Breeding Localized Varieties of Sweet Potatoes

My mother loves sweet potatoes. She plants some every year, and harvests a meager crop. The available varieties are not suited to this area, so they grow poorly here. The way to fix that seems to be to breed my own varieties that can grow decently here in spite of the short-season, and cold-nights. That requires growing sweet potatoes from pollinated seeds.

Sweet potatoes are generally self-incompatible, so at least two unrelated clones are required to make seeds. Additionally, commercially available varieties were selected for poor seeding ability in order to minimize weediness. Last winter when a couple of people sent me sweet potato seeds, I was hyper excited. I shared the heck out of the seeds, trying to get them into the hands of collaborators that might have a better chance of getting a second generation of seeds.

I planted about 20 to 30 seeds 13 days ago, and three of them have already germinated for me, and about that many for the collaborator who sent that variety to me. It is also a variety that seems to not have the self-incompatible trait. Woo Hoo. We're off to a good start. Additionally, we are both growing a few different clones of sweet potatoes hoping to get seeds from some of them. I'm intending to plant some of my sweet potatoes in the greenhouse, so that they can get a bit of extra heat during the summer, and have a bit longer growing season in the fall.

Is anyone else in the forum working on breeding sweet potatoes? Want to share your experiences?

Here's what my seedlings looked like this morning.

For the first time this year I'm growing three different varieties of sweet potatoes, which I hope might flower and set seed. So, not much to report yet except I'm trying!

Sweet potatoes are being grown in Southern Ontario and in Nova Scotia. These Northern varieties may prove suitable for Americans in colder areas as well.


http://www.aginnovationontario.ca/en/developing-made-in-ontario-sweet-potatoes/

Hot, sandy soil on the North shore of Lake Erie, that was formerly tobacco land, is the best place in Canada to grow sweet potatoes.

I continue to work on this project... Our collaboration network continues to grow.

Three sweet potato seedlings survived the winter (indoors). Eleven seeds have germinated this spring. I haven't been able to grow any seeds yet myself. A close collaborator grows seeds and shares them with me. (Thanks Mark R.) We are working first on developing varieties that make seeds readily, and that germinate quickly without special treatment. After that is taken care of, we will select for other traits like large early tuberization, and localization to my garden, or the other gardens where they are being grown.

Oh, this is exciting! Sweet potatoes are my FAVORITE. I have ordered a couple of bare-root plants from Baker Creek for this season--one red/orange, and one purple. I'm very interested to see whether they will cross-breed. I would also love to develop a variety that will grow well in my area. I'd eat nothing but sweet potatoes and ice cream if I could get away with it!

Sweet potatoes will often hardly bloom at all in a temperate climate.  I've seen mine start to bloom a little in the fall, just before harvest time.  I think it may be the daylength....that they need a short day and long night to bloom.  So you may need to have the plants in a warm indoor place (and they like it very warm....plants quit growing below 65 or 70 and start to die in the 50's) in order to get them to bloom and ripen seed.  In addition, you may need to hand pollinate them, especially if you're attempting to cross two varieties.  This could be a very detailed project, involving removing the male part of one variety's flowers and then moving pollen over from the other variety....

Rather than doing this project scientifically, we are doing it holistically. Growing the plants, and allowing their inherent diversity to solve those problems for us. We are not keeping pedigrees. We are not hand pollinating. We are not manipulating day-length or temperature. We are allowing bees to do the pollination. We are selecting for varieties that readily make an abundance of seeds. We are not giving the seeds special germination treatments. We might only get 10% germination, but we are working on the expectation that the children of quickly germinating seeds will also germinate quickly. In other words, our first goals with this project are turning sweet potatoes into a crop that produces an abundance of seeds that germinate quickly and easily, just like any other northern adapted crop.

We have identified some families that flower months earlier than others. We have identified some families that produce an abundance of seeds. We have identified some families in which the self-incompatibility mechanism seems to be inactive.  Once we get the seed production issue resolved, then we'll start selecting for taste, productivity, size, cold-tolerance, etc...

Hi Joseph,

was googling sweet potato breeding and ended up here.....what are the odds

A brief summary of my obsession with sweet potatoes. I have been growing them here in Melbourne (cool temperate with frost) for about 7 years. In the early years i grew Beauregard(orange skin and flesh) and northern star(purple skin and white flesh, starchy) both crop very well. A few years ago i got hold of some heirloom varieties and have been trialing them.

