Atractogloea stillata

The biology of this fungus is defined by its characteristic production of gelatinous spore masses. These microscopic structures appear on the bark surface and are instrumental in the pathogen's dispersal during wet weather conditions.

Mycelium of Atractogloea stillata spreads through the bark tissue, causing structural degradation. It thrives by absorbing nutrients from the bark cells, gradually weakening the host plant's exterior defenses.

The fungus is known to survive long periods in dormant states within the bark, waiting for moisture levels to increase. Its life cycle is closely linked to the physiological status of the host tree.

While not a primary killer of healthy trees, this pathogen is recognized as a factor in the long-term decline of woody species, often functioning as an opportunistic colonizer of damaged surfaces.

The primary symptom is the appearance of small, dew-like drops or gelatinous clusters scattered across the bark surface. These spots are often pale or colorless and easily overlooked by the untrained eye.

Over time, the affected bark may show signs of discoloration, shifting toward gray or dark brown tones. Cracking and scaling of the bark in the infected areas are common symptoms as the pathogen advances.

During humid periods, the gelatinous spore masses become more pronounced and hydrated, making them easier to detect on the trunk or large branches of the tree.

In cases where the fungus causes deep tissue damage, the host tree may exhibit stunted shoot growth and premature yellowing of leaves. These signs often point to a significant reduction in nutrient transport.

Visual inspection is the most common diagnostic tool, often followed by laboratory confirmation to differentiate Atractogloea stillata from other superficial bark fungi.

High humidity and consistent rainfall are the primary drivers of Atractogloea stillata development. The spores require a film of moisture on the bark surface to germinate effectively.

The fungus is most active during spring and autumn, when moderate temperatures combined with high moisture create an ideal microclimate for the colonization of bark tissues.

Poor orchard or forest management, such as overcrowding, reduces airflow and maintains elevated humidity levels around the stems, which significantly favors the growth of this fungus.

Physical injuries to the bark—caused by frosts, animal activity, or improper pruning techniques—provide immediate access for the fungal mycelium to penetrate deeper into the tree's living tissues.

Trees suffering from poor nutrition or drought stress are more susceptible to the encroachment of this pathogen, as their internal defense mechanisms are already significantly compromised.

The primary danger lies in the destruction of the bark's protective function, which leaves the tree vulnerable to secondary infections and colonization by wood-boring insects.

Continued fungal activity leads to local necrosis, which can result in the loss of individual branches and a steady decline in the tree's overall structural integrity.

In ornamental and productive gardens, the presence of the fungus impacts the aesthetic value and long-term health of the specimens, often requiring drastic pruning measures.

The cumulative effect of infection is a reduction in the tree's metabolic efficiency. Affected plants demonstrate lower vitality and decreased resistance to extreme weather conditions.

Although it does not usually cause rapid tree death, it facilitates a gradual decline, making the management of the tree increasingly difficult and costly over several seasons.

Control measures start with rigorous sanitation: pruning and destroying infected branches to prevent the further spread of spores to healthy parts of the garden.

Applying copper-based fungicides during the dormant season provides an effective barrier, inhibiting the germination of spores and protecting the bark from initial infection.

Maintaining optimal tree vigor through balanced fertilization and correct watering is essential, as healthy trees possess better natural resilience against fungal parasites.

• Sterilize all pruning tools after working on infected trees to prevent cross-contamination.
• Apply tree trunk protectors to prevent sunscald and frost cracks.
• Ensure proper spacing between trees to improve air circulation and reduce humidity.

For severe infestations, chemical control using approved fungicides should be considered, ensuring that applications are strictly followed according to the manufacturer's guidelines.