From August 3 to 5, the Yunnan Seed Management Station conducted the 2026 spring season seed market corn seed sample purity field inspection in Huize County, Qujing City, marking a key part of the province's annual seed quality supervision efforts.
An inspection team composed of experts from some prefectural and county-level seed management agencies was divided into four groups to work in the fields. They performed on-site field variety purity assessments on 112 corn seed samples collected from the province's spring seed market. The inspections strictly followed relevant standards and specifications, including the "Rules for the Inspection of Crop Seeds - Testing of Genuineness and Variety Purity" (GB/T 3543.5-2025), "Technical Code for Field Plot Inspection of Crop Variety Purity - Corn" (NY/T 4018-2021), "General Rules for Labeling of Crop Seeds" (GB 20464-2024), and "Seed of Food Crops - Part 1: Cereals" (GB 4404.1-2024).
After hearing a report on the field plot management, the inspection team carefully observed the main traits of each corn variety's plants in the field, including plant type, plant height, leaf shape, leaf color, ear height, tassel shape and branching, and anther and silk color. They marked and labeled self-pollinated plants and other off-types as non-typical plants, diligently distinguishing between the variety and off-types, and recorded the data. For samples with questions, the team collectively discussed and confirmed the inspection results. After strict evaluation, the purity of all 112 corn seed samples met the national crop seed quality standards, achieving a 100% pass rate with an average purity of 99.0%.
In 2026, the Yunnan Seed Management Station conducted three rounds of seed purity field inspections. The first was in April in Yuanjiang County, Yuxi City, assessing the purity of 20 corn seed samples taken from enterprise supervision and spot checks in the winter of 2025, along with 11 corn seed samples for disaster relief and emergency reserves. The second was in June in Jinghong City, Xishuangbanna Dai Autonomous Prefecture, assessing the purity of 15 rice seed samples taken from enterprise supervision and spot checks in the winter of 2025. Across these three sessions, a total of 158 corn and rice seed samples were inspected. Inspectors strictly followed technical procedures, the inspection sites were well-organized, and the purity of all samples met the values stated on their labels.
Seed purity is a core indicator for measuring the quality of crop seeds, directly impacting crop yield, quality, and planting efficiency. Impure seeds can lead to uneven plant growth in the field, inconsistent maturity, and reduced yields. Field plot inspection is one of the most reliable and accurate methods for determining variety genuineness and seed purity, visually reflecting seed quality and serving as a crucial step in crop seed quality testing. Through rigorous purity inspections, substandard seeds can be identified promptly, preventing fake and inferior seeds from entering the market and protecting farmers' interests. Simultaneously, it provides accurate quality feedback to seed companies, encouraging them to strengthen quality control awareness and improve seed quality.
Seed quality safety is vital for agricultural abundance, increased farmer income, and rural stability. Moving forward, the Yunnan Seed Management Station will continue to intensify seed market supervision and inspection, strictly control variety access and quality standards, urge seed companies to fully implement their quality responsibility, and continuously improve the long-term mechanism for seed quality supervision. This will ensure the safety of seed supplies for agricultural production in the province, providing a solid foundation for food security and stable, increased agricultural output.