Seed quality is more than a laboratory result or a number printed on a seed bag. According to Viwe Siwisa, Quality Testing Manager at Corteva Agriscience, quality assurance begins long before seed reaches the laboratory.
Speaking at the recent Smart Seeds & Fertiliser Innovation Forum in Pretoria, Siwisa emphasised the importance of building quality into every stage of the seed value chain.
“Quality is front loaded in the field. The lab is the guardian at the end of the value chain, ensuring transparency and accountability, but cannot compensate for poor practices upstream,” she said.
Field practices, environmental conditions, harvesting and post-harvest handling can all affect seed quality. Representative sampling, traceability, field inspections and properly trained personnel are therefore essential to maintaining consistent standards.
The laboratory remains a critical part of the process. Seed testing can include physical purity, germination, sizing and other characterisation tests. Corteva’s regional quality-testing network supports reliable and repeatable results across crops such as maize, soybeans, sunflower, canola and sorghum.
Precision and consistency in the laboratory
Modern seed testing depends on robust quality-management systems. International standards such as those developed by the International Seed Testing Association (ISTA) help promote consistency in seed sampling and testing, particularly for seed moving through international trade.
ISO/IEC 17025 also provides a framework for demonstrating laboratory competence and consistent testing practices.
At laboratory level, quality assurance involves controlled environmental conditions, standardised methods, calibrated equipment, competent personnel, proficiency testing and regular audits.
Equipment such as weighing balances and sample-reduction dividers must be verified and calibrated, while temperature and relative humidity need to be monitored to protect sample integrity and ensure accurate results.
People and processes are equally important. Proficiency testing and regular assessments can identify variations in analyst performance, allowing laboratories to introduce corrective action and targeted training.
Documentation is another important safeguard. Quality manuals, standard operating procedures and testing records must be properly controlled, reviewed and retained. Audits help identify gaps, improve processes and support continuous improvement.
Ultimately, effective seed quality assurance is a continuous process—from the field to the laboratory and through to the farmer.
“These quality systems provide farmers with confidence in the quality of their crops and strengthen the foundation for food security for the future,” Siwisa said.
She added that Corteva Agriscience would continue to support agriculture through “integrity, precision and innovation.”