotechnical measures include:
- thinning the crown and removing, cutting and destroying branches with caterpillar nests;
- cultivation of row spacing to control weeds;
Fertilizing plantings.
Chemical and biological control measures against the American white butterfly are used, if necessary, against each generation of the pest during the development of younger caterpillars. As a rule, chemical treatment is used to destroy first-generation caterpillars. Remedies against second-generation caterpillars are selected depending on the intensity of development and number of the pest, according to the “List of pesticides and agrochemicals approved for use in Ukraine.” To prevent the spread of the pest in walnut plantations, high-quality protective measures should be carried out on other neighboring fruit crops.
Since the agrobiocenosis of walnut plantations always has a certain supply of harmful organisms - pathogens and pests, to control their numbers and preserve trees, a mandatory measure is to conduct phytosanitary monitoring and a combination of various protection methods - agrotechnical, biological and chemical.
M. Konstantinova, Ph.D. agricultural sciences, consultant
Citation information
Dangerous pests of walnuts in the south of Ukraine / M. Konstantinova // Proposition. - 2017. - No. 2. - P. 156-158
Hazel or hazel (Corylus) is a representative of the Birch family. This genus is represented by deciduous trees and shrubs. It unites approximately 20 species. In nature they are found in North America and Eurasia. At the same time, in coniferous-deciduous forests they form undergrowth. The most popular type among gardeners is hazelnut or common hazel. The following cultivated species are often called hazelnuts: large hazel, Pontic hazel and common hazel. The hollow is one of the oldest cultivated plants Europe. For many centuries, hazel has been cultivated in Spain, France, Great Britain, Turkey, Italy and Germany. Hazel fruits appeared on the territory of Russia in 1773 in the process of exchange for velvet and leather. The word hazel comes from “leska”, which means hazelnut.
Hazel is represented by shrubs and trees. The height of the plant can reach up to 7 meters. Its crown shape is ovoid or spherical, with a cone-shaped top. Large sheet plates round or wide oval in shape and have a jagged edge. The flowers are monoecious as well as unisexual. Thus, male flowers begin to form in autumn time and form fluffy cylindrical earrings on short branches. They are revealed in spring time even before the leaf blades appear. Hazel blooms on last days March or the first - April. During it, a lot of pollen is formed; it is considered the main food for bees after a long winter. During flowering, the plant is decorated with golden earrings and flowers. The fruit is a not very large (approximately 20 mm in diameter) single-seeded nut, brown-yellow in color and spherical in shape. It is surrounded by a plus (tubular incised cover), as well as a woody pericarp. Fruit ripening is observed in August.
This culture prefers to grow in regions with subtropical and temperate climates. Hazel plantations are located in the southern part of Europe, Turkey, Azerbaijan, Ukraine, Cyprus, Georgia, Belarus, and also central Russia. However, in private gardens this crop is much less common than sea buckthorn, hawthorn, bird cherry, rose hip, actinidia, etc.
Hazel in open ground can be planted in the spring, before sap flow begins, and also in the fall - 15–20 days before the onset of persistent frosts. However, it should be noted that it is better to plant in the autumn.
When searching for a suitable area for planting, please note that it must be protected from drafts and be moderately lit. As for groundwater, it should lie no higher than 150 cm from the surface of the site. A location located in close proximity to the southern or western wall of the building is ideal. Those places where there is an accumulation of melt water in the spring are not suitable for planting. You also need to take into account that between the nearest big tree and seedlings, the distance should be from 4 to 5 meters, since the optimal feeding area for this plant is 16–25 m2. It must be remembered that the soil on the site should not be heavy, poor, loamy or swampy. Loose and light soil rich in humus is best suited for planting this crop, but it should be slightly acidic or neutral.
If you plan to plant several hazels at once, it is recommended to deeply dig up the entire area before this procedure.
The selected seedling should not have foliage. It should have 3 or 4 powerful stems, reaching at least 10–15 mm in diameter. At the same time, its root system should be very well developed. The roots should reach at least half a meter in length, but immediately before planting they are shortened to 0.25 m. When planting several specimens, the distance between them in a row should be from 4 to 5 meters, with a row spacing of about 6 meters. The preparation of pits for planting should be started 4 weeks before the planting day, during which time the soil in them will be compacted and settle well. If the soil on the site is saturated nutrients, then the width and depth of the pit should be only 0.5 m. If it is poor, then the width and depth of the pit should be increased to 0.8 m. Before planting, the pit should be filled with a nutritious soil mixture: soil from the top fertile layer should be combined with 2 Art. wood ash or 200 grams of superphosphate and 15 kilograms of rotted manure. It will be very good if you add a few handfuls of soil taken from under the hazel tree.
