Gnomoniopsis rot

The disease is caused by the ascomycete fungus Gnomoniopsis daii. This pathogen is a significant threat to chestnut plantations, known primarily for inducing fruit rot and causing necrotic damage to the host tissues of Castanea species.

The primary host for this fungus is the sweet chestnut (Castanea sativa). The infection can impact both young and mature trees, spreading through orchards and natural forests where host availability and environmental conditions favor the pathogen's lifecycle.

Clinical signs of infection include dark discoloration on the surface of the nuts, progressing to internal brown rot of the kernel. Small, black, erumpent fruiting bodies often appear on the pericarp of infected nuts. Additionally, the fungus may cause localized necrosis on stems and premature senescence of the foliage.

The development and spread of Gnomoniopsis daii are highly dependent on environmental moisture and temperature. Spores are disseminated by rain splash and wind, entering the tree through natural openings or mechanical wounds. The pathogen persists in the soil and on residual plant material, facilitating infection year after year.

The economic impact of this disease is substantial, as it significantly reduces market quality and causes storage losses. Integrated pest management strategies, focusing on the destruction of infected material and canopy management to improve airflow, are essential to minimize the impact of the disease in commercial plantations.

• Removal and destruction of fallen/infected nuts.
• Sanitary pruning of affected branches.
• Application of preventative fungicides during flowering.
• Enhancement of tree vigor through proper orchard management.