Borneo - white skin with pale yellow flesh with a hint of purple specks .....only crops fair

Wanmun - purple skin white flesh absolute feral (vigorous)  good yield anywhere it touches the ground makes harvest difficult....good if you had pigs

Solomon - pale orange skin white flesh very good yield all in a clump nice and shallow

Purple skin and flesh (just bought on eBay)

My quest is to breed purple/yellow flesh cold tolerant strain.

my understanding on seed production (outside of tropics)

- needs less that 11 hour daylight (10 hrs good) to induce flowering...need to cover plants at set time intervals

- grafting onto morning glory see link below helps induce more flowers ( this seems similar to return to resistance methods with normal spuds)

will keep you posted on my efforts

I find good consistent watering can double your crop.


https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjlsN2M2tjVAhWFyLwKHXaiDEEQFggtMAE&url=http%3A%2F%2Fwww.istrc.org%2Fimages%2FDocuments%2FSymposiums%2FFifth%2F5th_symposium_proceedings_0010_49.pdf&usg=AFQjCNHHqRUii1ploAMViiAD4fEQB7ht5g

Karl: Thanks for the grow report, and especially for photos... So if I planted my pencil diameter plants further apart, could I expect them to be more thumb sized? LOL! I envy those of you in warmer climates. I look forward to future grow reports.

One of the most exciting traits that we have discovered, is sweet potatoes that are not day-length sensitive. So they can flower and make seeds here in spite of the short season, and long summer days. There were sweet potato flowers in my garden on the longest day of the year.

LOL i just looked at your zone 4b! does that mean snow? .....i think we are 6 maybe 7. i do feel your pain with the fingerling crop my best largest plant that took over the whole garden didn't get one tuber.

wow that day neutral bloodline is a find .........the trick is to get the others to cross with it.

Once the sweet potato networks is going have you considered off site seed production?.......that is a willing permies member in the "deep south" could plant a few plants over the winter and send seed back to you for torture.....the first step is to get a sh@t load of seed right?

This video is worth a watch......a little waffle at the beginning but at minute 25 onward some good background to the plant and methods they use.

Hi Joseph and Karl,

if you want to conserve the pollen on a low tech way for over 2 years, there is a quite cheap way of deyhdrating it in vacuum.

It would be way easier to cross a good producing Sweet Potato with the day length insensitive one this way.

Sorry for the french article, but I have no time to translate right now. Look at the pictures to understand
https://www.cactuspro.com/articles/_media/conservation_du_pollen:conservation_du_pollen.pdf

Best

Hi Hans

Very interesting I've used a lower tech method with kitty litter (crystals) in a sealed container to dry seeds and pollen before freezing but never thought of vacuum!

here is the doc in English via google translate not pic but it will do for now.....didn't attached see paste

I'm just thinking out loud here but this opens the door to swap or trade pollen!...........the mind boggles.

