Saturday, 16 October 2010

What's that Other Andean Tuber...

...a bit like Oca, only dull brown, mundane, and suffers from lots of diseases. What's it called ... oh yeah -  the potato.

Straight away, I had better apologise to spud fans for that admittedly gross generalisation, and I do have to acknowledge a certain appreciation for Solanum tuberosum ordinaire when it arrives on my plate, even when it is dull brown, and agrochemical dependant.
But if we look beyond the few varieties grown en-mass for the supermarkets, it is actually a hugely interesting, diverse, and delicious food plant. For example...
Harvested 7th October
...these are the last of my spuds to be lifted - the late maincrop black-skinned and purple-fleshed Négresse. I've maintained this variety for a few years now, but there's very little information available about it. Some sources say it is the same as Vitelotte, and was brought from Peru to France in 1815. Cats tripe has photos of Vitelotte here and I'm not convinced they are the same. Vitelotte is said to flower rarely, which is not my experience with Negresse. Vitelotte shows white marbling through the purple flesh in all photos I have seen, whereas my Negresse is purple throughout, thus:

A US potato list gives it a mention here and surprisingly suggests that it is not Solanum tuberosum, but Solanum ajanhuiri.
So in summary, it's exotic, mysterious, beautiful and day-length sensitive (another way of saying 'late maincrop'!), all of which would be a fair description of Oca.

Thanks to Paul Coleman, potato breeder, for letting me try the next three varieties. All have something in common; they are crosses between Solanum tuberosum, and Solanum phureja.
The first, Mayan Gold (left below)...
... is commercially available and well enough known as a gourmet potato.
The second, nicknamed "Mr Nutty"  (centre) is more interesting, and cannot hide its tuberosum parent, Pink Fir Apple. It tastes fantastic! Here's another shot showing its graduated skin colour and primative good looks.

And finally a bright yellow-fleshed main crop which makes great buttery mash.
I've had universal unprompted positive feedback on the taste of all three varieties, so I'll be saving for next season.

Mayan Gold, harvested 22nd August.
And what's this all got to do with Oca? Not too much, except it's worth asking why the potato is a world nutritional mainstay, while Oca is almost unknown, when both started out alongside each other, with similar characteristics and limitations. Why did the potato benefit from selection and breeding in Europe, while Oca plodded along in Andean fields and terraces? It seems unlikely that the Conquistadors only picked up the plain-looking potatoes from markets when they were right next to spectacularly colourful Oca tubers. Maybe the tubers that looked best, and needed no cooking got scoffed by the ship's crew on the way home to Spain, leaving only the potatoes. That's my theory.

Anyway, Oca has some catching up to do.


  1. Sex must surely be at the root of the problem: obligate outcrossing with three stylar morphs and tiny seeds in piddling pods that explode unpredictably - breeding is never going to be as easy as picking nice big potato fruits and sowing the relatively much bigger seeds. Still, we won't let some minor difficulties like those prevent oca from taking its rightful place in our gardens.

  2. The Negresse look exactly like Congo and from the description they sound remarkably similar, mine were ridiculously late too.... this year they're going in the greenhouse in pots in late February if I can get the soil-warming sorted out.... I don't think either of them are Vitelotte as I grew them side-by side this year and the foliage does look different though it's a bit hard to describe how.... it was certainly obvious that the two weren't the same though.
    Any idea where I could get some of those PFA hybrids from?... always interested in anything developed from my favourite spud :-)

  3. Hi Rhizowen. Meanwhile we shall eat potatoes.
    Hi Chris, Interesting that you confirm Vitelotte is different. As for Congo/Negresse being the same, I cannot say. They do look similar, and could be different selections from the same original variety. The Congos I've seen had white marbling on the flesh, but this could be caused by cultural differences.
    As for starting them early, I don't think that will actually help to get an earlier crop; I think they are truly day-length sensitive, and need shortening days to tuberise (but I could be wrong, so it might be worth giving it a go).
    I can't promise anything on the PFA x phureja, but will make enquiries.

  4. Hello. I'm degzing at yahoo

    I've been asked to plan community gardens, next year and am having a terrible time finding brighter-colored Andean root crops in the US.

    I would be interested in making a purchase, either from you, or from a retailer who presently keeps them in stock.

    Thanks for your consideration.

  5. Hi Anonymous. I'd like to help, but given the import restrictions in the US, It's best to source them over there. Try Peace Seeds, and there are some other supliers. In any case you will have to wait 'till winter when tubers become available. Good luck with the search.