Influence of organic, inorganic and organo-mineral fertilizers on yield and quality of sweet potato (Ipomoea batatas)

The objective of this study was to evaluate the yield and quality of sweet potato under the influence inorganic fertilizer (NPK 15:15:15) at the recommended rate of 130kg/ha, organic fertilizer (Pace Setter) at the recommended rate of 3t/ha and organo-mineral fertilizer (combination of NPK 15:15:15 and Pacesetter organic fertilizer) at the rate of 1.5 t/ha. The fresh and dry weights of the samples were taken after which their proximate analyses were done to determine the levels of the quality determinants (moisture content, crude protein, ether extract, crude fibre, Vitamin A and ash content) in them. At the end of the experiment, harvesting was done to determine the yield per treatments as well as the quality parameters of the leaves and tubers. It was found that organic fertilizer could increase the quantity of ether extract, crude fibre and vitamin A contents of sweet potato tubers above other fertilizer treatments though organic fertilizer competed with the control in increasing the ash and crude protein contents of sweet potato tubers. However, inorganic fertilizer increased only energy content of the tubers above organic and organo-mineral fertilizer treatments. It is, therefore, concluded that organic fertilizer should be used to increase sweet potato tuber quantity and quality.Keywords: Sweet potato, growth, yield, quality and fertilizer treatment