In the middle of the pit, a mound should be formed on which the seedling is installed. Before planting hazel, do not forget to lower its root system into a clay and manure mash. It should be noted that after planting, the root collar of the plant should rise 50 mm above the surface of the site. The pit must be filled, after which the surface of the tree trunk is well compacted. You need to install a stake near the seedling and tie it up. The planted plant needs abundant watering, and 30–40 liters of water are poured under 1 bush, even if the planting was done in moist soil. After the liquid is completely absorbed into the soil, the surface of the tree trunk circle should be covered with a layer of mulch (humus, sawdust or peat), and its thickness should be 30–50 mm.
In the spring, the hollow is planted in the same way as in the fall. However, in this case, it is recommended to prepare the pit for planting in the autumn, so that during the winter the soil can be well compacted and saturated with moisture.
In order for the hazel to be accurately pollinated, experts advise planting at least 3 specimens on the site, and it is better if they are all different varieties. Also, do not forget to pour a few handfuls of soil from under the hazel into the pit when planting the plant, since it contains fungi that are very favorable for this crop. At first, it is recommended to protect the seedlings from the direct rays of the spring sun by shading them.
There is nothing difficult about growing hazel. And to make your task as easy as possible, trunk circle It is recommended to sow lupine, mustard or oats with vetch. When such grass is mowed, it will create an excellent mulch layer. Also, if desired, the soil in the tree trunk circle can be kept under black steam; in this case, it must be periodically loosened to a depth of 40 to 70 mm, removing all weeds. In addition, you will need to systematically remove root shoots, it should be taken into account that it is much easier to get rid of the offspring while they are still quite weak. To do this, the shoot should be dug up and cut off where it grows from the root of the tree. The cut areas should be sprinkled with crushed charcoal.
Holly grown in the garden needs timely watering. Seedlings planted in open ground should begin to be watered just 7 days after this. If the plant lacks water, this will have an extremely negative impact on the formation of flower buds, as well as on the ripening of fruits. During the growing season, the plant will need 5 or 6 waterings, and 60–80 liters of water should be poured under an adult tree at a time. If in summer time drought is observed, the amount of watering should be increased, since this plant is moisture-loving. But if the summer turns out to be rainy, then you won’t have to water the hazel tree at all. On average, watering is done once every 4 weeks. You should pour water under the tree in parts, because it should have time to be absorbed, and not stand in a puddle for hours. It is recommended to loosen the soil surface around the plant the next time after watering or rain.
Hazel growing in the garden needs timely feeding. In autumn, the tree needs phosphorus and potassium; for this, 20 to 30 grams of potassium salt, 3–4 kilograms of manure and 50 grams of superphosphate should be added to the tree trunk once every 2 or 3 years. In spring, such a crop needs nitrogen, so after the buds swell, 20 to 30 grams of urea or ammonium nitrate should be added to the soil under the tree. The hollow also needs nitrogen in July, at which time it is needed so that fruit ripening occurs simultaneously. It is recommended to feed young trees organic fertilizers(rotted manure or compost). This fertilizing should be done once every 2 or 3 years, and 10 kilograms of organic matter should be added per tree.
If the plant develops normally, it will definitely bloom. Flowering begins in April, with flowers blooming before the foliage opens. After the air outside warms up to 12 degrees, hazel catkins begin to actively grow, with their length increasing by 30 mm every 24 hours. It should also be noted that the drier the air, the faster the catkins will grow. After their length is 10 centimeters, they become loose and pollen begins to be scattered. The duration of this dusting is 4–12 days. Female flowers remain open for 14 days. Pollen from male flowers falls on female flowers, and it can come not only from its own tree, but also from a nearby tree. This is precisely why the recommendation is that at least 3 hazel trees should grow on the site.
There are several ways to propagate the hollow: layering, grafting, dividing the bush, seeds, suckers and cuttings. The generative propagation method is mainly used by breeders to obtain new varieties that will be adapted to certain climatic conditions. But amateur gardeners, as a rule, do not grow hazel from seeds, because it takes a very long time, and only 1 seedling out of 1 thousand grown can retain the varietal characteristics of the parent plant.
