Influence of Plant Density and Different Fertilizers on Growth and Tuber Yield of Sweet Potato (Ipomea batata. (L.) Lam) in Savanna-Forest Zone of Nigeria

The study was conducted in Jos South local Government area of plateau State, to assess the impact of different nitrogen sources and plant densities on the yield of the UMUSP-3 variety of sweet potato. The experiment was laid out in a Randomized Complete Block Design (RCBD) replicated three times in a 4 x 4 factorial design, the experiment consisted of four plant densities (P1=20,000, P2= 25,000, P3= 33,333 and P4= 50,000 plants ha-1) and four fertilizer types (Control, poultry manure, cattle manure and NPK fertilizer). Data were collected on vegetative parameters as well as yield components. The data were thereafter subjected to analysis of variance (ANOVA) using Proc GLM procedures (SAS version 9.2) to compute analysis of variance (ANOVA). The least significant difference test (LSD-test) at 5% probability was used for means separation when analysis of variance indicated the presence of significant differences. Results showed that plant density and fertilizer types significantly influenced vegetative parameters as well as yield components. Number of tubers plan-1 and average tuber weights significantly decreased with increase in plant density. The highest tuber yield plant-1 was obtained at the lowest density (P1=20,000 plants ha-1), while the highest yield ha-1 was obtained at the highest density (P4= 50,000 plants ha-1). Poultry manure consistently outperformed other fertilizers types in enhancing vegetative growth parameters as well as yield components. In conclusion, the authors recommend using a higher plant density to maximize yield ha-1 and prioritizing poultry manure as it significantly improves vegetative growth and tuber yield