Tea leaf blight

The disease is caused by the basidiomycete fungus Corticium theae, a serious pathogen known for affecting woody perennial plants. It is considered a significant threat in regions where tea is cultivated, particularly in tropical and subtropical climates with prolonged periods of rainfall.

The primary host for this fungus is the tea plant Camellia sinensis. While it primarily targets the foliage and young tender shoots, the pathogen can also colonize thicker stems, leading to severe structural damage if the infection is not addressed in the early stages.

Symptoms begin as small, dark brown spots on the leaves, which eventually expand and become necrotic. During humid conditions, a characteristic web-like mycelium may appear on the underside of the leaves or on the surface of the twigs. This leads to premature leaf fall and branch dieback, which is a hallmark of this condition.

Development and spread of Corticium theae are driven by high atmospheric humidity and persistent moisture. The fungus thrives in shaded, overcrowded areas of the plantation where air circulation is poor, allowing spores to germinate and spread to neighboring plants through rain splashes or wind.

The economic impact of this disease is substantial, as it reduces the photosynthetic capacity of the tea bush and results in lower leaf yield. Effective management requires a combination of sanitation and chemical interventions. Key practices include:

• Regular pruning to improve air circulation
• Removal and burning of severely infected debris
• Application of copper-based fungicides during the rainy season
• Regular monitoring of plantation health