Page 1
 1 CONSERVATION OF FREEZER POLLEN BY FREEZING       In 1955, as part of her thesis work in Wageningen, Tijs Visser was interested in Storage and in vitro germination of pear and apple pollen. On this occasion, He finds that the pollen germinates better when the water content has been lowered and when it has been Stored at very low temperatures. Viability is not affected after two years of storage at Minus 180 ° C.   It is therefore on the water content and the different conservation methods that Focus research for two to three decades. It was not only Viability of the pollen is retained, but also that the integrity of the envelope glycoproteins Stigma recognition allows for the germination of Pollen (Charrier 1990). This research was first conducted on woody plants Fruit and forestry, followed by cereals.   Despite differences in conservation suitability by species, On the lowering of the water content to the threshold of 5% to 2% by vacuum desiccation to Ambient temperature and storage at negative temperature. It is on the basis of a Freeze-drying and freezing preservation of the Pollens of the National Museum of Natural History of Paris from 1983 (Cerceau - Larrival, 1995). Among the 250 species included a board cactus: Harrisia nashii. Perhaps there - She still?   In 1998 (a, b) and 2000, Julia Buitink explains the maintenance of pollen viability by Physical and molecular mechanisms of intracellular vitrification (detailed In Derouet 2010, page 18). It shows the interactions between the temperature of Storage, water content and their influence on the aging of pollen.   It was in April 2000 that an Israeli team (Metz, Nerd and Mizrahi) published a Dehydration of the pollen in order to keep it for several months by freezing to achieve the cross-fertilization of two cactus (Hylocereus undatus and H. polyrhizus). These cloned plants Intended to produce fruit for consumption are self-sterile and have peaks of Offset flowers in the season. The technique developed and the means adopted seem to be sufficiently simple to Work by the cactus lover.     THE "HYLOCEREUS" TECHNIQUE     Pollens of Hylocereus undatus and H. polyrhizus Have a water content of 18% to 22% When harvested in the morning and 45% to 50% evening. It is known that water-rich pollen is not Viable for a long time. A few hours at most. They must therefore be dehydrated.       Fruit of Hylocereus undatus Photo by Maja Dumat - flickr.com
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 2 The dehydration It was carried out in a partial vacuum desiccator (half a atmosphere or - 50 kPa Or -38 cm of mercury relative to the mean atmospheric pressure). The recipient Contains crystals of silica gel to adsorb the water. The pollens stay there for two hours And half before reaching a water content of about 2%, regardless of The time of harvest.     The conversation In this experiment, pollens were Stored at several temperatures: +4 to Refrigerator, -18 ° C and -70 ° C in Freezers and -196 ° C in liquid nitrogen For 3 months and 9 months. Only the Results are reported here.     Fertilization The rehydration of pollen is Naturally by contact with the stigma. The pollinated flowers were fertilized at 100% for frozen pollen and Only 60% with pollen Stored at + 4 ° C.     Fruiting For temperatures of -18 ° C and -70 ° C, the weight of fruit produced (pitayas) was the same as orchards those harvested in (410 g to 330 g H. undatus and H. polyrhizus) after fertilization With fresh pollen of any kind. Fruits from pollen stored at -196 ° C Weight about 10%. Pollen stored at + 4 ° C produced fruit from 20 to 30% lighter.     Seeds The number of seeds Harvested is included in the Table opposite. These Are the average Of six samples per batch. The in vitro tests of Seed germination Were conducted with 400 Seeds per lot.     Balance sheet Finally, we see that these conditions successfully tested in the laboratory and then in the orchard are Transposable within the framework of a domestic practice. In fact, it is simply a matter of Dehydrate the pollen under a partial vacuum and store it in the freezer.  
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 3 THE VULGARIZED TECHNIQUE     For cactus lovers, until now, practices for the conservation of fresh pollen In the refrigerator allow fertilization for only a few days. This New long-term conservation technique will allow fertilization or hybridization Of species whose flowering gap extends over a whole season.     Manufacture of vacuum desiccator   We are trying to achieve a residual pressure of 50 kilopascals, that is half a bar. To do this, we must empty the container half of its air.           Technical Requirements   - Vacuum gauge purchased at ExpertByNet: 19,90 € + port http://www.expertbynet.fr/fr/manometre--et--vacuometre-- oil / 8682 - vacuum gauge - round - 1 - a - 0 - bars-- diameter - 63mm - m1--4-- 3283159024227.html     - Brass nipple: F 8x13 - M 12x17: € 1.45 (DIY plumbing department) - O-rings made of rubber: two from Internal diameter 6 mm, two diameter Inside 11 mm - Metal washers: one with an inside diameter of 13 mm for the vacuum gauge and two of 6 mm For the valves.       containers   Take jars called "TO" (Twist Off). I chose with a lid of 104 mm compared To a jar with an outer diameter of only 83 mm. It may be a bit Too large because the lid becomes very concave when it is under vacuum, with a click Characteristic to -0.2 bar. An intermediate option exists in the Pickle with Russian (Kühne) with a Diameter of 93 mm.     - Desiccator version pollen: a jar of Gizzards of duck confit and sliced ​​to 6.00 €. The same container exists with fat Duck or goose in the two euros ... - Desiccator version pollen and seeds: one Jar of cassoulet at 5,70 €  
