Plum diseases and the fight against them, photos to help the gardener. Who is threatening the plum tree? Yellow spots on plum fruits

The most dangerous diseases and pests of plums (Prunus) include clusterosporia, black and brown spots, cercospora, ovularia, leaf blackness, milky shine, rust and pollinated aphids. In some years, trees suffer from frost damage and sunburn.

To preserve the orchard, treating plums from pests and diseases is extremely important. effective drugs and implementation of the necessary protective agricultural practices.

Plum diseases: photos and how to treat trees

First, read the description of plum diseases and methods of treating trees.

Black nodularity, or cancer

The causative agent is a fungus Plowrightia morbosa . Young plum branches affected by this disease thicken, soft greenish swellings appear, which gradually harden and crack. The growths increase, which causes deformation of the branches, and the development of mycelium leads to the death of the wood and drying out of the branches.

Methods of treatment. Trim and burn branches with black knots, disinfect the cuts with 1% copper sulfate and cover with oil paint. To combat this disease of plums, carry out constant preventive spraying of trees before the leaves bloom with 1% Bordeaux mixture or its substitutes.

Hole spot, or clusterosporiasis

The causative agent is a fungus Clusterosporium carpophilum. Numerous, small, reddish spots appear on the leaves, becoming lighter over time in the center, with a vague crimson border. The affected tissue cracks and falls out, the leaf becomes holey.

With severe spread of the disease, buds, young shoots and fruits are affected. Shallow ulcers with gum form on the fruits, and reddish-brown spots with scaly elevations appear. The fruits become deformed and partially dry out. Affected leaves fall prematurely and affected shoots dry out.

Control measures. To treat plums against this disease, spray the trees before buds open, and again, immediately after flowering, with a 1% Bordeaux mixture, HOM or Abiga-Peak. If the disease develops severely, repeat spraying with the same preparations after harvesting the fruits.

Brown spot

The causative agent is a fungus Phyllosticta prunicola. The spots on the leaves are small, ocher in color with a thin dark rim. In the affected tissue, pinpoint dark fruiting bodies of the wintering stage are formed, necrotic tissue cracks and falls out. Affected leaves turn yellow and fall off prematurely.

Control measures.

Cercospora spot

The causative agent is a fungus Cercospora cerasella. The spots on the leaves are small, brown in color with a dark border. Dark sporulation pads form on the underside, the tissues of the spots crack and fall out, the leaves turn yellow and fall off.

Control measures. Collect and remove plant residues, spray trees immediately after flowering with 1% Bordeaux mixture or HOM, Abiga-Peak preparations.

In case of severe spread of spotting, to treat this disease, spray plum trees also with Abiga-Pik after harvesting the fruits.

Ovular spotting

The causative agent is a fungus Ovularia circumscissa. The spots on the leaves are large, concentric, brown and without bordering.

As can be seen in the photo, over time, with this plum disease, a gray coating develops on the surface of the necrotic tissue, the affected tissues crack and fall out:

Leaves fall prematurely.

Control measures. Collect and remove affected fallen leaves, spray trees immediately after flowering with 1% Bordeaux mixture or its substitutes. If the disease spreads strongly, repeat spraying after harvesting the fruits.

Plum rust

The causative agent is a multi-host fungus Puccinia pruni-spinosae. This plum disease manifests itself in spots described as rusty. Small yellowish circles form on the leaves, on the underside of which brown sporulation pads develop. Affected leaves dry out prematurely and fall off.

Control measures. Remove weeds, especially buttercup anemone, and spray the trees immediately after flowering with 1% Bordeaux mixture or its substitutes. Carry out 2-3 treatments with an interval of 7-10 days.

milky shine

Leaves acquire gray with a metallic sheen, become rigid, the wood of the branches does not change. Affected leaves drop prematurely, weakening the trees.

The affected wood on the cross section has brown spots of varying sizes, and the leaves acquire a silvery tint due to the formation of air cavities under the skin.

In mid-June, the affected leaves become deformed, become covered with brown spots and, starting from the tip, dry out. The trees are gradually drying up.

Control measures. Before treating this plum disease, remove dried trees, cut off individual dry branches, disinfect and seal the cuts and frost holes. Then spray with 1% Bordeaux mixture or its substitutes.

Leaf rabble

The causative agent is a fungus Fumago vagans. When there are a large number of aphids, the leaves become covered with their sweet secretions, on which a fungal infection develops. A black sooty film forms on the leaves, which is easily erased from the surface of the leaf blade.

Control measures. When aphids appear, spray the trees with fufanon kinmiks, spark, Inta-Vir, do not allow the pest to develop in large numbers. Spray against mobs with 1% Bordeaux mixture or HOM or Abiga-Pik preparations.

Frost and sunny-frost damage to plums

With sharp fluctuations in daily temperature, the sun-heated crust thaws during the day and freezes again at night. Light spots of irregular shape appear on the trunks and skeletal branches on the southern and southwestern sides of the tree.

The bark dries out and cracks, frost cracks form, turning into ulcers. If the root system is damaged, the trees dry out already at the beginning of summer; if the trunks are damaged, they slowly dry out. A fungal infection occurs.

Methods of treatment. Disinfect cracks and open wounds with 1% copper sulfate and cover with oil paint. Carry out preventive spraying before the leaves bloom with Bordeaux mixture or its substitutes.

Plum pollinated aphid ( Hyalopterus pruni) - a small sucking insect pest of pale green color, covered with bluish-white fluff. In the spring, the larvae hatch and feed on the sap of the buds, and later leaves and shoots.

Several generations of the pest develop; aphids cause the greatest damage in June - July. The leaves do not curl, but remain small and gradually dry out.

Control measures. To treat these plums immediately after flowering with one of the preparations: fufanon, karbofos, kinmiks. If there are a large number of aphids, to combat these plum pests, carry out repeated spraying in compliance with the waiting periods for the preparations.

» Plums

Plum is a fairly common plant that can be found in every garden. You can only get a good harvest of tasty and healthy fruits from a healthy tree. However, gardeners often encounter growing problems such as plum diseases and pests, which can lead to the death of the entire garden.

Tree diseases are associated with insufficient care and improper landing. Most often, plums are affected by viral and fungal diseases that appear on weakened trees. In order to start treatment on time, it is important to know the main signs of the disease.

Plum bushiness or sprouting

This fungal disease is popularly known as “witches broom”. The affected tree produces many thin, short shoots that are collected in bunches. Such shoots will not bear fruit. Only the destruction of infected plants will help in the fight against the disease.

As a preventive measure, not only mineral and organic fertilizers are used, but also Bordeaux mixture. In addition, to protect the site, only healthy seedlings are planted in the garden. They must be purchased only from trusted nurseries.

