Friday, 16 January 2015

Amphicarpaea - Talet Like It Is.

Happy New Year. Rather than make pronouncements on the forthcoming reformation of my character and  behaviour, my 2015 New Year's resolution is to abandon the concept of New Year's resolutions altogether and just get on with things. In that spirit, I am going to spend a few weeks rodding this blog's pipework in the hope of clearing the indigestible mass of half-finished posts that have been backing up. 

Here goes.

Back in the spring, I potted on a whole load of different talet varieties and left them to their fate. That was never my intention, of course. I meant to update regularly on their comparative vigour in the hope of identifying which of the six varieties was best suited to the Cornish climate. As per usual, life seems to have impeded my lofty plans, so here I am catching up once again.

Talking of loftiness, the plants became so top heavy that they kept falling over. It was politely pointed out to me that they constituted a tripping hazard, blocking as they did the narrowest defile in our famously narrow back yard. Come August, I finally took the hint and moved them down to the plot instead. It was also high time that they were repotted into something roomier than their budgie smuggler fit 7cm pots. Their leafiness, while providing a gratifying splash of green against the wall, had also meant that they were quick to dry out; resuscitation was needed on several occasions, with the poor things gasping and close to their permanent wilt point. Welcome to my world, where horticulture and homicide collide.

Originally I had randomly arranged the different varieties into those handy stackable blue crates; now I sorted them back into their individual varieties in order to compare each in terms of growth and nodulation. For illustrative purposes I set out the varieties in ascending order of vigour, left to right. 'Saratoga Battlefield' (SB) was the least vigorous, followed by 'Yabumame', which had a distinctly chlorotic cast about it.  The most vigorous of the six was the unimaginatively named 'Original', which I obtained (I think) from a Seed Savers Exchange member. In terms of nodulation, 'Original' seemed to be ahead of the pack, although 'FVK' (Frank van Keirsbilck) and 'GN' (Gardens North) were quite well endowed too. The latter two early varieties had already begun  producing aerial chasmogamous flowers, and also sported long and leafy axillary branches close to ground level.

Amphicarpaea varieties, August 2014
Arrayed in all their glory. August 2014. 

The repotting process gave me the perfect opportunity for a mid-season peep at what was going on below the surface of the compost. Talet, as I've previously mentioned, has the nifty ability to fix nitrogen; aside from producing damn fine beans, this is one of my prime motivations for growing the plant.

Amphicarpaea bracteata Gardens North Subterranean bean and nodules, August 2014
GN. Shows a small subterranean bean developing and a fair few nodules. Oh, and an earthworm.

Amphicarpaea bracteata FVK subterranean bean and nodules. August 2014
FVK: baby bean and some nodules.

Amphicarpaea bracteata Original, profuse nodulation. August 2014
Original: massive nodules, subterranean shoots ramifying nicely. Not a bean in sight.
As I searched the yabumame root mass for nodules, it was clear these were missing, or too small to be visible with the naked eye. This might explain their stunted growth and yellowish leaves - symptoms of nitrogen deficiency. Yabumame is known to associate with its own particular strains of Bradyrhizobium bacteria in Japan, which might well have not made the trip here with the aerial seeds I received - maybe in this case absence of evidence really was evidence of absence.

I potted on the plants into 1 litre pots and tried to keep them watered, despite the protracted warm and rainless spell, which led our stream to dry up. The early flowering varieties were the first to die back, while 'Original' continued to look green and healthy for weeks longer and grew much larger than any of the other types had managed in their noticeably shorter lives. 'Saratoga Battlefield' limped on in a strange, enfeebled state, a vegetable creaking gate hanging long on its hinges; yabumame retained its jaundiced look before eventually succumbing.

Finally, in November,  even 'Original' senesced and after a few weeks' hiatus, I decided to tip out the pots and assess the yields.


Differential sensecence in Amphicarpaea bracteata August 2014
State of play. November 2014
So these are the results, with individual the contents of each pot heaped together. When hunger stalks the land, don't come to me begging for Amphicarpaea beans.


Amphicarpaea edgeworthii, total yield November 2014
Yabumame.The total yield from five pots. Back to the drawing board on this one, I think.



Amphicarpaea bracteata, GN. total yield November 2014
GN. I've seen worse. Five pots.

Amphicarpaea bracteata, FVK  total yield November 2014
FVK. Six pots.


Amphicarpaea bracteata, Original,  total yield November 2014
And finally, the clear winner, Original. Six pots.
The two pots of Saratoga Battlefield failed to produce a single bean between them. Bah!

All in all, 'Original' was by far the most productive variety, with the others lagging way behind. But I'm not entirely satisfied with my experimental method. In fact, I'm intending to run the 'experiment' again this coming season; when you hear scientists say "more research needed", this is what I think they mean. Bigger pots, more water - I owe it to them to try again.

So, those are the results - but what of their interpretation?

It could be that I potted on the early varieties way too late; they may have already been too far down the seed development process to take advantage of  extra root room, nutrients and improved water availability offered by their new homes. I seem to remember noticing something similar years ago when I potted on a previous bunch of sorely neglected talet seedlings. Legumes are known to be quite thirsty when flowering and it's possible that seed development was affected by water stress at a critical stage. Perhaps 'Original', as a result of its later flowering, took advantage of the increased space, water and nutrients to grow much bigger before seed formation was initiated; it might then have directed the more abundant products of photosynthesis downwards to create fat subterranean beans.

