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Coniferous diseases are very diverse and can affect evergreens even with good care. In order to prevent the death of plantings, you need to know the main symptoms of wood ailments and methods of treatment.
Coniferous diseases and their treatment
Most coniferous diseases are of fungal origin and are very dangerous for plants. Symptoms of some ailments can be noticed immediately, others appear only after a while. In order not to miss the alarm signals, the gardener needs to know the photo and description of the diseases of the conifers.
Schutte
A disease called schütte exists in several varieties, it is customary to single out real, snowy and brown schütte. The disease affects pines and spruces, junipers and firs, as well as other conifers. A harmful fungus that provokes the appearance of any schütte develops under snow at temperatures above 0 ° C, and the symptoms of the disease appear in spring or summer, after the snow melts.
Signs of a schütte are a gray-black coating on the needles and microscopic black dots on individual needles. Snowy, real and brown schütte is 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.
For the treatment of the disease, it is necessary to treat the plantings with Bordeaux mixture throughout the warm period, as well as fungicidal solutions, such as sulfur-lime decoction, Abiga-Peak, HOM. Sanitary pruning of the affected branches and tillage is also necessary, the root zone needs mandatory treatment, since spores of the Schutte fungus develop precisely in the soil at the roots of conifers.
Rust
Fungal disease rust affects mainly pines and larches in summer cottages. The disease is characterized by the appearance of yellow-orange spots on tree needles in the spring, which eventually becomes brown and begins to crumble.
In the early stages, rust disease can be treated with fungicides and Bordeaux mixture. Severely affected plant shoots are best removed and burned. Healthy and slightly affected 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 action is manifested in the fact that the lateral shoots of the plant are strongly curved, and the apical shoot dies off. At the same time, yellow-orange swellings appear in chains on the needles. The development of the disease leads to the fact that the growth of a 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 a season. Particular attention should be paid to the processing of young trees; pines that have not reached 10 years of age are often affected by the spinner.
Fuzarioz
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 spruces and pines, but also for larches and firs. Outwardly, the disease manifests itself in the fact that the needles of trees acquire a red tint and crumble, and the middle part of the crown is mainly affected. Young trees often have root rot.
Treatment of the disease consists primarily in the treatment of coniferous trees with fungicidal preparations – Bordeaux liquid, phytosporin, alirin. It is also necessary to control the quality of the soil in the area with conifers, Fusarium most often develops on waterlogged soil with poor drainage.
Alternaria
Alternariosis fungus develops mainly on the trunks and needles of junipers and arborvitae. You can recognize it by blackish or dark gray spots on the shoots, these spots are fungus colonies and gradually spread through the needles, leading to the death of the plant. The disease appears most often on conifers, forced to develop in low light.
Thus, the best prevention of Alternaria disease is the careful choice of a place for planting thuja or juniper. Sick conifers must be treated with Bordeaux liquid, fast and pure flowers, spraying begins in early spring and is carried out monthly throughout the summer. The shoots of conifers affected by the disease are necessarily removed, and the sections are treated with copper sulfate to prevent the further spread of the fungus.
Bacteriosis
A great danger for conifers is a bacterial infection – vascular bacteriosis. An unpleasant feature of the disease is that the needles do not change their color and do not become stained, but simply dimmer, so often the disease is not immediately noticed. But, nevertheless, as the disease develops, the needles begin to crumble abundantly from the branches 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.
Biotorell cancer
A disease of fungal origin does not affect the needles, but the wood of evergreens. When infected with biotorella 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 sections 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 crumble.
In order to notice the disease in time, you need to regularly inspect the trunk and shoots of the plant. At the first symptoms of biorell cancer, treatment with Bordeaux liquid and proven fungicides is required, it is desirable to repeat it 2-3 times per season.
nectrium cancer
Another conifer disease manifests itself in the form of numerous microscopic red-orange growths that appear on the surface of the trunk. Gradually, the growths become darker and dry out, the bark begins to die off, and the needles turn yellow and fall off.
Treatment of the disease is carried out with the help of preparations containing copper, the soil at the roots of coniferous trees must be thoroughly shed with fungicides. Since the spread of fungal spores comes from the roots, it is necessary to carefully monitor the cleanliness of the near-stem circle and remove branch trimmings, fallen needles and other debris in time.
Gray mold
A disease called gray rot, or mold, is characterized by the appearance of an ash-gray cobweb coating on the needles. During its development, the fungus grows into the roots of conifers and quickly leads to tissue death and death. Especially gray rot is dangerous for young conifers who have not had time to get stronger after landing 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 the affected parts of the conifer, and then treat the trunks and needles with Bordeaux liquid and Ferbam’s solution – twice with an interval of 12 days. To prevent the disease, it is necessary to monitor the level of soil moisture and feed the conifers with potassium and phosphorus in a timely manner.
Shrinking branches
The disease affects mainly junipers, arborvitae and young pines, and the symptoms are manifested by the drying of the bark on the tree trunk and the appearance of brown and black growths on it. The needles of plants acquire a yellow tint and crumble, the shoots begin to dry and bend.
