Content
Conifer diseases are very diverse and can affect evergreen plants even with good care. To prevent the death of plantings, you need to know the main symptoms of tree diseases and methods of treatment.
Conifer diseases and their treatment
Most conifer diseases are of fungal origin and are very dangerous for plants. Symptoms of some illnesses can be noticed immediately, while others appear only after time. In order not to miss warning signs, the gardener needs to know photos and descriptions of conifer diseases.
Schutte
The disease called Schutte exists in several varieties; it is customary to distinguish between real, snow and brown Schutte. The disease affects pines and spruces, junipers and firs, as well as other conifers. The harmful fungus that causes the appearance of any shutte develops under the snow at temperatures above 0 ° C, and the symptoms of the disease appear in the spring or summer, after the snow melts.
Signs of Schutte are a gray-black coating on the needles and microscopic black dots on individual needles.Snowy, real and brown chutes are especially dangerous for young pines, spruces, junipers and other conifers. As the disease progresses, the needles of the conifers begin to turn yellow and brown, and then fall off.
To treat the disease, it is necessary to treat the plantings with Bordeaux mixture throughout the entire warm period, as well as fungicidal solutions, such as sulfur-lime decoction, Abiga-Peak, HOM. Sanitary pruning of the affected branches and tillage of the soil are also necessary; the root zone requires mandatory treatment, since spores of the Schutte fungus develop precisely in the soil at the roots of conifers.
Rust
The fungal disease rust primarily affects pine and larch trees in summer cottages. The disease is characterized by the spring appearance of yellow-orange spots on tree needles, which over time acquire a brown color and begin to crumble.
In the early stages, rust disease can be treated with fungicides and Bordeaux mixture. It is better to remove and burn severely affected shoots of the plant. Healthy and slightly damaged branches of a coniferous tree should be sprayed with medicinal solutions throughout the season - 3 times with an interval of 15-20 days.
Pine spinner
As the name implies, the fungal disease mainly affects pine trees. Its effect is manifested in the fact that the lateral shoots of the plant become strongly bent, and the apical shoot dies. In this case, yellow-orange swellings arranged in chains appear on the needles. The development of the disease leads to the fact that the growth of the coniferous tree stops, and after some time the pine may die.
Treatment of the disease in the early stages is carried out with Bordeaux mixture or Fundazol, spraying is carried out twice per season.Particular attention should be paid to the treatment of young trees; pines that are less than 10 years old are often affected by spinner.
Fusarium
The disease of coniferous plants, fusarium and root rot, is caused by pathogenic fungal flora that develops in the soil at the roots. Fusarium is dangerous not only for spruce and pine trees, but also for larches and fir trees. Externally, the disease manifests itself in the fact that the needles of the trees acquire a red tint and fall off, and the middle part of the crown is mainly affected. Root rot often occurs in young trees.
Treatment of the disease consists primarily of treating coniferous trees with fungicidal preparations - Bordeaux mixture, phytosporin, alirin. It is also necessary to control the quality of the soil in an area with conifers; fusarium most often develops on waterlogged soil with poor drainage.
Alternaria blight
Alternaria fungus develops mainly on the trunks and needles of junipers and thujas. You can recognize it by blackish or dark gray spots on the shoots; these spots are colonies of the fungus and gradually spread throughout the needles, leading to the death of the plant. The disease most often appears on conifers that are forced to develop in insufficient light.
Thus, the best prevention of Alternaria disease is careful selection of a place for planting thuja or juniper. Diseased conifers must be treated with Bordeaux mixture, fast and pure flowers; spraying begins in early spring and is carried out monthly throughout the summer. Coniferous shoots affected by the disease must be removed, and the sections are treated with copper sulfate to prevent further spread of the fungus.
Bacteoriosis
The bacterial infection vascular bacteriosis poses a great danger to conifers. An unpleasant feature of the disease is that the needles do not change their color or become stained, but simply become duller, so the disease is often not noticed immediately. But, nevertheless, as the disease develops, the needles begin to fall off the branches abundantly at the slightest touch.
In order not to miss the symptoms of bacteriosis, it is recommended to inspect trees for disease damage more often. At the first symptoms, the soil is treated with Fundazol, after another 3 days - with Fitosporin, and a few days after that - with Zircon. As a rule, the use of antiseptic drugs allows you to save diseased conifers from death.
Biatorella cancer
A fungal disease does not affect pine needles, but the wood of evergreen plants. When infected with biatorella cancer, the bark of conifers first turns brown, then becomes covered with cracks and begins to dry out and die. In place of the dead areas of the bark, long elongated ulcers form, and then resinous fungal growths appear in their place. As the fungus develops, the needles turn yellow and fall off.