Gum treatment

The disease is widespread on stone fruit crops that were previously affected by fungi. Most often, the disease begins to develop if the watering regime is disrupted or too much fertilizer is added to the soil. Resin on the tree can be released after frost damage or improper pruning. Signs of gum discharge are as follows:

• wounds and cracks are visible on the trunks and shoots;
• in places where the gum flowed out, transparent frozen drops appeared.

If you do not pay attention to the signs that appear in time, the tree may die. Affected bark is an excellent place for the development of bacteria that lead to tree cancer.

Affected areas on the trunks must be treated with a 1% solution of copper sulfate or garden pitch. It is better to cut out severely affected shoots. In order to further increase the plant’s immunity and avoid re-infection, you need to properly care for the plum.

Plum dwarfism

An insidious viral disease that occurs more often in hidden form. It is difficult to identify the affected tree. Dwarfism can only appear in the last stage, when fighting the disease is pointless. Therefore, all the gardener’s actions should be aimed more at preventative measures.

Signs of the disease:

• suppressed tree growth;
• unnatural leaf shape. They become elongated, gnarled and more like willow leaves;
• premature leaf fall. This happens because the leaf plate becomes brittle;
• decrease in yield;
• absence of peduncles or a small number of them. The flowers are ugly and underdeveloped.

At the last stage of virus development, there are practically no leaves on the tree branches; they are bare. Single needle-shaped leaves can be seen only at the tips of the shoots.

Infected trees cannot be treated and must be uprooted.

As preventive measures, resistant varieties of plums are planted in the garden, and plants are regularly treated for pests.

A fungal disease, the causative agent of which is the vocal fungus. Infection occurs in cold, protracted spring conditions when air humidity is high. Fungal spores penetrate the flowers of the tree, causing ugly ovaries to form.

The fruits of the affected plant are unsuitable for food; they grow deformed. The development of the fungus occurs inside the fruit, in a kind of pocket, so there is no seed in plums. The pulp becomes grainy and wrinkled. Since the fungus only affects fruits, the disease appears once per season.

Fighting methods:

1. Destroy the affected shoots in the first half of summer.
2. Collection and disposal of infected fruits is carried out until the fungal spores disperse.
3. Preventive spraying of plums with a 3% solution of Bordeaux mixture. The first time the treatment is carried out before buds open, then before flowering and after.

The mycelium overwinters in tree branches, so the fight against the disease must begin in the fall. To do this, sanitary cleaning and pruning of shoots, preventive spraying with copper oxychloride and copper sulfate are carried out.

Clusterosporiasis or hole spot

The fungal disease develops in conditions of long, warm but rainy summers, when air humidity exceeds 70%. The fungus overwinters under the bark. The mycelium begins to develop at a temperature of +4 degrees. It can be found on the shoots or buds of the plant in the form of a dark, weak coating.

Spores are transferred to young leaves by the wind and most pests. The disease spreads very quickly. Over the course of a season, many fungal colonies form, which has a detrimental effect on the condition of the tree.

Signs of damage can be seen on all tissues of the plant, but they most often appear on young leaves.

1. Small round spots of various colors that increase in size in a short time.
2. In the center of the spot, tissue dies, which leads to the formation of holes in the leaves.
3. The edges of the holes have a reddish border. This is the main symptom of clasterosporiasis, which distinguishes it from other types of spotting.
4. When the disease is advanced, the tree bark becomes covered with orange-red spots with a dark border. Subsequently, they are pressed into the trunk, crack and lead to gum leakage.
5. Gum also flows from the affected buds and shoots, which leads to their death and reduced productivity.
6. The fruits are affected by ulcers, become one-sided, dry out, harden and fall off. They may also leak gum.

To prevent the disease in the fall, they clean the garden, dig up tree trunks, destroy shoots, collect and dispose of affected fruits and fallen leaves. In addition, it is important to treat wounds and cracks on the tree in a timely manner, avoiding gum formation. For treatment, use a solution of copper sulfate, manganese or garden pitch.

Spraying the tree during the growing season will help fight the fungus. Treatments begin in early spring and are repeated in late autumn. The drugs Kuproxad, Skor, Horus, Topaz or Vectra are used. The last treatment is carried out 20 days before harvest.

Moniliosis

The causative agent of the disease is the monilia fungus. The tree becomes infected during the flowering period if there are changes or decreases in temperature. Cold spring weather only speeds up the process. The spores penetrate the plant tissue through the pistil, gradually affecting the entire tree.

Signs of damage:

• sudden drop of flowers;
• drying of peduncles and adjacent leaves;
• old shoots and branches crack, gum flows from the wounds formed;
• the whole tree looks “scorched.”

The disease spreads not only to the fruits, but also to the shoots and leaves of the plum. The pathogen overwinters in the affected tissues of the tree. Prevention of moniliosis begins in autumn. Cut out all affected shoots and treat the garden with Hom, Bordeaux mixture or copper oxychloride. To spray one tree you will need up to 4 liters of solution.

Small pox on plum

Sharka, popularly known as plum pox, is a viral disease. It appears on young leaves of the tree in the form of chlorosis, spots or stripes. Over time, the leaves acquire characteristic marbling and light areas appear on them. If no measures are taken, the disease spreads to the fruits. They become spotted, the flesh becomes coarse and loses its taste. In addition, the spots begin to deepen into the fruit. Sick plums ripen ahead of schedule, crumble or dry out right on the tree.

Unfortunately, it is impossible to fight the disease. All affected trees must be burned. Control measures are only preventive in nature, aimed at timely treatment of the garden from pests that can spread the virus.

Rust

In July, rusty spots can be seen on young plum leaves, which gradually increase in size. Affected trees shed their leaves earlier. You cannot leave the plum in this state. The winter hardiness of the plant and the future harvest are sharply reduced.

For preventive purposes, trees are treated with copper oxychloride before and after flowering. In the fall, after harvesting, spray with a 1% solution of Bordeaux mixture.

Rust-affected plum leaves

Coccomycosis of plum

A dangerous fungal disease that affects tree leaves and, less commonly, fruits and young shoots. The first signs of the disease are noticeable in early summer.

1. The leaves are covered with small, red-brown spots.
2. A whitish coating can be found on the back of the sheet. These are fungal spores.
3. The leaves quickly turn yellow and fall off.
4. The fruits do not develop, become watery and fall off.

Most often, the disease develops in warm and humid weather and reduces the winter hardiness of the tree. The fungus overwinters in fallen leaves, so in the fall it must be collected and burned. In addition, the tree trunk circle is sprayed with copper preparations or Bordeaux mixture.