Using generative methods of propagation, it is possible to completely preserve the varietal characteristics of a plant. To propagate hazel, horizontal layering is used. To do this, at the beginning of spring or in late autumn, you need to select annual branches that should be low-growing. Shallow grooves are made under them (depth from 10 to 15 centimeters) into which these branches are placed. They need to be fixed and the upper part remaining above the ground slightly shortened. Do not fill furrows with soil. Over time, vertical shoots will grow from the buds located on the branches. All leaf plates must be removed from the lower part of the grown shoots, and they will also require several hillings to the middle. Over time, the shoots will form their own roots and can be transplanted to a new location. Transplanting such seedlings to permanent place can be carried out only after 1 or 2 years, since they need to be grown.
Using the same principle, hazel can be propagated by arc layering. In spring, the selected branches should be bent in an arched manner to the soil. In the place where the branch comes into contact with the ground, the bark must be cut. Then the branch is fixed in a hole, the depth of which should be from 0.2 to 0.3 m, after which it is filled with soil so that top part towered above the surface of the site, and it needs to be tied to a peg installed nearby. The cuttings that have given root must be cut off from the parent tree in the autumn, after which it is dug up and planted in another place for growing. It can be transplanted to a permanent place after 1 or 2 years.
You can also propagate the hollow quite easily by vertical layering. When rejuvenating pruning is carried out in the spring, you need to find the stumps of fairly large branches and hermetically wrap them with film at a height of 0.5 m. This helps awaken the dormant buds and they begin to grow. After the height of the regrown young shoots is 15 centimeters, they should be hilled with humus to a height of 40–50 mm. But before that, do not forget to bandage them at the very bottom, and use them for this soft wire. After the length of the shoots reaches 0.2–0.25 m, they are hilled with humus to a height of 8 to 12 centimeters. And after their length becomes 0.3–0.35 m, they are hilled to a height of 0.2 m, and the surface around them is covered with a layer of mulch. When the shoots are hilled for the third time, you need to remove the film. During the summer period, the bush must be provided with regular watering and weeding. Don’t forget, before you start hilling, tear off all the lower leaf plates from the shoot each time. In autumn, you need to dig out the shoot very carefully, while trying not to injure the adventitious roots. Those cuttings that have given roots should be broken off at the point of constriction. Those shoots that have produced a small number of roots should not be separated.
Hazel shoots grow 100 cm in diameter from the trunk. The first offspring appear 1 or 2 years after planting the seedling; they grow from dormant buds located on the root system, and they appear from the soil at a distance from the parent bush. Hazel can be propagated by peelings - these are two- or three-year-old offspring that grow on the periphery. You need to remove such a shoot from the rhizome using an ax, after which it is transplanted into a school for growing. If desired, they can be planted in a permanent place, but in this case 2 or 3 peels should be placed in one planting hole.
Hazel can also be propagated by grafting. A wild hazel seedling can be used as a rootstock. However, experts recommend taking a bear nut seedling as a rootstock, which does not produce root shoots. Grafting is carried out in the summer using the budding method with a germinating eye or in the spring using the cutting method in the butt, behind the bark or in a split. As a scion, you should use cuttings taken from the middle part of the stem; you can also take the apical ones. Cuttings are prepared in winter time. They should be preserved until spring by placing them in a snowdrift or in the refrigerator.
Propagation of the hollow by dividing the bush is also a fairly simple procedure. The bush removed from the ground should be divided into several parts, and each division should have roots reaching 15–20 centimeters in length. The cut areas must be sprinkled with crushed coal, and then the separated parts are planted in holes, which must be prepared in advance.
For the first 2 or 3 years, young bushes should be wrapped with lutrasil or spunbond during wintering. Some gardeners cover the hollow in a different way. To do this, they bend young bushes to the surface of the plot and cover them with spruce branches. In this case, the stems not only will not freeze, but will also not be injured. Mature trees can overwinter without shelter.
Hazel can be trimmed in winter. But it is best to do this in spring at the late stage of flowering. The fact is that during flowering the plant will shake during the pruning process, which will have an extremely beneficial effect on the efficiency of pollination.
Hazel can be cultivated as a tree on a trunk, the height of which can vary from 0.35 to 0.4 m. However, a hazel tree shaped like a bush is easier and more convenient to care for. 7 days after planting the seedling in the garden, it should be shortened to 0.25–0.3 m. During the summer period, shoots will grow on the bush, which should not be removed; it must be remembered that hazelnut fruiting is observed on one-year-old wood. With the onset of spring, you need to start shaping the bush. All shoots except the 10 most powerful ones must be removed. The remaining shoots should grow from the center of the bush in different directions at a distance from each other.
