<p>Maize stalk rot caused by <i>Fusarium</i> spp. results in the internal decay and discoloration of stalk tissue, leading to hollow and weakened stalks that are prone to lodging, thereby reducing grain yield and quality. In this study, strains of <i>F. graminearum</i> (Fgra) of the 15-acetyl-deoxynivalenol (15ADON) genotype, <i>F. meridionale</i> of the nivalenol (NIV) genotype, and <i>F. cortaderiae</i> (Fcor) of the 3-acetyl-deoxynivalenol (3ADON) and NIV genotypes, all from the <i>F. graminearum</i> species complex (FGSC), as well as strains of <i>F. verticillioides</i> (Fver), were compared for their aggressiveness in causing stalk rot in popcorn maize (<i>Zea mays</i> var. Everta). Five strains of each species or trichothecene genotype were included in the study. The inoculation in stalks of plants grown in pots at the stage with six expanded leaves was performed using a toothpick contaminated with mycelia. Disease severity was assessed 12 days post-inoculation by measuring lesion length above and below the inoculation site. All strains were pathogenic, causing internal decay and discoloration of stalk tissue. Significant variation in strain aggressiveness was observed in intraspecies and trichothecene genotypes for Fgra-15ADON, Fmer-NIV, Fcor-3ADON, and Fver but not for Fcor-NIV. Orthogonal contrast analysis was conducted to evaluate the relative aggressiveness of different <i>Fusarium</i> species and genotypes. The analysis revealed that Fgra-15ADON, Fmer-NIV, Fcor-NIV, and Fcor-3ADON did not differ significantly in aggressiveness. However, they were more aggressive than Fver. Notably, this study is the first to demonstrate the pathogenicity of Fcor with NIV or 3ADON genotypes in maize stalks. These findings provide novel insights into the pathogenic variability of FGSC, its trichothecene genotypes, and Fver in maize stalk rot. Such information will help select popcorn or common maize genotypes with improved stalk rot resistance and develop additional control measures.</p>