Root cancer

Recently, the disease has become more frequent. The cause of its appearance is pathogenic bacteria in the soil that penetrate the plant tissue through cracks in the roots. Specific growths form on infected plum roots, which leads to the death of the tree. Severe drought and a slightly alkaline environment contribute to the development of the disease.

As a preventive measure, the garden is located in a place where there have been no previous outbreaks of the disease. Severely affected seedlings are destroyed. The planting site is disinfected with a solution of copper sulfate.

Dangerous fungal growths on tree bark. Penetrating through small cracks in the bark, the spores destroy the wood. Hollows form in the affected areas. After a few years, a solid fungal body grows in their place. Sometimes she looks completely harmless.

To prevent infection of the tree, you need to carefully treat wounds and cracks in the plum bark. The fruiting bodies of the fungus are destroyed before the spores disperse, usually in early June. The remaining wounds are cleaned of rot, washed with a solution of copper sulfate, and then filled with a mixture of cement and sand (1:4).

This is a bizarre-shaped insect that settles near the fruit buds of plums in growths called galls. One gall can contain up to 400 insects. At the end of May, overwintered individuals emerge on the surface of the bark and feed on the cell sap of the plant. At the sites of bites, reddish growths again form on the bark, where the females lay eggs. In one season, more than one generation of pests grows. Damage to a plum tree by a gall mite can be determined by its characteristic ugly growths.

You need to fight insects immediately after the plum blossoms. Several treatments are carried out with colloidal sulfur preparations. In case of mass damage, it is recommended to cut out and burn the shoots.

Goldentail

This is a white butterfly, the abdomen of which is covered with yellowish hairs. The pest's caterpillars overwinter in fallen leaves. The lacewing begins to cause harm after the plum buds open, actively eating them. Butterflies are nocturnal, laying eggs on the surface of leaves. The emerging caterpillars are very voracious and cause great damage to young leaves in a short period of time. They eat holes in them, slowing down the normal growth of the plant.

To combat insects, trees are sprayed with a solution of karbofos. In autumn, the fight against goldentail does not stop. They collect fallen leaves and loosen the soil under the trees, thereby destroying the nests of the pest.

The first time spraying is carried out before the plum blossoms.

Plum moth

This grey-brown moth causes damage to plum fruits. Its reddish caterpillars overwinter under the bark of a tree or in the top layer of soil. In early spring, butterflies lay eggs in still green fruits. When the caterpillars appear, they feed on the pulp of the fruit, after which they leave for the winter. Affected plums acquire a purple tint and fall off; drops of gum can often be seen on them.

Against the plum moth, preventive spraying with karbofos is carried out, hunting belts are put on trees, and the soil is also regularly loosened.

At the beginning of autumn, additional soil cultivation and loosening are carried out to destroy the pest nests. In addition, all wounds and cracks are washed with manganese and covered with garden thief.

Aphids on a tree

A small pale green insect that sucks cell sap. You can determine the presence of aphids with the naked eye:

• the tops of the shoots curl;
• the tree is stunted;
• pour dry and fall off;
• Small insects are visible on the back of the leaf.

At the beginning of the growing season, plums are treated with drugs against leaf-eating and sucking insects. Spraying is repeated after 10–14 days. The first treatment is carried out “along the green cone”.

hawthorn

A white butterfly that is diurnal. Its caterpillars feed on plum buds, leaves, buds and flowers. The methods of control are the same as with the lacewing and plum moth.

Why do worms appear in plum fruits?

Very often, gardeners complain that almost the entire plum crop is wormy. Why does this happen, leading to spoilage of fruits?

The presence of pests on trees is to blame. Sometimes there may be more than one insect.

Plum sawfly and wormy fruits

Plum weevil on leaves

The females of this insect eat plum buds and flowers, biting into the ovaries. There they lay larvae, which eat the fruits from the inside. The harvest is all spoiled. The larvae and beetles go into the soil for the winter. Trees should be treated in the spring.

How to get rid of fruit worms in a plum

Trees in the garden should be treated as early as possible, without waiting until the pests get to work and the fruits begin to rot. The first treatment should be carried out in early spring. You need to re-spray the plum before and after flowering. If the number of pests is very large, then treatments are repeated at intervals of 10 days. But the latter must be carried out no later than 25 days before harvest.

To prepare the working solution, use the preparations Phosfamide, Dursban, Metaphos, Bordeaux mixture or iron sulfate. When there are a small number of insects, spraying is done with infusions of tobacco, wormwood, dandelion or ash. Infusions are prepared in different ways.

A universal recipe for herbal infusion is prepared at the rate of 200 grams of dry parts of the plant per 1 liter of boiling water. Boil the mixture for 15 minutes, then strain and cool. Dilute with water to 10 liters.

How to deal with plum pests: preventive treatment

Every gardener knows that preventing a disease is easier than curing a garden. Therefore, prevention should always be.

1. Every tree needs proper care, regular watering and fertilizing.
2. Regularly carry out sanitary cleaning of the garden, cut out thickened branches, remove fallen leaves and dig up the soil.
3. In spring and autumn, not only the tree is sprayed, but also the soil underneath it.

It is very important that all actions are permanent. If your neighbor's garden is infested with worms, scab, coccomycosis or leaf curl, this means it's time to get to work and treat your own trees. You shouldn’t hope that “maybe it will pass.”

Conclusion

To reduce the risk of trees being damaged by harmful insects and various diseases, it is necessary to regularly inspect the garden. In addition, carry out prevention, and take immediate action at the first signs of illness. This will increase not only the yield of plums, but also the quality of the fruit.

Plum is one of the fastest-growing and highest-yielding among stone fruit crops. It can be successfully grown in regions that are characterized by harsh weather in winter period. In terms of winter hardiness, it is second only to cherries. Depending on the variety and growing zone, plum yield can be very high - more than 200 kg of fruit per tree. But for this you need to follow high agricultural technology.

EATERS OF FRUITS AND LEAVES OF PLUMS

The quality and quantity of the harvest is influenced by many factors, but one of the main ones is the physiological state of the plants, their resistance to pests and diseases. It is also important to what extent the trees are additionally protected from attacks by harmful organisms. Every year, significant damage to the plum crop is caused by the black plum sawfly, eurythoma, or plum thickipe - pests from the order Hymenoptera, as well as plum and eastern codling moths from the order Lepidoptera. It is possible to limit the number of phytophages if you control their vital activity during critical periods of development for them. To do this, you need to know how pests reproduce. are born, grow and feed. and when they are most vulnerable.

with sucking mouthparts (mites, aphids) and leaf-eating phytophages (moths, leaf rollers, moths, silkworms, hawthorn, lacewing, American white butterfly, or ABB). Rosaceae develop in one generation during the growing season. variegated golden and combative leaf rollers. Two or three generations per growing season are produced by currant, willow, reticulated, omnivorous and other types of leafrollers. Among the moths, the plum is damaged by the winter moth and the fruit moth. fluffy, moon-shaped and other species of this family.

