Content
Getting high yields is impossible without measures aimed at prevention and control of pests and diseases. To do this, you need to know what they are, when and how they multiply, which parts of the plant are affected, the factors that contribute to their spread. Diseases of the pear and its pests are usually closely related to one or another phase of the tree's development. Safeguards should be tied to them, rather than calendar-based.
Fungal diseases of pears and methods of struggle
Fungal infections account for about 80% of fruit tree diseases. The causative agents are living organisms multiplying by spores - fungi that feed on the threads of the penetrating plant tissue with the help of mycelium.
They are transmitted from infected pears to healthy ones by insects, wind, raindrops, through infected tools or the hands of owners or gardeners. Punctures and injuries caused by pests, frost holes, sunburn, uncovered wound surfaces left after pruning a pear contribute to the spread of fungal diseases.
Fungal spores hide in the soil, bark cracks, and under plant debris. With primary infection, the disease cannot be seen with the naked eye. Subsequently, the main sign of the colonization of the pear with fungal spores is the coating of the leaves with spots, and after a while - their shedding.
Brown spot
This disease most often affects the leaves, young branches and fruits of pears in southern nurseries or gardens. It manifests itself:
- the formation of rounded brown spots on the leaves;
- small dark brown elliptical depressed spots appear on the affected pear shoots;
- the fruit is covered with round carmine marks.
Over time, the leaves fall off on the pear, the fruits become bubbly and crack. The disease begins to manifest itself in late May or early June, reaching a peak in July-August.
The mycelium of the fungus hibernates in young shoots and on fallen leaves. Diseases are promoted by warm, damp weather and heavy blocking soil.
This is a common disease, it is impossible to get rid of it without 2-3-fold preventive spring treatments of pears from pests and diseases with copper-containing preparations or colloidal sulfur. The first is carried out on a green cone, the subsequent ones - after 10-14 days.
Pear moniliosis
All fruit crops are affected by fruit rot or moniliosis. It is a disease of inflorescences, branches and young shoots, but most of the spores are found on fruits. On the surface of pears there are scattered or characteristic circles of grayish or yellowish pads with spores.
If measures are not taken in a timely manner, within a week the disease can cover the entire fetus, which eventually dries out and mummifies. Most infected pears fall off, but some can hang from the tree for up to two years, constantly remaining a focus of the disease. During storage, the fruit may become glossy and blackened.
At the beginning of the season, moniliosis affects flowers and leaves - they dry out, but do not crumble, sometimes in damp weather grayish pads with fungal spores appear on the surface. When the disease affects the branches, the bark cracks, turns brown, shrivels. The tops of young shoots sometimes dry out.
Spores of fungi overwinter on mummified pears, fallen flowers and leaves affected by the disease, and plant debris not removed in autumn. They begin to live at temperatures from 2-3 ° to 32-35 ° C in rainy weather, but if the fruits are damaged by insects, the presence of moisture is not necessary. New conidia appear all summer and cause secondary infection.
The development of the disease can be caused by dirty hands or tools, and any mechanical damage to the fruit, including insects, contributes.
It is impossible to cure fruit rot unless all mummified pears and affected branches are removed from the tree. To prevent disease, it is imperative to carry out anti-aging and sanitary pruning, remove plant debris, especially carrion.
Pears are processed:
- after leaf fall in the fall and before the buds swell in the spring with 4-5% calcium polysulfide (lime-sulfur broth);
- immediately before flowering (on a white cone) and after it - 1% Bordeaux liquid.
Milky shine
There are two types of the disease:
- false milky shine caused by frostbite of a pear and is of a non-parasitic nature;
- a real milky shine, caused by infection with a fungal disease.
All fruit trees are affected, more often in cold regions with harsh winters. The outward symptoms of nonparasitic frostbite and fungal (often accompanied by cold damage) diseases of pear leaves are similar.
In both cases, the vegetative organs change color to light gray, with a milky tint. In leaves affected by a fungal disease, this color is explained by the penetration of the mycelium into the tissue. If you cut off an infected branch, the wood will be brown. By autumn, the fruiting bodies of the fungus are formed, similar to leathery growths up to 3 cm in size and attached to diseased branches.