All injured, competing, diseased, weak and deformed stems should be pruned. Make sure that the bush does not thicken. In the fourth year after planting the seedling in the soil, it will begin to bear fruit. At this time, it is imperative to carry out both thinning and sanitary pruning of the bush in a timely manner. When the age of the tree reaches 18–20 years, its yield begins to fall; to prevent this, they resort to rejuvenating pruning. Every year, 2 or 3 old trunks must be cut out into a stump, and they must be replaced with the same number of basal shoots, which should grow fairly close to the center of the bush. Young skeletal branches need to be shortened slightly, as this helps stimulate the growth of lateral shoots on them.
If you grow a hollow in the form of a tree, then 7 days after planting the seedling in open ground, all its stems should be removed, only the trunk should remain. As soon as new stems appear, you will need to trim those that are located at the bottom of the trunk. And in its upper part it is necessary to form 4 or 5 skeletal branches. Remember that it is very important to cut out all root shoots in a timely manner.
Hazel can be harmed by insects such as leaf beetles, aphids, nut weevils, longhorned beetles, and also bud mites.
The kidney mite is a small insect, reaching 0.3 millimeters in length. For the winter it hides in hazel buds, and in the spring it lays eggs in them. Those buds where the mite lives can be easily distinguished from healthy ones. So, they swell greatly and become similar in size to a large pea. Then, when healthy buds open, those that have become a “house” for pests dry out and fall off.
Aphids are very small sucking insects that suck cellular sap from trees. It should also be remembered that this pest is the main carrier of viral diseases. It is quite difficult to notice aphids on hazel, which is where the main danger lies. Because of this pest, the foliage becomes twisted, the buds and stems are deformed, they begin to develop relatively slowly, and the fruits do not fully ripen.
The nut weevil is a brown beetle that reaches 10 mm in length. The caterpillar of such a pest has a milky yellow body and a brown-red head. Its female lays her eggs in unripe fruits, and her larvae eat the pulp of the nut. If the tree is very badly affected, it is possible that up to half of all fruits will be spoiled.
The hazelnut (walnut) barbel is an extremely dangerous harmful insect, which is a black bug, reaching 1.5 cm in length, its legs are yellow. The larvae gnaw out the core of the stems, after which they begin to dry out, while the upper leaf blades turn yellow and curl.
The walnut leaf beetle is a beetle reaching 0.6–0.7 cm in length; its elytra are purple in color. This leaf-eating pest is the most dangerous. The larvae of this insect are painted dark green, so they are almost impossible to see against the background of foliage, on which they live and develop for quite a long time. This insect harms alder, hazel and willow.
Hazel has a relatively high resistance to disease, and it only suffers from branch rot, rust and powdery mildew.
Powdery mildew is a fairly common disease that any gardener is familiar with. The affected plant develops a whitish coating on the surface of the stems and foliage; after some time it thickens and changes its color to brown. Infected parts of the plant stop growing, they become dark and die. Ovaries do not form on the inflorescences, and the frost resistance of the tree is greatly reduced.
Rust is a fungal disease. In the affected plant, dark red tubercles appear on the front surface of the foliage, while oval or round pustules form on the back surface. Over time, the spots become stripes, and the leaves turn yellow and fly away.
White rot can affect the plant in various options, namely: as peripheral rot or as mixed rot of branches. In both the first and second cases, severe damage can be caused to the plant, which in some cases causes it to die.
If you find pests on the bush, it is recommended to cover the soil under it with polyethylene, after which the plant should be shaken until all the insects fall from it onto the film. When there are a lot of pests on the bush, it should be sprayed with a solution of an insecticidal preparation, and it should be remembered that sucking insects are gotten rid of with the help of an acaricide. The best results are shown by such products as: Actellik, Karbofos, Chlorophos and others of similar action.
If hazel is severely affected by a fungal disease, it must be treated with fungicidal preparations, for example: copper sulfate, Bordeaux mixture and others made on the basis of copper. In order to prevent fungal diseases, it is recommended to follow the agrotechnical rules of this crop and also properly care for the plant.
It was already mentioned above that there are approximately 20 types of hazel. At the same time, cultivated species have a large number of varieties, varieties and hybrids. Below we will describe those that are most popular among gardeners.
