EPIDEMIOLOGICAL SURVEY OF RICE VIRAL DISEASES AND PREVALENCE OF RYMV IN KWARA STATE, NIGERIA

Rice yellow mottle virus (RYMV) is a significant threat to rice production in sub-Saharan Africa, leading to yield losses and economic setbacks for farmers. A comprehensive field survey was conducted in September 2021 across 48 rice fields in Kwara State, Nigeria, to assess the incidence and severity of rice virus disease. A total of 600 leaf samples were collected from rice plants showing virus-like symptoms across four local government areas (LGAs): Ifelodun, Edu, Patigi, Ilorin South. The collected samples underwent serological and molecular analyses using Antigen-Coated Plate Enzyme-Linked Immunosorbent Assay (ACP-ELISA). Statistical analysis was carried out using the R programming language. Among the surveyed LGAs, Ifelodun recorded the highest disease incidence at 48.25%, whereas Edu had the lowest at 37.25%. The highest disease severity was observed in Ifelodun (62.25%), while Patigi recorded the lowest severity (50%). Despite the widespread occurrence of virus-like symptoms, laboratory tests confirmed the presence of RYMV only in samples collected from Belle town, Edu Local Government, highlighting the need for further epidemiological studies to determine the full extent of the virus distribution in Kwara State. This study represents the first documented research on RYMV in Kwara State, Nigeria, and underscores the importance of continued surveillance to prevent potential outbreaks. Future research should focus on expanding the survey to other rice-growing regions in Nigeria to assess the prevalence and genetic diversity of RYMV strains.