10th U6+ Consortium of African Universities International Conference

Maintaining high seed quality throughout the post-harvest handling chain remains a major challenge in commercial maize seed production. Harvesting stage, processing, storage and varieties are documented contributing factors to seed quality. Their interactive effects under commercial production systems remain poorly understood. This study evaluated the influence of these factors on the physiological and physical quality of maize (Zea mays L.) seed. Three hybrid varieties (H614D, H6213, and H629) were assessed at successive post-harvest stages using standard germination, electrical conductivity, mean germination time, moisture content, and mechanical damage. Data was subjected to Analysis of variance (ANOVA), correlation analysis, and principal component analysis. Seed harvested at physiological maturity recorded better seed quality, recording higher germination, lower electrical conductivity, and shorter germination time than seed harvested at harvest maturity (P < 0.0001). Storage duration was the primary driver of seed deterioration. The seed exhibited significant reductions in germination (96.72 to 90.65%) accompanied by increase of electrical conductivity (5.18 to 10.64 µS cm⁻¹ g⁻¹). Variety variation significantly influenced seed responses throughout processing, with H614D exhibiting superior membrane integrity and the least mechanical damage, H629 maintaining consistently high germination, and H6213 showing greater susceptibility to mechanical injury during processing. Shelling was identified as the stage introducing the greatest mechanical damage, whereas seed dressing type substantially influence seed quality under storage. The principal component analysis and the correlations done revealed that the mechanical damage and the electrical conductivity were the most significant factors influencing seed deterioration. The results indicate that the quality of the seeds deteriorates as a result of cumulative effects arising from the time of harvesting, processing, storage period, and genetic factor. Timing of the harvest, mechanical damage prevention during the process, and short storage periods are vital factors of consideration in seed quality management.