Sweet Potato Breeding Project

[kevin8715]

Just a little update since I have been inactive for a while. Sweet potatoes were planted late here, so won't be getting too many flowers. There is one volunteer plant which I am keeping an eye on. I am not dead, just had to refocus priorities for a while.

[reed]

I think if the style remains after the flower drops off then it has been pollinated, like the ones to the left. The whole stem drops off in a non-pollinated one. The clusters like on the right tend to have some dry up without fully maturing the seed. Plus they have just one or two seeds or one good one and a bad one. 

Once I see two or three pollinated ones in a cluster I have started removing the rest. I should know soon if this improves quality of the seed. One of the purple ones was a little later to start developing seed and it has fewer and larger pods so again will know soon if it makes a healthier looking seed.

The seconded generation seed grown plants are just now flowering abundantly and I have been crossing them to these. Up till now they were very sparce and I haven't found any developing pods on them yet. No point in marking individual flowers because the bees are still very active as well. 

[notonari]

Interesting reed. I seem to be getting some seed as well here, but they're not mature yet. Temperatures are forecast to fall pretty soon here, so hope they hang in there.

Haven't heard of Hong Kong or Patriot, where did you get those? How many varieties are you getting seed from?

[kevin8715]

If anyone here is interested, I have a unknown sweet potato variety that is able to overwinter in 10A. I have access to a greenhouse, so am interested in cuttings for other cultivars. I have cuttings right now, or tubers in a month or two.

[reed]

Sept 16, 2016 14:50:30 GMT -5 notonari said:

Interesting reed. I seem to be getting some seed as well here, but they're not mature yet. Temperatures are forecast to fall pretty soon here, so hope they hang in there.

Haven't heard of Hong Kong or Patriot, where did you get those? How many varieties are you getting seed from?

I got Honk Kong and Patriot as cuttings from Sandhill Preservation, www.sandhillpreservation.com/pages/seed_catalog.html they are making the most seeds so far. I don't know the variety of the purple ones. The later season local grown ones are just now starting to bloom a little. 

So far I'm getting seed from four kinds, Hong Kong, Patriot, unknown purple leaf , and seed grown purple leaf.  

[reed]

A couple branches of my sweet potatoes were hanging outside the fence and a stupid rabbit came along and ate all the leaves. That's not so bad I thought but it had several clusters of nicely developing pods so I tucked it up in the fence thinking it would be safe but I was wrong. Next day it was clipped off, about three feet of it with all those nice pods, crap.

Good news is each leaf joint had little root nubs so I put in the stream part of the pond with the cut end and all the little nubs in the water. That was a couple days ago and the pods appear to still be fine. Fingers crossed that they finish maturing this way. I still have more if they don't but I'm greedy and want them all.

[add] If those seeds mature I might cut other branches and do the same thing especially as it gets closer to frost. Might be a way to get still more seed from the ones that would otherwise freeze. 

[reed]

Looks like the seeds on the stem the rabbit severed are continuing to mature in water. Very encouraging that it might be possible to cut the ones that would otherwise get frosted and finish then up inside. In a normal year if there is such a thing anymore we could have frost anytime but the way it looks I don't expect it till well into October at the soonest.

There are not as many pods on the seed grown plants but I have confirmed it is possible to go from seed to seed in a season. The Hong Kong and Patriot are actually earlier than the seed grown so next year has potential to be better.

[jondear]

Sept 21, 2016 10:53:41 GMT -5 reed said:

Sprouting Seeds
Since sweet potato seeds have very hard seed coats, they germinate slowly and irregularly unless they are scarified. The easiest way to scarify large quantities of seeds is to soak them in concentrated sulfuric acid. If you have only a few seeds, you can hand-scarify them by scratching a small notch in each seed coat with a sharp needle or a small, 3-cornered file. Do not scratch the round side of the seed, since this will damage the embryo. (I find the use of concentrated H²SO⁴ to be in a word, stupid. Good to know though not to file the round side of the seed, I'll try that next year too.) 

Saltpetre might also soften the seed coat.

[reed]

I can say one thing for sure, it ain't easy to get sweet potato seeds. Here is today's haul of dry capsules.



And the seed they yielded. One there at top left is obviously molded as are two of the ones in the center although less obviously in the picture.  I thought at first there was a range of phenotypes but that isn't the case. The larger lighter colored ones are no good. They are soft and when they dry the rest of the way they wrinkle and pucker up and stay soft. 



Here's why, they have already tried to sprout and then rot without ever falling from the capsule. I have no idea what causes this or if there is a way to minimize it. I am pretty sure that even the non rotted one top left above is no good. Only the small black ones are mature and hopefully viable. So out of seven capsules I have six nice looking seeds. 





