Oca: Seedling Progress and 2014 Plans

We’re growing a lot of oca in 2014!  Plans are always subject to change, particularly where nature is involved, but the current incarnation of Oca Plan 2014 calls for 1080 plants.  530 of those plants will be established varieties, although we’re growing a lot more of those this year – 66 varieties at last count.  I think we’ll have sufficient quantities of about 25 of them for the seed shop this year – maybe as many as 40 if we have a really good year.

Some of the larger seedlings wintering over from 2013
At the top of the photo, you can see many other small
seedlings from the same sowing

The remaining 550 plants will be seedlings.  We have about 50 that we’re carrying over from last year.  On top of that, we sowed 2400 seeds indoors in late December.  I expect about 60% germination.  We’ll keep the top third of those that germinate for growing out in the field this year.  From there, my current intention is to grow one quarter (about 125) all the way to normal harvest time along with the 50 carryovers, which will leave us with 175 new ocas to look at.  The remaining 375 will be dug early – about October 15 – to look for evidence of early tuberization. Odds are pretty good that we won’t find any, but we couldn’t manage further grow-outs of that many seedlings anyway.

2400 oca seedlings are pretty compact at first.  We have them growing in 76 four inch pots, which should carry them through the next six weeks.  After that, it will become a bit more challenging, but by late Febrary we should be able to put them in our unheated storage building without much risk of freezing, so we can give them individual pots at that point.  Oca seedlings don’t seem to be too bothered by crowding and are very forgiving when it comes to transplantation stress.

Oca seedlings at 3 weeks

We only grew out about 200 seeds in 2013, so this much larger sowing has given us a chance to make some observations with a more informative sample size.  We’ve found overall 35% germination at 3 weeks, which is very close (just a bit higher) than what we experienced last year.  I expect that we’ll be at 50% by six weeks and 60% by eight weeks.  There are significant differences in germination rate correlated with the female parent of the cross.  Bolivian Red crosses have the highest early germination at 64% at 3 weeks.  Blush is 59%, Hopin is 52%, and Sunset 48%.  It declines pretty precipitously from there, with Amarillo at 36%, Orange at 31%, Mexican Red at 26%, BK08516.8 at 22%, Twilight at 12%, White at 4%, and Golden at 0%.  The best germination at 3 weeks (81%) was found in the cross Bolivian Red x Twilight (which is also interesting because the germination of all crosses with Twilight as the female parent has been very poor.)

We’ve also gotten surprisingly good germination from some of the difficult crosses, which makes me really happy.  It was very challenging to get flowers from Amarillo, but we ended up getting seeds from three different crosses and got some seedlings from each of them.  A single flower from the OAEC Pink variety produced eight seeds and has given us four seedlings.  The many mid-styled x mid-styled crosses that frustratingly set very few seeds have all germinated in numbers comparable to short x mid crosses, which is much better than I expected.

Having this many seedlings has also given us a chance to see more variations in form.  I’ve spotted a couple polycotyledonous (more than two cotyledons) seedlings.  In most plants, that is nothing to get excited about, since the difference tends to be limited to the cotyledons, but sometimes you get a plant that goes on to develop a different leaf arrangement, so we’ll keep an eye on those.  I’ve seen a lot of variation in early stem color and cotyledon size.  Some seedlings grow very large cotyledons before sending up the first true leaves, while others spring through the cotyledon stage to send up true leaves as quickly as possible.  In the picture to the right, all three seedlings are just revealing their first true leaves, but one has formed cotyledons twice the size of the others.

One thing that has been extremely consistent is the color of the cotyledons.  They have all been green.  So, it caught my attention yesterday when I spotted a seedling that has popped up with purple cotyledons.  I’ll be keeping an eye on it.  (Sorry for the low quality picture – it is not easy to get tiny oca seedlings and cheap cameras to cooperate.  There are two seedlings in the circle – one with the customary green cotyledons and the purple one.  You’ll have to enlarge the image to get much out of it.

Along with the seedlings, we have a lot of cuttings growing right now.  When I harvested tubers from the 2013 seedlings, I cut up the plants so that we could grow them out in greater numbers this year.  Two of those seedlings seem promising and we will be growing out about 20 plants of each, both from tubers and cuttings.

The seedlings have illustrated an interesting feature of oca, which is that new growth tends to be very red when grown under artifical light.  In general, ocas seem to have redder foliage in juvenile stages, but this seems really pronounced under lights.  Almost all of my oca seedling plants start out with green foliage, but become redder over time until I transplant them or move the pots outdoors.  You can really see the difference in this cutting, with the older green leaves that formed while it lived outdoors and the new red foliage that has come in while it has been growing under lights.

Anyway, that is the state of the oca.  I trust that there will be many more new and interesting things to observe as the year progresses.  Later this week when I hope that I will be able to get a suitable picture, I will have some interesting ulluco news to report as well.

By the way, we distributed over 3000 oca seeds within North America in 2013 and another 1800 to Europe, New Zealand, and Australia.  There could be a lot of new oca varieties by the end of 2014!

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