Breeding Sweet Potato in Australia

[whwoz]

SSR 2.

Tuber planted vertically, it produced green palmate leaves.  Tuber fully rotten.

2nd Photo showing plants 2 to 7 after knocking out of pot, but before disturbing roots

[whwoz]

SSR 3

Tuber planted vertically, Heart shaped Green leaves, purple skin and purple mottled flesh.  Forming small tubers.

[whwoz]

SSR4

Heart shaped Green leaves, Purple skin and Purple mottled flesh.  Forming small tubers.

[whwoz]

SSR 5

Planted vertically,  Green Heart shaped leaves, Purple skin and purple (non-mottled) flesh.

[whwoz]

SSR 6

Planted vertically, Green heart shaped leaves.  Purple skin and purple mottled flesh.  Forming one long thin tuber.

[whwoz]

SSR 7,

Planted vertically, Green palmate leaves.  Pale Pinkish (?) skin with white to cream flesh, vigorous shooter.  Probably most of interest to me as purple flesh does not always go down well with rest of family.

[S.Simonsen]

Hope they do well for you when given some more space and time. The season got away from me as well (getting 1 meter of rain over three days at the peak of the flooding made all cropping impossible).

[Richard Watson]

Its a shame that you are getting rot in the tubers. I haven't had that as a problem here

[whwoz]

Richard, those tubers were seed tubers, so not surprised that they rotted a bit.  Unfortunately the growing seasons for sweet potato between here and Queensland differ by about 6 months, so those tubers that were sent to me on February about the time that I should have been digging them. So I have to cross fingers and hope that I can keep the slips alive over winter.

[reed]

I don't can't really explain the difference scientifically, but sweet potatoes are actually roots rather than tubers. More specifically they are storage roots, and I guess the plant uses them to store both water and nutrients. An obvious difference that I've actually observed is for example you plant a potato, which is a tuber, it sprouts from what we call eyes to grow a new plant and the old tuber rots away.

If you plant a sweet potato storage root that same old root starts growing again and from what I've seen gets pretty ugly over the season with lots of sprouts and lots of little feeder roots growing from it. Basically, it turns into an overgrown mess and makes few if any new, good to eat, storage roots. I've only done that a couple of times and don't recall cutting the old ones open but would not be surprised if they had that same issue of internal rot.

The good news is storage roots are extremely easy to store  I have kept them for an entire year, and they are still good, both to eat or to sprout slips. They just need a cool, but not cold, dark place. A root cellar is almost too cold, and a refrigerator is way too cold. I store mine under old blankets in the spare bedroom upstairs.

Some more good news is they are extremely easy to sprout slips. Just get them out a little before planting time and expose them to some sun and water. I lay mine on their side in trays of damp sand in the south windows. The sand is just to hold them in place.

And some more good news is a slip needs almost no roots at all when transplanted out to the garden. They actually seem to make better storage roots if they start as mostly just a stem. I think having a lot of roots when planted causes them to make lots of little storage roots instead of a few nice ones. I have on many occasions just cut a stem and stuck it in the ground, in the hot sun with no roots at all. It wilts badly of course but keeping it well watered in less than a week it is growing again. Even discarded trimmings often root down and start growing.

And still some more good news is about any little slip is easy to keep over winter as a house plant. If you house is warm, and you have a nice sunny window it might even get pretty big and even make little storage roots in the pot. If it overgrows and gets annoying you can just chop off little pieces and restart them. If your house is like mine with drafty windows and a wood stove causing drastic fluctuations in temperature they might get a big tired looking but as log as they have a shred of live come spring your good to go.

[Richard Watson]

Richard, those tubers were seed tubers, so not surprised that they rotted a bit.

Ok, that is understandable. You should be able to keep the slips alive through winter being further north than me

[S.Simonsen]

Hi Reed
The rotted tubers were from me, sent at the end of a long, hot, wet summer. Storage of sweet potato roots under such conditions is much trickier than under cool temperate conditions (especially with our healthy sweet potato weevil population). The rot probably came from weevil holes in the tubers. I agree on the top parts being easy to keep going. We just had six months of flooding rain here on heavy clay soil (the highlight being one meter of rainfall over three days....that is not a typo). I knew I wasn't going to get my tubers planted again under these extreme conditions, so sent them to some other grows to try. I still have most of my original seed in storage so will try again when things improve (though on our heavy clay soil sweet potato isn't an ideal staple crop).

[whwoz]

Looks like at least five out of the seven lots of sweet potato slips have survived to some extent.  SSR 2 , the one which rotted completely in the big pot is unlikely to recover, always was the poorest grower and one of SSR three or four may not make it.  The rest will to a greater or lesser extent.

[whwoz]

So the majority of the SSR series sweets have survived a mild winter to some extent.  SSR2, the poorest grower did not make it, need to check SSR4.

SSR 1 is doing well, surviving in 3 or 4 pots and growing well. SSR 3 has only survived in 1 pot, with that slip now starting to grow well and have flower buds in every leaf axil.



SSR 7 has the most survivors and has grown the best of all, with multiple 3 in long new shoots on all slips growing.  I could probably get something above 25 if I were to separate all as I should, just time and space limiting thing at the moment.



SSR 6 would be the standout performer so far, may not have grown as many branches as SSR 7, but at least two of the surviving plants have flower buds in all new leaf axils, with the flower shown being number 3 opened for the season.



All of these are growing better than the couple of Beauregard slips potted up at the same time.
 

[whwoz]

Ok, time to update this in what has been a funny season.  I could not get the sweet potatoes, SSR1, SSR3, SSR4, SSR6 and SSR7 into the ground  until after Christmas, so was always going to be touch and go for good tuber formation if the weather turned cool early.  Fortunately the weather is up and down with some very good days in-between some wet ones.  SSR 1 has been a stand out performer in the flowering stakes, but it appears that no seed has set despite having 5 honey bee hives on the place until recently.

SSR 3 and 4 have grown slowly, but have flowered well, once again with no apparent seed set.  SSR 6 has grown well, flowered well but yet again has not set obvious seed.
These 4 clones are all purple flesh and skin.

SSR 7 has grown well, was much later to start flowering and does not appear to have set seed either.

I have cuttings of these 5 clones on the kitchen windowsill in water at the moment with roots under an inch long on 1, 3,6 and 7 in preparation for overwintering as cuttings again.

Time has been against me for digging the roots, but should hopefully get that done in next few days if the rats have left me anything to dig.  The purples appear to have been hit hard, while number 7, which is pale pink skin over cream flesh does not have any obvious digging around the plants. All of the plants have short stems, under 0.5 m/20 inches in length.

The struck cuttings will be potted up and go into a mini greenhouse with heat supplied on the colder nights.

Shortly I will be assembling a 5 X 12 m greenhouse and the plants will go into raised beds. Inside it for a season due to the rats.