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 4   Equipment   -- A drill - Wood drills with centering point of 6 mm and 13 mm       Drilling   - First drill a 3 mm hole at the future location of the vacuum gauge to accommodate the Center of the wick without deforming the lid. - Then start drilling the 13 mm hole for the vacuum gauge using the Centering through the outside of the lid without crossing, only so that the finish is clean. Turn the lid upside down and finish the hole from the inside of the lid without slowly. Finally, using the 6 mm drill bit, drill according to the same principle the hole of each Two valves.           Mounting   Remove the rubber hull around the vacuum gauge. It adds an unnecessary volume. To put An O-ring of 11 on the vacuum gauge and thread the assembly into the hole of the cover, To Inside the lid, add the washer of 13 then the nipple and tighten.   If you notice a lack of waterproofing, you can add a flat rubber gasket Which will make a wider seating for the O-ring on the cover. In the picture below, the Attached to the inside of the lid, under the washer, is not essential.   For the valves: put the O-ring on the valve, insert into the hole of the cover then Put a washer on the other side of the cover and the clamping screw. This is Valid for both internal and external valves.  
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 5             To make the vacuum, a refrigerator group recovered on an old refrigerator or a freezer Constitutes an excellent vacuum pump. A few seconds is enough to reach a Depression of - 38 cm of mercury. If you can not retrieve one, there is also a manual option.        
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 6 Dryer version caviste   A vacuum pump in the opened wine bottles may well be enough to create the Vacuum required for pollen dehydration. The pump, and its reusable cap, Sell ​​between 15 and 20 €. The vacuum at -50 kPa is quickly reached.       Vacuometer:   Same way to do that for the model previously described.       Manual vacuum:   - An Aqua Flow D1630 mounting junction Use only the central part (gray): 1,25 € http://www.leroymerlin.fr/v3/p/produits/jonction--de-- mounting - aqua - flow - d1630-- e144630 # & XT ™ = & junction xtcr = 2     - A reduced nipple. The female part will receive the part Center of the junction and the male part (diameter 16.5 mm Approximately) will pass through the lid.   - Seals of the required dimensions: one to be between the Lid and nipple, two (flat and / or toric) superimposed For sealing between the plastic joint and the part Female from the nipple.   - Any element to come screw on the nipple to Inside the jar.   - Same containers as for the version "group refrigerator", Lid diameter 104 mm or slightly lower (93 mm).   - Wine Pump (Vacu Pump): 15,90 € http://www.boutique--bar.com/pompe--vin--vacu--pump-- xml - 244_408--1340.html         Equipment required   Drill and two bits of wood with centering point: - One of 13 mm - One of 16 mm       Mounting   In this version, there are only two holes in the
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 7 Lid: one for the vacuum gauge and one for the vacuum pump since the system used Also allows the air to flow in.                                                                                                  
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 8 Pollen collection     The funnel The pollen is collected in a bag of crystal paper. For large flowers (Epiphyllum, Selenicereus and some Echinopsis), collection can be done by shaking the flower - above a Funnel connected to the crystal paper pouch.       The scissors For the other flowers, one can use a pair of scissors and cut just below The dehiscent anther. It is then sufficient to pour into the sachet the anthers and the pollen left On the blades of the scissors.       The cotton-tube The scissors technique The inconvenience of loading the bags Pollen and the remains of the anther. This set is then found On the brush during fertilization and could compete Occupation of the surface of Stigma by pollen. To separate Pollen pollen bags, it is necessary to So that this is done at the collection By a technique of suction of the pollen. Cottons are often Hollow plastic. The solution is simple: a cotton rod = two cotton tubes. Then, the cotton - tube must be connected suction device.   It is then enough to walk the cotton Tube from the stamens to Aspirate the pollen. Before stopping Suction, the tube must be straightened And then emptying it in a Bag and patting it on, or Possibly by blowing into the Cotton tube with delicacy.     Dehydration of pollen   The sachet containing the pollen is folded and closed with a scotch and placed in the jar whose Was previously filled with a moisture-absorbing product. The partial vacuum is made in the container. The system is very hermetic because it can The same vacuum for a very long time ... as much as a bike can remain inflated. After 3 or 4 Hours, the pollen is considered to have reached a water content consistent with freezing. The valve is unscrewed and there is heard the whistling of the air entering the container. It is also a means of verifying that the vacuum was indeed made.
