Content
Obtaining high yields is impossible without measures aimed at preventing and controlling pests and diseases. To do this, you need to know what they are, when and how they reproduce, what parts of the plant they affect, and factors that contribute to their spread. Pear diseases and pests are usually closely related to one or another phase of tree development. Protective measures should be tied to them, and not based on the calendar.
Fungal diseases of pear and control methods
Fungal infections account for about 80% of fruit tree diseases. The causative agents are living organisms that reproduce by spores - fungi, feeding with the help of mycelium, the threads of the permeating plant tissue.
They are transmitted from infected pears to healthy ones by insects, wind, raindrops, through contaminated tools or the hands of owners or gardeners. Punctures and damage caused by pests, frost holes, sunburn, and uncovered wound surfaces left after pear pruning contribute to the spread of fungal diseases.
Fungal spores hide in the soil, bark cracks, and under plant debris. During primary infection, the disease cannot be seen with the naked eye. Subsequently, the main sign of the colonization of a pear with fungal spores is the leaves becoming covered with spots, and after some time - their shedding.
Brown spot
This disease most often affects the leaves, young branches and fruits of pears in southern nurseries or orchards. It manifests itself:
- the formation of rounded brown spots on the leaves;
- small dark brown elliptical depressed spots appear on diseased pear shoots;
- The fruits are covered with round carmine marks.
Over time, the leaves on the pear fall off, the fruits become bubbly and crack. The disease begins to appear in late May or early June and reaches its peak in July-August.
The mycelium of the fungus overwinters in young shoots and on fallen leaves. The disease is favored by warm, damp weather and heavy, soaking soils.
This is a common disease, it is impossible to get rid of it without 2-3 times preventive spring treatments of pears against pests and diseases with copper-containing preparations or colloidal sulfur. The first one is carried out along the green cone, the subsequent ones - after 10-14 days.
Moniliosis of pear
All fruit crops are affected by fruit rot or moniliosis. This is a disease of inflorescences, branches and young shoots, but most of all the spores are found on the fruits. Grayish or yellowish pads with spores appear scattered or forming characteristic circles on the surface of pears.
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 on the tree for up to two years, constantly remaining a source of disease. During storage, the fruits may become glossy and turn black.
At the beginning of the season, moniliosis affects flowers and leaves - they dry out, but do not fall off; sometimes in damp weather, grayish pads with fungal spores appear on the surface. When the disease affects the branches, the bark cracks, turns brown, and wrinkles. The tops of young shoots sometimes dry out.
Fungal spores overwinter on mummified pears, fallen diseased flowers and leaves, and plant debris not harvested in autumn. They begin their life activity 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 throughout the 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 you remove all mummified pears and affected branches from the tree. To prevent the disease, it is necessary 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, 4-5% calcium polysulfide (lime-sulfur decoction);
- immediately before flowering (along the white cone) and after it - 1% Bordeaux mixture.
milky shine
There are two types of the disease:
- false milky sheen caused by frostbite of the pear and non-parasitic in nature;
- a real milky sheen, caused by infection with a fungal disease.
All fruit trees are affected, more often in cold regions with harsh winters. The external signs of non-parasitic diseases caused by frostbite and fungal diseases (often accompanied by damage from low temperatures) 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 turn 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.
Spores ripened in the fruiting bodies of mushrooms are sown twice - at the beginning and end of the growing season, and cause the re-development of the disease. Pear leaves infected with milky sheen become smaller and dry out.
The occurrence and development of the disease is facilitated by cold winters, insufficient preparation of the tree for winter, and lack of nutrients.
The fungus that causes milky shine on pears is considered relatively harmless. But its 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 entire tree may die within a few years.
Powdery mildew
Pears often suffer from infection with powdery mildew fungus; the disease manifests itself in the form of a white coating on flowers, leaves and young shoots. By mid-summer, the plaque grows, turns gray and resembles felt. Fruit growth slows down, they crack and become rusty.
The fungus overwinters in buds and on branches, rarely in fallen leaves. Spores disperse in the spring when the buds open and during the first warm rains. Cool, rainy weather favors the development of the disease.
It is necessary to combat powdery mildew by carrying out standard sanitary measures and repeated spraying against the disease with foundationazole or calcium polysulfide (it is better to alternate the drugs):
- I – at the beginning of leaf bud opening;
- II – when flower buds open;
- III – after the petals fall.
