Cercospora leaf spot of persimmon

The disease is caused by the fungus Pseudocercospora brevis, which acts as a specialized pathogen of persimmon foliage. It is recognized as one of the significant fungal diseases that impact the health of commercial and private persimmon orchards by disrupting photosynthesis through necrotic lesions.

The primary hosts for this pathogen are various species of the genus Diospyros, most notably the oriental persimmon (Diospyros kaki). The infection is most prevalent in areas with high humidity and warm temperatures, which provide ideal conditions for the colonization and dispersal of the fungus.

Symptoms initially appear as small, scattered spots on the leaves. These spots gradually become angular or circular and dark brown in color. Under high humidity conditions, a velvety gray or olive-colored fungal growth can be observed on the underside of the leaves, representing the sporulation of the pathogen.

The life cycle and dissemination of the pathogen are closely linked to moisture levels. Conidia are spread by wind and splashing raindrops. The fungus survives the dormant season as mycelium or conidia in fallen infected leaves, which serve as the primary source of infection for new growth in the spring.

The economic impact of the disease is significant because severe infections cause premature leaf drop. This defoliation severely reduces the tree's vigor, impairs fruit development and sugar accumulation, and makes the trees more susceptible to environmental stressors and subsequent damage.

Integrated management practices include:

• Strict sanitation by removing and destroying all fallen leaves at the end of the season.
• Pruning branches to improve light penetration and air circulation within the canopy.
• Timely application of copper-based fungicides or systemic chemical treatments during the vegetative phase.
• Monitoring orchard moisture levels and ensuring balanced tree nutrition.