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 9     Freezing pollen The pollen bags are then stored in a freezer in a sealed jar with Crystals of silica gel to maintain dehydration.         RESULTS       Influence of the pollen collection technique on the quality of fertilization   In the first stage, pollen was collected by cutting with the scissors the part Superior of the stamens with their pollen sac. The hypothesis of a competition of debris Pollen bags with pollen on stigma triggered comparison "aspiration" and "Scissors" on the number of seeds per fruit.   The pollen was therefore, either sucked on a flower, or collected with scissors on another flower Of the same plant, the same day. The fertilization also took place obviously on two different flowers of the same Plant on the same day. The harvest of the fruits of each plant takes place on the same day.         Of course, it is on a small number but it is found that the starting hypothesis was not Because in the present case, consisting solely of Echinopsis, fertilization by Pollen collected with scissors generate on average a little more seeds (400 vs 340). Both techniques therefore remain conceivable.     Influence of a greater vacuum on the number of seeds produced.   In their publication, Metz et al. Recommend a vacuum of -0.50 kPa. It was interesting to See if the amateur could dispense with a vacuum gauge to appreciate the depression in his Dehydration container.   Pollen was collected, bagged and dehydrated under a high vacuum between -0.88 and -0.92 KPa for 3 to 4 hours, then frozen. Twelve flowers were fertilized with these pollen and the Half of them have not been fruitful.  
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 10 These results are to be compared with the results of the 17 fertilizations obtained on Echinopsis With the 2011 pollen that was dehydrated under -0.50 kPa. The average number of seeds Obtained by fruit was 417.   It is found that Echinopsis sp. "Yellow flower" seems very sensitive, which is not the case for Harrisia sp. Sensitivity to high vacuum may not be the same for all species ...       It is certainly no coincidence that the Metz team set the vacuum value at -0.5 kPa. he There seems to be a deleterious effect on the viability of pollen and it is therefore essential to To be equipped with a vacuum gauge to stabilize the vacuum at about -0.50 kPa.       Influence of the longevity of pollen storage on the number of seeds produced   After 3 years of storage in the freezer, pollen remains viable even after several Brief exits at room temperature for fertilization, as below for 3 pollens:       CONCLUSION     After three years of testing, the demonstration is made that the technique is reliable and Simple enough to be implemented by the collector. It should Previously unrecognizable crossings because of the shifting of flowering.   There is thus a technique of future and new perspectives for the amateurs and the breeders.  
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 11 BIBLIOGRAPHY     Buitink J. C. Walters, J. Hoekstra FA & Crane 1998a, Storage behavior of Typha latifolia pollen at low Water content: interpretation on the basis of water activity and glass concepts Physiologia. Plantarum, 103: 145-153.   Buitink J., Claessens MAE, Hemminga MA, Hoekstra FA, 1998b, Influence of water content and Temperature on molecular mobility and intracellular glasses in seed and pollen, Plant Physiol. 118: 531--541   Buitink   J., Leprince O., Hemminga M. A., Hoekstra F. A., 2000, The effects of moisture and temperature On the aging of kinetics of pollen: interpretation based on cytoplasmic mobility, Plant, Cell & Environment, 23, 9: 967-974   Cerceau - Larrival M .-- Th. , Delange Y., Youmbi E., Derouet L., Verhille A. M. And Carbonnier - Jarreau M .-- C., 1995, Contribution to the Preservation of the Male Genetic Heritage of Plant Collections live National Museum of Natural History, Paris, Grana, 34, 6: 371 - 407   Charrier A., ​​1990, Pollen and genetic resources, Bull. Soc. Bot. Fr., 2: 101--104.   Derouet M., 2010, Seeds of cacti, from the flower to the seedling, page 18.   http://www.cactuspro.com/articles/graines_de_cactees_de_la_fleur_a_la_plantule     C. Metz, Nerd A., Y. Mizrahi, 2000. Viability of pollen of two fruit crop cacti of the genus Hylocereus is By HortScience, 35, 2: 199--201   Visser T., 1955, Germination and storage of pollen, Thesis, Mededelingen van de Landbouwhogeschool 55 (1): 68p, NL       Summary: Long - term storage of pollen is interesting for enthusiasts seeking cacti butts. This paper has popularize home - made experiment based on the study developped by Metz et al. (2000).   To obtain an efficient preservation of viable pollen, two processes are required: first Dehydration in a vacuum (about - 50kPa) (About 3 hours) and second, storage at subfreezing temperature.   in Practice vacuum, vacuum wine, refrigerating unit And the storage in a household freezer.   For pollination, the pollen is applied to mature stigmas Able to rehydrate the dried pollen.   Under these conditions, we get fruits and seeds after Three years of storage.     Key words: cactus, pollen, seed, dehydration, drying, storage, freezing     I thank Georges Marchand (†) and Jean - Didier Hary for their friendly collaboration.     Michel Derouet michelderouet@orange.fr Last updated May 14, 2014


