Patterns of pearl millet genotype-by-environment interaction for yield performance and grain iron (Fe) and zinc (Zn) concentrations in Sudan

• We assess G × E interaction for yield and grain Fe/Zn levels in Sudanese pearl millet.
• Different genotypes were best adapted to irrigated versus rainfed sites.
• Large genotype–year interactions underline need to select for yield stability.
• Agro-morphological traits and yield stability measures were mostly not correlated.
• Genotypes with high and stable grain yield, Fe and Zn contents were identified.

Pearl millet (Pennisetum glaucum (L.) R. Br., [syn. Cenchrus americanus (L.) Morrone]) is grown in the semi-arid tropics under climatically highly variable environmental conditions. To study the patterns of genotype-by-environment (G × E) interaction and stability of grain yield and nutrient concentrations in Sudan, 225 pearl millet accessions were evaluated for yield performance at three locations over two years (2010–2011). A sub-set of 30 entries was additionally analyzed for grain Fe and Zn concentrations across four location–year combinations. Wide ranges of environmental means were observed for grain yield (73.3–210.8 g m−2), Fe (37.4–45.4 mg kg−1) and Zn (35.5–38.8 mg kg−1). Genotypic, environmental and G × E interaction effects were highly significant (P < 0.01) for grain yield and both nutrients. The first two principal components of the additive main effects and multiplicative interaction (AMMI) explained 32.1%, 27.4% and 42.6% of total variances for grain yield, Fe and Zn concentrations, respectively. The irrigated Wad Medani sites (no drought) were consistently grouped into one mega-environment, revealing an opportunity for selecting for specific adaptation to this type of environment. Genotype-by-year (G × Y) and genotype-by-location-by-year (G × L × Y) interaction effects contributed largely to the total G × E interaction for grain yield in the rainfed environments (mild/moderate post-flowering and severe post-planting and post-flowering drought), underlining the need of selecting for yield stability. Depending on farmers’ risk aversion, assessment of yield stability should be done according to the static or dynamic yield stability concept – both types of stability measures were not correlated in the present study. Several outstanding genotypes in terms performance and stability (static or dynamic) of yield, Fe and Zn concentrations were identified. These are promising experimental varieties or germplasm sources for programs targeting pearl millet productivity enhancement in Sudan.