Patellariales

The color of the apothecia ranges from dark brown to deep black, making them visually distinct against lighter or decaying bark. Affected areas are frequently covered in microscopic cracks.

Changes in tissue color often appear around the infection zones, progressing into necrotic spots. Careful inspection may reveal signs of peeling or flaking of the top layers of bark where the mycelium has accumulated.

In early stages, the fungi may appear as barely visible dark spots that grow and merge into groups over time. This indicates active mycelial development within the plant tissues.

In neglected cases, affected branches begin to wither prematurely, losing their elasticity. Leaves on such shoots may yellow and fall off before the end of the regular growing season.

The causative agents are fungi of the order Patellariales, which belong to the class Dothideomycetes. These are primarily saprotrophic or weakly parasitic organisms adapted to living on lignified substrates.

A biological feature of these fungi is their ability to actively break down complex organic compounds, such as lignin, found within wood composition.

Patellariales fungi form apothecia that differ from the perithecia of other orders due to the specific structure of the hymenium. This protective adaptation allows spores to survive in adverse external conditions.

The spread of the fungus in nature occurs mainly via the air, with spores carried by the wind onto weakened areas of trees and shrubs. Transmission via raindrops is also possible.

Genetic studies indicate that this order encompasses diverse species that can exist either in symbiosis with lichens or independently, damaging weakened plants.

A key condition for the development of infection is high air humidity and the presence of damage to the plant bark surface. Fungi easily penetrate tissues through cracks, pruning wounds, or sunburn.

Dense plantings where natural air circulation is disrupted create an ideal microclimate for spore germination. Prolonged periods of heavy rain contribute to the rapid reproduction of the pathogen.

Reduced plant immunity due to nutrient deficiency or exposure to low temperatures makes them vulnerable to Patellariales attack. Healthy plants with intact bark are less susceptible to infection.

The temperature optimum for the development of most species in this order is within moderate ranges. However, they are capable of maintaining viability across a wide range from early spring to late autumn.

Plant debris left in the garden after pruning plays a significant role in spreading the infection. Fungi can maintain their pathogenicity on such debris for several seasons, serving as a constant source of inoculum.

The harmfulness of Patellariales fungi lies in the gradual destruction of the plant's conductive tissues, leading to impaired transport of nutrients and water.

Damage to shoots and trunks weakens the plant's overall condition, making it less productive. In commercial orchards, this leads to a noticeable decline in yields and poorer fruit quality.

Disease progression is often accompanied by secondary colonization of tissues by other pathogens, which accelerates branch dieback. Eventually, affected plants may die completely.

Systematic neglect of the problem leads to premature aging of plantings. This forces agronomists to conduct costly sanitary measures and replace damaged specimens.

Although these fungi rarely kill a tree instantly, their cumulative effect significantly reduces the economic efficiency of intensive agricultural production.

The foundation of protection is strict adherence to agronomic practices. It is crucial to perform timely sanitary pruning of damaged branches, which serve as reservoirs for the infection.

All cuts and wounds on trees must be immediately treated with disinfectant solutions or wound dressings. This prevents direct contact between spores and exposed wood.

Regular application of copper-based fungicide preparations is recommended for preventive treatment of trees at the beginning of the growing season and in the autumn.

• Removal of plant debris from the garden.
• Ensuring optimal planting density.
• Balanced fertilization to strengthen immunity.
• Protection of trunks from sunburn and frost cracks.

In case of massive infection, it is necessary to disinfect the entire area and limit the spread of spores by thoroughly cleaning tools after each use.