Germination and Vigor of Maize Seeds: Pilot-Scale Comparison of Low-Oxygen and Traditional Storage Methods

Abstract

Seed quality declines during storage depending on relative humidity, temperature, and oxygen concentration. Low-oxygen atmospheres significantly enhanced the germination and vigor of seeds during storage in laboratory-scale experiments. Low-oxygen atmospheres include self-modified atmospheres, where gas composition changes due to microbial respiration and oxidative processes, as well as modified atmospheres, where gas composition is initially altered from an external source without further adjustments. However, the potential of low-oxygen atmospheres to preserve the quality of maize (Zea mays) seeds in bags of 25–50 kg capacity, like those employed by seed companies and small-scale farmers, remains underexplored, hindering a broader adoption of this storage technology. Our study assessed the feasibility of applying low-oxygen atmospheres for seed storage on the pilot scale, i.e., hermetic containers of 25 kg capacity made of polyethylene and polyamide, under controlled conditions. We first evaluated the ability of the hermetic containers to maintain low oxygen levels over time. Then, we compared the germination and vigor of seeds stored in the hermetic containers under modified and self-modified atmospheres with those stored in traditional poly-paper bags under normal atmospheric conditions. The seeds had 14% moisture content (wet basis) and were stored at 25 °C and 10 °C. Maintaining low oxygen levels in polyethylene–polyamide bags was feasible. Moreover, at 25 °C, modified and self-modified atmospheres maintained higher germination values (95.8% and 94.4%, respectively) compared to traditional storage (68.3%), and both were as effective as refrigeration (97.6%). However, refrigeration was better for preserving seed vigor, with radicle emergence values of 85.2% in self-modified atmospheres and 78.9% in modified atmospheres, compared to 65.0% and 61.2%, respectively, at 25 °C. In conclusion, the advantages of modified atmospheres observed in laboratory-scale studies are achievable on a larger scale with a proper container design, advancing the prospects for the practical application of this technology for the seed industry and small farmers.