Desert Yam Ipomoea costata Grow log.

[Stillman]

I have been growing this interesting tuber out all year. I now have the opportunity to grow a moderate size trial crop out in local Brisbane, will be looking at accumulating data on yield variation of seed grown plants and slips.

Mother plant

Seedlings in the ground

future seedlings

Edited March 3, 2013 by Stillman

[Stillman]

https://sites.google.com/site/ipomoeacostatas/

A rough outline of my blog, I'll be tweaking this and improving on the core over the next few weeks.

[Stillman]

Have made a few updates to the page, plants are flowering and self seeding freely. Will be interesting to see what sort of tubers are produced.

[shortly]

Probably a longish fairly slim tuber when compared to a commercial sweet potato, it really depends on which desert sweet potato it is?

While botanists only recognize a single species the first ppl recognize at least 8 distinct different plants that science has lumped together as Ipomoea costata (quite possibly more?).

Not to say that the botanists have it wrong, but it is important to recognize that there are important subtle differences between the different populations.

[Bert&Ernie]

awesome grow log...

this grows quickly? if so it would make a good plant for if/when shit hits the fan.

have you tried the tubers yet? as in eating them... if so how are they taste wise.

[Stillman]

I still haven't had the opportunity to taste these yet, at the moment I'm just concentrating on seed for next generations grow out. But they are vigorous and prolific flowerers/ seeders so would be good as an ornamental for a dry public space or similar. I hope to get to do some cooking experiments with the tubers later in the year. What Shortly says interests me greatly and I have my eyes open currently for other sources of seed to see if there is any obvious variation in the plants. I have already noted from photos online that there is flower colour variation so would make sense that tuber production would be different too.

[gtarman]

Hmm. So this plant would be quite drought tolerant? Might be worth adding to my personal "when shit hits the fan" plant list as jwerta says!

[gtarman]

Whoa...just saw the video you posted on the other thread with the aboriginal women digging them up....that was like a proper mining excavation, in it up to their necks

Don't know if that's something I could justify to myself now thinking about it, going that far down haha.

EDIT: or do you reckon maybe the tubers are only so far down in such dry environments as the one in the video, to get closer to the water? What's your experience been growing them here in SEQ?

Edited March 28, 2013 by gtarman

[Stillman]

I'm thinking that depth is achieved in desert conditions, but I don't know. Thats what this grow is all about wether they are a viable food source, I also want to try and hybridise them out over a normal white sweet potato or at least one variety. (ie using I costata as male pollen over I batatas flower) not sure if this is actually possible. But I hope to give it a go before winter as some of my sweet potatoes are thinking about budding due to the shortening photoperiod.

[shortly]

It may also be possible that like some Dioscorea's the tuber gets pulled deeper each year? The really big deep ones being decades old.

[Stillman]

I have been talking to a seed supplier in Western Australia and they stated that the plant produces a larger heavier woody tuber which is the main but the smaller offsets are harvested and the large is left to continue. The small offsets of many can be eaten raw and are crisp to eat similar to Pachyrhizus erosus sp, will be interesting to observe wether our particular plants are palatable like this.

Also interesting news I have been discussing the plant with a geneticist who is taking some interest in the project. Not sure where this will lead but could be very interesting.

[Stillman]

http://ajcn.nutrition.org/content/45/1/98.full.pdf+html

p99 shows a break down of sugar and starch after cooking various root tubers and indigenous seeds. I costata and I batatas are both in the table.

Nutrient and vitamin comparison of uncooked orange sweet potato and uncooked Ipomoea costata

http://www.aminoz.com.au/-food-6403.html

http://www.aminoz.com.au/-food-8750.html

Edited April 12, 2013 by Stillman

[poisonshroom]

I saw heaps of them at Boulia, but none were as lush as that (its pretty dry out there - especially this year). I tried to dig out a small one, but after i got about 15cm down and the root hadnt even thickened I just tried to pull it out, but I couldnt even pull it out - Id say it has thin, deep tubers, but in a pot or in a garden in brisbane it would probably be a bit different.

The ones I saw had slightly different flowers, and smaller leaves, so they may be a different variety/species? Crossing with sweet potato sounds interesting, and would probably work.

[Stillman]

I'm trying to chase down other locality types I may be getting some seed from Northern Western Australia around Broome. If you ever get the chance to collect seed, I would be very interested in growing out a QLD variety. I think they traditionally would send runners deep into the ground in search of water and cool. I have no idea what they will do here, hopefully produce lots of Kipfler potato sized delicious tubers. lol. If I can get one of my sweet potato to flower at the same time as my I costata I will give the pollination a go. I was given a really interesting short node clumping white that crossed with a I. costata may produce something interesting.

[Micromegas]

It's funny that the first time I look at the Corroboree after moving to WA I see this thread.

Here's I. costata in the Pilbara:

Definitely a well regarded food for the aboriginal groups here, especially prior to european settlement obviously. They can grow into large bushes 5' x 5'. I've seen a few planted as ornamentals (I think, may have just been an accident but they were in a row). Apparently they come in all sizes and if you hit the ground and it makes a hollow sound there are tubers underneath. They were traditionally eaten with meat. There is a high diversity of convolvulaceae in the pilbara and all are well adapted to dry conditions. I. costata is uncommon but prominent when in flower.

I can keep an eye out for seeds if you like, fruiting up now i should think as all the flowers are gone.

[Stillman]

If you could get me some seed I would be very grateful. I can trade you what I have if your interested in growing another cultivar. What I have appears different from what is grown in Western Australia. How different probably only a geneticist could tell.

Edited April 27, 2013 by Stillman

[Micromegas]

Should be able to score some seed.

On further examination I have discovered this plant is extremely common on the coast in the pilbara. i saw some 8-9' tall with trunks maybe 15cm in diameter. Still flowering on the coast too so will keep and eye out for seed.

[Bert&Ernie]

i would say if you give them lots of water and nutes the tubers will fatten up nicely

[Stillman]

Jwerta in my climate they grow very vigorous and I would think they will produce plump little tubers. I'm interested in if these tubers can be used uncooked as well as cooked like Jicama. I contacted a Ecologist in WA and he thought that the woody "Mother" tuber is left on the plant as it is not edible over a certain size and only small tubers were removed. Children would eat the small tubers fresh so I'm assuming they must be quite palatable. And then we have other reports of the "potatoes" being backed in hot sand in the fire. So when I do finally get some tubers I will have to do some experimenting.

[Stillman]

Have made a few more updates to the blog added a few pics. The plants are still flowering heavily . I have put down nearly 80 seeds this week and have sourced 2 new seed sources. Apparently in certain regions WA I costata will show variation in flower colour. I'm hoping for something like that out of one of the seedlings. Haven't discussed this yet in the site, am waiting on an article from Uni as this is a fairly common trait within Ipomoea.

https://sites.google.com/site/ipomoeacostatas/home/sowing-the-seed

[random]

Wow, cool thread. So this is how mine is supposed to look lol.

Mine grows tiny here in Adelaide and dies down in winter only to re emerge in spring.

I can but dream of purple flowers. *sigh.

Will be keeping an eye on this thread thanks for sharing

[Stillman]

do they die right off in winter?

mine do too

[PhoenixSon]

any pictures of the tubers?

[Micromegas]

I have the seeds for this fellow now. Can send 5 packs of 10 or something. Wild Pilbara variety, same as pictured. PM address, may be long delay in posting I don't get to town too often (1 month +). Postage is free.

Pretty sure the tubers get as big as a football!

[Stillman]

Received the seed today. Very impressed with the size of the pods. I believe they are extremely different to everything I have but could just be environmental.