Diseases of plums: names and symptoms, methods of treatment and prevention measures

Plum is a fruit tree that is sensitive to all diseases. Trees are affected by fungus, infection, bacteria and non-communicable diseases. Signs of infection appear on leaves and fruits. In order not to miss the onset of the disease, plums are examined during the formation of the crown, buds and fruits. Otherwise, the infection will cover the entire tree and spread to other fruit crops.

Fungal diseases in plums

Plums are affected by fungi typical of garden plants and specific ones that are found on fruit trees.

Coccomycosis

Fungus appears on leaves in June:

• brown dots outside;
• white plaque spores on the reverse side.

Yellow dotted leaves fall, followed by fruits. The crop is not ripe. Fungus spores live in fallen leaves. To prevent their development in the spring, the leaves are burned in the fall. The soil of the near-trunk circle is sprayed with preparations with copper or Bordeaux liquid.

Rust

The causative agent of the disease is a fungus that overwinters in last year's foliage, and in spring develops on an anemone flower, anemone. The spores of the fungus are transferred to the plum tree in summer.

How the disease progresses:

• leaves are covered with light brown spots between the veins;
• black mycelium with spores form on spots;
• the tree loses its leaves, becomes vulnerable to frost and other diseases.

The first rust spots appear in July. At the same time, treatment begins. The tree is sprayed with a 1% solution of Bordeaux liquid or any fungicidal preparations. Then the treatment is repeated every 2 weeks. Disinfection is stopped 3 weeks before fruit ripening. Any nearby anemone should be destroyed as the spores persist in its rhizome and leaves.

Brown spotting

The disease manifests itself in the spring. Signs:

• red-yellow, brown markings on leaves;
• black dots;
• curling and drying leaves.

The crown of the tree is crumbling. The fruits rot, do not fully ripen and are deformed.

Treatment of brown spotting:

• spraying the branches and earth of the near-stem circle with a 1% solution of copper sulphate before flowering;
• treatment with 1% Bordeaux liquid 2 weeks after the start of flowering.

Bordeaux liquid will be replaced by Hom fungicide. A heavily affected plum orchard is additionally treated 20 days before fruit picking.

Plum pockets

Golomarsupial fungus spores develop in flowers. Plum orchards are sick with pockets after a long spring, rainy summer.

The disease manifests itself on green fruits with the following symptoms:

• elongated shape;
• overgrown pulp;
• no bones.

Fruits are covered with a matte white bloom, and then fall off. Signs are visible on the 15-17th day after the ovary. Branches and fruits affected by the fungus are removed and burned. In autumn, trees are sprayed with copper sulphate or Bordeaux liquid.

Clusterosporiasis

Spores of the fungus live in sections on shoots, buds. The causative agent is dormant in winter. Signs of fungus on leaves:

• brown spots with crimson border;
• the middle of the spots dries up and falls off;
• holes remain on the leaves.

The riddled leaf dries up and falls off.

Manifestation of the disease on the fruit:

• small red spots;
• marks increase, become convex;
• a resinous substance is released from the affected areas.

The fungus covers individual branches. They are covered with red spots. In the advanced stage, the bark cracks, the shoots dry up, and the tree dies.

For the treatment of plums, Bordeaux mixture is used:

• 1% solution - before the start of the growing season, during the budding period, after flowering and 3 weeks before fruit ripening;
• 3% aqueous solution - applied after the leaves fall in autumn, if the branch is badly damaged.

Clusterosporiasis is also treated with Horus, Topaz, Vectra. Processing is completed 20 days before the start of harvest.

Moniliosis stone fruit (gray rot)

The fungus overwinters on the branches and appears in two stages:

• damage to branches - the bark turns brown and darkens to a burnt color;
• fruit rot - brown spots cover the entire surface, covered with small round mycelium.

Sick branches and fruits fall off. Moniliosis originates in cracks in the bark and leads to the death of the tree.

How to cure a plum:

• cut "burnt" branches;
• fruits with signs of rot cut off;
• treat the tree with a 1% solution of Bordeaux liquid.

