Differential grain yield performance of single cross hybrid maize in varied nitrogen conditions

Presence of genotypic differences in maize ( Zea mays L.) grain yield in multi-environments would help plant breeders to make logical decisions in improvement programmes of the crop. Hence, the grain yield performance, heterosis and stability in hybrid maize in varied soil nitrogen (N) conditions in Nigeria were assessed using multiple biometrical techniques. Grain yield performance, heterosis and stability of 150 single cross hybrid maize were assessed with checks in severe N stress, N stress and optimal conditions in a replicated trial laid out in 19 × 8 lattice design for 2 years. The grain yield was subjected to analysis of variance for each N condition and combined across years. Heterosis was estimated for the trait, additive mean effects and multiplicative interaction (AMMI); and genotype + genotype × environment (GGE) models were used to analyse the hybrids' yield stability. The AMMI captured 93.7%; while GGE bi-plot accounted for 88.7% of total variation among the hybrids. Eight hybrids had high yields across the N conditions. Genotypes and environments affected heterosis for grain yield. Hybrids TZEI7×BD74-399, BD74-179×BD74-55 and BD74-175×BD74-147 were the most ideal genotypes for the N conditions; while severe N stress condition was ideal test environment. Hybrid BD74-170×BD74-31 adapted most to N stress; while TZEI1×BD74-399 adapted most to severe N stress and to optimal conditions. Based on yield, heterosis and stability, hybrids involving inbred line BD74-171 were recommended for N stress; while those with inbred lines TZEI1, TZEI4 BD74-170, BD74-128, BD74-179 and BD74-175 were adapted to N stress and optimal conditions. La présence de différences génotypiques dans le rendement en grains de maïs ( Zea mays L.) dans plusieurs environnements aiderait les selectioneurs à prendre des décisions logiques dans les programmes d'amélioration de maïs. Par conséquent, les performances de rendement en grain, l'hétérosis et la stabilité d' hybride de maïs dans les diverses conditions d'azote (N) du sol au Nigéria ont été évaluées à l'aide de multiples techniques biométriques. La performance de rendement en grain, l'hétérosis et la stabilité de 150 des hybrides de maïs simples croisés ont été évalués avec des contrôles du stress grave en N, du stress en N et des conditions optimales dans le cadre d'un essai répété présenté sur un réseau 19 × 8 pendant 2 ans. Le rendement en grains a été soumis à une analyse de variance pour chaque condition d'azote et com