Measuring seed lot purity

What is seed lot purity?

Seed lot purity is a measure of the impurities in a seed batch. These include

• weed and other crop seed, and
• inert matter

How is seed lot purity measured?

1. Select, at random, a sample of the seed. A good sample size is 100g.
2. Weigh the sample [A].
3. Remove all of the weed and other crop seeds and the inert matter.
4. Weigh the weed and the other crop seed matter that had been removed [B]
   1. 
      
5. Compute the weed percentage using this equation:
6. Weigh the inert matter removed from the sample [C], the percentage inert matter is calculated using the formula:
   1. 

For more information:

Visit the Rice Knowledge Bank website (http://www.knowledgebank.irri.org), email postharvest@irri.org; or call +63 2 580 5600.