Original French text:
La partie femelle recevra la partie
Contribute a better translation

We typically have snowcover from mid November till mid March. Overwintering propagules has been difficult for me.

There is a growing network of amateur plant breeders, in warmer climates,  who are working on the production of sweet potato seeds. I have been blessed that they generously  share seeds with me. They are getting really good at producing seeds. I haven't found my first seed yet, but it might happen this year. I have had two different varieties flowering right next to each other since June.

I could certainly freeze sweet potato pollen. I sometimes store and mail other types of pollen. In my dry climate, I don't need a vacuum. It dries quickly and simply in a bowl.

Here's an end of season update.

11 seedlings germinated quickly. They were planted to a row in the garden about early June. Some of the plants were flowering for the summer solstice. Yay! That means that they are not day-length sensitive. Seedlings kept germinating all summer long, and some of them were even planted out, but they didn't amount to anything.

I collected seeds from 3 of the plants: About 40 seeds total. I pulled the seedy plants and tossed them in a bucket of water in the greenhouse just before frost. About half the seeds were collected from them over the next two months. I kept clones of those 3 plants, and one other, which I am trying to keep alive indoors until spring.

A collaborator further south and at lower elevation produced an abundance of seed. Some of that was shared with me. Thanks, I feel honored. I couldn't do this project without wonderful plant breeders in warmer climates. I also returned seed to the collaborator.

I harvested some tubers. I'm trying to keep them alive until next spring for replanting. I managed to mis-sort while harvesting, so the tubers from seedy plants got mixed up with the non-seedy. Oh well. Better sorting next year. My first goal with this project is seediness, and quick treatment-free germination. The selection for treatment-free germination was stunningly successful. Here's hoping that it's a trait that can be passed on to the offspring!

We have been impressed with the seediness and great agronomic properties of some of the decorative sweet potato varieties.

so i live just outside New Orleans
i have a purple someone gave me, that i have let run and used as a ground cover
also good for adding N to the soil and organic matter, since i let them rot in place
not to mention they grow REALLY fast, and the leaves are great chop+drop too.

i havent tried to hard to use them, since my preference is for a golden to orange flesh type.

i like creamy testure, but also want to make french fries
(i had some a while back, and they were SOOO good !!!)

anyway, i would love to trade for some seed
or, even for slips of a good variety that would work well in this area.
moisture isnt a problem, as New Orleans is a very high rainfall city
AND i am in the garden a lot, and tend to water anything that looks a little dry

Obviously its a long season here.
but, we do get light frost on occasion.
Sometimes we go 2 or 3 years with no frost at all
sometimes we get 2 or 3 a year
but , rarely below 28F ish. (once a decade it may hit 24-25ish)

i have POTATO MINT (Plectranthus esculentus) tubers i can trade
lots of other stuff as well, mostly subtropical though.
goji plants or ??

cheers
Brad

Karl Trepka wrote:
My quest is to breed purple/yellow flesh cold tolerant strain.

my understanding on seed production (outside of tropics)

- needs less that 11 hour daylight (10 hrs good) to induce flowering...need to cover plants at set time intervals

- grafting onto morning glory see link below helps induce more flowers ( this seems similar to return to resistance methods with normal spuds)

will keep you posted on my efforts

Cool! I also dream of a sweet purple flesh / yellow flesh sweet potato i can plant here from true seed!

Interesting about the morning glory grafting technique. I had wondered if that might work. We have LOTS of bindweed here that i thought might work for that. Flowering little buggers everywhere!

Sounds like great minds think alike!!

Keep me posted! Any updates?!

any update on this project?  I'm having trouble getting my sweet potatoes (Beauregard variety) to size up during our short season here in New Hampshire.  I would be willing to pay postage for anyone willing to send me self-fertile seeds.

I harvested some nice sweet potatoes this year from seed grown plants.

In spite of the meager harvest of tubers and seeds, I am thrilled with the results. Many of the tubers are much bigger than pencil width, which is how big they would get when we started this project.

I am liking this experiment alot, wondering if they could cost with manroot also.
https://oikostreecrops.com/products/perennial-vegetable-plants/manroot/ocpage=1/

Davis Tyler wrote:any update on this project?  I'm having trouble getting my sweet potatoes (Beauregard variety) to size up during our short season here in New Hampshire.  I would be willing to pay postage for anyone willing to send me self-fertile seeds.

The fair market value for sweet potato seeds is about $70 per seed,  accounting for materials and a modest wage for the plant breeders involved. A great way to get involved in this project, would be to buy a dozen different varieties of sweet potatoes, including some decorative varieties. Then plant them close together, and grow them in conditions under which sweet potatoes are known to thrive. Hand pollinate the plants, and pay close attention to harvesting the seeds as they mature, because they are shattery. Post photos of your progress. About the time you produce your first seed, you will find yourself embedded into a community of sweet potato plant breeders. They will joyfully share a $2000 packet of sweet potato seeds with you.

