Curvularia lunata

Curvularia lunata is a widespread filamentous fungus belonging to the Ascomycota phylum. It functions as a facultative plant pathogen capable of causing diverse diseases, primarily leaf spots, seed discolorations, and root rots across a broad range of host plants, including major cereals like maize and rice.

The disease symptoms typically begin as small, chlorotic lesions that expand into dark brown or black necrotic spots, often surrounded by a yellow halo. In severe cases, the pathogen leads to comprehensive tissue necrosis, blight, and significant reduction in photosynthetic capacity, which directly results in reduced crop yields and diminished commercial value of grains.

The biology of Curvularia lunata is characterized by the production of pigmented conidia, which serve as the primary inoculum. The fungus can survive as saprophytes on crop debris in the soil or remain dormant within seeds. Upon favorable environmental conditions, the conidia germinate and colonize host tissues, utilizing various enzymes to degrade plant cell walls.

Development and dissemination of this pathogen are heavily influenced by environmental factors, most notably temperature and moisture. Warm temperatures (25–30°C) combined with high relative humidity significantly accelerate the life cycle and spore dispersal. Poor field drainage and high-density planting can create microclimates that favor rapid infection spread within the canopy.

Management strategies require an integrated approach to reduce the pathogen load in the field. Effective control measures include the use of certified pathogen-free seeds, chemical seed treatments, and systemic foliar fungicide applications during high-risk growth stages. Additionally, removing crop residues and ensuring optimal crop rotation are essential to disrupting the pathogen's survival cycle.