North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

On a few occasions I've found that some larger seeds, from slightly smaller than pawpaw, will float even though they are viable.  For some reason, the floaters have a condition in which the seed halves pull apart inside the seed coat, leaving a space between them that acts like an air bubble, so that the seed floats even though it's perfectly able to grow.  It's not really obvious by the outward appearance of the seed, though.  It appears that the seed developed under stress, which either caused the deformation, or prevented the seed halves from quite filling out all the way.  I have no proof, only observation.
-Lon Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com  Winner of the Garden Writers Association "Best Talent in Writing" award for 2003.
On Nov 14, 2005, at 3:28 PM, road's end farm wrote:


On Nov 13, 2005, at 8:29 PM, Richard Moyer wrote:

> Am cleaning pawpaw seed to ship to someone who will germinate them.  About 1/2 sink and about 1/2 float.  Does one 1/2 or the other have a higher germination rate, after cold stratification, or do I assume they are all equally viable?  Anyone with pawpaw seed experience in this area?
>  

Don't know about pawpaw; but with vegetable seed, at least the kinds I've saved, the sinkers are likely to be viable and the floaters almost certainly are not. Viable seed is denser, floaters immature or not pollinated; as floaters don't have the embryo and/or sustaining nutrients for it they weigh less, I think is the explanation. It would make sense if this also applied to fruit (though because something makes sense to me doesn't always mean it's so).

--Rivka
Finger Lakes NY; zone 5 mostly_______________________________________________