Pine rot is a very dangerous pathology that often affects coniferous trees. The risk of developing this disease increases with improper care and weakening of crops by pests. To cope with the disease, it is important to take timely measures. To do this, the plant should be treated with fungicidal preparations and provided with high-quality care.
What it is
Pine whirlwind is a rather serious disease, the development of which is caused by fungi Melampsora pinitorqua. WITHpermogonial and ecial developmental stages occur on pine, and summer and autumn - on aspen leaves and some varieties of poplars.
Pine infection is observed in spring. This process involves basidiospores, which are formed during the germination of teliospores on fallen aspen leaves. The time of formation and duration of dispersal of pathogens directly depend on temperature indicators and air humidity parameters in the spring. The formation of pine whirlpool basidiospores can be detected by the golden coating on the bottom of fallen aspen leaves.
The duration of the incubation period of the pathology is influenced by weather factors. At a temperature of +14-15 degrees and a relative humidity of more than 90%, this process takes 9-14 days. With parameters of +18-21 degrees it decreases to 6-8 days. If the air temperature is less than +12 degrees, the incubation period increases to 18 days.
Signs of a spinner
With the development of pathology, the first symptoms appear in early June. In this case, first of all, young shoots and needles suffer. First, spermogonia form there in the form of yellowish dots that are barely visible.
After a few days, aecial sporulation of the fungus occurs. It is laid under the epidermis of the branches, and by the time the aeciospores mature, it comes to the surface. In this case, long orange pads are formed, up to 15-20 millimeters in size and 2-3 millimeters wide. Then the ripe aecia rupture and damage the integumentary tissue. After which the aeciospores disperse from them.
On pine branches in areas where fungal mycelium develops, tissue death is observed, and open elongated ulcers appear, which heal after some time. With the active development of pathology, the fungal mycelium rings an impressive part of the circle. As a result, the shoot becomes less stable, and its upper part hangs down. In this case, the shoot does not die off and its growth continues. As a result, it takes on the S-shape characteristic of this disease.
If measures are not taken in time, pine spinner develops over several years on one plant. In this case, the affected shoots die. As a result, the tree becomes multi-vertexed. With a later defeat, when annual shoots have time to form in time, they do not bend. After the spores disperse, aetia appear on them, which subsequently transform into small ulcers. After some time they become overgrown.
How rust starts on wood
The development of pathology is associated with infection with special fungi Melampsora pinitorqua. The name of the disease is associated with the presence of a peculiar symptom. Under the influence of fungal microorganisms, the shoots become S-shaped.
The appearance of the fungus is observed on the tree in late spring, after which the pathogens lead to the defeat of intermediate hosts - aspens and poplars. Pines affected by this infection rarely die. However, they can take the form of a bush.
It is not only an unfortunate neighborhood that leads to the development of pathology. Risks increase under the influence of such factors:
- Active development of weeds. It is important to promptly remove unwanted vegetation. It provokes the spread of rust and other pathologies, and also attracts parasites.
- Purchase of infected seedlings. Infection of pine can occur in the nursery. Therefore, before purchasing, it is important to carefully examine the seedling and treat it after planting.
- No spraying. Infection may be associated with non-compliance with prevention rules. To keep the garden healthy, it is recommended to spray the plants with fungicidal preparations.
Danger of disease
In spring, as infected shoots develop, they undergo varying degrees of deformation. Sometimes they die off. On the cut of such branches there are areas of necrosis in the area of internodes. This is what creates the prerequisites for the development of S-shaped deformation.
At the nodes of the shoots, many renewal buds are formed. They form underdeveloped shoots that hang down. They form whorled weeping branches. If pines are affected at a young age, there is a high probability of the formation of bush forms.
Protection measures
To prevent the development of pathology, pine nurseries are not located closer than 250 meters from plantings with aspens and poplars. With strict adherence to the rules of agricultural technology, the resistance of pine seedlings to spinner increases. To avoid the development of pathology, it is recommended to feed the seedlings with fertilizers based on potassium and phosphorus.
In May and the first half of June, it is important to monitor the appearance and development of pathology. If the risk of disease is high, it is necessary to carry out two preventive sprayings. For treatment, a suspension of systemic fungicides is used - “Topsina M”, “Fundazol”. Its concentration should be 0.2%.
Timely destruction of aspen growth is of great importance. This is especially true for pines less than 8-10 years old.This will help stop the subsequent development of the pathology.
Pine whirlwind is considered a fairly common pathology that leads to undesirable consequences for trees. This disease often causes deformation and stunted growth. To cope with the disease, it is important to use fungicides in a timely manner.
