Diseases of fir: why needles turn yellow, what to do, photo

Content

1 Why does the fir turn yellow
2 Fir diseases and their treatment
3 Fir pests and control
4 Preventive actions
5 Conclusion

Fir is an evergreen tree that adorns city parks and gardens. Although the plant is considered unpretentious, it, like any crop, requires care, protection from diseases and pests. Diseases of the fir and other unfavorable factors lead to yellowing and shedding of its needles. As a result, the tree loses its decorative appearance and develops slowly. If measures are not taken in time, the plant may die.

Why does the fir turn yellow

When the fir needles turn yellow, the first thing they pay attention to is the place of cultivation. For a plant, a site in partial shade with fertile moist soil is chosen. If the planting rules are violated, then the fir does not develop well and loses its decorative properties.

Reasons for the yellowing of fir after planting:

The order of work has been violated. When planting plants, soil shrinkage is taken into account. It is best to dig a hole in advance and leave it for 2 to 3 weeks. During work, it is not recommended to bury the earthen ball and root collar. With a low fit, over time, a small depression forms where moisture accumulates. The root collar gets wet, which ultimately causes fungal diseases.
Surrounding plants. Fir is not planted next to large trees that take a lot of moisture and nutrients from the soil: such as linden, oak, maple, and fruit crops. They maintain a distance of 3 - 5 m between trees. If the crops are planted close, in this case, more moisture and minerals are introduced.
Soil quality. Fir develops best in loamy soil. At the same time, the land should be moist and fertile. On poor soils, conifers lack nutrients. In sandy soil, the tree will not receive enough moisture, and in clayey soil, it will suffer from its excess.
Saplings. When buying, they pay attention to the quality of the planting material. Seedlings are chosen at the age of 2 - 4 years, without cracks, rotten areas and other defects. The earth ball must remain intact. Otherwise, the fir does not take root well and is subject to disease.
Watering. With a lack of moisture, the growth of fir stops, and the needles turn yellow and begin to fall off. With an excess of moisture, the roots receive little oxygen, as a result of which fungal diseases develop.
Freezing. Young fir can turn yellow after spring cold snaps. If frost is coming, ephedra are covered with agrofibre or other material.

Fir diseases and their treatment

Many fungal and cancerous diseases also cause yellowing of needles. The first group of lesions appears at high humidity. To combat them, special drugs are used. The most dangerous are cancers that do not respond to treatment.

Needle diseases

The main diseases of fir with a photo:

Rust. The disease-causing fungus spreads to the lower part of the shoots. As a result, rows of yellow-orange blisters up to 4 cm high are formed. Gradually, the lesion covers all branches. Fir often gets infected from other plants - linden and lingonberry. The disease is most dangerous for young conifers;
Brown shute. A fungal disease that affects different types of fir. Its symptoms appear immediately after the snow melts. The needles are covered with dark brown mycelium. Gradually, the needles turn yellow and die off. The disease spreads in places where the snow cover is slowly melting. The reason for the shute is poor drainage, thickening of plantings, the presence of diseased plants on the site;
Brown needles. This fir disease, which also causes yellowing of the needles, can affect both young and mature trees. In spring, yellow spots appear on the shoots. They gradually turn brown and spread throughout the tree. Sporulation of the fungus begins in the summer. Then, on the underside of the needles, black dots are formed in rows;

Advice! For the fight against diseases of the needles, preparations containing copper are most effective.
Spring burn. This disease is not infectious. In the spring, the needles are seriously affected by sunburn. This usually happens in clear weather, when the snow cover has not melted yet. Under the influence of the sun and wind, the needles lose moisture and turn yellow. To avoid burns, plants are covered with a white non-woven cloth in spring.

Before treatment for fungal diseases, all affected shoots are removed. Garden var is applied to the sections. It is recommended to burn branches with signs of the disease. This will help prevent further spread of the fungus.

For the treatment of conifers, Bordeaux liquid, Oxyhom, Abiga-Peak, Ordan preparations are used. Chemicals are diluted with water at the concentration indicated on the package. When working with solutions, take precautions: protect the skin and respiratory organs. Spraying is carried out on a cloudy day or in the evening. Re-processing of plants is carried out after 2 - 3 weeks.

Diseases of trunks and branches

If the fir turns yellow and crumbles, diseases of the trunk or shoots can be the cause:

Dying off of shoots. Fungal disease affecting Siberian fir species. It appears on annual branches. Gradually, the needles on them dries out, turns yellow, then red. Dark tubercles form on the shoots. In the affected tree, the top remains green, while in the lower part the shoots are thinning;
Rusty cancer. The causative agents of the disease are fungal spores. With the development of the lesion, vertical shoots appear on the branches. They are also called "witch brooms". The needles on the branches thicken, in addition, tumors form on the trunks. The disease is viral in nature;
Bacterial dropsy. The defeat covers trees of different ages. First, the needles turn yellow, then turn red. Cracks appear on the trunks, from which black liquid protrudes. At the same time, the wood has a sour smell.