The spores that matured in the fruiting bodies of fungi are sown twice - at the beginning and end of the growing season, and cause the disease to develop again. Pear leaves infected with milky shine shrink and dry out.
Cold winters, insufficient preparation of the tree for winter, and lack of nutrients contribute to the onset and development of the disease.
The fungus that causes a milky sheen on the pear is considered relatively harmless. But his treatment includes the removal of the affected branches, in which it is necessary to capture 15 cm of healthy tissue. If you do not pay attention to the disease, the whole tree can die in a few years.
Powdery mildew
The pear often suffers from a powdery mildew infection, the disease manifests itself as a white bloom on flowers, leaves and young shoots. By the middle of summer, the plaque grows, becomes gray and resembles felt. Fruit growth slows down, they crack and become rusty.
The fungus hibernates in buds and branches, rarely in fallen leaves. Spores dissipate in spring when the buds open and during the first warm rains. Cool, rainy weather contributes to the development of the disease.
It is necessary to fight powdery mildew by carrying out standard sanitary measures and repeated spraying from the disease with basezol or calcium polysulfide (it is better to alternate preparations):
- I - at the beginning of the disclosure of leaf buds;
- II - with the opening of flower buds;
- III - after the fall of the petals.
With a strong development of the disease, you need to do 2 more treatments with an interval of 2 weeks.
Scab
If the leaves on the pear have darkened and become stained with olive bloom, and on the fruits there are clearly delineated, cracked areas of the same color, the tree is sick with scab.Shoots are rarely affected by this fungus. The scab reduces the quality and quantity of the crop, pears lose their presentation, become deformed, and become woody in the affected areas.
The fungus hibernates in fallen leaves. Spores germinate at temperatures from 0 to 30 ° C. Primary infection in most cases occurs immediately after flowering, in summer - secondary. Young growing organs are especially susceptible to infection. For the development of the disease, high air humidity is needed.
To prevent the development and appearance of the disease, plant debris is removed from the site in the fall. Spraying with 1% Bordeaux liquid or other copper-containing preparation is carried out at least 4 times:
- when isolating flower buds;
- on a pink cone (opening of flower buds);
- when petals fall;
- 2 weeks after flowering.
With severe infestation or no treatments in previous years, additional spraying may be required.
Blue scab spraying
Instead of multiple treatments in spring and summer for pears from scab, you can carry out one, at the very beginning of the season. As soon as the flower buds swell, the tree is sprayed with 4-6% Bordeaux liquid. It is impossible to delay with this procedure - a copper-containing preparation in high concentration can ruin the harvest, rather than a disease.
If the spring was rainy, after 30-45 days, a control treatment of pears with 1% Bordeaux liquid is carried out.
Rye on pear leaves
Pear trees do not infect each other with rust. An indispensable condition for the occurrence of this fungal disease is the proximity of a juniper. A sign of infection is the appearance of burgundy spots on the leaves of a pear with an orange edging on top, and below - yellow or orange pads with spores. Swollen spots form on shoots and fruits.
In the spring, before the buds bloom and after the petals fall off, the pear is treated with a copper-containing preparation, and after leaf fall - with a concentrated (0.7 kg per 10 l) urea solution.
Sooty fungus
It is correct to call this disease rabble, not sooty fungus. It manifests itself as a black, easily washable film covering the leaves, fruits, and pear shoots. These are spores and mycelium of the fungus, so the rabble does not infect the tree, and is not a parasite. The disease simply settles where insects have already "worked", emitting sticky sap when the green organs of the plant are destroyed.
The sooty fungus actually harms the pear, although it does not directly feed on its leaves and flowers. But the mob covers them with a black bloom, which covers the stomata and interferes with photosynthesis. The disease depresses the plant, does not allow it to eat, breathe and fully produce chlorophyll. Fruits covered with a sooty fungus have a deteriorating taste and appearance, and their market and consumer value decreases.
Before fighting the rabble, you need to destroy the cause that caused the appearance of the disease - pests. First, the pear is sprayed with an insecticide, and after 2-3 days - with a copper-containing preparation.
