Lentinous wood rot

The primary visual sign of infestation is the appearance of characteristic funnel-shaped or fan-shaped fungal fruiting bodies on trunks, stumps, or large branches.

Wood in the affected area changes color over time, becoming whitish or yellowish, soft, and fibrous, losing its mechanical strength and structural integrity.

As the disease progresses, the bark may exhibit necrotic patches, depressions, or cracks, which may leak exudate during periods of high humidity.

Internal wood condition during lentinous rot is characterized by the formation of deep cavities (hollows) filled with decayed wood debris interlaced with white mycelial strands.

In advanced stages, the tree shows signs of general decline: premature leaf yellowing, drying of terminal shoots, and increased branch brittleness during windy weather.

The causal agents of lentinous wood rot are fungi from the Lentinaceae family, which belong to the group of wood-decaying xylotrophs. Key species include members of the Lentinellus and Lentinus genera that cause destructive white rot.

The fungus mycelium penetrates plant tissues through mechanical bark damage, pruning wounds, or cracks formed due to frost or sunburn injuries.

During the colonization process, the fungus secretes specialized enzymes such as oxidases that actively decompose lignin and cellulose, the main structural components of wood cell walls.

Fungal spores are dispersed by wind, insects, or raindrops, allowing the infection to spread rapidly across orchards, forests, and park areas.

These fungi are capable of developing both on weakened live trees and on freshly cut wood, making them a significant threat to forestry and urban landscaping.

Optimal conditions for the development of lentinous rot include high air humidity (above 70%) and moderate temperatures ranging from 18 to 25 degrees Celsius.

The disease spreads most actively in dense plantations where natural air circulation is restricted, contributing to moisture retention on the bark surface.

Poor tree maintenance, including leaving pruning wounds untreated, provides ideal entry points for parasitic fungal spores to establish infection.

Reduced host immunity due to mineral deficiency, drought stress, or pest damage significantly increases the tree's susceptibility to fungal colonization.

Seasonal temperature fluctuations leading to frost cracks in the bark are powerful risk factors, as exposed internal tissues become highly vulnerable to spore entry.

Lentinous wood rot causes significant economic loss by inducing premature tree death in orchards and reducing the quality of timber in forest stands.

The degradation of the tree's internal structure results in the loss of structural stability, posing a severe risk of branch or whole-tree collapse near infrastructure.

In fruit trees, this disease leads to a sharp decline in yield and productivity by disrupting the vascular transport system (xylem and phloem) responsible for nutrient and water distribution.

Decay processes are largely irreversible; even if visible decay is removed, fungal mycelium often persists deep within the heartwood, continuing its destructive activity.

Infected trees become focal points for infection for surrounding healthy specimens, requiring prompt localization and management of the affected individual.

The primary method of prevention is adherence to good arboricultural practices, including timely pruning and disinfection of wounds with grafting wax or fungicidal pastes.

Regular sanitation of the area to remove deadwood, stumps, and fallen branches is essential, as these serve as the primary reservoir for the fungus.

If fruiting bodies are detected, they must be carefully removed and destroyed via burning to prevent further spore dispersal and contamination.

To enhance tree resistance to fungal attacks, it is important to provide balanced nutrition and irrigation, while also maintaining optimal spacing between trees.

In cases of severe trunk infestation, the entire tree should be removed, including the root system, to prevent the mycelium from spreading through the soil or root grafts.