Before and after flowering, plums should be sprayed with a 1% solution of iron or copper sulfate;

Witch's broom of plums

A disease-causing fungus settles in the crowns of trees and infects certain areas of them.

Signs of a witch's broom:

• thin shoots without fruit;
• small pale green leaves with a scarlet tint;
• grey patina.

The affected areas resemble a tangled panicle. Branches with pathology are pruned. In the spring, the trees are treated with Bordeaux liquid: a 3% solution before the buds open, a 1% solution before fruit set.

Milky shine

The disease develops in spring on trees damaged by winter frost or late frost.

The disease is recognized after the leaves have appeared. Signs:

• cavities under the skin of leaves;
• silver patina;
• reddish-brown spots on the branch cut.

As the disease progresses, the leaves turn dark and dry, and the branches and trunk become covered with leathery stripes. Sick branches are pruned. The saw cuts are treated with copper sulphate, oil paint.

Fruit rot

Spores of the fungus are activated in dampness. A favorable time for their development is a rainy summer. Spores enter fruits damaged by birds and insects. Signs of disease:

• fast growing dark brown spot;
• gray-brown round mycelium with spores.

Affected fruits are removed, burned or buried. Plums are sprayed with a 1% solution of Bordeaux liquid.

Plum tinder fungus

Plum or red tinder fungus is a fungus that causes branches and trunk to rot from the inside.

External signs:

• thick growths-hats;
• single formations connected by thin bridges, or a continuous cover;
• the surface of the caps is smooth or cracked, brown or black.

The fungus occurs on saw cuts, in crevices and frozen sections of the trunk. Infected tissue turns yellow, covered with red-brown stripes along the edges. Rotting rises up the trunk and descends to the roots.The only cure is destruction. A small affected area is cut out and treated with garden pitch. A branch with a large mushroom is cut off. If the tree is densely covered with tinder fungi, it is dug up. Sick branches and trunks are burned.

Sooty fungus

Sign of the disease - a black coating on the leaves, similar to soot. The tree is infected by insect pests. The disease interferes with photosynthesis.

To get rid of black fungus, the tree is sprayed with a solution of soap and blue vitriol. For 10 liters of water, 100 grams of grated household soap and 5 grams of copper sulfate are required.

Scab

The fungus first appears on half-ripe fruits. Signs and course of scab:

• small blurry olive spots appear;
• green spotting turns into dark, with clear contours;
• fruit crusted with cracks.

Scab should be treated with Skor, Raek, Horus. Affected fruits are removed before processing. Since the spores persist in the bark and leaves, re-infection begins in late summer.

Powdery mildew

If the plum leaves are covered with white bloom, then the tree is infected with powdery mildew. The fungus overwinters on tree trunks and in fallen leaves, and in the spring it releases flour-like spores. A sticky coating with small black mycelium appears on the fruits and branches.

Fungicides are used against powdery mildew. Spraying is repeated after 14 days. For greater efficiency, they change the means.

Lichen

The symbiotic organism of a lichen consists of a fungus and algae. The formation feeds on solid particles from the air and does not directly harm the plum. Lichen secretes substances that kill pathogenic microorganisms.Farmers believe that the thallus of the fungus retains moisture and creates a favorable environment for the reproduction of bacteria.

Lichen occurs on old trees with little bark growth. In a well-groomed garden with young trees, it does not happen, since the symbiotic organism cannot firmly gain a foothold on the growing branch.

The appearance of a lichen on a young plum is a sign of inhibition of its growth due to care errors, moisture due to surface groundwater or dense planting.

Infectious diseases

Plums become infected through dirty tools and pests. Plant infections are difficult to treat. Therefore, infected trees are immediately dug up and burned.

Plumpox (sharka)

Feature of the disease - in the early ripening of the fruit. Signs are already visible on young leaves:

• light spots in the form of rings or lines;
• marble green coloration.

The peel of early fruits is also covered with curly stripes and spots. The flesh becomes bright red, hard and inedible. To recognize the disease at an early stage, you need to look through the leaves to the light. Then curls are clearly visible.

Timely control of smallpox of fruit plants is the main task of farmers, as the disease makes the crop unsuitable for sale and processing. Trees with signs of sharka are immediately destroyed.

