Olojede A.O, A.C. Ohiri and G.O Chukwu
Six new (fertilizer formulations were evaluated at four rates (0,400, 800 and 1200 kg ha1) for seed yam production using the minisett technique. The field trial was conducted in 1994 at
University of Uyo, Main Campus, Uyo – Akwa Ibom State while the repeat trial was sited at the experimental farms of the National Root Crops Research Institute, Umudike in 1995. The aim of the trial was to provide a complete production package for yam minisett technique through appropriate fertilizer formulation and rate for seed yam production in nutrient deficient soils of the Southeast agro-ecology. A combined analysis of the two year data showed that fertilizer formulations had significant (P < 0.05) effects on yam tuber yield, total calorie yield and net returns while fertilizer rates significantly influenced all parameters considered for the two years. For seed yam production under this cropping situation, fertilizer of higher K ratios performed better. There was no apparent yield advantage of calcium blended fertilizer types over non-calcium ones. Zinc blended formulation (20:10:10+ 2S + Zn) gave a better yield of yam tubers and net returns followed by the popular NPK 15:15:15 and 27:13-13. A rate of 800 kg ha-1 irrespective of fertilizer formulation was found adequate and economical having 49% profit margins over the control.