At least I've established that if you plant one fat Amphicarpaea bean, you might get nine back - if you use the right variety and treat the plants with a modicum of respect, horticulturally speaking. I've wanted to know this indispensable piece of information for years. It isn't isn't too bad a deal, bearing in mind that talet is, as far as I'm aware, an unimproved wild plant. The next challenge is to quadruple that yield - a forty fold increase between sowing and harvest would be something like acceptable levels for a crop plant.

The variety NS (Nova Scotia) grown from aerial seeds obtained from Edward MacDonnell produced a few small beans. I'll add it to this coming season's trial. I also have seeds of a variety from Ohio, which was kindly sent to me by James Cheshire. And seeing as I still have aerial seeds of SB left over, I guess I'll give it another chance. Come to think about it, I'm sure I have some other varieties knocking around, in the form of those indurate aerial seeds. May as well liberate them too.

Monday, 1 December 2014

Radix Alphabetical Advent Calendar

When it comes to Christmas, I'm a bit of a "bah, humbug!" sort of a bloke. I am however, a fervent believer in recycling; this extends not to just glass bottles, cardboard and milk cartons, but to previous blog posts - no point reinventing the wheel or torturing untold thousands of oca seedlings to come up with the same old tired prose. Due to a period of retrenchment (some of which has been spent with a trenching spade in hand), I haven't been able to give either our plot or this blog the attention they deserve. I'm hopeful that I will get back on track next year with more regular posts and some interesting developments. In the meantime, I offer up my Radix Alphabetical Advent Calendar, with the letters of the alphabet standing in for corresponding dates in the month. Beat that, Alan Turing!




Today is December 1st, so I give you A and the first root in the Radix lexicon: aandegopin.


P.S. I'm really worried about Christmas Eve....

Wednesday, 20 August 2014

Oca: Six Degrees of Separation


It occurred to me the other day, as I evicted yet another bunch of volunteer ocas from their chosen homes, that I've been doing this for a few years now. In fact the 2014 seedlings are the sixth generation descendants of the original oca varieties that I started with. For those who love this sort of thing, the six degrees of separation theory posits that we are all connected with one another by a chain of, at most, six intermediaries; it's an intriguing idea, the likelihood of which must surely be increasing as the internet's hyphae ramify ever further across the globe. Oh and it was also a passably good film.


Here are my ocas - the great, great, great, great grandchildren of the original varieties. They're still going strong, or at least they appear to be if the above image is to be believed.  So what effect has being Generation Six had on my charges?

But before all that, an extensive caveat. I'd like to be able to say that I've made a significant breakthrough in breeding a ravishingly beautiful, delicious, dayneutral oca. Maybe I have, but due to conflicting pressures and responsibilities, I haven't been been able to devote anything like enough time to the methodical recording of tuber yields. Something or other has got in the way every time - frost damage, voles, vine weevils, midnight ambulance rides to hospital - that kind of thing. That and the more humdrum exigencies of earning money.

And when I say breed, I really mean stand and stare at the bees and hoverflies transferring pollen as they flit from flower to flower - very relaxing. Back in the early days, I rushed to hand pollinate and bag flowers individually and I think I even went to the trouble of recording parentage, but I now no longer have time or the inclination for such niceties. If you want to look at someone who's far more methodical than me, check out Bill's blog.

Proper breeders are supposed to apply some sort of directional selection pressure to their charges. I've done very little of this, I must confess. There are two reasons: firstly I started with only a few clones and I thought it wise to conserve as much variation as possible before culling ruthlessly.
Secondly, I'm a softie at heart and don't like to institute a reign of terror on my charges - I'm not Ivan the Terrible, I'm Rhizowen the lily-livered.

So as a bystander to oca's unfolding evolution, what conclusions can I actually draw? Here are a few, off the top of my head:
  • Oca seedlings are variable - leaf, stem, and tuber colour, pubescence, height, you name it, it varies.  
  • Oca seedlings generally flower much more readily than commercially available varieties.
  • There are many more of the short and mid-styled varieties than long styled ones.
  • Oca seeds germinate fairly easily and grow quite fast; they can go from seed to seed outside in one season here in Cornwall.
  • Tubers from oca seedlings are perfectly edible and not always tiny, knobbly and misshapen.
  • Oca pods require careful management - when they pop, those seeds don't stop.
  • Corollary of the above - oca volunteers will appear where you probably don't want them.
  • Voles and other rodents love to eat oca tubers.
  • Unlike the voles, I hate harvesting oca tubers in the late autumn when our soil is cold, sticky and squelchy. 

Bearing in mind that I started with so few varieties, the overriding question is this:
have I been blissfully - inadvertently - purging oca's genetic load, thus producing an oca master race, or merely subjecting the unfortunate plant to the perils of inbreeding, spawning a clutch of web-fingered banjo players?  Deliverance from these sorts of questions at three o'clock in the morning would be very welcome.

And I know it's bad form to use the c word so early in the year, but could I have the following for Christmas, please:

A bunch of ten or more people, ocaphiles to the hilt, with whom to explore some of the possibilities of oca improvement. There are so many questions to be answered, so much more work to do.
Until such time as the above dream team materialises, I will ponder and ruminate. So here's my final question, which neither Bible scholars nor oca breeders have yet been able to answer definitively: will the mistakes of the "breeder" be visited unto the seventh generation? I'll let you know - next year.



















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