Empirical Study of the Adoption Rate and Yield Impact of Striga-Tolerant Sorghum Varieties in Benue State

Striga hermonthica (witchweed) is the most devastating parasitic weed in sorghum production in the Guinea savanna, causing yield losses of 40 to 80 percent in heavily infested fields, and Striga-tolerant varieties offer the most economically accessible management option for resource-limited farmers in Benue State. This study empirically examined the adoption rate and yield impact of Striga-tolerant sorghum varieties among farmers in Logo, Guma, and Kwande LGAs of Benue State, North Central Nigeria. A cross-sectional survey combined with matched on-farm yield measurement was conducted across 120 sorghum farmers during the 2023 growing season. Adoption of Striga-tolerant varieties was verified by seed morphological and molecular markers on samples from 40 adopter farms. Striga shoot counts and sorghum grain yield were measured at harvest on adopter and non-adopter matched pairs. Adoption rate of certified Striga-tolerant varieties was 29.2 percent, with an additional 18.3 percent planting farmer-saved seed labelled as Striga-tolerant but unverified. Grain yield on confirmed Striga-tolerant variety farms was 62.4 percent higher than on non-adopter farms in high-Striga density fields (Striga count above 15 per m2). The seed authenticity analysis showed that 38.7 percent of farmer-claimed Striga-tolerant samples were not the certified variety. The study provides adoption rate and yield impact data absent from the literature for Benue State and recommends a seed traceability system and farmer community variety verification training as the most critical adoption quality improvement interventions.

Keywords: Striga tolerance, sorghum variety adoption, yield impact, Benue State, seed quality