The height of this multi-stemmed shrub is 4–6 m. The crown is spreading and wide, reaching 4 meters in diameter. There is pubescence on the surface of the stems. round leaf plates reach 9 centimeters in width and 12 centimeters in length. This plant blooms before the leaves open. The spherical nuts, up to 15 mm in diameter, are covered with a brownish peel. Their ripening is observed in September. This species can be found both in natural conditions and in culture.
The fruits of this decorative species are very tasty. It is considered the only one of all species that is represented by trees. Its height is about 8 m, but in regions with a warm climate such a tree can grow up to 20 m. The lifespan of this plant is approximately 200 years. Broadly ovate leaf plates are placed on petioles reaching a length of 50 mm. The fruits of such a plant have large size Compared to other types, however, their kernels are smaller, but much tastier compared to hazelnut kernels.
The height of such a multi-stemmed, highly branching shrub is about 5 meters. The bark is fissured, dark gray in color. A characteristic feature of this species is the fruits and foliage of an oblong shape. The fruits have a prickly coating, making them relatively difficult to peel. This species is found in nature on Far East and in China.
The height of the bush is about 300 cm. Its top is truncated, and the foliage is bilobed. In spring, catkins of male inflorescences grow on it, and inconspicuous buds of female flowers, painted red, are also formed. The formation of fruits is observed in a leaf wrapper of 2 or 3 pieces. In nature, this shrub can be found in China, the Far East, Japan and Korea. The species is distinguished by its unpretentiousness to climatic conditions, and it grows well in mid-latitudes.
The height of this ornamental shrub varies from 4 to 6 meters. The crown is very dense. The leaves have a dark purple color, which changes to green closer to autumn. The buds and earrings are dark burgundy. Thanks to this species, a large number of hybrids have appeared, as well as varieties that are very popular among gardeners.
The height of the bush is about 10 meters. The nuts are placed in a tubular wrapper, and it is a couple of times larger than the fruits themselves. The fleshy kernels have an elongated shape. Under natural conditions, such hazel grows in Italy, Turkey and Asian countries.
There are also such species as: Chinese, American, Colchian, horned, Himalayan, or fearsome hazel, Siebold, etc.
In mid-latitudes the following varieties of hazel are most popular:
Even in the middle latitudes, varieties such as Ekaterina, Moscow Rubin, Pamyat Yablokova, Pervenets, Pushkinsky Red, Ivanteevsky Red, Kudraif, Moscow Early, Purpurny, Sakharisty, Sakharny, a series of varieties Severny, Tambovsky Early, Tambovsky Late, Lentina, are popular. Alida, Lena and others.
And in Ukraine and in the southern regions of Russia, varieties such as Panakhessky, Altai, Cherkessky, Kuban, Perestroika, Futkurami, etc. are popular.
Hazelnuts contain many useful substances which are necessary for the human body. Thus, the kernel contains vitamins A, PP, C and E and B vitamins, as well as amino acids, fatty oils, iron, iodine, calcium, magnesium, copper, fluorine, manganese and potassium. In terms of their biological indicators, nuts are equivalent to proteins; therefore, experts advise eating them separately from other foods.
Benefits of hazelnuts:
An infusion of hazel leaves is indicated for varicose veins, prostate hypertrophy, thrombophlebitis and trophic ulcers. An infusion of the bark is used for diabetic retinopathy; it can also improve blood circulation in small vessels. This infusion also has a vasoconstrictor effect. It is recommended to wash your hair with a decoction of plusa and bark so that it becomes darker in color. A decoction of the leaves can eliminate swelling of the eyelids and redness of the skin.
An infusion of hazel bark and foliage increases blood pressure, so it is not recommended for hypertensive patients. Eating kernels can cause exacerbation of neurodermatitis and other skin diseases. Also, the fruits should not be eaten if you have psoriasis or if you have an individual intolerance.
Hazelnut pests
Growing hazelnuts on an industrial basis is becoming increasingly popular. Due to its resistance to adverse conditions environment and high yield (with correct selection varieties) in our region the crop has great prospects. Since the area of industrial plantations and the area where hazelnuts are grown are growing every year, and the circulation of planting material, including international, is insufficiently controlled, the number of pests in hazelnuts is increasing. Now in countries where hazelnuts are a traditional industrial crop, crop losses due to pest damage reach 20-30%, but if weather contribute to pests, and the maintenance of plantings is inappropriate, then losses can increase up to 80%.
Let's talk about them in more detail.
