A germination percentage is the share of tested seed units that produce normal seedlings under the AOSA method assigned to that seed kind. It is not the share that swelled, cracked, produced a short root, or showed green tissue. A valid result depends on representative sampling, four replicates, controlled environmental conditions, prescribed count dates, and crop-specific seedling evaluation.
Four replicates protect the result
AONSK uses four replicates of 100 seeds for AOSA germination testing. Replicates are labeled and handled separately so the analyst can see whether the sample behaves consistently. A mean percentage can hide a problem if one replicate is much lower than the others. Replicate tolerance helps distinguish normal sampling variation from a test that needs review or repetition.
Each replicate must account for every seed placed in the test. At final count, the total of normal, abnormal, hard, dormant or fresh, and dead seed should reconcile to the number evaluated.
The method controls the environment
The AOSA method card specifies the approved substrate, temperature program, light, dormancy treatment when applicable, and count schedule. Some crops are tested at a constant temperature. Others use alternating temperatures, often with the light period aligned to the warmer phase. Moisture must support imbibition and oxygen exchange without leaving seed submerged or encouraging avoidable decay.
Temperature, light, moisture, contamination, and any deviation are recorded throughout the test. A correct final percentage depends on a controlled test, not only on the arithmetic at the end.
Normal seedlings determine the germination percentage
A normal seedling has the essential structures and development required to continue into a satisfactory plant under favorable conditions. The exact criteria change by crop family. Cotyledons, hypocotyl, epicotyl, primary root, secondary roots, shoot growth, decay, and mechanical damage are evaluated according to the applicable seedling rules.
An abnormal seedling has germinated but lacks the structures or condition needed for satisfactory development. Hard seed has not imbibed water where the rule recognizes that category. Dormant or fresh seed may remain viable without producing a seedling during the standard test. Dead seed is nonviable at final evaluation.
First count and final count answer different questions
The first count removes normal seedlings that have developed early enough for a confident evaluation. This reduces crowding and decay while recording the fastest normal response. Unresolved seed remains under the prescribed conditions until final count.
At final count, every remaining unit is classified. The analyst reviews seedling structures, contamination, substrate condition, temperature records, and replicate agreement before the result is approved.
Laboratory germination and field emergence are related, but not identical
AOSA germination testing measures the lot under favorable, controlled conditions. Field emergence adds soil temperature, crusting, pathogens, depth, compaction, moisture swings, insects, and planting damage. A high germination result supports planting value, but field conditions still determine how much of that potential becomes a stand.
That is why AONSK reads germination together with moisture, purity, vigor, storage history, and crop-specific risk.
