Survey of Root Rot Diseases of Groundnut (Arachis hypogaea) in Kano State, North West Nigeria

Groundnut (Arachis hypogaea) cultivation in Kano State serves as both a livelihood source and a component of household nutrition for thousands of smallholder farming families. Root rot diseases, however, have been persistently associated with significant yield depression in this region. This survey was undertaken to identify the causal agents of root rot, determine their distribution, and assess their impact on groundnut production across four local government areas in Kano State. Sampling was conducted during the 2023 and 2024 growing seasons, focusing on wilted, yellowing, and stunted plants with visible root discolouration. Laboratory isolation and identification procedures confirmed the predominant roles of Fusarium solani, Sclerotium rolfsii, and Aspergillus niger in causing root and stem rot under field conditions. The overall disease incidence was 41 percent, with the highest prevalence recorded on farms with low organic matter content and compacted soils. Sclerotium rolfsii-related symptoms were more widespread in sandy loam soils typical of the northern districts surveyed. Observations indicated that infected crop residues left in the soil contributed to inoculum build-up between seasons. Farmers generally lacked awareness of crop rotation or biological control options that could break the disease cycle. This study calls for targeted training programmes and the introduction of soil health monitoring strategies in groundnut-growing communities. Keywords: groundnut, root rot, Fusarium solani, Kano, disease incidence.