Hazel weevil (Curculio nucum L.)- a beetle of dark brown, almost black color. The body is covered with yellow-gray stripes, on the wings yellow spots. The legs are long, covered with light gray hairs. The female's body is up to 8 mm long, the male's is up to 7 mm, the head has a long thin proboscis (in the female up to 6 mm, in the male - 4 mm). Freshly laid eggs are white, shiny and oval. The larva is legless and curved, 7-10 mm long, pale cream, the head is brownish-red or brown, the jaws are black. The body of the larva is covered with light gray fibers that stick out randomly. The pupa is milky white, 8-9 mm long, the proboscis is long, like a beetle, and tightly pressed to the body. The species damages hazelnuts and wild hazel, and less often spreads to oak acorns. The larvae overwinter in the soil (in the cradle) - after overwintering, they pupate there in the second half of April. The pupal stage lasts up to 15 days. At an average daily temperature of +15 ... + 16 ° C, the beetles begin to revive and come to the surface and settle in the crown of trees, where they immediately feed. The buds are eaten first, and then the leaves and fruits. In mid-May, at an average daily temperature of + 18 °C, adults mate en masse, and 6-7 days after this, the females begin to lay eggs in the shell of the fruit. To do this, they gnaw out small holes in the top or central part of young nuts and place one egg there. After this, seal the hole with a piece of gnawed out peel tissue. The average fertility of one female is 45 eggs (maximum 60). During the oviposition period, the female mates several times, so egg laying lasts about a month, until mid-June. Embryonic development of the larva lasts 7-10 days. Having been revived, the larva feeds on the contents of the nut, and by the end of its development, it completely eats up the kernel and falls onto the soil, making a cradle in which it overwinters. The pest forms only one generation.
The pest is common in all regions of Europe where hazelnuts are grown, with the exception of Corsica. Crop losses due to pest feeding can reach 50-80%. Varieties, depending on the thickness of the top and shell of the fruit, are damaged with different intensity.
For protection in the spring, before the beetle emerges to the surface, insecticides are applied to the soil. At the end of April - beginning of May, when beetles appear on plants, insecticidal spraying is carried out. Prematurely fallen fruits are collected and destroyed. In autumn and early spring, the soil in the root zone of plants is loosened.
Walnut barbel (Oberea linearis L.)- one of dangerous pests nut-bearing The beetle is black. The body is loosely covered with black-brown hairs, the legs are yellow. 11-16 mm long. The beetle season begins in May and lasts until mid-June. Females lay eggs under the bark of young shoots. The first larvae appear in mid-July and immediately gnaw out the core of the shoots, forming 20 cm long channels there. A characteristic sign of a plant being colonized by the walnut longhorn beetle is dry, broken shoots with twisted, dry leaves hanging on the remains of the bark. After wintering, the longhorned beetle larvae continue to harm the plant, burrowing into the thick part of the branch and damaging 2-3-year-old wood. While feeding, the second instar larvae cause the death of the entire branch.
If the hazelnut garden is affected by the nut longhorn beetle, all dry branches are cut off in March-April. The cut is made 10-15 cm below the drying area, and the cut pieces are burned. Young infected shoots are cut out in July-August, the cut is made 10-15 cm below the dried leaves, removing 2-3 healthy leaves. During the beetle feeding period before oviposition (mid-May), the garden is treated with insecticides.
Walnut bud mite (Phytoptus avellanae Nal., Cecidophyopsis vermiformis Nal.)- adult specimens of the pest are white and 0.2-0.3 mm long (very small!), shaped like a cigar. On one kidney there can be from several hundred to several thousand mites at the same time. The hazelnut bud damaged by this pest enlarges significantly and acquires an unnatural, cabbage-like appearance. figurative form, after a while it dries up and falls off. Adults and larvae overwinter inside hazelnut buds. In the spring they reproduce very intensively, and in early May they leave damaged buds and come out. During this period, the kidneys form white coating. Pests move to leaves and shoots, and when the plant begins to lay new buds, they move into them. By winter, several generations of mites develop in buds damaged by walnut bud mites; the life of each generation lasts 30-40 days.
Since the nut bud mite leaves the damaged buds en masse from mid-May to mid-June, then the plantation is treated with acaricides. On young plants, damaged buds are collected by hand and destroyed.
Hazel aphid (Myzocallis coryli Goeze)- larvae from overwintered eggs are reborn in late April - early May. During the growing season, the population has two peaks of development, spring and autumn. On hazelnut trees, aphids inhabit the lower part of the leaves; under favorable conditions, the pest can completely colonize young shoots. By feeding on sap, aphids are capable of transmitting viral diseases. Honey dew, which is formed as a result of the activity of aphid colonies, is a breeding ground for smut fungi, and this significantly increases the harmfulness of the species in plantings. As a result of aphid infestation, shoot growth is suppressed, leaves dry out prematurely and fall off. Damaged plants freeze slightly in winter. They are used for protection in plantings.
