Ipomoea batatas - breeding of Sweet Potato - Camote - New Zealand

[reed]

I discovered that little trick a while back when I was starting them inside and one day when I lifted the cover water dripped off and landed on one, a few minutes later the seed shell popped off. When I said I had rarely had one die after sprouting I forgot about those back then that I killed trying to pry the shell off.

This year I planted them a litter deeper than before, about 3-4 centimeters or so, in seemed to work pretty good. I think a little longer trip out of the ground helps drag it off. 

[Chris Morrison]

Precocious much? My first two from seed. Both from native EFR. One clearly EFR x BB (Purple), and the other EFR x G1 (Green), unless EFR is self fertile which I greatly doubt. Now both, being just over a month old, are setting up seed heads of their own. The green one has about 4 buds (need to zoom in sorry), and the purple one a single bud. This is consistent with what I saw in the field during Feb~May, G1 was 5 times as seed productive as BB, with EFR a distant 3rd.

[Richard Watson]

To have flower buds now this early is a great sign.

[reed]

Looks like your on your way. From what I've seen most very early flowers don't set seed. I think it might be because there aren't enough overall and on different plants to catch the attention of the bees and get good pollination going.

Not to worry though, if they have a few now they should have a whole bunch later and then you'll see the capsules forming.  If you do see capsules from the first few flowers it might indicate self-pollination. 

[Chris Morrison]

Interesting. The flower buds on my 2 earliest seed grown plants, are quite different. The purple one, which I suspect id native EFR x BBCuzzie, has a long flower stem , perhaps 30mm. I recall BBCuzzie having very short, chunky flower stems, perhaps 10mm?. The Green one has shorter, perhaps 15mm, quite similar to its prolific parent, G1?

[reed]

Ah, don't reckon I ever paid much attention to that, I'll make a note to check mine when it quits raining. That first one though looks like it might have several flowers on that stem and the second one maybe just one or two. There are technical terms for both the primary stem and the individual stem of each flower but I don't recall what those terms are right now.

Seems like generally that those with just one or two flowers per, tend to have them at pretty much every single leaf joint and the leaf joints are farther apart. They also seem to have higher percentage with a full four seeds per capsule and again generally, have longer vines. I think overall they make less seeds but maybe higher % of what I think of as quality seeds.

I've defined quality seed as perfectly shaped and dark black but I might have to rethink that cause I now know that ones I used to think of second rate sprout just fine.

[Chris Morrison]

Yes is clear to see, even at 6weeks of age, what will be bushy (the purple ones in the pic) vs runners (the green one). Now the green one native EFR x G1 has longer inter-nodes, whilst the bushy type, obviously much shorter.  The Green runner, has a flower stem every node, so will be a prolific bloomer. The earliest purple bloomer has 1 flower stem, now 60mm long, the other is barren.

[Richard Watson]

Once the warmth of summer kicks in you are going to have plenty of flowering going on.

[Richard Watson]

how mine are looking

[Richard Watson]

[Chris Morrison]

Hopefully that is a Green Runner :-)
I had 1 more pop up y/day, so total now 22. Will keep watching. Mark reckoned can take up to 2 months, well that is in a week.
Need to get the biggest few into 5gal fabric pots and outside, a job for next week

[reed]

It can take even longer than two months. I've found volunteers in spots where I grew them two or three years ago so they can lay in the dirt a long time before sprouting.

I used to think low germination rate was because a lot of seeds were not viable but now I think the extremely hard seed coat is what causes them to be so unpredictable in sprouting. If a seed looks good, no mold, not shrunken up or soft, it is good. It just might not be in the mood to sprout right when I want it to. I guess that's why some of the university guys soften them up with sulfuric acid before planting.

I've just been selecting for those that sprout easier on their own and it's working but maybe I shouldn't go too overboard on that. The hard seed coat might also be why they stay good for a very long time in storage and I don't want to completely lose that.

[Richard Watson]

We have a native tree call Kowkai https://www.doc.govt.nz/nature/native-plants/kowhai/ it has a really hard shell so I use the point of a steak knife to chip it, I wonder if that would work also for these

[Chris Morrison]

Well that explains why I dig around and find hard seed just 'sitting there'. Not sure what to do with the 200 odd unsprouted seeds now. Maybe just co-mingle in on 5gal pot and keep a rough eye on them, over summer?

[Steve1]

Well that explains why I dig around and find hard seed just 'sitting there'. Not sure what to do with the 200 odd unsprouted seeds now. Maybe just co-mingle in on 5gal pot and keep a rough eye on them, over summer?

If they have a hard seed coat and that is impeeding germination chipping should work. I've done 100 or so wild species peas in a about 20 min using a nail clipper. Just work out where the germ is and chip the other side, you'll get your eye in and just take the coat after a bit of a warm up. Possibly easier on peas as they are round... Then, what will you do with 200 more of them??