Two field experiments were conducted at the Multipurpose Crop Nursery of the Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development, Asante Mampong Campus from September to December, 2017 and April to August, 2018 during minor and major rainy seasons respectively to determine growth and yield response of sweet potato to organic and inorganic fertilizers in the forest-savannah transitional zone of Ghana. The experiment used was a 2×4 factorial arranged in randomized complete block design (RCBD) with three replications for both cropping seasons. The factors studied were; (i) two varieties of sweet potato (Ogyefo and Ogyatanaa) and (ii) Four different fertilizer rates (5 t/ha chicken manure, 300 kg/ha N.P.K. (15-15-15), 150 kg/ha N.P.K. + 2.5 t/ha CM and no fertilizer (control). The results showed that the application of chicken manure and inorganic fertilizer applied either alone or in combination influenced the soil chemical properties. Ogyefo established between 10 to 13 days earlier than Ogyatanaa in the minor and major cropping seasons respectively. Ogyefo and the 300 kg/ha N.P.K produced the highest number of branches at 86 DAP and the least number of unmarketable tubers per plot in the minor rainy season. Ogyefo and the 150 kg/ha N.P.K + 2.5 t/ha CM produced the widest vine girth at 86 DAP. Ogyefo and the 5 t/ha CM produced significantly (p<0.05) higher total tuber weight per plot, number of tubers per plot and per plant than other amended plots and the control as well as least number of forked tubers per plot in the minor rainy season. Ogyatanaa and the 300 kg/ha produced significantly (p<0.05) higher number of marketable tubers per plot than Ogyefo and other amended plots and the control in the minor rainy season. It is recommended that sweet potato farmers should grow Ogyefo using 5 t/ha CM and/or 300 kg/ha N.P.K and their recommended amounts of integrated nutrient management approaches to enhance better productivity.

Keywords: Ogyefo, Ogyatanaa, marketable tubers, vine girth.