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 7 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 7 environment (GGE) models were used to analyse the hybrids\u2019 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 7BD74-399, BD74-179 7BD74-55 and BD74-175 7BD74-147 were the most ideal genotypes for the N conditions; while severe N stress condition was ideal test environment. Hybrid BD74-170 7BD74-31 adapted most to N stress; while TZEI1 7BD74-399 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 pr\ue9sence de diff\ue9rences g\ue9notypiques dans le rendement en grains de ma\uefs ( Zea mays L.) dans plusieurs environnements aiderait les selectioneurs \ue0 prendre des d\ue9cisions logiques dans les programmes d\u2019am\ue9lioration de ma\uefs. Par cons\ue9quent, les performances de rendement en grain, l\u2019h\ue9t\ue9rosis et la stabilit\ue9 d\u2018 hybride de ma\uefs dans les diverses conditions d\u2019azote (N) du sol au Nig\ue9ria ont \ue9t\ue9 \ue9valu\ue9es \ue0 l\u2019aide de multiples techniques biom\ue9triques. La performance de rendement en grain, l\u2019h\ue9t\ue9rosis et la stabilit\ue9 de 150 des hybrides de ma\uefs simples crois\ue9s ont \ue9t\ue9 \ue9valu\ue9s avec des contr\uf4les du stress grave en N, du stress en N et des conditions optimales dans le cadre d\u2019un essai r\ue9p\ue9t\ue9 pr\ue9sent\ue9 sur un r\ue9seau 19 7 8 pendant 2 ans. Le rendement en grains a \ue9t\ue9 soumis \ue0 une analyse de variance pour chaque condition d\u2019azote et combin\ue9 sur plusieurs ann\ue9es. L\u2019h\ue9t\ue9rosis a \ue9t\ue9 estim\ue9e pour le trait, les effets moyens additifs et l\u2019interaction multiplicative (MAIM); et des mod\ue8les g\ue9notype + g\ue9notype 7 environnement (GGE) ont \ue9t\ue9 utilis\ue9s pour analyser la stabilit\ue9 du rendement des hybrides. Le MAIM a captur\ue9 93,7%; alors que les bi-parcelles GGE ont repr\ue9sent\ue9 88,7% de la variation totale parmi les hybrides. Huit hybrides ont eu des rendements \ue9lev\ue9s dans les conditions d\u2019azote (N) du sol. Les g\ue9notypes et les environnements ont affect\ue9 l\u2019h\ue9t\ue9rosis pour le rendement en grain. Les hybrides TZEI7 7 BD74-399, BD74-179 7 BD74-55 et BD74-175 7 BD74-147 \ue9taient les g\ue9notypes les plus id\ue9aux pour les conditions N; tandis que la condition de stress N grave \ue9tait l\u2019environnement de test id\ue9al. Les hybrides BD74-170 7 BD74-31 \ue9taient les mieux adapt\ue9s au stress N; TZEI1 7 BD74-399 \ue9taient plus adapt\ue9s \ue0 l\u2018 intense stress li\ue9 \ue0 l\u2019azote et aux conditions optimales. En se basant sur le rendement, l\u2019h\ue9t\ue9rosis et la stabilit\ue9, des hybrides impliquant la lign\ue9e consanguine BD74-171 ont \ue9t\ue9 recommand\ue9s pour le stress sous N; tandis que ceux avec des lign\ue9es consanguines TZEI1, TZEI4 BD74-170, BD74-128, BD74-179 et BD74-175 ont \ue9t\ue9 adapt\ue9s au stress N et \ue0 des conditions optimales