I've just noticed that a couple of my oca seedlings are starting to flower. I'll have to get up close and personal to see how they're hanging with regards to stigmas and stamens. This would at least allow a slightly more systematic approach to breeding new varieties, although the serendipitous production of seeds and the subsequent rearing of the seedlings has been entertaining and educational in itself. What's really important is a reliable way to get lots of different varieties to flower simultaneously so we can maximize the potential for fortuitous genetic recombination. When I say "we", I mean you too.
I have tried stem girdling as a way of stimulating flowering in the past - all that happened was I got a lot of extra cuttings - the first bit of windy weather snapped the brittle stems. I have seen references to pruning being used to encourage flowering, but that seems to consist of little more than lopping the top off the main stem to encourage side shoots. My plants have plenty of those already.
Another possibility would be artificially shortening day length - a bucket over an individual plant would probably suffice, but I've never yet managed to do this systematically enough to produce good results. Even if it didn't stimulate flowering, it might well encourage tuber development a bit earlier than usual. A more sophisticated approach would be to use gibberellin, but getting the dose right could be tricky.
Anyway, back to my seedlings. There are distinct differences in vigour, leaf hairiness, anthocyanin on the petiole and probably a whole host of other characteristics I'm not aware of. The simple, yet strangely tedious truth is that I really ought to do some proper characterisation of them. I should power up the Radix oca database and record in exhaustive detail the general appearance, flower morph, tuber size and colour, yield, taste and disease resistance of each variety in my possession. Somewhere, buried in a cardboard box, is a list of oca descriptors from CIP which I could use to assist me in this work. Maybe if I make a public declaration of intent on this blog, I will be shamed into action. So I'd better not then.
Post Script: a few days of wet and windy weather (summer!) have washed away the first flowers, but I notice more buds lurking in the leaf axils. I shall keep an eye out for the next batch and take some pictures in the glorious summer sunshine that will soon, Insha'Allah, illuminate the land once more.