Seed Processing and Storage:
Comments on Seed Production Manual
by Ben Gabel
The following email regarding the Seed Processing and Storage Manual was received (Jan. 6, 2006) from Ben Gabel and has been transferred here from the former Saving our Seeds blog:
"Hi Jeff, your seed saving booklets came through just fine. I've just started reading them and wanted to say that they're great!
I had a couple of comments so far - after reading the 'seed processing' one.
You mention a query about the effects of UV light on seed when sun drying. It just happens that about 18 years ago I did a small undergrad project looking at the effects of UV light on the leaves of small rosette-shaped weedy things growing in grassland. The Ozone Hole was big news at the time and though I can't remember all the details, we zapped these poor plants with a whole range of UV intensities, and then looked at changes to the leaf structure under the electron microscope.
The relevant point is that even at the highest UV rates (much higher than predicted 'naturally') the only part of the plant that was affected was the topmost surface layer of cells, with no damage to the mesophyll at all. So I think that any seed with any decent sort of coat is pretty unlikely to be affected by UV during drying.
Also re heat treatment of seeds: here we use a wide-necked thermos flask for tomato seed. Get the water inside to just the right temperature and then pop in the seeds. Obviously only works on small quantities (cooling by mass of seeds) but much easier than any other method I know, as it stays the right temperature for ages with no extra heat input.
Also I can add to your water-treatment list: Elephant Garlic seeds: 50 - 55 Centigrade for 30 minutes with minimal loss of viability. I assume that leek would be similar but haven't tested it. I was trying to get rid of white rot from an old variety."
Editor's note: Ben Gabel publishes The Real Seed Catalogue, Brithdir Mawr Farm, Newport, Pembrokeshire SA42 OQJ.