Paddy seed lot at the procurement centre
At a cooperative seed procurement centre in eastern Uttar Pradesh, a grower delivers 4.2 tonnes of paddy seed of variety 'Sarjoo 52' (certified class). The lot was threshed six days ago and stored in gunny bags under a tarpaulin. The centre's moisture meter reads 14.6% on three samples. A quick germination test on 100 seeds shows 86% normal seedlings at 7 days, but 18 seedlings are thin and 9 seeds remain hard. Physical purity is 98.1%, other crop seed 12/kg, weed seed 6/kg and inert matter 1.8%. The procurement officer wants to accept the lot because germination exceeds the 80% minimum and issue a certification tag immediately. The centre has a batch dryer, but it is booked for the next two days. The grower needs payment before the weekend for his next crop. The centre also has a re-cleaner and a small sample dryer. Advise the officer.
1. Which findings in the lot are quality failures and which are warning signs, and why does a germination result of 86% not settle the question?
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Findings fall into three groups.
- Moisture: 14.6% is too high for safe paddy seed storage; the usual safe level is about 12–13%. At this moisture, respiration and mould can continue, and germination may fall during the two-day wait, especially in bags under a tarpaulin.
- Purity: 98.1% is above the usual 98% minimum, but other crop seed (12/kg) and weed seed (6/kg) exceed the usual limits of 10/kg and 5/kg. Inert matter at 1.8% is within the usual 2% limit.
- Germination/vigour: 86% is above the 80% minimum, but 18 thin seedlings and 9 hard seeds show low vigour or immaturity/dormancy. A favourable germination test can overstate field emergence.
So germination alone cannot justify a certification tag. The lot fails on moisture and likely on weed/other-crop seed, and its vigour is questionable.
2. What should the officer do about payment, drying and certification?
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Do not issue the certification tag yet.
- Draw and retain a representative sample, record the lot identity and issue a provisional raw-seed receipt rather than a certified tag.
- Dry the lot in the batch dryer at a low temperature-for paddy seed, keep the drying air below about 43°C-until moisture is at or below the safe level. Do not use high temperature to rush the job.
- Re-clean through the re-cleaner to bring other crop and weed seed within limits; re-test purity, moisture, germination and a vigour test.
- Only if all results meet the standard for the class should certification proceed. If the grower needs cash, pay against the raw lot with a lien or advance, not against certified seed.
If the dryer is booked, arrange temporary aerated storage or negotiate the queue; do not leave the lot bagged and covered.
3. What should the grower be told about the hard seeds and thin seedlings, and about mixing this lot with a better one?
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The grower should be told clearly that hard seeds are not a bonus. They may be dormant, immature or dead; dormancy can break later and give uneven emergence. The thin seedlings point to low vigour, which matters more in the field than a laboratory germination figure. The practical route is dry, clean, re-test, and if the lot still has low vigour, sell it as grain or use it only after a field-emergence check. Reject any suggestion to mix it with a better lot to lift the average; that hides the problem and destroys lot identity.