Rock tumbler results

Thanks to the generous spirit of Colin, I had 7 hard shelled species to play with instead of 3 or 4. This experiment was to discover just how much tumbling in a rock tumbler it takes to grind away enough shell for germination to come easy to these hard shelled species..

I really like these little experiments, because they always give you some never dreamed of data. Remember the beans?

In this experiment, I used a common rock tumbler, but I used small snoose cans instead of the larger tumblers, because I could get 10 snoose cans on the tumbler, allowing for a greater number of species. I used #80 silicon carbide grinding grit, and tumbled them for nearly 12 hours.

I carefully weighed each group of seeds, before and after the tumbling and put the data in this table. You will have to enlarge it to read it. It amazed me how much some of the seeds weighed.

It is also interesting that if we had 50 species to do something like this with we could create a hardness scale for those species seeds.

The several species that weighed out at no shell weight loss, did in fact have some weight loss, but it was too small to register on my scale, which is sensitive to 1 miligram. Enjoy Frank

I am sorry the readability is not better, but when I made this table, I had no intention of posting it, consequently you must decipher some. Now it is time for a rest. Frank

Better copy.................



This message was edited May 28, 2009 12:45 PM

There............. now you can actually read the results. Sorry about that.

One further note, about the little digital scale, and how it reads out.........It will read as 0 if the total weight is 4 miligrams or less, above that it is accurate to 1 milligram. So in the tumbling process, those seeds resistant to the tumbling, if they read 0, they can actually be anywhere between 0 and 4 mg. knowing this helps to extrapolate and to interpolate.

This concludes a long and legubrius project. This project was done at the dinner table, not in a lab, therefore all the household distractions are part of the margin of error. lol
Frank

fantastic frank :-)... just love dinner table science projects... thanks for sharing the second pic it's much easier to follow...

...now will it get those pesky S tillifolia to sprout? i hope so!

Neat experiment, Frank!

I wonder if a finger nail file would work? Or sandpaper?

Becky, nicking doesn't work with the hard shelled SPECIES, because the shell is the problem. It takes so long to soften up, that it keeps a death grip on the enbryo. The end result usually is that the swelled up embryo ends up rotting in the shell, after it has tried to germinate. The hard shelled ones are like pecans. That is why I tried the tumbler. I think too that if you grind the shell away, you also get rid of mystery chemicals that fight the germination process. With the hard shelled ones, you literally waste most of the seeds, and with some species, all of them. They are too hard to come by to waste, so I am experimenting, in quest of a short cut. Stictocardia seems very diffifult. The seeds are so hard to get I just hate guessing.

One of the hardest to germinate was that I. sepacuitensis from South America, that is now available again on epsecies at ebay. The shell just never relaxes or goes soft enough fast enough.

Frank

Makes you wonder how these things germinate in the wild. I have just germinated some hard coated species called Operculina turpethum and 2 of the seeds came out rotten

Terpethum was one of them in my test group. Last night I gave a few more the max treatment that worked for me on S. maculosi last year. I used a dremel tool with an abrasive disk and cut a deep X all the way up and all the way across one side. This hopefully will allow the embryo to escape as it swells. The ones that rot seem to me, rot because the seed coat never softens. It just maintains a death grip on the swelling embryo.

Last year with S. maculosoi, I did the same thing with the dremel, but on both sides of the seed. then put them in a petri dish with disinfectant, and kept them at 98 degrees F for a week or so, and they didn't rot. This is extremely time consuming. The vines you do get in the long run are rewarding. My maculosoi vine is clear to the ceiling with large leaves now.
Good luck. Frank

Frank, I got lucky with what seems to be germiination of Ipomoea violacea, just by grinding a hole into the hard seed coat using sandpaper. The seed coat is split all around the hilum, and the seed seems visibly larger than the other 2 seeds that appear not to have imbibed yet. I am patiently waiting for the seed root to appear!

Joseph

Dealing with seed coats can be very enigmatic. Many of us have had the frustration of seeing prescious seed rot, after the seed swelled up, because the seed coat did not soften. I am bringing this forward FYI. The data in the table above tells you something about who has the hardest shells in the group in this test.

I guess it is time to get out the tumbler and dust it off again.

Peroxide won't that help soften the seed coat plus give oxygen too??Just a little not to get carried away with it.

Dana - That's what I use when I soak them. Peroxide helps keep the seeds from rotting, IMHO. And nicking the seeds works, too! As far as tumbling goes, Frank can play around with that, no time or patience for me to do that! JMHO.

If you look at the second chart above, you will see that there is an enormous hardness difference in the seed coats, between the hard shelled species. Trying the rock tumbler is an attempt to grind the seed coat down untill it is thin enough, that it won't do the helmet thing to the germinating seeds. The helmet effect just helps the damping off organisms.

The chart in the first posting above was not clear enough to read, the second was much better.

I just wrap a small wet piece of paper towel on the seed coat "helmet" to soften and expand it so that the seedling can free itself. Works like a charm every time!

I am glad that works for you Beck. Macalusoi is a horse of a different color. It has a shell like a Macadamia nut. I think this is why we don't see Macalusoi around, but lots of beraviensis. It makes me think that where they are native, they are gathered and buried in the ground by rodents. And when the rains return, they get wet and stay wet underground for a long time, and then germinate. When they germinate, they have more than average soil to weave their way up through. No doubt, as the seed rises to the surface, the soil helps pull the now, softened , seed coat off.

My 2 cents .. I use cuticle scissors to relieve helmet head .. they are very sharp, bowed and pointed .. works well for me.

X, good to see you're there. You might be on to something there. I have every kind of nail snipper and clipper available around here, enough to need their on box, just never thought to try them on the helmet effect. I am too afraid of damaging the cotyledon. Radio shack has a nibbling tool too, for nibbling of thin metal for those electronics buffs. I just need to gather them all up again. Thank you X for all your solid contributions to our forum. Frank