To notice the disease in time, you need to regularly inspect the trunk and shoots of the plant. At the first symptoms of biatorella cancer, treatment with Bordeaux mixture and proven fungicides is required; it is advisable to repeat this 2-3 times per season.
Nectria cancer
Another disease of conifers manifests itself in the form of numerous microscopic growths of red-orange color that appear on the surface of the trunk. Gradually, the growths become darker and dry out, the bark begins to die, and the needles turn yellow and fall off.
Treatment of the disease is carried out using preparations containing copper; the soil at the roots of coniferous trees must be thoroughly watered with fungicides. Since the spread of fungal spores comes from the roots, it is necessary to carefully monitor the cleanliness of the tree trunk circle and promptly remove branch cuttings, fallen pine needles and other debris.
Gray rot
A disease called gray rot, or mold, is characterized by the appearance of an ash-gray cobwebby coating on the needles. During its development, the fungus grows into the roots of conifers and quickly leads to tissue death and death. Gray rot is especially dangerous for young conifers that have not had time to grow stronger after being planted in the ground. Most often, the disease affects conifers growing on waterlogged soil with a lack of sunlight.
To treat gray rot, it is necessary to remove all affected parts of the conifer, and then treat the trunks and needles with Bordeaux mixture and Ferbam solution - twice with an interval of 12 days. To prevent the disease, it is necessary to monitor the level of soil moisture and promptly feed the conifers with potassium and phosphorus.
Drying branches
The disease mainly affects junipers, thujas and young pines, and symptoms are manifested by drying out of the bark on the tree trunk and the appearance of brown and black growths on it. The needles of the plants acquire a yellow tint and fall off, the shoots begin to dry out and bend.
Treatment of the disease is carried out by spraying conifers with fungicidal preparations and Bordeaux mixture. Since drying out of branches most often develops on conifers that grow too densely and receive insufficient sunlight, if necessary, the plants can be planted further away from each other.
Necrosis
The fungal disease mainly affects young conifers under 10-15 years of age. The main symptom of the disease is redness of the needles, and the needles do not begin to fall off immediately. The bark of conifers also takes on a reddish tint, and microscopic black growths form in its cracks.
With a moderate level of necrosis, diseased conifers can be treated with Bordeaux mixture and preparations with a high copper content.
Spruce canker
The fungus, which mainly affects spruce trees, manifests itself in the form of abundant tarring on the shoots of the plant. Over time, dead areas appear in the tarred areas, then the bark becomes covered with cracks, and numerous ulcers, dry or wet, covered with thin brown hairs, form on the trunk.
When symptoms of canker cancer appear, the affected spruce shoots must be removed and burned. The soil under the roots of the plant is shed with fungicides, and the crown is treated with preparations containing copper. When ulcerative cancer is advanced, spruce trees often die, so plantings must be regularly inspected for infection.
Pests of conifers and their control
Fungal and infectious diseases are not the only enemies of conifers. Insects pose no less of a danger to trees, and to successfully combat them you need to know the pests of conifers in the photo and their treatment.
Hermes
A small insect called hermes is one of the most common and dangerous pests.The insect settles on the shoots of pines, junipers, spruces and any other conifers in entire colonies, lays eggs and feeds on tree sap. Hermes larvae damage the young buds of conifers, and over time the plant dies. You can suspect the presence of Hermes by the yellowing of the needles and the slowdown in tree growth; upon closer examination, microscopic insects, as if covered with a little fluff, and Hermes larvae will be found on the needles.
Pest control involves spraying conifers with insecticides - Aktara and Komandor. Spraying needs to be done several times a season, since the invasion of Hermes on conifers can occur at the end of June, in August and even in September.
Bark beetle
A dangerous pest of conifers is the bark beetle, which feeds on the wood of the plant. An unpleasant feature of the insect is that the bark beetle is quite difficult to notice; it lives and reproduces under the bark. Its primary colonization can only be indicated by sawdust that suddenly appears under the trunk of a conifer, but this symptom is easily overlooked. In the later stages, it is often possible to recognize the presence of a pest only when the conifer begins to lose vitality and turn yellow.
Therapeutic and preventive control of bark beetle involves treating conifers with insecticides - spraying is best done annually to prevent the appearance of the pest. In addition, a special pheromone trap can be hung on heavily affected conifers; it will attract a large part of the beetle population, and then the pests can be destroyed along with the dying conifers.
