Effect of Fertilizer on Growth and Yield of Three Varieties of Sweet Potato (Ipomea batata) in Igbariam, South East Nigeria

Abstract: A field experiment was conducted at Research Farm of National Root Crops Research Institute Sub-Station, Igbariam to study the effect of NPK 15:15:15 fertilizer application rates on the growth and yield of three varieties of sweet potato (Umuspol, Ex-Igbariam and Tis87/0087) during 2023 cropping season. The experiment was set up as 4 x 3 factorial laid in a randomized complete block design (RCBD) with three replications. The main factor comprises combination of four levels of fertilizer rates (0, 200, 400 and 600 NPK 15:15:15 kg/ha) while the sub-factor consisted of three varieties of sweet potato (Umuspol, Ex-Igbariam and Tis87/0087). Data collected on the growth and yield of the crop were subjected to analysis of variance (ANOVA) using Genstat 4th edition statistical software. The significant mean were separated using the Fisher’s least significant difference (F-LSD) at 5% probability level. The result obtained indicated that Umuspol variety vine length, number of leaves and branches significantly had the highest values as 151.3cm, 160.9, and 14.9 respectively. While, Tis87/0087 had the lowest values of vine length, number of leaves and number of branches as 32.5cm, 46.3, 6.5 respectively. Fertilizer application rate at 200 kg/ha significantly influenced the length of tuber, width of tuber and tuber weight with highest values recorded in as 18.3cm, 10.1cm and 2.8kg/ha.