Cytosporosis
Pear leaves wither, branches and whole trees dry up - all these are signs of a dangerous fungal disease of pome crops, cytosporosis. The infection is introduced to the sites of damage on the trunk:
- frost breakers;
- in time not treated wound surfaces left after trimming a tree;
- violations of the integrity of the bark resulting from sunburn;
- mechanical damage of any nature.
First, small pieces of bark turn reddish-brown or brown-yellow in size, then dry out. Small swellings (fruiting bodies of mushrooms) appear on the dead areas of the pear.At the border with living tissue, cracks appear, inhabited by spores, and the disease spreads further.
Cytosporosis can proceed in a chronic form, destroying the pear slowly, or at lightning speed, when whole skeletal branches dry out in 1-2 months. In appearance and the course of the disease, this one is very similar to black cancer. The differences are that during cytosporosis, the bark remains reddish-brown, and does not turn black and is poorly separated from the wood.
Pear bacterial diseases and treatment
A group of diseases caused by unicellular organisms that penetrate plant tissues through stomata and pores, or trauma of any origin:
- on time, not oiled cuts left after pruning the pear;
- frost breakers;
- wounds left on leaves and fruits by pests;
- damage to the bark and shoots.
Externally, bacterial diseases of pear appear as rot, the affected areas first become covered with oily spots, then turn brown and die off.
Pear bacteriosis
The disease manifests itself in the spring with a darkening of the edge of young leaves. Therefore, it is initially confused with frostbite. Gradually, the leaves of the pear turn brown completely, the disease spreads to the petioles and shoots. On the cut of the branches, darkening of the wood is visible - this is a defeat of the vascular system of the plant.
Pears of any age can be affected. Treatment consists in removing the affected branches and treating the tree with copper-containing preparations.
Bacterial burn
A dangerous infectious disease that proceeds quickly and often leads to the death of a pear. The bacteria, along with the juices, are carried through the tissues and cause their death.
Treatment is carried out by spraying with copper-containing drugs or antibiotics. In case of severe damage, the infected branches are removed. If the disease is left unattended for a long time, the pear may die.
Pear bacterial cancer (necrosis)
The disease causes damage to the skeletal branches and stem, usually on adult fruiting pears. First, small cracks appear on the bark, then they grow and turn into wounds surrounded by brown spots. The pear leaves and fruits turn red, flowers and shoots turn brown. Then the vegetative organs dry up, but do not fall off.
Dark rings and stripes are clearly visible on the cut of pear branches affected by bacterial cancer. The disease softens the wood, it becomes brown, wet. Often in the spring, the bark first swells, then bursts and remains hanging in rags.
This disease can be easily introduced to healthy plants, if you immediately go to work on a healthy tree from an infected pear. Insects take part in the spread of necrosis, but rarely. The bacterium is often introduced through the apical buds and damaged areas, and occasionally penetrates through the stomata.
The disease oppresses the pear, reduces its yield, and sometimes destroys the tree. Even if the infection is detected on time and timely treatment is carried out, it is impossible to completely get rid of it.
Bacterial cancer on a pear can be prevented or slowed down, not cured. Anyway;
- the affected branches are removed, capturing about 10-15 cm of healthy tissue:
- cuts are treated with garden varnish or special paint;
- if the disease spreads to the stem, it is cleaned, cutting out all the diseased wood and part of the healthy one;
- prepare a talker from a mixture of mullein and clay (1: 1), diluted to the consistency of sour cream with Bordeaux liquid, coat the wound surface with it;
- a bandage impregnated with a copper-containing preparation is applied on top.
The pear is treated with copper-containing preparations in spring and autumn.
Viral diseases of pear trees
Viruses penetrate into the cell and multiply there. External manifestations of the disease:
- leaves become variegated (mosaic);
- vegetative organs are deformed;
- the leaves on the pear become small;
- parts of the plant die off.
The carriers of viral diseases are insects that carry infected cell sap from an already infected tree to a healthy one. Owners can infect pears and other fruit crops through dirty hands or garden tools.
By and large, viral diseases are still a mystery even to scientists. There is no reliable way to control them and the affected plants often have to be destroyed in order to prevent the spread of infection.
Grooved wood
The furrow virus is usually transmitted by plant grafting or pruning. Therefore, most often the disease affects young pear seedlings, which become infected in 2-3 years and do not live long.
