Hybrid maturity influence on maize yield and yield component response to plant population in Croatia and Nebraska

Maize (Zea mays L.) yield component analysis is limited. Research was conducted in 2012 and 2013 at Zagreb, Croatia and Mead, Nebraska, United States with the objective to determine the influence of environment, hybrid maturity, and plant population (PP) on maize yield and yield components. Three maturity classes of maize hybrids were produced at five PP ranging from 65,000 to 105,000 plants ha−1 under rainfed conditions. Yield, ears m−2, rows ear−1, ear circumference, kernels ear−1, kernels row−1, ear length, and kernel weight were determined. Average yield was 10.7 t ha−1, but was variable for hybrids across PP. The early maturity-hybrids had lesser ear circumference, more kernels ear−1, greater ear length, and fewer rows ear−1 than mid- and late-maturity hybrids. Kernels ear−1 had the highest correlation with yield (r = 0.47; P −2, kernels ear−1 and kernel weight had similar direct effects on yield for early-maturity hybrids (R = 0.41 to 0.48) while kernels ear−1 had the largest direct effect (R = 0.58 versus 0.32 to 0.36) for the midand late-maturity hybrids. Rows ear−1 had an indirect effects on yield (R = 0.30 to 0.33) for all hybrids, while kernels row−1 had indirect effect (R = 0.46) on yield for mid- and latematurity hybrids. Yield component compensation was different for early-maturity hybrid than the mid- and late-maturity hybrids, likely due to the proportion of southern dent and northern flint germplasm present in these hybrids