Proximate and mineral compositions of pepper (capsicum spp.) varieties as affected by nitrogen fertilization in Northern Guinea Savannah of Nigeria

Although Capsicum is high-value commodity with the potential for improving the income and livelihood of smallholder farmers in Nigeria and for diversifying Nigerian’s export earnings, the crop is confronted with various production and market-related problems. There is also information gap on the proximate and mineral compositions of locally cultivated varieties compared with the exotic ones. A field experiment was conducted during the rainy season of 2023 in Jos (Latitude 090 57’N, Longitude 080 53’E, altitude of 1,159 m above sea level) to study the effects of nitrogen fertilization on the proximate and mineral compositions of two exotic and one local varieties of pepper. The experimental treatments consisted of three pepper, namely (two Habanero varieties, F1BT and SAFI, and a local check, Miango local) varieties and six rates of N- fertilizer (0, 30, 60, 90, 120 and 150 kg N ha-1). These were factorially combined and laid out in a randomized complete block design with three replications. Proximate analysis was carried out to determine the nutrient and mineral compositions using the standard methods of the Association of Official Analytical Chemists (AOAC). Ascorbic acid, β- carotene and capsaicin were determined using the rapid high-performance liquid chromatography method. Results showed that lipid, ash content, moisture, fiber, free nitrogen extract and capsaicin were higher in the Miango Local than in the other varieties. Protein, dry matter content and β-carotene were higher in the variety F1BT than in the other varieties. All the nutrients studied were higher at 150 kgN ha-1 than at the other levels of N-fertilizer application. Calcium, potassium and phosphorus were highest at 150 kgN ha-1 and lowest at 0 kgN ha-1.Significant interactions of N- rate and variety on crude protein, lipid, ash content, moisture content, and dry matter content, ascorbic acid, β- carotene, capsaicin, calcium, potassium and phosphorus were observed. For optimum productivity, proximate and mineral composition of pepper in the Jos – Plateau environment, application of N- fertilizer at the rate of 150 kgN ha-1 is recommended. The two Habanero and the Local varieties of pepper used in this study have potentials for high yield.