They have sprouted! 24 out of 31 seeds in Group S, and 38 out of 40 in Group T.
It was fun tracking the germination process daily. We were quite confident initially that Group S was the "primed" group since the seeds all sprang out first. But a couple of days later the seeds in Group T grew fast and furious, and we weren't so sure anymore.
We submitted our results after the last seed germinated, and the secret was revealed to us: Group S was the "primed" group afterall!
Let me know if anyone wants a tomato plant...