Monday, 11 March 2013

True Oca Seed — Germination and Selection

Last year I saved a small amount of true oca seed, survivors of the mouse incident, painstakingly collected from plants in my old allotments before my house move. Despite domestic chaos, in February I set up the heated propagator on a window ledge, and sowed the precious few within.
Then I waited ... and waited. And nothing happened.
After a month I was resigned to the idea that this was just going to be another failure, and so evicted the seed tray from the propagator to make way for more reliable crops.
It was dumped in the greenhouse for another few weeks before it started to get in the way there too, and was ruthlessly removed to the 'slow death table', an outdoor surface reserved for horticultural failures which should really be flung, ... usually the last stop before the compost bins.
But in early July, I noticed some characteristic greenery in the tray (right of centre below)....
... yup. Oca seedlings fully five months after sowing! I can only speculate that the seed requires high light levels, and/or has a long dormancy period. Anyway, I swiftly potted them up, and resumed their basic care.

In the search for day-length neutral varieties of oca, some sort of early selection is needed to cull the no-hopers, and my chosen method is simply to examine roots at the start of October, and discard any plants that show no sign of tubers. This may seem hard, and perhaps risks loosing certain desirable traits (such as floriferousness or taste), but if I don't do it I'm going to end up with massive numbers of plants to manage and record.

Here are my seedlings undergoing the October test...
... notice the small tubers on the left plant, which means it will be planted out in the lazy beds.

... and some other varieties grown in Root trainers get the same treatment ...

So I would now like to introduce what will hopefully be the first of a long line of home-brewed oca varieties...
... to be known for now as IOW 2 (that's Isle of Wight 2, after its birthplace) ... by far the best performer from my seedlings, producing a respectable yield straight from seed in one season. This year I can grow it conventionally from tubers to give a fair comparison with established varieties.

They'll have to wait a bit though; it's -2°C and snowing outside.

9 comments:

  1. Excellent work, Ian. Your ruthlessness is much to be admired. If enough people grow enough seedlings, a day-neutral variety will turn up. I noticed that the outdoor seedlings came up much later last year than in previous seasons - I can only assume they didn't care much for the weather. can't blame them.

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    1. Hi Rhizowen, yes, I'm trying to forget last year; not much went to plan. Mind you I'm glad I didn't go ahead with my original idea of using sunken beds to avoid drought. That was one good decision.

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  2. Very cool. I am hoping to produce some oca seed this year, so I am following your developments studiously.

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    1. Thanks Bill. Good luck with your efforts. From your blog it looks like you have enough varieties to obtain seed, but so much is down to chance and the weather.

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  3. thanks for the update. I was wondering where this project was going.

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  4. Great Doku Ian, and I feel a little bit tiered, never harvest seed in germany.
    Look like a very good Varieties:-)

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    1. Don't give up. I think seed forms more often than is thought, but does not always get noticed.

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  5. Got to agree with "seed forms more often than is thought". Last year's oca bed was well dug over, but I'm still finding (& weeding) tuber-free volunteers coming through.

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