Many people familiar with the HG forum are already familiar with this project so rather than start all over I thought I would just give a run down of how it stands now. My eventual goal is to release and sell true seed producing sweet potatoes as breeding material under the OSSI pledge. I just need to produce sufficient quantities, develop a good naming convention for the different lines and find out, in the event I want to release some as clones, what legal hoops I'll need to jump through to send them through the mail.
Anyway, five years after discovering my first true sweet potato seed I have a total of 8 of my own seed grown clones that meet my criteria of short season production (100 days or less) of both food quality roots and seeds. I recently became aware that there is also more interest in lines developed more for greens over roots than I realized. That might greatly increase those I keep as clones. Up till now I have been mostly discarding those that only produce foliage, even if they did make seeds.
As it stands now along with those 8 seedy clones and a few other, non-rooting ones and after finding a pack I had forgotten about I have approximately 2500 seeds. Half or more of those are buried deep in the ground in well sealed stainless steel canisters.
I'm interested also in developing lines that are easy to grow and tolerant of poor conditions or neglect so I take no special actions to insure germination. I start them in cool conditions on a drafty window sill on a cheap heat and without any artificial lighting. Germination in successive generations under these conditions has increased from about 5% within a week to about 20%. Germination in an outside cold frame of just a few seeds in that time was 2%. Germination by folks I'v shared seeds with using much more controlled conditions was reported much higher, in the neighborhood of 90%.
My friend Richard in New Zealand had germination of 20% or higher, I think using a technique similar to mine and some of his plants are currently blooming. The climate there is not especially friendly to sweet potatoes so I'm watching his reports closely and keeping fingers crossed he gets good roots and seeds.
I hope in 2019 to get reports from New York and Germany. Other locations where they have been trialed include;
Sweden - no real report on germination or success
North Carolina - poor germination using techniques similar to mine, good root production on those that did grow, no seeds. No seeds was due to poor observation and repeated destruction of the vines by rabbits and deer. (*interesting, you can still get a harvest even if vines are seriously damaged)
Minnesota - no report, I think he may not have planted them yet.
Texas - excellent germination direct seeding in mid May, excellent root production, few seeds. I don't know a reason for the poor seed production there.
California - excellent germination, excellent seed production but most with poor stringy roots. I imagine by selection, crossing to new varieties and mutation the stringy root problem can soon be solved.
Utah, Ah, Ha, this is the most exciting. This farmer and you know who you are Joseph Lofthouse did cheat some by tightly controlling germination conditions and got very good results. Still in a high desert with cold nights and a frost free season of less than 100 days managing to harvest food sized roots AND seeds FROM seed is pretty exciting.
I'm thinking for this year I will focus on continuing to push the extreme of germination under poor conditions (for sweet potatoes) even farther and plant about 500 seeds in the unheated cold frame. Select from them the first 20 or so that sprout and discard the rest. I'll also maybe keep some of the later sprouting volunteers which I expect because of my poor seed collection practice last year. I may not start any inside this year.
I'm also going to grow more individual plants of my saved clones instead of just one or two to increase the number of harvested roots from them. Those 8 all make good roots and seeds so I hope to cross them with several new commercial clones I'll get from Sandhill Preservation and elsewhere.
I want to up my seed production to 5000 this year. It's an ambitious goal not because it will be that hard to get the plants to do it, just have to have enough of them. It's ambitious because they are not exactly what you could call determinate. They just keep making seeds, you can't just harvest them all at once like you might with dry beans, there are only at most 4 in each capsule instead of hundreds like in a tomato. You have to spend an hour or more every single day looking for and collecting the seeds and there is a narrow window before they shatter. O'well, somebody's gotta do it I reckon.