Pests of the second group include codling moths - plum moth, oriental moth (it also damages shoots), sawflies, plum moth. goose and chafers (adult insects supplement their “menu” with leaves). The most common phytophage from the second group is the black plum sawfly. In plum plantations massively populated by the sawfly, up to 95% of the ovary falls off. Under the infected trees, in the trunk circles, there is a large number of fallen fruits with black exit holes on each. They were made by the larvae, leaving for cocooning in the soil after completing their development cycle.

The plum moth and plum moth, multiplying uncontrollably in plum plantations, occupy an “honorable” second place in terms of harmfulness after the sawfly. If the development of the larval stage of the codling moth takes place in the stone, then the larvae of the plum moth feed in the pulp of the fruit. During this period, they make a passage around the seed to the stalk, gnawing at the same time the vascular system in the plant tissues and disrupting the circulation of nutrients. Fruits damaged by codling moths and moths are prematurely colored purple and fall off.

The habitat of the eastern codling moth has been formed; the species is widely distributed in all peach and plum growing areas. In the fight against the eastern codling moth. except spraying chemicals, mechanical methods are effective - if you cut out and burn damaged, wilted shoots of all fruit crops (especially peach) in a plot in time, this will limit the number of the pest.

Scale insects and false scale insects are included in the third group of phytophages. They suck juices from the leaves and bark of branches, which leads to drying out and death of young trees. As a result of the toxic effect of the saliva of the Californian scale insect, longitudinal and transverse cracks appear on the trunk and branches. When feeding, the acacia false scale excretes a large amount of honeydew, on which sooty fungi then develop, contaminating the leaves and branches.

The California scale insect and the American white butterfly are quarantine pests - if they appear in fruit plantations, protective measures must be taken regardless of the number of individuals.

WHEN TO START SPRAYING A PLUM OR DO YOU COUNT EVERYTHING!

In order to carry out all the necessary protective spraying on time, it is necessary to rely on indicators of the economic harmfulness of pests (Table 1). The number of pests is determined visually by shaking them off trees, as well as installing and periodically cleaning pheromone traps. Before each spraying, which is carried out during the growing season, they first examine the degree of damage to trees by pests and decide whether it is now advisable to treat the plants with chemicals.

The number of fruit sawflies is determined during the white bud phenophase, until the air temperature exceeds 10 °C. To do this, in the morning, when adult insects are inactive, they shake the tree branches and count the fallen individuals. A more effective method of controlling the development of this pest is white glue traps. If the number of adults in the trap exceeds the threshold (Table 1), then treatment is necessary. After treating plums with Aktara preparations 25% w.c. g. or Confidor Maxi (Table 2). which is carried out against sawfly adults before plum blossoms, repeated treatment (against larvae after flowering) is no longer necessary, since these drugs long term action (21 days).

Owners of summer cottages and garden plots sometimes find it difficult to decide on the advisability of treatments against the plum moth - they simply do not have enough data for this. Firstly, in order to predict the number of pests in the current season, you need to know how many insects there were in the previous one. Secondly, the number of codling moth butterflies during the growing season is determined using pheromone traps. They make it possible to control the population density of a species and signal the need for protective measures if the quantitative composition of butterflies exceeds the economic threshold of harmfulness (ELT).

If pheromone traps are not freely available, you can rely on the first indicator - the degree of harmfulness of the species in the previous year. If 2% of the crop was damaged, then treatments against the codling moth are necessary this year. For spraying to be effective. It is important to set the processing time correctly. The basis for their determination is the phenophases of fruit trees, weather indicators and direct observations of pests.

The period of spraying against the plum moth is determined by the sum of effective temperatures of 200 °C (threshold 10 °C), at which the first generation caterpillars begin to hatch. Against this pest, in addition to Matcha, Lufox and biological products (Table 2], pyrethroids are also effective - Decis Profi, Karate Zeon, Arrivo, Fastak, approved for sale to the public. There is a limiting factor in their use - the air temperature should not rise above values ​​20 °C. high temperature ultraviolet rays destroy the active substance of drugs and reduce their effectiveness. Insecticides from the pyrethroid group should be used during the hatching period of moth caterpillars, in the morning or evening.

According to the experiments of scientists at the Institute of Horticulture, drugs from a new group - insect growth and development regulators (Match. Lufox) are very effective against lepidoptera, and their effect does not depend on weather conditions. The duration of the toxic effect of Matcha and other insecticides of this group is 28-35 days after their use. The match is effective against caterpillars of codling moths, leaf rollers, moths, and mites. The effect of the drug is manifested in the inhibition of chitin synthesis in caterpillars during the transition from one age to another; as a result, the treated individuals cannot complete this process and die.

The spectrum of action of the drug is expanded due to the ovicidal effect - when females lay eggs on the pre-treated surface of leaves or tree bark, caterpillars do not hatch from them. Match, 5% k.e. and Lufox 105 EU, k.e. should be used on plum varieties of different ripening periods at the end of May - the first ten days of June, during the peak summer of butterflies, mass oviposition and hatching of caterpillars. Plum plants of mid- and late-ripening varieties are sprayed a second time (with one of the above insecticides) 28-35 days after the first treatment. Late varieties of plums are sprayed against the plum moth three times during the growing season.

Among the diseases that affect plums, the most common are cleasterosporiosis (hole spot), fruit rot, red spot (polystigmosis), cytosporosis, rust, gommosis (gum disease), plum pockets, plum pox or plum pox (viral disease). In all plum growing regions, clusterosporiasis “dominates”. Polystigmosis affects trees mainly in the southern regions. Other pathogens of plum diseases are found everywhere, to varying degrees.

To obtain stable and high-quality fruits, scientists recommend an integrated protection system (IPS) for plums, developed at the Institute of Horticulture. It is aimed at combating both pests and diseases, and takes into account the characteristics of their development and spread. According to the IZS, highly effective drugs are used to protect the garden.

ECO-METHODS FOR PEST CONTROL OF PLUM

For connoisseurs of environmentally friendly products, there is a simple method of protecting fruits using microbiological insecticides. Bitoxibacillin (BTB), lepidocide, and gaupsin are effective against plum moth and other species of lepidoptera. The production of these environmentally safe and highly effective preparations is seriously pursued at the Odessa Engineering and Technology Institute “Biotechnika”, at the Institute of Plant Protection (Kiev), as well as at some regional plant protection stations. The drugs are available in liquid form, with a consumption rate of 100 ml per 10 liters of water. Two treatments are carried out against each generation, with an interval of 8-10 days.

