Economic Impact of Black Sigatoka Disease on Plantain Farmers in Cross River State, South South Nigeria

Black Sigatoka disease caused by Mycosphaerella fijiensis is the most economically significant leaf disease of plantain globally and has been extensively reported in the humid South South zone of Nigeria. Understanding the direct and indirect economic costs attributable to this disease is essential for prioritising investment in management programmes and supporting policy development. This study quantified the economic impact of Black Sigatoka disease on plantain farmers in Cross River State using a combination of field disease assessment, farmer income surveys, and partial budget analysis across 150 farming households in four local government areas. Disease severity was rated seasonally across sampled farms, and yield loss models from the literature were adapted to local conditions. Annual economic losses attributable to Black Sigatoka were estimated at an average of 312,000 naira per hectare, representing 38 percent of potential gross revenue at local market prices. Farmers spending on fungicide inputs for disease management averaged 85,000 naira per hectare per season, with significant disparities between resource-rich and resource-poor households. Farms without any disease management interventions showed bunch weight reductions averaging 34 percent. The partial budget analysis confirmed that investment in a minimum fungicide programme incorporating mancozeb-based products at three critical growth stages yielded a positive net economic benefit under prevailing market conditions. The study argues for a subsidised fungicide access programme for resource-poor plantain farmers and investment in tolerant hybrid variety deployment in Cross River State. Keywords: Black Sigatoka, plantain, economic impact, Cross River State, partial budget.