If the disease develops strongly, you need to do 2 more treatments with an interval of 2 weeks.
Scab
If the leaves on the pear have darkened and are covered with spots with an olive bloom, and clearly defined, cracked areas of the same color appear on the fruit, the tree has developed scab. Shoots are rarely affected by this fungus. Scab reduces the quality and quantity of the harvest, pears lose their presentation, become deformed, and become woody in affected areas.
The fungus overwinters in fallen leaves. Spores germinate at temperatures from 0 to 30° C. Primary infection in most cases occurs immediately after flowering, and secondary infection occurs in summer. Young growing organs are especially susceptible to infection. For the disease to develop, 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 mixture or other copper-containing preparation is carried out at least 4 times:
- with the separation of flower buds;
- along the pink cone (opening of flower buds);
- when the petals fall;
- 2 weeks after flowering.
If the infestation is severe or no treatments have been done in previous years, additional spraying may be required.
Blue scab spray
Instead of multiple treatments for scab in the spring and summer, you can carry out one treatment at the very beginning of the season. As soon as the flower buds swell, the tree is sprayed with 4-6% Bordeaux mixture. You cannot delay this procedure - a copper-containing drug in high concentration can destroy the crop more likely than a disease.
If the spring was rainy, after 30-45 days a control treatment of the pear is carried out with 1% Bordeaux mixture.
Rust on pear leaves
Pear trees do not infect each other with rust. A prerequisite for the occurrence of this fungal disease is the proximity of juniper. A sign of infection is the appearance on pear leaves of burgundy spots with an orange border on top, and yellow or orange pads with spores on the bottom. Swollen spots form on shoots and fruits.
In the spring, before the buds open and after the petals fall, 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 appears as a black, easily erasable film covering the leaves, fruits, and shoots of the pear. These are spores and mycelium of the fungus, so the blackworm does not infect the tree and is not a parasite.The disease simply settles where insects have already “worked”, releasing sticky juice when destroying the green organs of the plant.
The sooty fungus actually harms the pear tree, although it does not directly feed on its leaves and flowers. But the mob covers them with a black coating, covering the stomata and interfering with photosynthesis. The disease depresses the plant, preventing it from eating, breathing and fully producing chlorophyll. Fruits covered with sooty fungus deteriorate in taste and appearance, and their commercial and consumer value decreases.
Before fighting the mob, you need to destroy the cause that caused 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 entire trees dry out - all these are signs of a dangerous fungal disease of pome crops, cytospora. The infection penetrates into places of damage on the trunk:
- frost breakers;
- wound surfaces left after pruning the tree that were not treated in a timely manner;
- violations of the integrity of the cortex resulting from sunburn;
- mechanical damage of any nature.
First, small pieces of bark become reddish-brown or brownish-yellow, then dry out. Small swellings (fungal fruiting bodies) appear on the dead areas of the pear. At the border with living tissue, cracks appear, populated by spores, and the disease spreads further.
Cytosporosis can occur in a chronic form, destroying the pear slowly, or at lightning speed, when entire skeletal branches dry out in 1-2 months. In terms of external signs and course of the disease, this is very similar to black cancer. The differences are that with cytosporosis, the bark remains red-brown, and does not turn black and is poorly separated from the wood.
Bacterial diseases of pear and treatment
A group of diseases caused by single-celled organisms that penetrate plant tissue through stomata and pores, or injuries of any origin:
- cuts left after pear trimming that were not lubricated in time;
- frost breakers;
- wounds left on leaves and fruits by insect pests;
- damage to bark and shoots.
Externally, bacterial diseases of pears appear as rot; the affected areas first become covered with oily spots, then turn brown and die.
Bacteriosis of pear
The disease appears in spring with darkening of the edges of young leaves. Therefore, at the initial stage it is confused with frostbite. Gradually, the pear leaves turn completely brown, and the disease spreads to the petioles and shoots. On the cut of the branches, darkening of the wood is visible - this is a damage to the vascular system of the plant.
Pears of any age can be affected. Treatment consists of removing the affected branches and treating the tree with copper-containing preparations.
Bacterial burn
A dangerous infectious disease that occurs quickly and often leads to the death of the pear. Bacteria, along with juices, spread throughout the tissues and cause their death.