External manifestations of wood furrowing:
- branches are flattened, and over time they twist;
- young pear leaves turn yellow and fall off ahead of time;
- the wood affected by the disease dies off;
- clearly visible necrotic grooves and spots appear on the bark.
As a result, the connection between the crown and the root system is disrupted, the pear dies. There is no point in treating the disease, but the tree must be removed from the site as quickly as possible and burned.
Witch's broom
This collective name may hide:
- fungal infection of the pear;
- viral disease;
- evergreen parasitic plant mistletoe.
Outwardly, they are similar to each other and do not benefit the tree. But if the fungus can be treated, and the mistletoe can be fought, then if the pear is affected by viral proliferation, the plant must be uprooted and burned.
At the point of penetration of the disease, dormant buds wake up and many thin shoots grow with underdeveloped, quickly crumbling leaves. They get tangled together and form a globular cluster that really looks like a mistletoe.
If it is a fungal disease, then there are light lumps on the shoots, the pear needs to be treated. The mistletoe can be recognized by its elliptically elongated attractive leaves. It is impossible to get rid of the virus. The pear will have to be destroyed.
Mosaic disease
This viral disease usually affects young trees. External manifestations become clearly visible closer to the middle of the growing season. The disease covers pear leaves with light green, yellow, or white spots and bizarrely curved stripes. There are several strains of mosaic, differing in the speed of propagation and the sharpness of the pattern. The venation of the pear leaf becomes clearly visible.
The virus has no cure. On mature trees, the external signs of the disease are poorly expressed. Only pale spots appear on the leaves of the most susceptible to the virus varieties of pears.
Pear pests
There are many species of insects for which plants are not only a habitat, but also a breeding ground, an object of food. In a short time, they can cause significant harm even to adult trees, and if you do not take measures to exterminate pests, destroy or spoil the crop.
Unfortunately, it is impossible to prevent the invasion of insects on pears and other fruit crops. But the gardener is able to destroy pests for at least one season and reduce their population.
By the nature of their nutrition, insects parasitizing plants are divided into two groups:
- gnawing (beetles, caterpillars) - those who eat pear leaves and buds damage pear fruits;
- sucking (mites, aphids) suck the juices from the vegetative organs, piercing them with the proboscis, which is why the young leaves of the pear turn yellow, the buds crumble, the fruits lose their marketable and nutritional value.
Hawthorn
A butterfly belonging to the Belyanka family with translucent white wings up to 7 cm wide, decorated with black veins. Caterpillars about 5 cm long hibernate in cocoons, from which they emerge during the opening of the buds. Each butterfly lays 200-500 eggs.
The massive invasion of hawthorn, lasting 3-4 years, is replaced by a decrease in the number of the pest, lasting 6-7 years. In Russia, the butterfly is common in Siberia, the Far East and the entire European part.
The hawthorn caterpillars cause significant harm to the pear - they eat the buds, buds, and can damage up to 15% of the leaves. During the years of mass reproduction, they are able to completely bare the fruit tree. Parasitizing on pear leaves, the pest rolls them into a tube and tightens them with cobwebs.
Before budding, the pear is processed:
- Nitrofen;
- Bicol;
- Lepidocide.
During the growing season, spraying is recommended:
- Alatar;
- Herald;
- Samurai Super;
- Cyperus;
- Bitoxibacillin;
- Aliot.
Pear pipe wrench
The pear is most harmful to adults during the laying of eggs - they fold the leaf into a tube, which makes it dry out. The pear or grape pipe runner is a yellow-green beetle with a bluish tint 6-9 mm long. They give one generation per year, each female lays up to 250 eggs - 8-9 eggs in one “tube”.
Pests hibernate in the ground, burrowing 5-10 cm, a small part - under plant debris. At the end of April, immature beetles go outside and eat pear buds.
To combat the pipe-runner, you need to remove the fallen leaves and dig up the ground under the trees. During the growing season, pears are sprayed with pesticides:
- Alfashance;
- Clonrin.
During the period of mass release of beetles from wintering, trees are shaken off 3-4 times, pests are collected on tarpaulin or agrofibre and destroyed. Straw soaked with insecticides is laid out under the pears.