The treatment of the disease is carried out by spraying the conifers with fungicidal preparations and Bordeaux mixture. Since most often the drying of branches develops on conifers that grow too densely and receive insufficient sunlight, if necessary, the plants can be planted away from each other.
Necrosis
Fungal disease affects mainly young conifers under 10-15 years old. The main symptom of the disease is reddening of the needles, while the needles do not begin to crumble immediately. The bark of conifers also acquires a reddish tint, and microscopic black growths form in its cracks.
With a moderate level of necrosis, diseased conifers can be treated with Bordeaux liquid and preparations with a high copper content.
Spruce ulcer
The fungus, which mainly affects spruce trees, manifests itself in the form of abundant pitching on the shoots of the plant. Over time, dead areas appear on the tarred places, then the bark becomes covered with cracks, and numerous ulcers form on the trunk, dry or wet, covered with thin brown hairs.
When symptoms of ulcerative 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. With advanced ulcerative cancer, spruces 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 are no less dangerous for trees, and in order 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 whole colonies, lays eggs and feeds on tree sap. Hermes larvae damage the young buds of conifers, and over time the plant dies. The presence of Hermes can be suspected by the yellowing of the needles and the slowdown in the growth of the tree; upon closer examination, microscopic insects, as if covered with a little fluff, and Hermes larvae will be found on the needles.
Pest control consists in spraying conifers with insecticides – Aktara and Commander. Spraying should be carried out several times per 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 a bark beetle that feeds on the wood of a plant. An unpleasant feature of the insect is that the bark beetle is quite difficult to notice, it lives and breeds under the bark. Only sawdust that suddenly appeared under the conifer trunk can report its initial colonization, but this symptom is easy to overlook. 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 beetles consists in 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 most 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 the season, the tick is able to give up to 8 colonies; in the absence of opposition, the pest can quickly destroy pine, spruce or juniper.
However, dealing with spider mites is quite easy. First of all, it is not difficult to notice it on the branches of a plant; the pest entangles the shoots of the conifer with the thinnest white web. Control measures are reduced to the disease by regularly spraying conifers with acaricidal solutions – Actellik, Agravertin and others. Spraying is necessary at intervals of once every 15-20 days.
Shield
Scale insects are insects that mainly affect junipers, arborvitae and yews. The pest looks like a small bug with a shiny brown shell-shield, it mainly affects the shoots closer to the middle of the crown. Under the influence of the scale insect, the needles quickly acquire a brown color and crumble, and, in addition, the scale insect provokes the curvature and drying of the shoots.
The fight against scabies is carried out with drugs Admiral, Aktellik 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 pines and spruces. The main danger is not adult insects, but numerous larvae that feed on needles and young shoots. Under the influence of the pest, the conifer can completely lose its needles.
You can recognize the sawfly by yellowing and shedding of needles, upon closer examination in May and June, pale yellow larvae will be found on the shoots. You can get rid of the pest with the help of insecticidal agents – Aktellik, Decisa and Fury, you need to treat the conifers from the disease from the beginning of May and throughout the summer with interruptions.
Pine silkworm
The butterfly insect affects mainly pines, 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 juices of a coniferous plant, damaging it until the end of June. Under the influence of the sawfly larvae, the conifer loses a significant part of the needles, and sometimes the pest colonies begin to eat even the bark.
You can rid the conifers of the sawfly with the help of insecticidal agents. Processing is necessary from early spring to the end of June. It also does not hurt to spray conifers at the end of August, when adult insect butterflies begin to massively lay eggs for the next year.
aphid
A dangerous pest for conifers, and especially for spruces, is the common aphid. The insect is tiny in size and rarely exceeds 2 mm in length; the aphid’s color merges with the bark and needles, so it is quite difficult to notice it. However, the presence of the pest is reported by yellowing and falling of the needles of the conifer, especially if this happens in May and early June.
In order to verify the presence of aphids, you can substitute a white paper sheet under the conifer branch and shake the shoot. If there is an aphid on the branch, it will fall on the paper. The extermination of a harmful insect is carried out with insecticides, spraying is repeated several times at intervals of 1-2 weeks, until the aphid disappears 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 the coloring it is quite difficult to see it. Insect larvae hibernate at the roots under cover of fallen needles and plant debris, and in the spring they get out and take to feed on the juices of the plant. 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 with the help of conventional insecticides – Actellik, Aktara and others. It is better to start spraying with the onset of heat, at the moment when the pest larvae are just starting to wake up.
Preventive measures
Preventing diseases and pests of conifers is much easier and more convenient than treating them. Diseases can affect any conifers, however, with good care, ailments occur much less frequently.
- In order to avoid the appearance of diseases and infections, it is necessary to carefully approach the choice of 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 attack by diseases and pests and can resist their effects for longer.
- The use of fungicidal and insecticidal agents is recommended not only for treatment, but also for preventive purposes. Since most fungal diseases and pests wake up immediately after the snow melts, you need to spray the conifers in early spring, before stable warm weather is established.
Conclusion
Coniferous diseases number in the dozens and can quickly lead to the weakening and death of trees. But with careful observation of the plantings of most ailments, you can simply avoid or cure the affected plants with insecticidal and fungicidal agents.