Spider mite
Microscopic spider mites are dangerous for conifers because they feed on their juices and also multiply very quickly. During a season, the mite can produce up to 8 colonies; in the absence of counteraction, the pest can quickly destroy a pine, spruce or juniper tree.
However, dealing with spider mites is quite easy. First of all, it is easy to notice on the branches of a plant; the pest entangles the shoots of the conifer with the finest white web. Control measures against the disease come down to regular spraying of conifers with acaricidal solutions - Actellik, Agravertin and others. Spraying must be done every 15-20 days.
Shchitovka
Scale insects are insects that mainly attack junipers, thujas and yews. The pest looks like a small beetle with a shiny brown shell-shield; it mainly affects shoots closer to the middle of the crown. Under the influence of the scale insect, the needles quickly become brown and fall off, and, in addition, the scale insect provokes curvature and drying out of the shoots.
The fight against scale insects is carried out with Admiral, Actellik and Fury. Since female scale insects lay larvae several times per season, spraying should be done 2-3 times during the summer, taking a break for 1-2 weeks.
Sawfly
Harmful sawfly insects prefer to settle on pine and spruce trees. The main danger is not adult insects, but numerous larvae that feed on pine needles and young shoots. Under the influence of a pest, the ephedra may completely lose its needles.
You can recognize the sawfly by the yellowing and shedding of its needles; upon careful examination in May and June, pale yellow larvae will be found on the shoots. You can get rid of the pest using insecticidal agents - Actellik, Decis and Fury; you need to treat conifers from the disease from the beginning of May and throughout the summer with breaks.
Pine silkworm
The butterfly insect primarily affects pine trees, but can also inhabit other conifers. The danger to trees is not the silkworm itself, but its larvae, long brownish-gray caterpillars. Pine silkworm larvae appear in mid-March and feed on the sap of the coniferous plant, causing damage to it until the end of June. Under the influence of sawfly larvae, the conifer loses a significant part of its needles, and sometimes colonies of the pest begin to eat even the bark.
You can rid conifers of the sawfly using insecticides. Treatment should be carried out from early spring until the end of June. It also doesn’t hurt to spray the conifers at the end of August, when adult insect butterflies begin to lay eggs en masse for the next year.
Aphid
A dangerous pest for conifers, and especially spruce trees, is the common aphid. The insect is tiny in size and rarely exceeds 2 mm in length; the color of the aphid blends with the bark and needles, so it is quite difficult to notice it. However, the presence of the pest is indicated by yellowing and falling of conifer needles, especially if this occurs in May and early June.
In order to verify the presence of aphids, you can place a white paper sheet under a conifer branch and shake the shoot. If there are aphids on the branch, they will fall on the paper.The extermination of harmful insects is carried out with insecticides, spraying is repeated several times at intervals of 1-2 weeks, until the aphids disappear completely.
Pine bug
The pest is a small insect with a reddish or yellow shell, not exceeding 3-5 mm in length. The pine bug lives on the bark, and due to its color it is quite difficult to see it. Insect larvae overwinter at the roots under cover of fallen pine needles and plant debris, and in the spring they emerge and begin to feed on plant juices. Under the influence of the bug, the conifer begins to turn yellow and lose vitality, the needles become weak and fall off.
The fight against pine bugs is carried out using conventional insecticides - Aktellika, Aktara and others. It is better to start spraying with the onset of warm weather, at the moment when the pest larvae are just beginning to wake up.
Preventive actions
Preventing diseases and pests of conifers is much easier and more convenient than treating them. Diseases can affect any conifer, but with good care, illnesses occur much less frequently.
- To avoid the occurrence of diseases and infections, it is necessary to carefully select a site for conifers; the place should be well lit, with soil drainage, without waterlogging and groundwater passing close to the ground.
- It is recommended to plant conifers at a decent distance from each other so that they can grow quietly without shading their neighbors. Otherwise, even in a sunny area, individual plants will lack light.
- Once a year for planting, it is necessary to carry out sanitary pruning - remove all dry, broken and diseased shoots.A well-groomed, healthy tree is not as susceptible to attacks from diseases and pests and can resist their effects longer.
- It is recommended to use fungicidal and insecticidal agents not only for treatment, but also for preventive purposes. Since most fungal diseases and pests awaken immediately after the snow melts, conifers need to be sprayed in early spring, before stable warm weather sets in.
Conclusion
Coniferous diseases number in the dozens and can quickly lead to weakening and death of trees. But with careful monitoring of plantings, most diseases can be simply avoided or the affected plants can be treated with insecticidal and fungicidal agents.
