Plant Population Influence on Maize Yield Components in Croatia and Nebraska

Abstract

Analysis of yield components to address inconsistent maize (Zea mays L.) grain yields across plant populations is limited in Europe and the United States. The research objectives were to compare maize yield components at low and high plant populations in eastern Nebraska and central Croatia using path analysis to better understand maize grain yield determination with changing plant population and determine relative importance among maize primary and secondary yield components. Research was conducted by planting three maize hybrids at 65,000 plants ha−1 to 105,000 plants ha−1 in 2012 and 2013 at Zagreb, Croatia, and Mead, NE. Grain yield, ears per square meter, rows per ear, ear circumference, kernels per ear, kernels per row, ear length, and kernel weight were determined. Average grain yield was 10.7 Mg ha−1 and plant population influence on yield was inconsistent and <2 Mg ha−1. Among yield components, the number of rows per ear (direct effect of 0.54 [P ≤ 0.01] with kernels per ear and 0.39 [P ≤ 0.01] with kernels per row) and the number of kernels per ear (direct effect of 0.54 [P ≤ 0.01] with grain yield) were of most importance for maize at high plant populations, while the number of kernels per row (direct effect of 0.93 [P ≤ 0.01] with kernels per ear and 0.61 [P ≤ 0.01] with kernel weight) and kernel weight (direct effect of 0.47 [P ≤ 0.01] with grain yield) were most important at low plant populations. Future maize management research for low plant population environments should focus on production of the number of kernels per ear and kernel weight, while for high plant populations, the focus should be on the number of rows per ear.