Treatment is carried out by spraying with copper-containing preparations 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.
Bacterial cancer of pear (necrosis)
The disease causes damage to the skeletal branches and trunk, usually on mature fruiting pears. First, small cracks appear on the bark, then they grow and turn into wounds surrounded by brown spots. The leaves and fruits of the pear turn red, the flowers and shoots turn brown. Then the vegetative organs dry out, but do not fall off.
On the cut of pear branches affected by bacterial canker, dark rings and stripes are clearly visible. The disease softens the wood, it becomes brown and wet. Often in the spring the bark first swells, then bursts and remains hanging in rags.
This disease can easily be spread to healthy plants if you immediately move from an infected pear to a healthy tree. Insects take part in the spread of necrosis, but rarely. The bacterium often penetrates through apical buds and damaged areas, and occasionally penetrates through stomata.
The disease suppresses the pear, reduces its yield, and sometimes destroys the tree. Even if the infection is detected in time and treated promptly, it is impossible to completely get rid of it.
Bacterial canker on pear can be prevented or slowed, not cured. Anyway;
- the affected branches are removed, capturing about 10-15 cm of healthy tissue:
- saw cuts are treated with garden varnish or special paint;
- if the disease has spread to the trunk, it is cleaned by cutting out all the diseased wood and some of the healthy wood;
- prepare a mash from a mixture of mullein and clay (1:1), diluted to the consistency of sour cream with Bordeaux mixture, coat the wound surface with it;
- A bandage soaked in a copper-containing preparation is applied on top.
Pears are treated with copper-containing preparations in spring and autumn.
Viral diseases of pear trees
Viruses penetrate into cells 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.
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 combat them and affected plants often have to be destroyed to prevent the spread of infection.
Grooving of wood
Groove virus is usually transmitted by plant grafting or pruning. Therefore, most often the disease affects young pear seedlings, which become infected at 2-3 years and do not live long.
External manifestations of wood grooves:
- branches flatten and twist over time;
- young pear leaves turn yellow and fall off prematurely;
- diseased wood dies;
- clearly visible necrotic furrows and spots appear on the bark.
As a result, the connection between the crown and the root system is disrupted, and the pear dies. There is no point in treating the disease, but the tree needs to be removed from the site as quickly as possible and burned.
Witch's broom
This collective name may hide:
- fungal infection of 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 mistletoe can be fought, then if the pear is affected by viral proliferation, the plant must be uprooted and burned.
At the site of penetration of the disease, dormant buds wake up and many thin shoots grow with underdeveloped leaves that quickly fall off. They get tangled together and form a spherical cluster that really looks like mistletoe.
If it is a fungal disease, then there are light lumps on the shoots, the pear needs to be treated. Mistletoe can be recognized by its elliptical, 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 intricately curved stripes. There are several strains of mosaic, differing in the speed of spread and sharpness of the pattern. The venation of the pear leaf becomes clearly visible.
The virus has no cure. On mature trees, external signs of the disease are weakly expressed. Only in the most susceptible pear varieties to the virus do pale spots appear on the leaves.
Pear pests
There are many species of insects for which plants are not only a habitat, but also a breeding ground and food source. They can cause significant damage even to mature trees in a short time, and if measures are not taken to exterminate the pests, they can destroy or spoil the crop.
Unfortunately, it is impossible to prevent insect attacks on pear and other fruit crops.But the gardener has the power to destroy pests for at least one season and reduce their population.
Based on the nature of their feeding, insects that parasitize plants are divided into two groups:
- gnawing (beetles, caterpillars) – those who eat pear leaves and buds damage the pear fruits;
- sucking (mites, aphids) suck the juices from the vegetative organs, piercing them with their proboscis, which is why the young pear leaves turn yellow, the buds fall off, and the fruits lose their marketable and nutritional value.
hawthorn
A butterfly belonging to the Belyanka family with translucent white wings with a span of up to 7 cm, decorated with black veins. Caterpillars, about 5 cm long, overwinter in cocoons, from which they emerge when the buds open. Each butterfly lays 200-500 eggs.
A 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.
Hawthorn caterpillars cause significant damage to the pear - they eat buds, buds, and can damage up to 15% of the leaves. During the years of mass reproduction they are capable of completely denuding the fruit tree. Parasitizing on pear leaves, the pest rolls them into a tube and tightens them with a web.
