Names and symptoms of plum diseases, treatment methods and preventive 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 inspected 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 attacked by fungi typical of garden plants and specific ones that are found on fruit trees.

Coccomycosis

The fungus appears on the leaves in June:

• brown spots on the outside;
• white spore coating on the reverse side.

Yellow leaves with dots fall off, followed by fruits. The harvest does not ripen. Fungal spores live in fallen leaves. To prevent their development in the spring, the leaves are burned in the fall. The soil around the tree trunk is sprayed with preparations containing copper or Bordeaux mixture.

Rust

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

How the disease progresses:

• leaves become covered with light brown spots between the veins;
• black myceliums with spores form on the spots;
• the tree loses its leaves and 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 mixture or any fungicidal preparations. Then the treatment is repeated once every 2 weeks. Disinfection is stopped 3 weeks before fruit ripening. An anemone growing nearby must be destroyed, as the spores remain in its rhizome and leaves.

Brown spot

The disease appears in the spring. Signs:

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

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

Brown spot treatment:

• spraying the branches and soil around the tree trunk with a 1% solution of copper sulfate before flowering;
• treatment with 1% Bordeaux mixture 2 weeks after the start of flowering.

Bordeaux mixture will be replaced by the fungicide Hom. A heavily affected plum orchard is additionally treated 20 days before harvesting.

Plum pockets

Spores of the vocal fungus develop in flowers. Plum orchards suffer from pockets after a long spring and rainy summer.

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

• elongated shape;
• overgrown pulp;
• absence of seeds.

The fruits become covered with a matte white coating and then fall off. Signs are visible 15-17 days after ovary. Branches and fruits affected by the fungus are removed and burned. In autumn, trees are sprayed with copper sulfate or Bordeaux mixture.

Clusterosporiasis

Fungal spores live in cuts on shoots and buds. The pathogen hibernates in winter. Signs of fungus on leaves:

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

The riddled leaf dries out and falls off.

Manifestation of disease on fruits:

• small red spots;
• the marks increase in size and 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 out, and the tree dies.

Bordeaux mixture is used to treat plums:

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

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

Stone fruit moniliosis (gray rot)

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

• damage to branches - the bark becomes brown and darkens to a burning color;
• rotting of fruits - brown spots cover the entire surface, covered with small round myceliums.

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

How to cure plum:

• trim “burnt” branches;
• pick off fruits with signs of rot;
• treat the wood with a 1% solution of Bordeaux mixture.

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

Witch's broom plum

The fungus that causes the disease settles in the crowns of trees and affects certain areas of them.

Signs of a witch's broom:

• thin shoots without fruits;
• small pale green leaves with a scarlet tint;
• gray coating.

The affected areas resemble a tangled panicle. Branches with pathology are pruned. In the spring, trees are treated with Bordeaux mixture: 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 frosts.

The disease is recognized after the leaves appear. Signs:

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

As the disease progresses, the leaves darken and dry out, and the branches and trunk become covered with leathery stripes. Sick branches are pruned. The cut areas are treated with copper sulfate and oil paint.

Fruit rot

Fungal spores become active in damp conditions. A favorable time for their development is rainy summer. Spores end up in fruits damaged by birds and insects. Signs of the disease:

• a rapidly 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 mixture.

Plum polypore

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

External signs:

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

The fungus appears on saw cuts, cracks and frozen areas of the trunk. The infected tissue turns yellow and is covered with red-brown stripes along the edges. Rotting moves up the trunk and down to the roots. The only cure is destruction. A small affected area is cut out and treated with garden varnish. A branch with a large mushroom is cut off. If the tree is densely covered with tinder fungi, it is dug up. Diseased branches and trunks are burned.

Sooty fungus

A sign of the disease is a black coating on the leaves, similar to soot. The tree becomes infected from insect pests. The disease interferes with photosynthesis.

To get rid of sooty fungus, the tree is sprayed with a solution of soap and copper sulfate. 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;
• the fruit becomes covered with a cracked crust.

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

Powdery mildew

If the plum leaves are covered with a white coating, it means that the tree is infected with powdery mildew. The fungus overwinters on tree trunks and 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. After 14 days, spraying is repeated. For greater efficiency, change the means.

Lichen

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

Lichen occurs on old trees that have little bark growth. This does not happen in a well-kept garden with young trees, since the symbiotic organism cannot firmly attach itself to a growing branch.

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

Infectious diseases

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

Plum pox (sharqa)

The peculiarity of the disease is the early ripening of fruits. Signs are noticeable already on young leaves:

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

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

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

Plum dwarfism

Signs of the disease:

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

With advanced dwarfism, the leaves become brittle and gather in bunches. Flowering stops. The tree does not grow and dies. The infection cannot be treated. To prevent the disease from spreading, the affected plum is dug up and burned.

Cytosporosis

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

The remedy against the disease is pruning damaged branches and a 3% solution of Bordeaux mixture. Trees need to be treated before buds open.

Bacterial diseases

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

Root cancer

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

Root canker pathogens live in slightly acidic soil and become active when there is a lack of moisture and high air temperatures. The affected plums are dug up and the soil is disinfected with a solution of copper sulfate.

Bacterial burn

Signs of the disease:

• flowers are dark brown, fall 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 becomes covered with red cracks.

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

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

The fungicide is diluted in a ratio of 500 grams per 10 liters, and the antibiotic - 50 milligrams per liter. Trees are treated before flowering, 3 times with a break of 4-5 days.

Non-communicable diseases

Non-infectious diseases arise due to unfavorable environmental conditions, improper selection of fertilizers and, as a result, other diseases.

Gum treatment

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

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

Brown tears appear due to the application of large amounts of fertilizer. Trees are also damaged by freezing. After formative and sanitary pruning, wounds remain. If the damage is not disinfected with garden varnish, a brown discharge similar to burnt sugar appears on it.

How to deal with the disease:

• clean 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 varnish.

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

Drying out

The plum dries out after planting in unsuitable conditions:

• with a superficial location of groundwater;
• in alkaline soil, saline soil;
• in harsh climates with cold winters.

A sign of the condition is uniformly dried, brown leaves curled into tubes. To stop drying out, it is necessary to create favorable conditions for the tree: reduce the acidity of the soil, replant it in a dry place protected from bad weather.

Prevention of plum diseases: calendar

Preventive measures to combat diseases include in the schedule of seasonal work in the garden:

• March, April - cut off damaged branches, clean and disinfect cracks in the bark with garden varnish. Before the buds open, the plums are sprayed with a 1% solution of Bordeaux mixture, and with the appearance of greenery - with fungicides. Tree trunk circles are mulched with ash to prevent insects;
• May, June - sprayed with insecticides against gnawing and sucking insects at the beginning of budding and with the appearance of fruit ovaries. To prevent clasterosporiasis, plums are treated with the fungicide Skor at the beginning and end of flowering. During flowering, trees are not sprayed;
• July, August - insecticides and fungicides are used if pests or signs of disease appear;
• September, October - the garden is treated with copper preparations, insecticides and fungicides after the leaves 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 tissue. The soil around the tree trunks is also disinfected, since larvae and spores hide in it.