Co-application of biochar and organic fertiliser for improved productivity of sesame (Sesamum indicum L.) in the humid tropics

Sesame (Sesamum indicum L.) grain yield has recently declined partly because of the limited use of organic nutrient sources on degraded tropical soils. The study assessed the agronomic performance of three sesame varieties (V) as affected by organic nutrient sources (T) application. The two factors were arranged in a split-plot with V (White Benue, Cameroun White, and E-8) as the main plot and T (T1: Control, T2: biochar at 2.5 t / ha, T3: biochar at 5.0 t / ha, T4: organic fertiliser at 5.0 t / ha, T5: organic fertiliser + biochar at 2.5 t / ha and T6: organic fertiliser + biochar 5.0 t / ha) as the subplot in a Randomised Complete Block Design and replicated three times. Data were collected on agronomic traits of sesame. The varieties were significantly (p < 0.05) different in number of days to flowering, capsule formation, and physiological maturity in 2020. Varietal and organic nutrient source effects were significant (p < 0.05) for height at flowering and harvest in both years. Factor T (T4 – T6) significantly (p < 0.05) increased capsule and seed weight per plant, and grain yield in both years relative to T1. The V × T interaction was significant for height to the first capsule and seed weight per plant in 2020. Sesame grain yields recorded under T3 – T6 were significantly higher (p < 0.05) than the control (T1) in 2020 (1.2 – 1.5 t / ha) and 2021 (1.3 – 1.6 t / ha). Prospective organic sesame producers can apply organic fertiliser at 5 t / ha (T4) alone in the humid tropics.