Grain Iron and Zinc Concentrations and their Relationship with Selected Agronomic Traits in Early and Extra-Early Maize

Abstract

ABSTRACTImprovement of iron (Fe) and zinc (Zn) concentrations in maize (Zea mays L.) is of prime importance in combating malnutrition and food insecurity in sub-Saharan Africa. The choice of suitable base population is crucial in making satisfactory progress from selection for a target trait. Twenty-four open-pollinated maize cultivars were evaluated for certain agronomic characters and for Fe and Zn concentrations in maize kernels to identify those with improved Fe and Zn concentrations. Relationship of Fe and Zn with agronomic traits was also studied. Data were subjected to analysis of variance and correlation analysis. Cultivar 2009TZEE-OR1STR had the highest zinc (5.29 mg/g) and iron content (11.42 mg/g) in grain. Grain yield had no relationship with Fe and Zn concentrations, suggesting that yield and micronutrient concentrations were not controlled by the same genetic system/mechanism. There was a significant positive correlation (r = 0.80**; r2 = 64%) between Fe and Zn concentrations, which indicated that the two micronutrients can be improved simultaneously in maize. Maturity significantly affected relationship of Fe and Zn concentrations with the agronomic traits. There was a significant correlation (r = 0.88**) between Fe and Zn only for extra-early germplasm and a significant correlation between Fe concentration and grain yield (r = 0.63**) only for early-maturity cultivars. In conclusion, 2009TZEE-OR1STR was the best cultivar in Fe and Zn concentrations as well as for grain yield and other agronomic traits and it could be promoted for further genetic improvement.