I have tried growing sweet potatoes from slips here in Ohio and mostly got long vines but no sweet potato tubers. I am considering them as a greenhouse crop. They have relatives that grow wild up here and I wonder if a cross would be beneficial. I am also considering getting my buddy in Japan to send me some seed from their landrace variety from the mountains around Kyoto.

I know it's an odd time of year to resurrect this post, but whatever.

I was gifted some sweet potato seeds last spring. Yay! I used the commercial varieties to put good stuff into my soil, and I'll continue with that.

Two of the seedlings actually produced flowers, but only one produced (6) seeds. I saved those two to overwinter.

However, of the two one is exceptionally susceptible to environmental problems. Any level of dry or chill and it keels over, moaning about its horrible fate. The other sails through with no problems. The one that seeded appears to be self compatible, since none of the others bloomed at all and the two flowering plants were at opposite ends of the property.

I put them out in the greenhouse, with extra protection, to see if the "cold tolerance" will stick. After nearly a month in 30-40 degree temperatures, the strong one was still strong. The other appeared to have died. I pulled them and will start the roots in February.

I have started more seeds. I will torment the new plants this summer, as usual, but these survivors will go in the garden.

Many years for about 30 years I grow Sweet Potato in my hoophouse or large cloches. Some years I get greens and I am fine with that. This year, my son over-wintered the plants inside. I then held/grew them for a few months on the propagation bench in the hoophouse. So they had been getting very warm in the day and very cold- for sweet potatoes- during the night. . When the soil temperature got above 60F I planted them in in a bed in the same hoophouse. Now for the first time I see flower buds on one of the two varieties I have this year. It is a "Japanese Purple", not sure which variety.

It may or may not be self compatible. If not it seems a waste to not try to get pollen to put on the flowers. I have a range of other options including selfing, BUT.......

Can someone send me some dry pollen of northern or cold tolerant or purple sweet potato pollen? Please. I can work out some kind of trade or pay for postage.

Thanks

Out of curiosity, possibly showing extreme ignorance of the science behind plant genetics, could sweet potatoes (Ipomoea batatas) be hybridized with North American native wild potatoes (Ipomoea pandurata - aka man-of-the-earth)? Granted, offspring could be sterile (assuming that I'm remembering correctly from high school how taxonomies work...), but might be an interesting experiment and could create clones that are more tolerant of the growing conditions in the more northern states. The question arises as I have wild potatoes growing in my yard not too far from my garden spot. Of course the question arises about whether one should attempt the hybrid... do wild potatoes even taste good?? Edible doesn't necessarily mean delicious. I haven't tried as I'm a little nervous about incorrect plant identification and poisoning myself.

Katie Nicholson wrote:..., could sweet potatoes (Ipomoea batatas) be hybridized with North American native wild potatoes (Ipomoea pandurata - aka man-of-the-earth)?  

I dabbled with that very thing a little bit. Managed once to get two hand pollinated seeds form batatas, pollinated by pandurata but flowers were not protected from bees crossing with other batatas so it is possible they were not actual crosses. In any event neither one sprouted the next year. Also dabbled a little with grafting pandurata stems onto batatas roots. It worked but I did it in the fall and it didn't survive till the next spring. Still, I think it's something that might be expolred further, I just have too many other projects going on.  

I tasted small roots of pandurata and they tasted pretty much like nothing, I was chicken to actually eat them.

I wanted to harvest some seeds but never could find them. I had some but not many flowers. Is it possible that they flower but don't set seeds or do the seeds fall down easily?

Angelika Maier wrote:I wanted to harvest some seeds but never could find them. I had some but not many flowers. Is it possible that they flower but don't set seeds or do the seeds fall down easily?

Yes, both of those things are possible, however had they set seed you should have been able to see the capsules developing even if they later ended up aborting and dropping off. Also, the capsules shatter easily on their own, losing the seeds but you would have seen them while they developed, they are about the size of a pea.   Most varieties are not self-compatible for pollination, so unless you had at least two varieties flowering at the same time it's most likely they did not set seeds.

Hmm.  If sweet potato pods shatter that easily, maybe I should put blossom bags around them while they're drying down?  That way, I could catch the seeds more easily, rather than losing them?

This is my first year growing sweet potatoes, and I have two clones that are supposed to be able to flower and set seeds.  I'm hoping they will for me!

My most successful method of gathering sweet potato seeds involved cutting off the vines with the first fall frost, and allowing them to dry in the greenhouse. Seeds continued to mature with the stored energy of the vine. That minimized shattering, and even if they did shatter, I could collect them on a tarp.  

