Thursday, 29 July 2010

Getting High with Sweetpotato Seeds

Now here's something you don't see very often - sweetpotato seeds. Not for illicit ignition and inhalation as was reportedly the fate of other morning glory seeds when I was at school. And not just any sweetpotato seeds, mind you. These are from Papua New Guinea. From the Eastern Highlands region, where they grow in diverse profusion despite the cool climate. Exciting - especially when you read the accompanying note about growing conditions: "long misty mornings and cold nights". That sounds about right.

There is the promise of more seeds at some stage. Excellent. One thing you can be sure of - I won't be smoking any of them, they're far too precious.

Imagine my surprise when they turned up, all unexpected. Last year, at about this time (which is close to my birthday), I issued the Universe a challenge - provide me with the seeds of high altitude New Guinea sweetpotatoes, among several other things. Well, it would be churlish to complain about the speed of the service and the fact that a few items on that list are still outstanding. But I've always been a bit churlish, so thanks, Universe, but what about some Ipomoea minuta, Apios fortunei and true ulluco seed of the day-neutral persuasion?

Thursday, 22 July 2010

Blight is Busting Out All Over

The recent prolonged spell of wet weather has meant that potato blight has devastated our potatoes and outdoor tomatoes. Again. It's singularly dispiriting to look at the mark of the beast all over that formerly healthy foliage and it's hard not to feel that some sort of divine retribution is involved. Since this picture was taken, things have got a whole lot worse. I could wax lyrical about suppurating sores, expanding lesions and stem collapse, but I'll spare you the gory details.

Cornwall does seem to be an evolving centre for Phytophthora diversity - I suppose our moist, mild and humid climate is responsible for that. Potato blight (Phytophthora infestans) has been around for a long time, although it has recently undergone rapid evolution due to the rampant coupling of the original A1 strain with A2, which arrived in 1978. This unholy union produces oodles of oospores, the tough walled, overwintering products of sexual reproduction. These germinate to give all sorts of charming new variants, ready to attack previously "blight resistant" varieties. I'm hoping that Tom Wagner and his worldwide web of collaborators will be able to develop some new varieties of both potatoes and tomatoes to deal with this challenge.

We also have Phytophthora ramorum, the ominously-named Sudden Oak Death, which, ironically, has mainly been killing rhododendrons. Lately it has jumped hosts and is now attacking Japanese larch (Larix kaempferi), an important forestry tree hereabouts. On a recent train ride along the edge of Bodmin Moor, I could easily see the damage - trees with brown crowns, releasing millions of highly infective spores. Some 250 hectares of Japanese larch are due to be felled in this region, in an attempt to contain the spread of the disease. If it's anything like potato blight, I expect that it's already too late. And let's not forget - we have our very own Cornish Phytophthora - P. kernoviae, first described from the Truro area in 2003. Its favorite host is, at present, the rhododendron, which is plentiful, in both the wild form (Rhododendron ponticum) and numerous ornamental varieties. It also likes beech and magnolias. Owners of historic Cornish gardens must be quaking in their boots.

The Peruvian Purple potatoes were the first to go - we'll lift them a bit later. I was more interested in trying Rote Emma. This is a pink-skinned, pink fleshed variety that was given to me by Ulrike Paradine. I know very little about it, other than it tastes delicious. Unfortunately the slugs seem to agree, so an early harvest might not be such a bad thing. Thanks, Phytophthora.

Here are some Rote Emmas fresh out of the ground. Blight-blasted foliage removed for the sake of propriety.

Here they are after a bit of a wash, with a cut tuber to show the flesh colour. I expect they're full of healthy antioxidants.

And last but not least, boiled, with a pat of artery-clogging Cornish butter. Comfort eating at a time of crisis.

Friday, 16 July 2010

Mecha-mecks are Doing Swell

I wouldn't go quite that far, but swelling is what they're doing, as this shot shows. Top growth has been disappointingly minimal, but it seems like they are concentrating their energies into developing their storage roots; these appear to be a combination of swollen hypocotyls as well as roots proper. Perhaps due to the limited rooting space, they're now pushing up, rather than down. I suppose this should be my cue that it's time to pot them on. I've avoided this so far, partially through laziness, but also because I've read that they resent root disturbance.

