Sampling over-yeared seed
Getting a representative seed sample from big bags can be more difficult than it looks. A successful sample is important to ensure the subsequent tests are representative of the contents. APHA have “Instructions to Licensed and Official Seed Samplers in England and Wales“ that give some good advice on how to sample seed lots and what is the best equipment to use (stick sampler). This advice can be seen below.
Sampling from large containers or seed in bulk
When sampling from bulk seed (more than 100kg), the below should be followed:
- Primary samples must be taken from different horizontal and vertical positions selected at random or systematically.
- The following must be regarded as the minimum requirement:
Number of primary samples to be taken
Up to 500kg
At least five primary samples
Stick samplers (e.g. stick trier including walking stick trier, sleeve type trier)
In the case of a multi-chamber type stick sampler with compartments:
- The aperture must be closed before insertion.
- The instrument must be inserted diagonally into sacks or vertically or horizontally into the container so that all apertures are fully covered.
- The apertures must be opened.
- The instrument must be agitated so that seed enters.
- The apertures must be closed gently to ensure that trapped seed is not broken or damaged.
- The instrument must be withdrawn and if the chambers are full the contents must be emptied onto a clean surface or into a clean container.
- If all the chambers are not full, the contents must be discarded and procedures at 1 to 6 in this list must be repeated.