Oh, nice!  That sounds a lot simpler than blossom bagging!

Did you cut off the whole vine, and pile it all in together?  Or just the portions that had seed pods?

Here in wet temperate south america sweet potatoes do quite well. Mostly done from shoots that are put on the ground by august.
They do well in humid clay soil and need no watering. Produce cuantity and quality is very impressive.

Wow, Very impressive work!   [update: Ugg, this was a 6 yr old thread? Where have I been?]
Years ago when I wanted to add sweet potatoes to our garden, I found this site. Chock full of useful information. The main emphasis was a formula for attaining the minimum number of "Heat Units"

"Forget what climate zone you are in.  That has nothing to do with growing annuals, that is for over wintering plants. Parts of coastal Alaska are in  zone 7b. Here in Iowa we are in zone 4b.  If we set out plants in the garden on the same day in both places it is almost certain the folks in Alaska will not have anywhere near the success we will have here."

"This is the most important thing when it comes to sweet potatoes.  It is the heat units that determines success, not the number of days nor plant zone, but heat units. "

"It takes about 1200 heat units for our early varieties to reach a decent crop of usable size roots.  "

https://www.sandhillpreservation.com/sweet-potato-growing-information

Hope this helps someone. I'm definitely going to check back to this thread this winter and go for sweet potatoes next year.

Here in zone 4b, I grow sweet potatoes every year, by sprouting last year's tubers suspended in water in a jar in a sunny window. I remove the sprouts and put them in water to grow roots, and then plant them as slips.  No seeds necessary.  It's good to have loose soil fairly deep, as in a raised bed. BTW, the sweet potato vine tips, lightly steamed, are a delightful addition to salads.  After harvesting, and the requisite heat treatment, I just put the tubers in shallow cardboard trays, not touching, under the bed.  A few stringy ones dry out, but most last all winter.

Have there been any attempts to impart more cold-hardiness to sweet potatoes by way of hybridizing them with their other tuber-forming cousins of the ipomoea genus known as “manroot” - Ipomoea leptophylla and/or Ipomoea pandurata? Perhaps there are others that I’m unaware of. These species don’t seem to be easy to obtain online.

Jonathan de Revonah wrote:Have there been any attempts to impart more cold-hardiness to sweet potatoes by way of hybridizing them with their other tuber-forming cousins of the ipomoea genus known as “manroot” - Ipomoea leptophylla and/or Ipomoea pandurata? Perhaps there are others that I’m unaware of. These species don’t seem to be easy to obtain online.

I have been breeding sweet potatoes for about ten years now. You can read some about it here Reed's Sweet Potaotes although I have not kept it updated and have learned more since that original posting, so some information may be out of date or inaccurate. Ipomoea pandurata is not common but it is native to my area, so I have access.

Anyway, yes, I have had success obtaining seed from a batata x pandurata cross, but the seeds did not sprout. It could be that something like embryo rescue is needed, which I am not skilled and knowledgeable enough about to undertake. I also have successfully grafted pandurata cuttings to sweet potato roots.

I think there is possibility here and intend to take it back up at some point but for now am focusing on continuing to adapt my sweet potatoes to short season maturity and compact growth so that they can be grown by more people in more varied locals and in pots or as houseplants for folks with limited or no access to traditional gardens or farms.

Mark Reed wrote:I have been breeding sweet potatoes for about ten years now. You can read some about it here Reed's Sweet Potaotes although I have not kept it updated and have learned more since that original posting, so some information may be out of date or inaccurate. Ipomoea pandurata is not common but it is native to my area, so I have access.

Anyway, yes, I have had success obtaining seed from a batata x pandurata cross, but the seeds did not sprout. It could be that something like embryo rescue is needed, which I am not skilled and knowledgeable enough about to undertake. I also have successfully grafted pandurata cuttings to sweet potato roots.

I think there is possibility here and intend to take it back up at some point but for now am focusing on continuing to adapt my sweet potatoes to short season maturity and compact growth so that they can be grown by more people in more varied locals and in pots or as houseplants for folks with limited or no access to traditional gardens or farms.

Mr. Reed,
Thank you for your response. I’d love to hear an update on what you’ve learned in that other thread you linked to. I don’t even know what “embryo rescue” is, but it would be neat if you or someone else could successfully germinate the seeds that way. Do you have any experience with the “leptophylla” species?

-Jon