Seed Quality Testing and Certification
Seed Quality Testing and Certification
This domain tests laboratory tests (purity, germination, moisture, vigour, health) and the certification process from application to tag. Expect sampling rules, test calculations and the difference between certification and a laboratory report.
Tests and certification steps
- Draw a representative sample from the seed lot using a probe or sampler; sampling only the bag tops biases the result.
- Purity analysis separates pure seed, other crop seed, weed seed and inert matter.
- Germination tests use a specified substrate, temperature and light; count normal seedlings, abnormal seedlings, hard seeds and dead seeds.
- Moisture is measured by a moisture meter or oven method; record it at receipt and before storage.
- Certification includes application, field inspection, seed sampling, laboratory testing, lot approval and tagging.
Worked example
A 1,000 g purity sample contains 20 g inert matter, 5 g other crop seed, 1 g weed seed and 974 g pure seed. Physical purity = 974 ÷ 1,000 × 100 = 97.4%. If the standard is 98%, the lot fails on purity even if germination is high.
Traps that cost marks
Confusing purity with germination; sampling from one bag; using an expired test; counting abnormal seedlings as normal; and assuming certification guarantees field performance.