Diseases of this kind weaken the trees, as a result of which they gradually dry out. The trunks become susceptible to rotting and insect attack. In mass and single plantings, diseases are not amenable to treatment. Affected trees are cut down and the soil is disinfected.

Root diseases

Yellow needles signal that the tree is not getting enough nutrients. This may be due to diseases of the root system.

Important! Root system diseases are difficult to treat. Therefore, special attention must be paid to prevention.

Common diseases of fir roots:

Variegated rot. The disease appears in the core of the trunk and roots. Gradually, the lesion rises up to a height of 3 - 4 m. The affected wood has a strong smell of turpentine and emits a lot of resin. Gradually, it becomes reddish-brown, covered with black dots and white spots. At the base of the tree, the fruiting bodies of the mushrooms are formed;
Fibrous rot. Appearing in the lower part of the trunk, this lesion is light yellow in color with black stripes. The disease rises to a height of 8 m. As a result, fruiting bodies up to 15 cm in size appear on the trunk. They are yellow-brown at the top, rusty at the bottom;
White sapwood rot. With the development of the disease, fibrous mycelium and dark sinuous formations appear in the wood. The lesion is observed from the base of the plants to a height of 3 m. At the same time, large growths are formed at the roots.

Fir pests and control

Fir is also susceptible to attack by various types of insects. Many of them are found on other conifers.Fir pests eat buds, shoots, needles, trunks, root system and cones. As a result, the needles turn yellow, and the tree begins to develop slowly. In addition, many insects are disease vectors.

Types of fir pests:

Needle-gnawing. These insects feed on buds and needles. This includes moths, leafworms, wolfworms, and silkworms. In Siberian forests, silkworm caterpillars inflict enormous damage on coniferous plantations. The needles of the affected trees turn yellow, while a cobweb remains on it;
Sucking. Pests suck nutrients from needles, branches and trunk. Aphids, scale insects, hermes can be found on fir. Insects prefer young trees in nurseries and large plantings. The pests are small in size and brownish-green in color, so they are difficult to detect visually. The most noticeable are their traces - a sticky discharge that is covered with a gray coating. Under the influence of sucking insects, tree growth slows down;
Advice! For the treatment of fir disease in the form of white bloom, it is important to eliminate all sucking pests on the site.
Stem. Pests feed on the bark and root system of conifers. These are bark beetles, golden beetles, glass beetles, weevils, moths. Often these insects choose dead or weakened trees, in the wood of which they gnaw passages;
Pests of cones. These include caterpillars of leaf rollers, moths, gall midge flies. Insect-affected cones grow slowly, become covered with resin drops, change shape;
Root pests. The greatest damage to fir is caused by wireworms and beetles. Their larvae eat not only fir crops, but also other plant species. They gnaw through the roots, which weakens the development of trees. If insects are found, the entire garden is treated. The control of the larvae of these pests is complicated if the site is located next to a forest.

Single insects are harvested by hand or collected using traps. Affected shoots are cut with a knife. Then they begin to process the fir with special means - insecticides. The drugs Fufanon, Decis, Rogor are effective against crop pests.

A solution is prepared for spraying fir. For this, the required amount of the drug is dissolved in water. Landings are processed every 1 - 2 weeks. The solution is applied with a spray bottle on a cloudy day or in the evening. Up to 4 treatments are performed during the season.

A weakened tree requires additional fertilizing, in the quality of which a complex fertilizer for conifers containing phosphorus and potassium is introduced into the soil. Substances can be dissolved in water and watered plants.

Preventive actions

The best way to avoid fir diseases is to follow agricultural practices. Preventive measures for caring for ephedra include watering, feeding, control over soil moisture.

The list of works to help protect the fir from diseases:

watering should be normalized, excessive moisture should not be allowed;
to improve drainage into the ground, drive in plastic tubes up to 30 cm long;
it is necessary to shade plants in the spring with the help of agrofibre;
make phosphorus-potassium supplements;
carry out soil mulching;
carry out pruning, avoiding thickening of the plantings.

To prevent the spread of pests, the following measures should be taken:

digging up the soil in the fall;
spraying plantings with insecticides in the spring and autumn;
pruning shoots, control over plant density.

Conclusion

Fir diseases spread quickly and can completely destroy trees. Therefore, it is important to identify the symptoms in time and start treating the plant. In addition, yellowing of the needles can be caused by improper care and the spread of pests.

What to do if the fir turns yellow