Sawyer
A flying insect similar to a reduced fly with a yellowish-brown body and transparent wings up to 6 mm long is common in the southern regions. Adults are practically harmless; white-yellow larvae about 1 cm long pose a danger to pears.
The female lays eggs in flower buds, 1 piece. The hatched larva does not come out, but feeds on the ovaries. After destroying one fruit, she moves on to the next. Before hibernation, each caterpillar manages to spoil 3-4 pears. If nothing is done, up to 80% of the crop can be destroyed.
The larvae overwinter in the ground, pupae develop from them in the spring, long before the pear blossoms. By the time the buds appear, the sawyer has time to hatch and reach puberty.
You can fight the pest by spraying pears 5-6 days before the buds open and immediately after the petals fall off with preparations:
- Fufanon;
- Zolon;
- Intra-Ts-M;
- Di-68;
- Iskra M.
The ovaries damaged by the sawer are torn off by hand and destroyed.
Moth
The pear moth is a butterfly belonging to the Leafworm family with a wingspan of 17 to 22 mm. She feeds exclusively on pear fruits, and prefers early varieties.
The upper wings are dark gray, decorated with transverse wavy lines and a brownish spot, the lower ones are reddish, with gray fringes. When folded, they stretch along the abdomen. During the growing season, one generation of moths appears. Each female lays 35 to 80 eggs, which hatch off-white caterpillars 11-17 mm long with a brown-yellow head.
They cause the greatest harm to the pear, gnawing holes in the fruit, eating seeds and filling cavities with excrement. This stage lasts 22-45 days, depending on weather conditions.
The moth is most common in the southern regions and Siberia. In case of mass accumulation, the pest can spoil up to 90% of the pear harvest - the fruits eaten away by caterpillars lose their consumer and market value.
Fall plowing will help reduce the insect population. The remaining caterpillars are fought with the help of organophosphate pesticides, processing the pear before and after flowering. It is recommended to use:
- Sail;
- Karbofos;
- Agravertine;
- Spark;
- Clinmix.
Aphid
There are about 4 thousand species of aphids, all of them parasitize on plants and feed on their sap.Some damage pear trees, although one variety would be enough to rank the insect as especially dangerous.
Aphids not only pierce young vegetative organs and drink cell juice from them, secreting a sticky secret. They can spread viruses and other diseases, cause warts and other abnormal formations on pear leaves.
Aphids are small winged insects several millimeters long. It is characterized by symbiosis with ants.
It is with the destruction of ants that you need to start the fight against aphids, otherwise all measures will be taken in vain. The natural enemies of the pest are beneficial insects:
- ladybugs;
- hoverflies;
- lacewing.
Before budding, pears are treated with aphids with an insecticide Preparation 30 Plus. Before and after flowering, trees are sprayed with Litox and Sumition, during the growing season - Fufanon, Iskra M, Intra-Ts-M.
From biological preparations Fitoverm is recommended. Good results are obtained by processing folk remedies.
Preventive measures
Spraying with pesticides and folk remedies give good results. But is it worth waiting for the leaves to turn brown on the pear, or some insect starts to gnaw them? Better to prevent diseases and pests.
For this you need:
- carefully carry out all sanitary measures;
- increase the tree's own immunity;
- comply with the rules of agricultural technology;
- carefully cover up with paint or garden varnish all damage, including those remaining after pruning;
- process the pear in the spring from pests and diseases;
- prevent frostbites, sunburn and damage to the trunk by hares;
- whitewash the skeletal branches and trunk of a pear with milk of lime in autumn and spring;
- peeling old bark;
- dig up the trunk circle in autumn and spring.
Disease-like problems can arise with improper care. For instance:
- with a lack of phosphorus, bronze leaves appear on the pear;
- critical lack of moisture causes drying of vegetative organs and shedding of the ovary;
- overflows can cause decay of the root system, the development of putrefactive diseases, and make the leaves on the pear purple.
Conclusion
Pear diseases affect poorly maintained trees. It is easier for pests to feed on the flabby leaves of a weakened plant. Only proper care and timely preventive treatments will make the pear healthy and allow you to get a good harvest.