Before the buds open, the pear is processed:
- Nitrophen;
- Bicolom;
- Lepidocide.
During the growing season it is recommended to spray:
- Alatar;
- Herald;
- Samurai Super;
- Cyperus;
- Bitoxibacillin;
- Aliot.
Pear tube gun
Adults cause the greatest harm to the pear when laying eggs - they roll the leaf into a tube, causing it to dry out. The pear or grape trumpetworm is a yellow-green beetle with a bluish tint, 6-9 mm long.They produce one generation per year, each female lays up to 250 eggs - 8-9 in one “tube”.
Pests overwinter in the ground, burrowing 5-10 cm, a small part under plant debris. At the end of April, immature beetles emerge and eat the pear buds.
To combat the pipe roller, you need to remove 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 emergence of beetles from wintering, the trees are shaken off 3-4 times, the pests are collected on a tarpaulin or agrofibre and destroyed. Straw soaked in insecticides is laid out under the pears.
sawyer
A flying insect that looks like a miniature fly with a yellowish-brown body and transparent wings up to 6 mm long, it is common in the southern regions. Adults are practically harmless; the danger to the pear is represented by white-yellow larvae about 1 cm long.
The female lays eggs in flower buds, one at a time. The hatched larva does not come out, but feeds on the ovaries. Having destroyed one fruit, she moves on to the next. Before leaving for the winter, 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, and their pupae develop in the spring, long before the pear begins to bloom. By the time the buds appear, the sawfly has time to hatch and reach sexual maturity.
You can fight the pest by spraying pears 5-6 days before the buds open and immediately after the petals fall with the following preparations:
- Fufanon;
- Zolon;
- Intra-C-M;
- Di-68;
- Iskra M.
The ovaries damaged by the sawyer are torn off by hand and destroyed.
codling moth
The pear moth is a butterfly belonging to the Leafroller 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 wings are reddish, with a gray fringe. When folded, they stretch along the abdomen. During the growing season, one generation of moths appears. Each female lays from 35 to 80 eggs, from which dirty white caterpillars 11-17 mm long with a brown-yellow head emerge.
They cause the greatest harm to pears by gnawing holes in the fruit, eating seeds and filling cavities with excrement. This stage lasts 22-45 days, depending on weather conditions.
The codling moth is most common in the southern regions and Siberia. If there is a massive accumulation, the pest can ruin up to 90% of the pear harvest - the fruits worn out by the caterpillars lose their consumer and market value.
Fall plowing will help reduce the insect population. The remaining caterpillars are controlled using organophosphorus pesticides, treating the pear before and after flowering. Recommended use:
- Sail;
- Karbofos;
- Agravertine;
- Spark;
- Cleanmix.
Aphid
There are about 4 thousand species of aphids, all of them parasitize plants and feed on their sap. Some damage pear trees, although one variety would be enough to classify the insect as particularly dangerous.
Aphids not only pierce young vegetative organs and drink cell sap from them, secreting a sticky secretion. They can spread viruses and other diseases and 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 the fight against aphids must begin, otherwise all measures will be taken in vain. The natural enemies of the pest are beneficial insects:
- ladybugs;
- hoverflies;
- lacewings.
Before the buds open, pears are treated against aphids with the 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.
Among biological preparations, Fitoverm is recommended. Treatment with folk remedies gives good results.
Preventive measures
Spraying with pesticides and folk remedies give good results. But is it worth waiting for the leaves on the pear to turn brown, or for some insect to start gnawing on them? It is better to prevent the occurrence of diseases and pests.
To do this you need:
- carefully carry out all sanitary measures;
- increase the tree’s own immunity;
- follow the rules of agricultural technology;
- carefully cover with paint or garden varnish all damage, including those left after pruning;
- treat pears in spring against pests and diseases;
- prevent frost damage, sunburn and damage to the trunk by hares;
- whiten the skeletal branches and trunk of the pear with lime milk in autumn and spring;
- clean old bark;
- dig up the trunk circle in autumn and spring.
Problems similar to disease damage can arise with improper care. For example:
- with a lack of phosphorus, bronze leaves appear on the pear;
- a critical lack of moisture causes drying out of the vegetative organs and shedding of the ovary;
- overwatering can cause rotting 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.
