Fir diseases: why the needles turn yellow, what to do, photo

Content

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

Fir is an evergreen tree that adorns city parks and garden plots. Although the plant is considered unpretentious, it, like any crop, requires care and protection from diseases and pests. Fir diseases 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 fir turn yellow?

When fir needles turn yellow, the first thing people pay attention to is the place of cultivation. For the plant, choose a site in partial shade with fertile, moist soil. If planting rules are violated, the fir develops poorly and loses its decorative properties.

Reasons for yellowing of fir after planting:

The order of work has been disrupted. When planting plants, take into account soil shrinkage. It is best to dig a hole in advance and leave it for 2 - 3 weeks. During work, it is not recommended to bury the earthen ball and root collar. With a low landing, over time, a small depression forms where moisture accumulates. The root collar gets wet, which ultimately causes fungal diseases.
Nearby 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. A distance of 3 - 5 m is maintained between trees. If crops are planted close, then more moisture and minerals are added.
Soil quality. Fir develops best in loamy soil. The soil must be moist and fertile. On poor soils, conifers lack nutrients. In sandy soil, the tree will not receive enough moisture, and in clay soil, it will suffer from its excess.
Saplings. When purchasing, pay attention to the quality of planting material. Seedlings are selected at the age of 2 - 4 years, without cracks, rotten areas and other defects. The earthen lump should remain intact. Otherwise, the fir does not take root well and is susceptible to disease.
Watering. With a lack of moisture, fir growth stops, and the needles turn yellow and begin to fall off. When there is excess moisture, the roots receive little oxygen, as a result of which fungal diseases develop.
Frost. Young fir may turn yellow after spring cold snaps. If frosts are imminent, the conifers are covered with agrofibre or other material.

Fir diseases and their treatment

Many fungal and cancer 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 cancers are those that cannot be cured.

Needle diseases

Main fir diseases with photos:

Rust. The fungus that causes the disease spreads to the lower part of the shoots. As a result, rows of yellow-orange bubbles up to 4 cm high are formed. Gradually, the lesion covers all branches.Often the infection gets to the fir from other plants - linden and lingonberries. The disease is most dangerous for young conifers;
Brown Schutte. 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. The disease spreads in places where snow cover is slowly melting. The cause of the shutter is poor drainage, dense plantings, and the presence of diseased plants on the site;
Browning of needles. This fir disease, which also causes yellowing of needles, can affect both young and mature trees. In spring, yellow spots appear on the shoots. Gradually they become brown and spread throughout the tree. In summer, sporulation of the fungus begins. Then black dots arranged in rows form on the underside of the needles;

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

Before treating fungal diseases, remove all affected shoots. Garden varnish is applied to the cuts. It is recommended to burn branches with signs of disease. This will help prevent further spread of the fungus.

To treat conifers, Bordeaux mixture and the preparations Oksikhom, Abiga-Pik, and Ordan are used. Chemicals are diluted with water in 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. Repeated treatment of plants is carried out after 2 - 3 weeks.

Diseases of trunks and branches

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

Dying of shoots. A fungal disease affecting Siberian fir species. It appears on annual branches. Gradually the needles on them dry out, become yellow, then red. Dark tubercles form on the shoots. The top of the affected tree remains green, while in the lower part the shoots thin out;
Rust cancer. The causative agents of the disease are fungal spores. As the lesion develops, vertical shoots appear on the branches. They are also called "witches' brooms." The needles on the branches thicken, and tumors form on the trunks. The disease is viral in nature;
Bacterial dropsy. The lesion covers trees of different ages. First the needles turn yellow, then turn red. Cracks appear on the trunks, from which black liquid emerges. The wood has a sour smell.

Diseases of this type weaken trees, causing them to gradually dry out. The trunks become susceptible to rotting and insect attack. In mass and single plantings, diseases cannot be treated. Affected trees are cut down and the soil is disinfected.

Root diseases

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

Important! Diseases of the root system 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 part of the trunk and roots. Gradually, the lesion rises 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. Fungal fruiting bodies form at the base of the tree;
Fibrous rot. Appearing at the bottom of the trunk, this lesion is light yellow in color with black stripes. The disease rises to a height of up to 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. As the disease develops, fibrous mycelium and dark twisting formations appear in the wood. The lesion is observed from the base of the plants to a height of 3 m. Large growths form at the roots.

Fir pests and their control

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

Types of fir pests:

Needle-eaters. These insects feed on buds and needles. This includes moths, moths, moths, and silkworms. In Siberian forests, enormous damage to coniferous plantations is caused by silkworm caterpillars. The needles of affected trees turn yellow, while cobwebs remain on them;
Sucking. Pests suck nutrients from the needles, branches and trunk. Aphids, scale insects, and 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, making them difficult to detect visually. The most noticeable are their traces - sticky discharge, which is covered with a gray coating. Under the influence of sucking insects, tree growth slows down;
Advice! To treat fir disease in the form of white plaque, it is important to eliminate all sucking pests in the area.
Stem. Pests feed on the bark and root system of conifers. These are bark beetles, borers, glass beetles, weevils, and moths. Often these insects choose dead or weakened trees, in the wood of which they gnaw passages;
Pests of cones. These include leaf roller caterpillars, moths, and gall midge flies. Cones affected by insects grow slowly, become covered with drops of resin, and 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 roots, which weakens the development of trees. If insects are found, the entire garden is treated. The fight against the larvae of these pests becomes more difficult if the site is located next to a forest.

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

A solution is prepared for spraying fir. To do this, the required amount of the drug is dissolved in water. Plantings are treated every 1 - 2 weeks. The solution is applied with a spray bottle on a cloudy day or in the evening. During the season, up to 4 treatments are performed.

A weakened tree requires fertilizing, in which complex fertilizer for conifers containing phosphorus and potassium is added to the soil. The substances can be dissolved in water and watered over plants.

Preventive actions

The best way to avoid fir diseases is to follow agricultural practices. Preventive measures for caring for conifers include watering, fertilizing, and controlling soil moisture.

List of works that help protect fir from diseases:

Watering should be rationed and excessive moisture should be avoided;
to improve drainage, drive plastic tubes up to 30 cm long into the ground;
it is necessary to shade plants in spring using agrofibre;
apply phosphorus-potassium fertilizers;
mulch the soil;
perform pruning without allowing the plantings to become dense.

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

digging up the soil in the fall;
spraying plantings with insecticides in spring and autumn;
pruning shoots, controlling the density of plantings.

Conclusion

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