Plum dwarfism

Signs of illness:

• narrow, uneven leaves;
• appearance of brown spots in greenery;
• deformed peduncles.

When the form of dwarfism is advanced, the leaves become brittle and bunch up. Flowering stops. The tree does not grow and dies. The infection is not cured. To prevent the spread of the disease, the affected plum is dug up and burned.

Cytosporosis

The fungus infects damaged branches, penetrates through cracks in the bark. A prerequisite for the disease is the neglect of sanitary pruning. Under the action of the fungus, the plant tissue dies, and black growths appear. The periods of distribution of cytosporosis are early spring and late autumn, when the trees are at rest.

Remedy against the disease - pruning of damaged branches and a 3% solution of Bordeaux mixture. Trees need to be treated before bud break.

Bacterial diseases

Diseases caused by bacteria are transmitted through soil and garden tools. Mature trees are also infected from purchased young seedlings.

Root cancer

Trees pick up disease from contaminated soil. Bacteria get into the microcracks of the roots. The root system is covered with growths. The tree does not receive food and dies.

Root cancer pathogens live in slightly acidic soil and become active with a lack of moisture, high air temperature. Affected plums are dug up, and the soil is disinfected with a solution of copper sulfate.

Bacterial burn

Signs of illness:

• flowers dark brown, falling off;
• young branches with dark watery spots, leaning down;
• black leaves curl;
• soft bark with amber resinous secretions.

The tree turns black, as if after a fire. In the advanced stage, the bark is covered with red cracks.

Azophos fungicidal solution and antibiotic will help fight the disease. Suitable antibacterial drugs:

• chloramphenicol;
• rifampicin;
• streptomycin;
• gentamicin.

Fungicide is diluted at a ratio of 500 grams per 10 liters, and antibiotic - 50 milligrams per liter. Trees are processed before flowering, 3 times with a break of 4-5 days.

Noncommunicable diseases

Diseases of a non-infectious type occur due to adverse environmental conditions, improper selection of fertilizers and, as a result, other diseases.

Gum flow

When gum disease occurs, resin appears on the tree trunk. Causes of disease:

• abundant watering, high humidity;
• increased soil acidity;
• open wet pruning areas.

Brown tears appear due to the application of a large amount of fertilizer. Trees also deteriorate from freezing.After formative and sanitary pruning, wounds remain. If the lesions are not disinfected with garden pitch, brown discharges appear on them, similar to burnt sugar.

How to deal with the disease:

• peel off the gum with a sharp clean knife;
• lubricate the branch with a solution of copper sulfate 1%;
• grind fresh sorrel leaves and rub them on the affected area;
• treat the bark with garden pitch.

The second name of the disease is gommosis. It is dangerous because tarry areas become a favorable environment for further infection.

Shrinking

Plum dries out after planting in unsuitable conditions:

• with surface groundwater;
• in alkaline soil, s alt marsh;
• in a harsh climate with cold winters.

Sign of condition - evenly dried, brown leaves twisted into tubules. To stop drying out, it is necessary to create favorable conditions for the tree: reduce the acidity of the soil, transplant to a dry, weather-protected place.

Prevention of plum diseases: calendar

Preventive disease control measures included in seasonal gardening schedule:

• March, April - cut off damaged branches, clean and disinfect cracks in the bark with garden pitch. Before opening the buds, the plums are sprayed with a 1% solution of Bordeaux mixture, and with the appearance of greenery, with fungicides. Trunk circles are mulched with ash against insects;
• May, June - sprayed with insecticides against chewing and sucking insects at the beginning of budding and with the appearance of fruit ovaries. To prevent clasterosporiasis, plums are treated with fungicide Skor at the beginning and at the end of flowering. Do not spray trees during flowering;
• July, August - apply insecticides and fungicides if pests or signs of disease appear;
• September, October - treat the garden with preparations with copper, insecticides and fungicides after leaf fall.

Autumn spraying is carried out at temperatures above 0 degrees, in dry weather. In frost, the liquid freezes in microcracks in the bark and damages plant tissues. The soil of the trunk circles is also disinfected, as larvae and spores hide in it.

Recommended