Green garden bug (Lygocoris pabulinus L.)- a sucking pest with incomplete metamorphosis. The adult is up to 10 mm long, the body is shiny green and flat, oval in shape. Adults are very active and fly well. The forewings are leathery and overlap when at rest, the hind wings are membranous. The larvae are bright green, with red eyes and similar to adult insects, but smaller and without wings. The tips of the antennae are orange-red. The eggs are up to 3 mm long, creamy, and shaped like a banana. The pest overwinters with eggs on the bark of branches and shoots. The larvae are reborn in the spring and move to young shoots and flower buds, where they feed on sap. The larvae are also mobile. In summer, females lay eggs in green tissue. Damaged leaves become discolored and wrinkled, buds and inflorescences fall off, and fruits slowly develop on affected plants. In case of invasion, protective insecticidal treatment is carried out during bud break.
Hazel piperunner (Apoderus coryli L.)- beetle 6-7 mm long. The head is pulled out into a long and wide rostrum, wider in front, sharply drawn in behind. The antennae are club-shaped, attached to the rostrum. Body black, elytra and rear end the backs are red. The larvae are white, thick, legless and blind, and feed in plant tissue. The pupa is open, white, and overwinters in the soil in a cradle. The fertilized female cuts the leaf crosswise, rolls it into a tube and lays eggs there. The larvae, reborn, feed inside the tube. The curled leaf dries out and falls to the ground along with the larvae; after a while the larvae emerge, go deeper into the soil and pupate. Preventive spraying against the pest is carried out during leaf bloom.
Common moth (Erannis defoliaria L.)- butterfly, hazelnut pest. An adult male is a butterfly with a wingspan of 30-35 mm, the forewings are light or brown-yellow, with two dark transverse lines. There is a dark spot in the center of the wing, the hind wings are light yellow, covered with brown dust. The female is wingless, 11-13 mm long, dark yellow with black spots on the back and belly. The egg is 0.5-0.7 mm in size, first yellow, then light orange. The caterpillar is 30-35 mm long, the back is red-brown, with a longitudinal double black line, the belly is yellow, the head is yellow or red-brown. Pupa up to 15 mm, dark brown, shiny. The pest overwinters with eggs, the caterpillar is reborn in April, first damages the buds that bloom, later skeletonizes and gnaws through the leaves, and in adulthood they completely gnaw the leaf blade. When the pest multiplies massively, the crown of the tree is exposed. Having completed feeding, the caterpillar leaves the food tree and pupates on the ground surface; the butterflies emerge in September-October. Males fly in the evening and at night; a fertilized female lays 200-300 eggs, placing them in cracks in the bark and under the scales of the buds. One generation develops per year. In early spring, before buds open, if there are more than 5 eggs per 1 m of planting branches, the plantings are treated with ovicidal preparations. During bud break, if there are 9 caterpillars per 1 running meter of a branch or more than 10% of the buds are damaged, an insecticide is used.
Did you know? Walnut is also called Voloshsky, Greek, royal, and sometimes mahogany.
The main reasons why hair nut can get sick:
In order to identify walnut diseases in time and begin their treatment, it is necessary to inspect the tree more often for changes in appearance. As a rule, the first signs of the presence of the disease appear in the form of various kinds of spots on the leaves and shoots.
And in order to avoid illnesses, it is important to carry out preventive spraying in spring, sanitary pruning, cleaning fallen leaves and fruits. You need to know what to spray nuts with in the spring to prevent various diseases.
Favorable conditions For the development of bacteriosis on walnuts, they appear during warm and damp spring weather. The disease manifests itself as dark spots on leaves, shoots, fruits, and flowers.Greatest harm can be applied during flowering, destroying most of the flowers. If bacteriosis develops after flowering, then the wood of such trees becomes brown, and young shoots die. The fruits become covered with dark spots.
Control measures. To prevent bacteriosis, walnuts should be treated in the spring before flowering with a 3% Bordeaux mixture. Repeated spraying must be done two weeks after flowering.
Important!To make treatment with Bordeaux mixture have a greater effect, you can add a 0.3% urea solution to it.