If possible, you should abandon the use of chemicals against plum moths or reduce their quantity and rate of application (the so-called economically feasible reduction), since insecticides applied in the summer destroy beneficial insects that can keep populations of mites, aphids, and leafminers on sub-threshold level.

Goldentail

To reduce the consumption of chemical insecticides, herbal preparations with insecticidal properties are used. Hot peppers are effective against aphids and codling moths. (1 kg of fresh or 0.5 kg of dry pods is poured into 10 liters of water, kept for two days, boiled for 1 hour, cooled and left for two hours). The prepared broth is stored in a dark place in well-sealed containers. Before flowering use 0.2

l of concentrate, after flowering - 0.1 l per 10 l of water. A decoction of wormwood is also used as an insecticide. To do this, during the flowering period, the leaves and upper parts of the plant are collected, then half a bucket of fresh or 700-800 g of dried mass is poured into 10 liters of water, left for 24 hours, boiled for 30 minutes, cooled and 10 liters of water are added.

ADDITIONAL MEASURES FOR PEST CONTROL OF PLUM

When carrying out protective measures on fruit-bearing plums or other crops, it is advisable to use pesticides and mineral fertilizers together. Tank mixtures of insecticides, fungicides and fertilizers are simultaneously effective against insects, pathogens, and have a wide range protective action, prevent the emergence of resistant populations of harmful organisms, and create favorable conditions for plant development.

Combined compounds of insectofungicides with mineral fertilizers (nitroammophoska, urea or ammonium nitrate) are highly effective. When using mineral fertilizers with a consumption rate of 30-50 g per 10 liters of water, the technological quality of the working solution improves - suspensions and emulsions are more stable, they better wet the leaf surface and “stick” well, remaining on it. By adding fertilizer to the working solution, you can reduce the consumption rate of insecticides by 20-30%.

In addition to protective measures, it is important to maintain agricultural technology high level. Caring for fruit trees includes watering and fertilizing. Plants need an additional portion of moisture in the summer, in the heat, and in late autumn they also need moisture-replenishing watering. Fertilizer feeding (root and foliar) improves the physiological state of trees and increases their resistance to adverse environmental conditions.

In addition to biological, chemical, mechanical and agrotechnical methods of protection, immunological ones also occupy an important place in IPS. By cultivating plum varieties that are resistant or tolerant to one or more types of pests, it is possible to reduce the number of protective sprays and still obtain good harvests quality fruits.

The plum borer massively damages the fruits of the varieties Vengerka azhanskaya, Stakhanovka, Vengerka kozievskaya, Katerina, Velyka sonya, Pombrion, Perdrigon mugasty, less so - Renklod green, Vengerka opishnyanskaya. Victoria, weak - Peach, Early, Edinburgh, Hungarian Italian, Prince, Anna Shpet.

The plum varieties Renklod Kievskiy, Ugorka Azhanskaya, and Anna Shpet are relatively resistant to klyasterosporiosis.

The varieties of plums most vulnerable to plums are common Vengerka, Empres, Vengerka Italiana, and Renklod collective farm. Chachanskaya Rodna and Hungarian Wangenheim are relatively stable. Kirke, Valor, Oneida, Early blue, Herman, Renklod Ulena, Anna Shpet, Hungarian Azhanskaya. The varieties Rutgersteter and Renclad Altana are tolerant. Renklod Kyiv, Opal, Stanley, Sanctuss gubertus, Chachanskaya naiboliya, Chachanskaya lepotika, Chachanskaya early, Ganita, Top, Voloshka, Oda, Titmouse.

Plum is one of the most common fruit crops in personal plots. The yield of a tree directly depends on how competently agrotechnical measures are carried out. At proper care the plant pleases with delicious fruits for many years, and if the gardener makes mistakes, it gets sick and becomes vulnerable to pests. Later in the article we will dwell in more detail on what plum diseases the most dangerous, and we’ll figure out how their treatment.

Types of diseases

In order to select a drug that can destroy pathogen and to help the tree recover, it is necessary to determine what kind of ailment has affected the plant. They are divided into:

In addition, the plum can be colonized by insect pests. They can cause great damage to the garden.How to deal with plum worms,can be found below.

Viral infections

The causative agents of this kind of illness are representatives of a special form of life - non-cellular complexes of organic molecules. They can only be observed using a powerful microscope. Viruses are transmitted by insects; infection sometimes occurs when infected cuttings are grafted onto a healthy crop, or when using tools used to trim diseased plantings.

Small pox on plum

The second name of the disease is sharka. The causative agent of the disease has a thread-like shape; the virus consists of one large molecule. The most common route of infection is through pruning with untreated pruners and loppers. Sometimes the infection is transmitted by insects. The disease significantly reduces the tree's immunity. The main signs of infection are:

• yellow spots on the foliage;
• dark stripes on the fruits that gradually become denser, gum therapy;
• early leaf fall;
• underdevelopment of fruits and their falling off, plum pulp - red inside, dense.

Unfortunately, there are no drugs that can remove the virus from wood tissue. Fight it can only be to prevent the further spread of the disease.

The affected plant must be cut down, after which the stump must be uprooted. All parts of the tree must be burned. The only reliable way to avoid the misfortune is to plant varieties of plums that are resistant to smallpox (“Presenta”, “Tegera”, “Elena”, “Topper”, “Tophit”, etc.)

Chlorotic ring spot

The disease spreads through the process of vaccination, through pollen. Stages of manifestation of the disease:

• the leaves are covered with yellowish or bright green rings, the width of which is 2.5 - 3 mm;
• foci of necrosis appear in the spots, tissues fall out, and holes;
• plant growth slows down, branches begin to die.

Chlorotic blotch is distinguished from clusterosporia blotch by the persistence of mosaic patterns around the openings. Due to the virus, yields are almost halved. Infected plants are uprooted and burned. To prevent disease, it is necessary to plant only known healthy material.

Dwarfism

The causative agents of this disease spread through the sap of infected plants, carried by ticks, aphids and some other insects. The disease can be recognized by the following signs:

• leaves become small and fragile;
• clusters of abnormal leaf plates form at the tips of the shoots;
• a diseased tree stops growing and the process of dying begins.

Treatments for dwarfism does not exist: the plant will have to be completely destroyed. You can only prevent the occurrence of the disease by purchasing seedlings only from trusted suppliers. In spring, the garden should be treated with the following preparations: “Akarin”, “Fitoverm”.

Fungal

Clusterosporiasis or hole spot

The fungus only affects stone fruit culture. Sourceplum blightis the infected substrate (branches, trunks trees), where pathogen spores are stored and carried by wind and insects. High humidity is favorable for fungal activity.

