The quality of soybean (Glycine max L.) seed as affected at storage by packaging materials, temperatures and genotypes

Food insecurity is strongly influenced by post-harvest management constraints, particularly those limiting seed storability. This study evaluated the combined effects of packaging materials and storage temperatures on the conservation of soybean seed from five genotypes over 12 months. Two cold storage conditions (fridge at 3–5°C and deep freezer at − 18 to − 14°C) and three packaging materials (polypropylene bags, polyethylene bags, and paper envelopes) were tested under room storage. After six months, germination under room conditions declined to 62.3% (envelopes), 68.1% (polypropylene), and 90.1% (polyethylene). By 12 months, germination dropped to 0% in all room-stored samples, while fridge and deep freezer maintained 100% germination regardless of packaging. Insect damage appeared from the third month and increased progressively in all conditions, with no significant difference between cold and room storage. However, seed discoloration was significantly reduced under cold storage (3.0–11.0%) compared with room conditions (4.0–29.5%). Across all varieties, polypropylene bags showed higher discoloration than polyethylene and envelopes. Among the genotypes, S check medium TGX 1448-2E consistently exhibited lower discoloration across storage environments. Overall, cold storage in fridge or deep freezer effectively preserved seed viability and quality for at least 12 months, while polyethylene bags maintained acceptable germination and quality for up to 6 months at room temperature. These findings suggest that low-temperature storage and appropriate packaging are critical strategies to extend the shelf life of soybean seed and mitigate post-harvest losses.