Influence of sowing time on Fusarium and fumonisin contamination of maize grains and yield component traits

The main aim of this research was to study the effect of two sowing times (early and late) on Fusarium and fumonisin contamination and some yield component traits of two maize hybrids from the FAO maturity groups 500 (ZP 560) and 600 (ZP 666) within a two-year growing season (2016–2017). F. verticillioides and F. subglutinans have been identified as Fusarium ear rot (FER) pathogens and potential producers of B-type fumonisins (FBs), with F. verticillioides as the predominant Fusarium species in both years. The incidence of F. verticillioides and FB levels were affected by sowing time and maize hybridity. With early sowing and the mid-maturity hybrid ZP 560, F. verticillioides and FB contamination were lower than with late sowing and the late-maturity hybrid ZP 666. Yield parameters also differed significantly between sowing time and maize hybrid treatments. Early sowing increased ear length (EL), number of grains per ear (NGE), grain weight per ear (GWE), and grain yield per hectare (GY). The late-maturity hybrid ZP 666 had higher yield component traits and GY than the mid-maturity hybrid ZP 560. EL, GWE, thousand-grain weight (TGW), and GY were affected by year. Interactions between sowing times and maize hybrids were highly significant (p ≤ 0.01) for FB level, GWE, and GY. The obtained results indicate the importance of applying early sowing to achieve high maize grain yields with lower contamination by F. verticillioides and FBs. Although mid-maturity hybrid ZP 560 and late-maturity hybrid ZP 666 showed significant differences in terms of levels of F. verticillioides and FB contamination, both were susceptible to F. verticillioides, with high FB levels. These results should be useful to breeders of maize hybrids to create genotypes more resistant to these fungal contaminants