Pathological process during infectionClusterosporiosisis divided into several stages:

• on young leaves small yellowish ones appear -brown inclusions;
• the spots increase (their size can reach 1 cm) and darken;
• inclusions dry out and formholes in leaves;
• the foliage turns yellow and falls prematurely.

If infection occurs during dormancy tree , in spring most of the buds do not open. The branches acquire a purple-red hue and are covered with cracks with gum inside. Gradually the tree dries out. How to treat plum cluster blight? Affected perforated spottingfragments of wood should be cut off and burned, then treated with one of drugs with low phytotoxicity (“Abiga-Pik”, “Granuflo”). In early spring, plantings are sprayed with organic products such as “Figon”, “Fthalan”, “Tsineb”, “Kaptan”. It is more effective to use such drugs before swelling,how to treat klyasterosporiosisin a neglected form.

Moniliosis or monilial burn

For this fungal The infection is characterized by rapid development. The pathological process begins in the spring, when plum blossoms occur. Spores carried by insects land on the stigmas, which leads to the darkening of the opened flowers. They wither, yields fall catastrophically. The leaves dry out and the tree looks burnt. On the affected moniliosis In the substrate, a gray sporogen can be observed. After removing the “burnt” parts of the plant togetherwith black leavesit is necessary to immediately treat the plum with chemicals:

• "Topsin-M";
• "Switch";
• "Horus";
• "Fitolavin".

Spraying with fungicides during flowering will prevent further spread of the disease.

Signs of coccomycosis

A diseased tree is easy to recognize:plum leaves are turning red. At first the spots are small, but then they grow larger and merge with each other. On the underside you can see gray-pink growths , containing disputes. Dead tissue falls out in places: leaves are observedinto a small hole. Already in early August, leaf fall occurs. Young shoots can also be subject to deformation. Fruit do not have time to ripen, their pulp acquires a watery consistency. Coccomycosis spreads in windy weather, and spores can also be carried by insects. It is very important to collect and burn dry leaves and grass on the site: this will serve as a preventive measure. If a disease is detected, branches with leaves that have changed color are removed entirely. Then treatment is carried out with the drug “Skor” (1 ampoule dissolves in 10 liters of water).

"Pockets" - marsupial disease

The infection is transmitted through dirty tools, and high humidity contributes to the development of the disease. The surface of the fruit becomes covered with powdery white coating containing fungal spores. A seed does not form inside; the plums take on an elongated bag-like shape. The pathogen overwinters between the scales of the buds, on the shoots.

Branches with diseased fruits must be cut out and destroyed. Affected fruits should also be burned.

To treat wood, use 1% Bordeaux mixture. “Kuprozan”, “Kaptan”, “Zineb” are also suitable.

Milky shine and its types

• Potassium chloride must be added to the soil;
• all mechanical damage to the tree should be immediately process 3% copper sulfate.

Polystigmosis or red spotting

The disease spreads in dry, windy weather, when fungal spores are carried by air currents. First symptoms appear from the beginning of summer:

• observed red dots on leaves, which gradually increase, reaching about 1 cm in diameter;
• the affected tissue becomes thicker, its color turns burgundy.

Many people are interested in why polystigmosisfallen leaves turn black. This process means that the fungus goes through a marsupial stage of development.

As a result of the disease, the process of photosynthesis is disrupted, the plant weakens, its yield and frost resistance sharply deteriorate. To protect the plum:

• fallen leaves must be destroyed;
• in the spring (before the sap begins to flow) the tree is sprayed with the fungicide “DNOC”;
• immediately after removing the affected substrate, treatment is carried out with the drug “Chorus” or “Switch”.

Brown spot

The disease has a second name - gnomoniosis. The disease spreads if autumn measures to remove fallen leaves are neglected. Infection can spread through dirty tools. When affected, plum leaves become covered with smallred spots, having an ocher tint, which are surrounded by a purple border. After some time they appear black formations containing disputes.

When the spots merge and cover the entire leaf, it curls and falls off. Most fruits do not have time to ripen, on plums deformed areas are observed. Diseased branches must be cut off. The fungicide "Hom" is suitable for spraying. in autumn fallen leaves must be completely collected and destroyed, and the soil under the tree must be dug up. Next spring, before flowering begins, the trees are sprayed with a 1% solution of copper sulfate, and after the end of the phase - with Bordeaux mixture (100 g per 10 liters of warm water).

Rust and spread

Infection is facilitated by the presence of weeds around garden plot, a large number of insects. The pathogen spreads easily, since the plum has no immunity from rust . Signs of damage:

• the appearance of small dots on the leaves orange colors that gradually increase in size;
• the appearance of brown bulges with spores on the underside;
• premature drying and falling leaves.

Control measures with the disease should, first of all, include the destruction of affected leaves and small branches, as well as weeds in and around the garden. After the end of flowering, the plantings are sprayed with the following preparations: “Zineb”, “Kaptan”, “Khomecin” or copper oxychloride.

Sooty fungus or niello

• the appearance of small black spots on leaves, fruits and young branches;
• their subsequent fusion, as a result of which plant fragments are covered with a sooty film;
• stopping the growth of plantings.

Treatment black plaque on plumyou need to start by removing infected branches. Then the plantings are sprayed with Fitoverm. After 1.5 - 2 weeks, the trees are treated with chemicals to eliminate insects. It should be taken into account that the manipulation is carried out either 1 - 1.5 months before the harvest ripens, or after the end of the fruit harvest. For this purpose, insecticides are used: “Aktellik”, “Aktara”, “Biotlin”.

Plum curl

The spores of the causative agent of this disease are easily spread by strong wind. Insects also contribute to the spread of the scourge. Signs curly is the deformation of the branches. The leaves bend, become “corrugated”, and then turn yellow. Their color gradually becomes brown-black. The fungus also affects the fruits: they become practically inedible. Twisted shoots and blackened leaves should be cut out and burned. After this, the wood is treated with 3% Bordeaux mixture. When planting, preference should be given to resistant varieties (“Hungarian”, “Anna Shpet”, “Renklod”).

Black nodularity

Nodularity (cancer), caused by a pathogenic fungus spreading through gardening tools or diseased cuttings. The main symptoms of the disease are:

• thickening of young shoots, appearanceon the branches of black tubercles;
• gradual hardening and cracking of growths;
• deformation of larger branches, death of wood.

Methods to combat fungus on the trunkconsist of pruning and burning the affected shoots. After the procedure, the wounds must be covered with oil paint or varnish. To prevent infection, trees should be sprayed with Bordeaux mixture according to the instructions. The manipulation is carried out before the leaves bloom.

