Relationship between stalk, root, and kernel rots in maize hybrids and their impact on yield

Abstract

Maize (Zea mays L.) is one of the main crops, but its yield is affected by fungal diseases such as stalk and root rots, caused by Fusarium spp. and Cephalosporium sp. This study evaluated the susceptibility of two maize hybrids (Pioneer 32R22 and Pioneer 3456R) by isolating and identifying fungi in stalks, roots, and kernels. The experiment was conducted in Santa Catarina over two growing seasons, assessing the hybrids at phenological stages V8, R1, R4, and R6. The incidence and severity of rots were analyzed in the field and laboratory, while kernel infections were assessed through seed pathology. The hybrid Pioneer 32R22 showed a higher incidence of stalk and root rot, reaching 51.11% at R4 and 100% at R6 (2019/20), with a severity of 39.48% at R6 (2020/21). F. verticillioides and Cephalosporium sp. were more frequently isolated from the kernels of this hybrid. In contrast, Pioneer 3456R exhibited lower susceptibility and higher productivity (11,999 kg/ha in 2019/20 and 11,124 kg/ha in 2020/21). Integrated strategies, such as selecting resistant hybrids, are essential to mitigate these diseases.