One of the most serious diseases of walnuts is bacterial blight. It affects leaves, flowers, shoots and fruits. This disease is the reason why walnut leaves turn black. At first they become covered with watery spots, then become black, however, even when they die, they do not fall from the tree, but remain on the branches for a long time. Walnut stems become covered with cankers. The shoots wither, the buds die. The affected parts of the plant are covered with drops of liquid.
Bacterial burn also causes nuts on the tree to turn black. First, black spots appear on the fruits, and then the entire kernel turns black and becomes unsuitable for food.
Factors that are favorable for the development of bacterial blight on nuts are prolonged heavy rainfall. The causative agent of the disease is spread by insects and wind.
Control measures. If symptoms of a bacterial burn are detected, treatment with preparations containing copper (Bordeaux mixture, Zineb, HOM, etc.) will be required. The affected parts of the tree must be destroyed.
Important! Treatment of walnuts against diseases should be carried out in dry, windless weather with mandatory observance of personal safety measures. Eyes should be protected with goggles, hands with gloves, nose and mouth with a mask.
Brown spot spreads to fruits, young shoots and leaves of the tree. The first symptoms are oval spots irregular shape brown color on the leaves. These leaves dry out quickly and fall off prematurely. The disease is especially dangerous during the flowering period, as it can harm up to 90% of flowers. Accordingly, the crop loss will be very significant.
Wet weather and prolonged rainfall contribute to the development of the disease.
Control measures. In order to prevent brown spot, walnuts must be treated with 1% Bordeaux mixture before budding. Repeated treatment is carried out in the phase of leaf appearance, the third – two weeks after the previous one. Affected leaves and shoots must be destroyed by burning.
Root cancer affects the roots of the plant and penetrates them through cracks and damage.
As a result of the disease, growths form on the root system. In case of severe damage, the tree may stop growing and stop producing fruit.
Control measures. When found of this disease growths from the roots should be removed, then the rhizome should be treated with a 1% solution of caustic soda. After treatment, the roots should be rinsed well with water.
Did you know? Depending on the growing conditions, a walnut tree can produce from 10 to 300 kg of fruit per season.
The main measures to combat walnut pests will be regular inspections to detect caterpillars - the sooner you notice their settlement, the faster and easier you can get rid of them. You also need to promptly trim and burn damaged branches to avoid the spread of pests to the entire tree.
American white butterfly caterpillars pose a serious threat to walnut trees, as they produce two to three generations per season. For the same reason, it is very difficult to fight them.
The first generation goes to harmful fishing in July - August, the second - in August - September. And the third eats leaves in September - October. Thus, an invasion of these insects can destroy almost all the foliage on a tree.
Control measures. You can fight American white butterfly caterpillars by mechanical means, discovering and burning their nests. You can also use catching belts to prevent the caterpillars from reaching the leaves, but to catch them on the trunk, then destroying them by burning. In advanced cases, microbiological preparations are used: “Bitoxibacillin”, “Lepidocid”, “Dendrobacillin” or insecticides.
Such a walnut pest as sapwood is initial stage lesions cannot be detected, since it settles under the bark. The first generation of beetles appears in May, the second in August. Gradually, the beetles gnaw out the bark, and their presence can be seen in curved canals that are located next to the buds and bases of the petioles. It starts at the tree oozing.
As a rule, sapwood settles on weak plants.
Control measures. For the purpose of prevention, it is necessary to carry out timely sanitary pruning of the nut, which involves the removal of diseased, weak, damaged branches. If the tree is infested with a beetle, it must be sprayed with insecticides.
Did you know?The vitamin C content in walnuts is almost 50 times higher than in citrus fruits and 8 times higher than in currants.
Sucking insects are usually miniature in size, and cause enormous damage to the plant. Thus, the walnut warty mite reaches sizes of up to 1 mm, and can significantly damage the leaves already at the stage of their formation. Signs that a mite has settled on a nut are small “warts” dark brown on the leaves.
Control measures. If symptoms of walnut wart mite infestation are detected, the tree should be treated with any acaricide approved for use on nuts.
Mole in walnuts it is difficult to notice, since it has a protective color and, with its wings closed, is practically indistinguishable from the bark. Its caterpillars damage the leaves by gnawing out the pulp.
Control measures. To get rid of nut moths, use systemic poisons recommended for fruit plants in the same dosage.
The nut moth causes serious damage to nut kernels. The first generation of its caterpillars damages the kernels, causing them to fall from the tree. The second brood settles inside the fruits and eats away the cotyledons. One caterpillar can damage several nuts.
