It is important for yield test sites to elicit differences among genotypes, minimize redundancy of performance information, and generate a genotype × environment interaction representative of the targeted region. The objective of this study was to use corn (Zea mays L.) variety trial data from three relative maturity group (MG) tests (early, medium, and late) at five Tennessee locations spanning 14 yr to compare test location uniqueness and redundancy via genetic variance estimates and cluster analysis. Principle component analyses allowed for location comparisons of genetic variance expression among cultivars in different MG tests. Individual location–test–year genetic variance estimates ranged from <1 to 584 (Mg ha−1)2. Years and locations affected the magnitude of genetic variance, with years largely driving genetic expression within MGs in these environments. However, the late MG consistently had the greatest variance estimates. Across 14 yr, there was minimum duplicative information provided across the five yield test sites. Consequently, all locations were needed and none could be eliminated without compromising cultivar yield trial information for the three MG tests. Correlations between mean yields and genetic variance showed a weak relationship across locations (environments), years, and MG tests (r = .021); thus, high‐yielding environments did not correspond with increased genetic variance expression. These types of analyses are useful for evaluating the discriminating ability and duplicative or correlated expression of genetic information across locations for robust variety trials within and across maturity groups and targeted regions.