Nalanthamala diospyri

Nalanthamala diospyri is a fungal pathogen responsible for severe canker disease in persimmon trees. This fungus colonizes the woody tissues of the host plant, disrupting vascular functions and often leading to the eventual death of branches or the entire tree if left untreated.

The primary host for this pathogen is the persimmon (Diospyros species). The disease affects the bark, cambium, and xylem layers of the stems and branches. Entry points for the infection are typically wounds created by pruning, frost cracking, or insect damage, which expose the vulnerable inner tissues to fungal spores.

Clinical symptoms include the formation of sunken lesions (cankers) on the bark, accompanied by tissue necrosis and wood discoloration. As the infection progresses, the foliage above the affected branch turns yellow and wilts. If the canker girdles the main stem, the tree will experience rapid decline and potential systemic collapse.

Environmental conditions characterized by high humidity and moderate temperatures favor the production and release of spores. These spores are easily disseminated by wind and rain splashes, facilitating the spread of the pathogen throughout the orchard. Crowded planting and poor tree hygiene significantly increase the risk of an outbreak.

Effective management requires a proactive approach including regular orchard inspections and immediate removal of symptomatic branches. All pruning tools should be disinfected regularly to prevent cross-contamination. Applying protective fungicides, particularly copper-based compounds, during dormant and early growth stages is essential for maintaining tree health and preventing new infections.