Defeat by false tinder fungi

These mushrooms settle on weakened, old trees. False polypores cause destruction of the core of the tree. Rotten fabrics on the cut have a light gray or white. The fruiting bodies reach 7-8 cm in diameter, their shape most often resembles a pillow. The caps of young mushrooms have a brown tint; with age, the color turns into dark gray.

If an old tree is damaged, it is advisable to get rid of it.

If a young plant is sick, you can try to correct the situation. To do this you need:

• remove the bodies of mushrooms, and if they have settled on small branches, cut off the entire shoots;
• disinfect wounds with a 3% solution of copper sulfate;
• cover up the damage with garden varnish;
• add urea or superphosphate to the soil to improve plant nutrition.

With timely localization of the disease, there is a possibility of self-healing of strong plantings.

Scab and its symptoms

The disease is caused by a marsupial fungus and is widespread in areas with temperate climatic conditions. The pathogen spores are spread through fallen leaves. Since their germination requires moisture and low temperatures, the peak incidence is observed in years with a cold, long spring. Young leaves are very susceptible to infection. Here's a shortdescription of the disease:

• leaves become covered with spots with an olive tint;
• dark areas appear on thin branches, and then on fruits;
• The blackened areas harden and crack, and the fruit becomes ugly.

Darkened branches must be cut off. Then the plant should be sprayed with “Skor” or “Chorus”. After 14 days, the procedure must be repeated. For preventive purposes, in early spring, plantings are treated with a solution of copper sulfate.

Bacterial

Bacterial diseases are caused by single-celled microorganisms. Healing plantings in such cases is possible if you choose the right drug. Then crop losses will be minimized.

Bacterial spot

Not only plums are susceptible to the disease: almost all stone fruits can be affected by this scourge. The causative agents are bacteria, the wintering place of which is buds and small cracks on the branches. Signs of the disease:

• the emergence of small dark spots round shape on the leaves;
• the appearance of depressions on the fruits that look like sores.

If signs of the disease appear, special attention must be paid to the thoroughness of autumn cleaning: all fallen leaves should be burned. To destroy pathogens, the tree is sprayed with 3% Bordeaux mixture.

Witch's broom plum

This phrase refers to fragments of the crown, the branches of which have an abnormal shape. The disease spreads through untreated instruments and infected cuttings. At the site where the pathogen settles, the increased growth of thin shoots begins, which subsequently turn out to be sterile. The leaves become reddish, small, and quickly fall off. If an illness is detected, you must:

• cut out diseased branches and burn them;
• carry out treatment with “Cuprozan” or “Kaptan”;
• In the spring, treat the plantings with 3% Bordeaux mixture.

Root cancer

The disease is caused by bacteria that enter the root system from the soil. Factors provoking the development of the disease are the lack of watering during prolonged drought and planting plums in poor, low-nutrient soils. Multiple brown growths appear on the roots, the plant gradually dries out and dies without visible damage to the above-ground parts. The fight against root cancer that appears on the site should consist of:

• uprooting and burning diseased specimens;
• disinfection of the soil at the site where the tree grows with a solution of copper sulfate.

Bacterial burn - “Antonov fire”

The disease is spread by insects. Both young and mature plants can be affected. The first manifestations can be seen on the flowers - they become dark and fall off. The branches are coveredbrown spots, then turn black, acquiring a “burnt” appearance. Necrotic lesions appear on the leaves. The disease can quickly spread throughout the garden. As a result of the damage, the fruits turn black, the bark becomes soft and cracks. The disease must be localized as soon as possible. Affected specimens will have to be destroyed. For prevention in the spring, it is necessary to treat the garden with a solution of copper sulfate (100 g diluted in 10 liters of water). At the end of spring, the plum is treated with Azofos fungicide. It is necessary to regularly uproot wild fruit trees, growing within a radius of 100-150 m from the site.

Non-communicable diseases

The appearance of this kind of ailment is facilitated by errors in caring for plantings: lack of timely watering and improper application of fertilizers. Studying agricultural technology will help you avoid misfortune.

Gum formation or gommosis

Gum is a sticky transparent mass that exudes from wounds on the trunk and branches of trees. Gommosis is caused by mechanical damage to the bark when the cambium is affected. The process is dangerous because pathological fungi or bacteria can get into the wound. Plantings more often react with the loss of gum if they grow on acidified soil. clay soil, in conditions of high humidity, when the grafted cuttings are incompatible with the rootstock. To prevent a pathological process, it is necessary to handle the plantings as carefully as possible. Do not scrape off dead bark, as this may expose living tissue. After cutting off the branches, the cut areas must be covered with garden varnish.

Three times a season, the trunks and lower parts of the skeletal branches of the plum tree should be bleached: this measure will protect the plantings from sunburn.

Drying out

The cause of the disease lies in improper care. All stone fruits have increased sensitivity to watering. During dry periods, the process of wood dehydration may begin, which leads to a decrease in yield and causes the death of the tree. Plants that have just overwintered at unusually low temperatures are especially sensitive to lack of moisture. As a result, the leaves curl and dry out, and then the branches. To prevent drying out, the plantings must be provided with watering. The lower part of the trunk needs to be protected in winter: the snow around the tree should be raked and compacted. You should not choose northern slopes or lowlands for planting plums, where cold air can stagnate.

Signs of pest damage

This topic is very extensive and therefore requires consideration in a separate article. Let us briefly highlight the main points. Competent pest controland prevention of damage by them is extremely important for plantings: such measures help prevent deterioration in yield and damage to the marketable appearance of fruits. Among the insects that cause the greatest damage to plantings, the most common one is the plum sawfly. Leaves can be seen on a diseased tree in the holes . Pests also attack the ovaries, as a result the yield is reduced by 80-90%.

The plum moth is an insect whose larvae live inside plums. Wormy fruits They darken early and fall off prematurely. The waste products of the larvae make plums unfit for consumption: their pulp dark inside , its structure is destroyed. Cane aphids are insects that live on leaves and shoots. The plant is covered with a bluish coating, which interferes with the normal functioning of the plant. A lover of plum trees is the wrinkled sapwood.

This is a small black bug, about 3 mm long. The insect damages the bark on thin branches. To destroy insects that attacked the plum tree, in late autumn it is necessary to carefully dig up the soil in the near-trunk area. Those pests that live under the soil layer will appear on the surface and die in winter. In early spring, you should regularly monitor the growth of buds. Insects that attack the ovaries can be collected by hand or shaken off.

Prevention methods

The most important thing is to regularly inspect the plantings for the appearance ofworms in fruits, rot , deformation of plant parts.Treatment for diseasesmay be effective, but preventing illnesses is still much easier. First of all, the situation should be alarming if:

• appeared here and thereholes in leaves;
• shoots and foliage began to become covered rusty spots;
• any fragments of the plantingcovered with a white coating;
• abnormal branches have appeared (curved, thickened, darkened or too thin);
• some shoots turned black;
• individual leaves of the planting blushed.