 

[reed]

Getting more seeds ever day now including some from the second year plants. Lucky that the weather is staying warm.

[reed]

Current count of TSPS stands at:

251 -  for Patriot or Hong Kong mother plants, based on weather forecast and number of still maturing capsules I expect this to go past 300.

94 - for first year purple clone mother, should easily go to 150. These are the largest, most uniform color and shaped seeds.

2 - for Barb & Gene, a longer season and larger vined mother given to me by my aunt and uncle and grown local by them for a long time. There will be no more of these this year, a stem that had several capsules and hung outside the fence was eaten by deer or rabbits.  I think only one of these is likely good. 

6 - for 2nd year purple mother (seed from seed) was really hopeful to get more of these and thought for a while I would. Turned out the earlier ones were the big brown soft ones, no good. Also the lions share of these aborted and dropped off soon after capsules began to form. Good news is another 20 or so capsules are nearing maturity so hopeful of getting a few more good seed. These capsules  are small but that just indicates there is only one or two seed rather than four. 

Except for some from a rabbit severed stem that I stuck in the pond there will be no hydroponic grown seed. Big fat frogs stomped on them and knocked them all into the water, stupid frogs!

Some stems cut and put in a vase in the window finished maturing just fine. 

I already collected up some black locust leaves, sand and screened compost which I will mix up and heat sterilize to start them in next year. That is the most extra measures I'm taking for them, I need plants that don't need pampered too much. I don't intend to do anything as far as stratification either. This year I had about 10% sprout under what I'm sure was less than ideal conditions so next year I'll just start with many more seeds. The sterilized mix is all they get. 

Even keeping some in reserve and accounting for some already promised out, I have more than I need. If any one in a climate similar to mine in SE Indiana would like to try increasing (seed from seed) and sending some back let me know in a pm. 

Had all the fertilized flowers this year produced good seed I bet I would easily have had a thousand or more, still I'm pretty happy. 



 

[walt]

Reed. I'm game for some seeds. Nothing to trade just now, but I could pay cash. Or I could sharecrop them, as you said. Or some of both. I'm in Kansas. That is a little like Indiana.

[reed]

walt , I can send you 10 each of the P or HK and 1YP. PM your address.

They are going pretty fast, I have just one more set of ten each. I might have one or two more depending on how the rest of the harvest goes. 

I don't know what to think about self compatibility or incompatibility. I know that it goes against all literature on the topic but the 2YP plants grew from a plant that was all by itself in 2014. I'm pretty sure this year's 1YP seeds came from that same clone material, at least it looks exactly the same and came from the same source. That being said I'm sure that most varieties are self incompatible so all the P or HK seeds are hybrid between them or the others. Even if the 1YP is self compatible more than likely most of them are also hybrids, the bees were pretty thorough every day. 

I have no idea how selfing or not selfing may have carried on into any of these seeds. For insurance I recommend going to www.sandhillpreservation.com/  and getting another variety that they describe as blooming a lot. One other than Patriot or Hong Kong. I will probably do that too next season and after that try growing just from seed, eventually growing some in isolation to see if any  selfers show up.

Here it is November with highs in 80s, I'm getting impatient to see what the roots look like but the old timers here say you don't dig sweet potatoes till frost takes the vines. Besides I'm still getting seeds. 




  

[reed]

Brought in 32 more nice seeds today, about 1/2 and 1/2 1YP and P/HK. The percentage of the soft brown seeds seems to be going down.

[reed]

well it close to frosted the other day and supposed to get colder so I went ahead and dug up the sweet potatoes, here is how they turned out. 



1YP - Only had one plant so it is by far the winner in number of good looking seed produced, not much on usable root but I will taste them after they cure for a little while. The roots pictured is all it made. It bloomed plenty early but most seed set on later flowers. In a year where frost comes in October instead of November not near so many would be harvested. 

2YP - Again not much on roots and same on blooming, plus probably over 95% of seeds aborted and 90% of the rest were the big rotted ones. Aganin that is all the roots it made from two plants. Six seeds total and only four look very good. 

P or HK - Got good amount of seeds and a good percentage were from earlier flowers. Look back a Sandhill's web site and learned the bigger purple ones are Hong Kong and the others Patriot. They described Patriot as a heavy producer but I got about 8 lb from two HK plants only about 2 1/2 lb from Patriot. 

Local grown unknown variety -  two seed from later flowers, only one looks good. About 15 lb of roots from three plants. 

There in the jars are the remaining capsules, the last ones that matured in water appear to be good seeds but they take a long time. I should get a few more before I'm ordered to get them out of the kitchen window.

Now, I'll only have room for maybe twenty plants next year so have to decide how to proceed. Get the other Sandhil varieties described as blooming a lot? grow combination of these by slip and seed? grow only seed? 

Comments and suggestions welcome.