Agricultural Biodiversity Weblog
Agrobiodiversity is crops, livestock, foodways, microbes, pollinators, wild relatives …
Robert reads a writer’s mind:
He claims that “old-fashioned seeds are better at dealing with variable weather”. It is my impression that he wanted to avoid that his readers draw the conclusion that these seeds should therefore be reinstituted; which would seem logical. And so he brings it up to dismiss it, as “their use will mean less food”.
I’m not so sure.
I’ll be in Ecuador later this week, but alas nowhere near “the upriver area of the Guayas River Basin in the lowlands of southwestern Ecuador”. If I were, you know that I would be investigating arriba chocolate and beans with all the assets at my disposal. Instead I’m relying on a post at a very interesting artisanal chocolate blog, Destination Ecuador. ((Incidentally, one of the most visually challenging blogs I’ve seen in a long time; to see the text of links I have to ensure that the mouse is hovering inside the post, which turns the background grey, which makes the yellow text of the links almost visible, if I squint. Whatever their designer is using, I’ll have some.))
The problem seems to be that the Nacional bean — source of arriba chocolate — is susceptible to witches broom, and is being replaced by a variety called CCN-51, and “while a very good quality chocolate can be made from CCN-51, it requires different fermentation and post-harvest treatment from Nacional beans”. It also tastes different. Currently, however, there’s absolutely no incentive for growers or buyers to separate CCN-51 from Nacional. Arriba carries a price premium as chocolate, but the beans don’t, and as a result one could pay the premium for non-arriba chocolate. In other words, a rip-off.
The post is very informative about the forces that act on cacao biodiversity and marketing — and will make me look more carefully at any chocolate I do chance upon.
Ask how much crop diversity has been lost in the past century or so and one answer is bound to come up. “[A]pproximately 97 percent of the varieties given on the old USDA lists are now extinct. Only 3 percent have survived the last eighty years.” That’s how it appeared in the 1990 book Shattering: Food, Politics, and the loss of genetic diversity, and that’s one of the numbers that has become accepted as a scary measure of genetic erosion.
Pat Roy Mooney and Cary Fowler took a list of vegetable varieties available from US seed catalogues in 1903 and asked how many of them were still held in the USDA National Seed Storage Laboratory in 1983. Their answer: 597 out of 8045, or 3%.
Except that, as is now obvious, 597 out of 8045 is not 3%.
A new paper by Paul Heald and Susannah Chapman at the University of Georgia in the USA says that the figure is wrong, on two counts. First, there’s the little matter of a mathematical error in the original analysis, as presented in Shattering. Rather than 3% — the headline figure — the true survival rate is 7.8%. Or actually, if you count bits of a subsequent analysis by W.W. Tracy, the bloke who compiled the original 1903 list, 7.4%. Tracy noted, as many others have done before and since, that a single variety may go under more than one name. Thus of 578 garden bean varieties listed in the original study, only 185 represented distinct varieties. That difference is essentially trivial.
The other sense in which Heald and Chapman claim that the 3% (or 7.4%, or 7.8% — it really doesn’t matter) figure is wrong is that while 93% of varieties may have disappeared, they have been replaced by other varieties. In their survey of 2004 catalogues, Heald and Chapman count 7100 varieties, “only 2 percent fewer than one hundred years earlier. By this measure, consumers of seeds have seen almost no loss of overall varietal diversity”.
True, as far as it goes. But having berated Fowler and Mooney for not paying sufficient attention to multiple names, it would behoove Heald and Chapman to consider whether, among those 7100 varieties, the amount of genetic diversity is as great as it was in 1903, and whether gardeners are actually getting what they want.
This is certainly not the case in the UK and many other places in Europe, where, for example, there may be many more pea varieties available today, but none of them are the tall-growing varieties with an extended picking season that many gardeners say they would prefer. ((A fresh study of the losses associated with the UK’s National List and the EU Common Catalogue would be a good idea, come to think of it. Defra, are you listening?)) If I were a betting man, I’d bet that the same is true, though to a lesser extent, in the US.
Heald and Chapman recognize the problem of “how much diversity has been lost” in their summary:
If the meaning of diversity is linked to the survival of ancient varieties, then the lessons of the twentieth century are grim. If it refers instead to the multiplicity of present choices available to breeders, then the story is more hopeful. Perhaps the most accurate measure of diversity would be found in a comparative DNA analysis of equal random samples of old and new varieties, work that remains to be done.
Available to breeders? That’s hardly the point. In any case, I’m not sure the story is more hopeful. I agree that a DNA study would be interesting. Would it, though, change anyone’s perception?
We’ve been keeping a vague eye on Asian soybean rust ever since it was first found in US soybean fields in 2004. Truth to tell, there’s nothing like the prospect of disease-induced panic, fed by genetic uniformity, to give us a warm inner glow. So we’ve actually been a bit disappointed that as yet there have been no direct losses to soybean rust in the US. Of course, there have been economic costs associated with spraying fungicides, but that’s not the same. Today, with a teeny shiver of Schadenfreude, we bring you State has first loss to soybean rust, from the Mississippi Agricultural News.
The Evil Fruit Lord sounds off:
I have gotten more and more alarmed over the past few years at the level of hostility found among many well-educated, progressive people, to the very concept of intellectual property rights in plants (as in people owning rights to plant varieties, not plants themselves holding patents, which I’m not sure I’m cool with either). On some level I take this really personally, because it almost seems like its saying, basically, that what I do as a plant breeder has no real value. Why else would it be absolutely okay for everybody to share freely in the products of my labor?
There’s more. Should we worry about the end of plant breeding?