Normal Seedling: The Assessment Class That Produces the Germination Figure
At the end of a germination test there is a dish of one hundred seeds, and somebody has to decide which of them count. The normal seedling is the class that counts: a young plant whose root and shoot are formed such that a plant will come of it in soil. Anything that has sprouted without showing that formation counts as abnormal. A lot’s germination figure is thus the result of a judgement rather than a plain tally.
The criteria in hemp
Two parts are assessed. The root counts as sound when the main root is neither stunted nor crooked; numerous side roots will serve instead where the main root is weak. The shoot counts as sound when seed axis and leaves stand undeformed.
If either fails, the seedling is abnormal. A seed that pushes out its root tip and then stops has visibly germinated and still contributes nothing to the germination figure.
Three classes, not two
Beside the normal and the abnormal seedling stands the dead seed, where nothing happens at all. This three-way split carries information that a bare percentage throws away.
A lot with many abnormal seedlings and few dead seeds is alive and suffering from its conditions. A lot with many dead seeds and hardly any abnormal ones has aged or was poorly processed. Both can carry the same germination figure and call for different responses.
Why the conditions shift the class
The share of abnormal seedlings depends on how the test is run. Across five lots of one variety, placing seed on top of paper produced the most abnormal seedlings in every case, at 6.00 % to 7.75 % against 1.25 % to 3.25 % for the method between two layers of paper. The authors attribute this to moisture, which is harder to keep steady on an open surface.
That finding comes from one variety at one site in one harvest year and says nothing about how hemp behaves in general. It still means something for assessment: a high share of abnormal seedlings can lie with the seed and equally with the setup of the test.