Leftwood said:No worries about the graph. I am 61 and not an engineer, and I wrongly assumed with you being so young, that your background in engineering would require you to be fully adept at digital graphing. I thought it would be a simple task for you.
The "boil" effect is interesting. Never heard of it before. I suspect the anomaly is quite rare and that it might only happen with a certain set of conditions. At any rate, conditions that would not normally be encountered in the natural world.
I don't think we, in non-scientific experimenting, can actually measure the physical depth of a scarification. More importantly, I think the best we can do is estimate how close the scarification is to the seed inside by examining color variations as the surface approaches inner seed contact. Of course, colors may vary depending on the species. If you are soaking the seed in water rather than planting in soil, my prediction would be that scarification size (in diameter, not depth) would be fairly inconsequential.
I'm not 100% sure, but I think the boil effect was a symptom of only the seed coat breaking down and swelling with water without reaching the cotyledons as a result of a file scar that was too shallow (or the ratio of exposed seed coat to exposed cotyledons was heavily skewed to the seed coat side, so all it could do was swell and boil out while the inside was swelling at the same time, just not nearly as fast).
I totally agree, measuring exactly how deep into the seed coat we are isn't possible when my only tool is a caliper. Measuring the mass shaved off would be good alternative, but I can't do that either - I don't have a scale. I don't expect people to want or need to measure their seed mass as they file to get optimal results, it's just not feasible. But I must admit that the more I thought about it the more excited I was to at least try it.
Because all I can measure is how large my file mark is, that's what I'll do. I'll have an untouched control seed, a seed with only the seed coat filed and no internals showing, and then 3-5 other seeds with varying depths of cut that I will measure in terms of exposed area of the cotyledon.
From what I observed for this experiment, I think (and this is just a guess) that when you scarify the seed coat, the innards absorb water first and swell, putting pressure on the seed coat. Normally, the seed coat has time to uniformly absorb water and uniformly break down before the inside of the seed has a chance to absorb much moisture, so when it does it has an easy time expanding and breaking free of the seed coat. I think with this scarification, you skip that part and I believe that there should be a Goldilocks zone where you remove enough seed coat and cotyledon to expose as much seed coat to water as possible, so it breaks down as fast as possible, while also exposing the most non-seed coat to water and breaking that down quickly. The ideal scarification should remove so much material as to speed things up, but also not so much that you harm the seed and it can no longer germinate.
I should be able to see this change in the graphs based on which setting reaches maximum swell the soonest while remaining viable at the same time.
I get this is a lot of fus for something that could just be as simple as knicking a seed and tossing it in some water for a day, but the more I thought about the experiment the more curious I got. I'm between semesters now, so if I will ever have time to do this experiment, it will be now so short of any objections or suggestions, I'll give it a go tomorrow and post here with the results. The graphs it produces should be really neat.