I was hoping for bindweed type growth to issue forth from the top of the plants like Silly String and wrap itself around any available object; what I've got so far is shown to the left. It could be, as I suspected, that it's not really warm enough here for that kind of exuberance. Or, another possibility - they're storing up energy for a more impressive performance next year. One can live in hope. In either case, it doesn't seem polite at this stage to take a bite out of any of them - not just yet. I am tempted, though. In the name of scientific enquiry, you understand.

Monday, 12 July 2010

July Is Busting Out All Over

Starting to, anyway. By which I mean that the first oca flowers of the season are here - on 09081, one of the seedlings I raised from from plant 0908. It does sometimes feel like a bit of a merry-go-round, hence my scrap-salvage adaptation of the old song title from Carousel, a musical whose plot still perplexes me. I'm dizzied by trying to manage the ever-expanding oca brood and everything else that life demands. Or, switch that rotating axis from vertical to horizontal and you have another take on it - an oca treadmill. Enough free association already - let's get back to the matter in hand.

The parent 0908 produced a good yield of tubers (about 240 grams after frost wastage, according to my records and the tubers were a reasonable size). It was a big and vigorous plant, with a short styled flower.

Looking at the flower of 09081 more closely, I do feel a little confused; it doesn't seem to conform to the three morph theory of oca flowers. The anthers and styles appear to be clustered together, more or less, at the top, without the usual segregation into distinct whorls. So has oca pulled a flanker yet again, after my strenuous efforts to understand floral inheritance in this wild child of the Andes? According to my CIP descriptors and the handy illustration contained therein, it most resembles number 4, the semi-homostylous form, a slight variation on the theme of the bog standard mid-styled morph. At least I think it does.
09081 has inherited neither the same floral morph, nor the same axillary markings as its parent - below, on the left is 0908, with 09081 on the right. I wonder what other characteristics have/haven't been inherited by the daughter plant?

There are others not far behind in this floral dance. It will soon be time to get out there and assist in pollination duties. Here's a view along the bed. There are considerable differences in both vigour and habit of growth between individuals, which although not obvious in this shot, can be seen as you walk along the rows.

And here's a sneak preview of within-plot diversity, including some self-sown Amphicarpaea bracteata plants twining around the bamboo canes. Differences between the ocas can be seen quite clearly.

The mild and humid weather has encouraged the growth of many plants, but, right on cue, blight has appeared on the purple potatoes. Drat, drat and double drat. Don't think I can realistically hope for any outdoor tomatoes this year.

No blight on the ocas, but I did find this fella munching through one of the oca seedlings. Most likely it's the caterpillar of an angle shades moth, Plogophora meticulosa, a generalist feeder found on a wide range of host plants. I'd prefer it to indulge its catholic tastes elsewhere and leave my ocas alone. Result? A maiden flight before metamorphosis into a nearby patch of mixed vegetation.

Thursday, 1 July 2010

Another Oca Shocker

"Lucky" is not alone. I was weeding by the edge of a bed yesterday, when I noticed some more oca seedlings. Several more. So it seems that oca seeds can overwinter, then germinate and develop quite well here. I find this revelation rather comforting, as it suggests that it might be possible to sow seeds directly outside (I'm thinking by the thousand) and select for early germination and tough, fast growth.

I have to admit that all these seedlings look healthier than my own ones did at a similar age. I'm guessing that they won't make anywhere near as much growth as their cosseted counterparts before winter, however. Maybe that doesn't matter. It may still be possible to select outstanding individuals from the mob. Alternatively, it might be possible to use some sort of cloche system to warm the soil and get them started earlier, then remove it before they get spindly (as all my indoor seedlings did). I could try it next year.

These country cousins seem to have cobby conformation and a sanguine outlook on life. I kind of like the idea of a self-sowing Inca root crop that inveigles its way into your existing crops. Presumably new oca varieties appear this way in their Andean highland home. You've heard of TPS (True Potato Seed - if not - look here). May I introduce the latest in oca acclimatization technology - TOS - True Oca Seed. Once I've figured out how to get large crops of seeds on a regular basis, I'll be looking for a bunch of fellow TOSsers to help grow and select them. RSVP.

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