Assessing the Potential of Extra-Early Maturing Multiple Stress-tolerant Maize Hybrids Under Different Rates of Nitrogen

Decline in soil fertility is a major constraint to maize production. This study aimed to assess the agronomic performance of improved maize varieties under different nitrogen rates to identify low nitrogen tolerant varieties. Five multiple stress-tolerant maize hybrids, developed by maize improvement program of the International Institute of Tropical Agriculture (IITA), and an open-pollinated variety used as check were evaluated under three levels nitrogen at two locations during 2019 growing season. The experiment was laid out in a split-plot experiment with three replications at each location. Nitrogen rates and varieties were the main and secondary factors, respectively. Data collected on grain yield and its related traits and were subjected to analysis of variance at 5% level of significance. The average grain yield of the six varieties under different nitrogen levels ranged from 2.2 t/ha at 0 kgN/ha in Angaradébou to 5.3 t/ha at 76 kgN/ha in Komkoma. Hybrid TZEEQI 342 × TZEEQI 7 showed high grain yield (4.0 t/ha) across the two agro-ecologies while varieties TZEE-W Pop STR QPM Co × TZEEQI 7 (3.7 t/ha) and TZdEEI 91 × TZEEI 21 (3.6 t/ha) had comparable grain yield. These hybrids were also less susceptible to nitrogen stress. They are the promising genotypes for Angaradébou localities while farmers around Komkoma should continue to cultivate TZEE-W Pop DT STR QPM.