Abstract

Kogbe J. O. S. and Adediran J. A.

 Field trials testing the effects of five rates each of N, P and K application on three hybrid and two openpollinated maize varieties were conducted in three separate experiments on an Arenic haplustalf (USDA) at Ilora in the derived savanna and Typic paleustalf (USDA) at Mokwa in the southern guinea savanna of Nigeria. The hybrid maize varieties planted were 8516-12, 8321-18 and 8329-15 and were compared with the open-pollinated maize, TZSR-Y and TZSR-W. Nitrogen was applied at rates 0-200 kg ha-1 in the first trial, while P and K were supplied as basal nutrients. In the second trial, P was applied at rates 0- 80 kg P2O5 ha-1 using basal N and K fertilizers. In another trial, K was applied at rates 0-120 kg ha-1 with blanket application of N and P. The hybrid maize gave higher yields and used N and P more efficiently than the open pollinated at both trial locations. The yield of maize was higher in the southern guinea savanna than in the derived savanna. The performance of the hybrid varieties followed in the ascending order of 8516-12, 8321-18 and 8329-15. The optimum rates of N and P for maize grown in the derived savanna were 100 and 40 kg ha-1 respectively. In the southern guinea savanna the open pollinated and hybrid varieties responded up to 150 and 200 kg N ha-1 respectively. The 8516-12 showed higher N and P use efficiency than other varieties. Consequently, planting such variety could be advantageous, using minimal dose of fertilizer most especially, where farmers have less access to fertilizer.