Factors affecting incidence of narrow brown leaf spot of rice caused by Passalora janseana

Fertilizers, weeds, and planting density affect the narrow brown leaf spot (NBLS) disease in rice. This study was conducted to assess the factors contributing to the occurrence of NBLS at different stages of paddy cultivation during the Maha and Yala seasons. The degree of the disease occurrence was evaluated by calculating the Area Under the Disease Progress Curve (AUDPC). Nitrogen fertilizer influenced the determination of the disease incidence index in both seasons and its effect was greatest during 64-72 days after sowing. The presence of weeds throughout the life cycle affected the disease incidence index during the Yala season.