Evaluation of nitrogen fertilizer rates on growth and yield of commercially grown maize genotypes in southwestern Nigeria
Journal of Food, Agriculture and Environment
Department of Agronomy, University of Ibadan, Ibadan, Nigeria
Experiments were designed to estimate the nitrogen requirements of some commercially grown maize genotypes and those under research trials. The first experiment consisted of four rates of nitrogen fertilizer (N 0, 25, 75 and 100 kg/ha) with three maize genotypes: single-cross hybrid (Oba Super1), and two open pollinated genotypes, I-WDC3Syn and ACR-91Suwan1-SRC1, while in the second experiment, six fertilizer rates were used (N 0, 50, 75,100,150 and 200 kg/ha) and two additional maize genotypes (STR double cross and STR 3 way cross) were included. Experimental designs were split plot with fertilizer rates as the main plots and maize genotypes as subplots. Data were taken on morphological parameters, growth rates, dry matter production, yield and components of yield. No consistent differences were recorded for most growth and morphological parameters; though the parameters increased with increasing nitrogen. Grain yield of maize genotypes significantly (P = 0.05) increased with response up to N 200 kg/ha; however, no significant increase was obtained above N 75 kg/ha. Grain yield increase of 18.1, 64.8 and 71.8% were recorded at N 25, 75 and 100 kg/ha, respectively, in the first experiment, while increase of 37.5, 42.6, 60.5, 59.3 and 73.4% were recorded at N 50, 75, 100, 150 and 200 kg/ha, respectively, for second experiment. Grain yield of commercial hybrid was higher than that of the open pollinated genotypes in all the nitrogen fertilizer rates. Hybrid maize genotype (Oba super1) outyielded the open pollinated genotypes ACR-91Suwan1-SRC1 and I-WDC3Syn by 13.4 and 20.4%, respectively, in the first experiment and 17.6 and 32.8%, respectively, in the second experiment. In conclusion, hybrid maize genotypes were superior to open pollinated genotypes, indicating that hybrid maize does not require more nitrogen fertilizer than open pollinated in exhibiting their potential yield, also, additional maize grain increase with respect to fertilizer cost was not profitable above N 100 kg/ha. © 2015, World Food Ltd. and WFL Publishers. All rights reserved.
nitrogen fertilizer; agricultural parameters; Article; biomass production; chlorophyll content; experimental design; genotype; genotype environment interaction; grain yield; growth rate; leaf area; maize; Nigeria; nonhuman; plant growth; plant height; plant structures; plant yield component; plantation; soil analysis