Such trees need to be monitored daily, after first removing the first affected parts of the plant. In addition, preventive measures must certainly include:

• autumn harvesting of leaves and burning them, even if there are no signs of disease on the trees;
• in the spring, before the buds swell, garden plantings should be sprayed with a 1% solution of copper sulfate.

Pests and diseases of pluma lot, and the damage they cause is significant. If, for example,all the leaves are in holes, the tree is not able to receive adequate nutrition, as photosynthesis is disrupted. Fruit diseases cause them to become inedible. Therefore, the gardener should pay attention to the prevention of diseases first of all.

Material prepared by:

President of the Association of Gardeners of Russia (APYAPM), Doctor of Agricultural Sciences

Danilova T.A.
APPYAPM specialist

Using material Barbara Błaszczyńska doradca sadowniczy

Plum diseases

Plum, like other fruit crops, is affected by many types of diseases - fungal, bacterial and viral. In plum orchards, trees are susceptible to infection during the growing season, which can lead not only to large crop losses, but also to the death of the orchard.

Moniliosis, gray fruit rot(Monilia fructigena Pers.). Fungal disease. The causative agent of the disease overwinters on mummified fruits and infected branches. In spring (during flowering), plants become infected with spores carried by wind and insects. The disease spreads especially strongly in years with prolonged flowering and high air humidity. A small brown spot appears on the surface of the fruit, which within 10 days grows over its entire surface. Then pads (fungal spores) form on the fruits. The pulp of plum fruits becomes loose and tasteless. Wounds appear on the skin of the fruit, from which rotting begins. Infection can occur through close contact with a sick fetus. A high degree of damage leads to significant crop losses.

Rice. 1. Moniliosis: fruits, shoots and flowers are affected

Sharka (pox) plum(PPV Virus). Chlorotic spots of various sizes appear on plum leaves. They can be round, in the form of rings and stripes. If the disease progresses, the leaves acquire a bright marble color with yellow-green areas. Dark green spots in the form of stripes and rings appear on the fruits in July. The fruits take on an ugly shape and fall off. Individual fruits become mummified. Often the leaves dry out prematurely and fall off. Then the branches begin to dry out, and later the whole tree. The disease is most often spread by aphids. But the virus can still be transmitted during budding and vaccination. With a high degree of spread of the disease, you can lose not only the crop, but the entire garden.

For the purpose of prevention, it is necessary to destroy aphids in the garden. Currently no effective methods fight against the shark.

Rice. 2. Plum ball.

milky shine(Chondrostereum purpureum Pers.). Air voids form in leaves damaged by frost. The leaf blades become silvery-whitish. Gradually, the leaf tissue dies off and they dry out. The wood of the trunks and branches becomes dark.

Rice. 3. Milky shine

Cytosporosis (Leucostoma cincta, L. Persoonii). Signs of this disease are wilting of leaves, drying out of young shoots, branches and even entire trees.

Infection usually occurs during the dormant period of trees - early spring and autumn. The causative agent of the disease easily penetrates the tree tissue through mechanical damage to the bark and cracks. Large, rapidly growing ulcers form on the bark. The bark darkens, turns red-brown and dies. When you try to separate the bark from the wood, it wets instead of peeling off. On the surface of the dead bark, a papillary mass forms in the form of small swellings (dark pycnidia of the fungus), which in damp weather appears in the form of red and yellowish mucus.

Rice. 4. Cytosporosis

Plum pockets, Taphrina pruni is a fungus that attacks fruits that grow but do not form a seed. The surface of damaged unripe plums is covered with a white powdery-waxy coating with sporangia of the fungus. Marsupial disease is detected immediately after plum blossoms. The development of the disease is promoted by high air humidity. Affected fruits have no value - they remain empty, inflated, inedible. The surface of damaged fruits is covered with a powdery white waxy coating. The fungus overwinters as spores on bud scales and as mycelium on shoots.

Rice. 5. Plum pockets

Bacterial burn, cancer(Pseudomonas syringae pv. Morsprunorum).

Trunks, skeletal branches, young shoots, buds, leaves and flowers are damaged. The bark in damaged areas darkens, peels off, and shallow wounds form. Damaged buds and leaves turn black, dry out and remain on the tree. Trees are affected mainly in spring and autumn. Wet and rainy weather is especially conducive to the spread of the disease, which often leads to the death of trees.

Rice. 6. Bacterial burn

Clusterosporiasis, hole spot (Clasterosporium carpophilum Aderch.). Pale brown round spots with a diameter of up to 6 mm, framed by a reddish border, appear on the leaves. Within 1-2 weeks, the spots crumble and holes form in the leaf blades. With severe damage, plum leaves begin to dry out and fall off. Depressed growing purple spots appear on the affected fruits. As they grow, they become brown and take on a convex shape. Gum leaks from the swollen spots. The pulp in places where spots form dries to the bone. The intensity of the process of assimilation of the leaf blade decreases.

Rice. 7. Clusterosporiosis on plum

Polystigmosis or red spotting(Polystigma rubrum Pers.) The leaves suffer the most; swellings appear on them, having a fairly bright orange. Spots form both on the underside of the leaf and on the top. The disease is especially severe in years with heavy spring rains - in July the leaves become heavily spotted. The disease can cause massive early leaf fall. Affected trees weaken, their winter hardiness decreases, and flowers and ovaries may fall off. However, polystigmosis cannot be called too dangerous a disease.

Rice. 8. Plum polystigmosis

Gommosis (gum discharge). A painful phenomenon that occurs most often in tree crops. It is characterized by the secretion of an amber or brown, thick and sticky liquid on the above-ground parts - mainly on the trunk, branches, fruits, and less often on the leaves.

The causes of the phenomenon are varied - wounds, frost damage, unfavorable growing conditions, damage by insects, damage by microorganisms. Resin is released in places where branches are cut and where the bark has suffered from sunburn or frost damage. As a rule, the affected branches dry out. Hommosis can be caused by excess nitrogen and moisture in the soil. Gum production is dangerous in cold and damp seasons, especially if the plants are weakened by pests, severe pruning or other diseases. Bark impregnated with gum is a favorable environment for the development of colonies of bacteria that cause cancer of the trunk, branches and twigs.

To avoid the appearance of gum, do not allow mechanical damage to the tree. Any wounds that appear should be immediately cleaned and disinfected with a 1% solution of copper sulfate and covered with petralatum. If the branches are severely affected, they should be removed.

Table 1.
Plant protection from diseases

Table 2.
Methods for combating plum diseases

+ - low, ++ - medium, +++ - high