Saturday, 31 December 2011

Oca Harvest? Wait for It, Wait for It...

These are my main 'eating crop' of Oca...
It's more than two weeks since frost killed off the top growth, and received wisdom says now is the best time to harvest for maximum yield.
They certainly look as if they've completely snuffed it — until, that is, the top layer of dead foliage is pulled back...
The stems underneath are still green and succulent.
And below ground, roots and subterranean stems are also alive and well, continuing to build tubers...
An interesting approach would be to try to enhance this self-protecting effect by using closer plant spacing. The resulting denser foliage might provide sacrificial protection against significant frost in much the same way as a covering of horticultural fleece.
Using raised beds, earthing up, and planting under suitable taller crops are also cultural methods that may give partial frost protection.

It's a gamble to wait too long, as I found to my cost in 2009, but the weather has been mild and as a result vermin have not been digging up the tubers much. The ten-day forecast shows no imminent frost that would spoil tubers close to the surface, so on balance, I think it's worth waiting to give those tubers the maximum time to bulk up.

Friday, 30 December 2011

Oca Breeder-Packs Up for Grabs!

I'd been planning to be able to send out small packs of true Oca seed (TOS) to any interested growers, but it turns out that TOS was the preferred high-protein snack of a particular ex-mouse, and my bountiful stock has been decimated (in the modern, not the relatively trivial Roman army sense).

So I'm doing the next best thing by offering packs of tubers suitable for breeding.
These consist of a range of tuber varieties that I can guarantee from previous experience contain the necessary potential flower power and variance to allow successful pollination. You will notice my careful use of the word 'potential'; any grower will still have to provide suitable conditions, have a climate that favours flowering, spend time and care pollinating, and additionally have fair luck to obtain simultaneous flowering of dissimilar flower forms. There are more full details of the process here.

I'm offering these free (postage costs appreciated), or for swaps. Stake your claim as a comment below (first come first served), and  send me an email (obtainable from my Blogger profile) with your postal details.

By the way, if you want tubers just to grow a crop, these are not necessarily the most productive varieties, and you will do better by obtaining tried-and-tested stock from Real Seeds.

Update 13/1/12. I've just sent out the packs. Here are the tubers sorted and ready to bag...
Everybody gets about nineteen varieties, one tuber of each. I've selected them from productive healthy plants, and have chosen the cleanest, best-shaped, unbranched tubers. They are not necessarily the largest, but there are no tiddlers either. Mid styled flowerers are in the majority, but there are definitely some of the other flower types in there.
Some of you are getting other seeds etc thrown in by arrangement. They are labeled separately.

The offer is now closed. Good luck for this year Oca breeders!

Tuesday, 13 December 2011

Assessing Some New Oca Varieties

Back in spring Frank Van Keirsbilck sent me a package of tubers to supplement my usual planting. These were grown from true seed, and thus relatively untested as productive varieties. Last week the weather was still holding frost-free and perfect for continued tuberisation, but I decided that lifting them early would be a good idea. They are going to be used solely for propagation material, so hanging on for maximum tuber size would be no advantage. In fact, lifting early would be better for identifying any less day-length-sensitive individuals. Also I was impatient.

This is "NZ003", his reference variety, which he also sent me, already showing a good yield...

The plants have been rigorously neglected all season as part of their selection process. They were planted in newly cleared ground, then left unweeded, unwatered and unattended.
By the way, if anyone doubts Oca's ability to outcompete weeds, have a look at this...
... Folding back the mass of foliage reveals completely clean soil.

Anyway, as would be expected there was a lot of variation in tuber appearance...

and also in productivity. A couple of plants expired during the growing season, some produced feeble crops, while others challenged the reference variety on productivity.  I've listed all the varieties, with their crop weight on this Google doc if you want to have a look at the details.

Of note would be 026 which produced this fasciated tuber...

...and 023, very productive, and many of whos tubers are characteristically elongated and possibly fasciated. This seems very interesting, and could be a route to increased tuber size.

014 and 008 yielded beautiful clean tubers...

This last one is not one of Frank's. It's grown from slips taken from the pink striped tuber that I got from Joel Carbonnel. Strangely the tubers are neither striped nor pink, but show varied colouration, and tiny flecks of purple at the ends of some eyes. It seems as if there is some instability going on, so this could be  one for development. In any case it's a good cropper.

Meanwhile my main bed of 'eating' varieties was frosted back the other night, so they'll be ready to lift in time for Christmas.

Monday, 12 December 2011

Grand Theft Oca !

Yesterday this tray contained about 700 true Oca seeds, ...

... the culmination of a season's painstaking hand-pollination and collection. Today it contains two seeds and a few shriveled seed capsules.
They were undergoing their final drying, sitting 'safely' on a table in my work room.  I was planning to offer most of them for distribution or swapping.
Given that there were no signs of breaking and entry, and that no-one in the house has a history of sleepwalking, I was left with the possibility of...  ...Hmmm, there had been rumours of a mouse in the house for a while now.  It didn't seem very likely that it could have climbed the stairs, then the smooth painted steel table, ignored rows of farinaceous delicacies such as dried heritage peas and assorted tubers without giving them a nibble, then polishing off all those seeds in one sitting.
But there was no other possibility,  so it's a job for Little Nipper and a tahini-smeared raisin. The penalty for this crime is death!

Bingo. One rather well-fed mouse! I did seriously consider an autopsy to recover the stolen goods, but I think they would already be mouse droppings by now.

He did leave two seeds, and there are a few more from a final batch of pods yet to ripen, so I'm not quite wiped out, but this is still a massively disappointing setback,

...and another lesson learned.