Evaluation of maize (Zea mays L.) genotypes for yield and yield components and carbon storage

Introduction Maize is a global commodity crop cultivated under monocropping systems and diverse environmental conditions. While different genotypes exist with various abilities to store carbon into tissues and into the soil to mitigate against climate change and soil degradation, the links with grain yield remains uncertain. Methods Therefore, the present study aimed to screen a series of maize germplasm planted in southern Africa for carbon storage and agronomic performance to assess the link between these and identify superior genotypes. We evaluated as a first attempt, forty-five genotypes using a 5 x 9 alpha lattice design across two South African sites during the 2022/23 growing season. The recorded agronomic traits include plant height (PH), grain yield (GY), total plant biomass (PB), shoot biomass (SB) and root biomass (RB) together with total plant carbon stocks (PCs), shoot carbon stock (SCs), root carbon stock (RCs), root to shoot carbon stock ratio (RCs/SCs), and grain carbon stock (GCs). Results Significant (p< 0.05) genetic variations were recorded for all the assessed agronomic traits. The high yielding maize genotypes were TZECOMP3DT-C2, TZE(OMP3DT/WHITEDTSTRSYN)CZ and DT-STR-Y-SYN14. The maize genotypes which sequestered more carbon were TZE(OMP3DT/WHITEDTSTRSYN)CZ, 9022–13 and ZDIPLOBC4-C3-W. High phenotypic and genotypic coefficient of variations were recorded for PB and GY, respectively. The GY showed significant positive correlation with PH, SB, RB and PB. The principal component analysis highlighted that RCs, RCs/SCs, PCs, SCs, and GCs as key contributors to carbon sequestration. Discussion Genotypes TZECOMP3DT-C2, TZE(OMP3DT/WHITEDTSTRSYN)CZ, TZECOMP5C7/ TZECOMP39TCZ and 9022–13 were selected for their high GY production and carbon storage capacity. The selected genotypes are recommended for production and future breeding.