Twice as much conserved, or about the same extinct?

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or 7.8% — it really doesn’t matter) figure is wrong is that while 93% of varieties may have disappeared, they have been replaced by other varieties.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?

Nibbles: Goats in Europe, Horse domestication, Food map, IITA training, Asian collaboration, Tom Wagner, Tomatoes

BBC Radio discovers African Leafy Vegetables

BBC Radio 4 has one of the longest-lived series devoted to all aspects of food: The Food Programme. Today’s broadcast looked at the importance of traditional African vegetables and fruits in nutrition, health, and offering farmers additional options for earning a better living. The programme rounded up many of the usual suspects from among our friends at Bioversity International, to very good effect. At least, that’s our opinion, and we’re sticking with it. Programme details are available at the Food Programme’s web site, which also has links that let you listen online. We’re hoping the episode will go into the archive, in which case we’ll post a link to that here. If not, well, there are other options …

Vegetable landraces of England and Wales

While lawyers and some scientists jump through hoops in their efforts to define — or at least describe — what they mean by “landrace” the Department for Environment, Food and Rural Affairs (Defra) in Britain has quietly published the results of a project entitled “Vegetable landrace inventory of England and Wales”. ((Heads should roll for the typo in the first sentence on the UK Genetic Resources for Food and Agriculture portal. But they won’t.)) We haven’t had time to even skim the full report, but judging by the Information Bulletin that accompanied it, this is a very important piece of work. The Bulletin, which is extremely readable, explains clearly the importance of landraces and why they are under threat. It outlines the sources of information, from commercial seed companies that still maintain varieties on the UK Vegetable ‘B’ List (which is also explained) through to NGOs, smaller seed companies, and individual farmers. It offers a snapshot of the landraces that have been preserved, and even valiantly attempts to answer the question “What is a landrace?”. As for another question — How many English and Welsh vegetable landraces are there? — I can do no better than to quote from the Bulletin:

The answer to this question is we currently dont know and may never be able to give a precise estimate, partly because some varieties are marketed or grown under different common names, but also because gaining access to information about who is growing landraces is hampered by a number of challenges as highlighted earlier. However, if we are to retain this national resource we need to continue to build the inventory and gradually increase our knowledge of the diversity that exists before it is lost forever.

If ever there was a universally applicable set of ideas, this is it, and it deserves to be taken up widely around the world. The Defra project has shown that it is possible to gain an accurate understanding without spurious precision, and should be a model for any organization interested in gathering information and materials. You insist you want numbers?

Four UK seedbanks are primarily responsible for the maintenance of English and Welsh vegetable landrace diversity — the Heritage Seed Library (HSL), the John Innes Centre (JIC — notable for pea and bean collections), Science and Advice for Scottish Agriculture (SASA) and Warwick HRI’s Vegetable Genebank (WHRI). Collectively, they are responsible for the maintenance of seed samples of at least 327 vegetable landraces; however, we know that the actual number is higher because at present not all landrace samples are distinguished as landraces in their database maagement systems. Work is currently in progress to ensure that all landace material is identified.

Again, that should be resonating loudly around the world.

The project examined the identity of varieties on the B list (essentially traditional varieties that were in place before the EU Common Catalogue and its registered varieties came along) and discovered that the greatest number of varieties is among the brassicas, which account for 91 of the 345 landraces listed on the B list. No great surprise there, given that outbreeding Brassica oleracea makes it possibly the easiest species in which to find some slightly different characteristics (although that also makes it one of the hardest in which to maintain all the characteristics of a variety).

One of the interesting trends that the project identified is that government genebanks are increasingly taking on the work of maintaining traditional varieties landraces when, for one reason or another, their maintainers lose interest. SASA is currently responsible for 42% of the landraces. That represents a sea-change from when I was personally directly involved with this kind of thing. Are they making the seeds available, though, to gardeners and others less interested in breeding than in simply growing the varieties? They do offer a back-up scheme, which will replace a landrace should a grower lose it for some reason, an effort that the study says should be extended to England and Wales. The report also mentions Seedy Sunday and Seedling Saturday as community-organised events to promote the exchange of diversity and the knowledge to use it, and praises grower and breeder days organized by the four main genebanks.

One thing I’d suggest to expand the range of landraces of England and Wales would be to go looking in other government and NGO genebanks, especially in ex-colonies. Emigrants invariably took their seeds with them. Some that may no longer be available in the old country have surely survived in the new and could be repatriated to the delight of all.

A final quote:

[W]hile the loss of old varieties and the irreplaceable diversity that has gone with them is of concern, we may now be in a new period of expansion of locally-based vegetable crop diversity as a result of a strong resurgence of interest in growing traditional varieties and in grower-based breeding amongst both amateur and professional growers — the formal sector needs to work with the maintainers to put in place strategies to capture this diversity, as well as nurturing the culture that is responsible for creating and maintaining it.

All in all, this is very heartening news about the state of vegetable landraces in England and Wales. But is it a bit too heartening? We’d love to hear from people there who have on-the-ground experience.

Adapting in the Pacific

The New Agriculturist is out, and, among many other things, it features an interview with my old boss at the Secretariat of the Pacific Community (SPC), Aleki Sisifa. Aleki has some very sensible things to say about adapting to climate change. Here’s an example, but read the whole thing.

We need to help farmers stay ahead of climate change, and genetic resources are going to be crucial for that. At SPC we hold the genetic resources for the Pacific region, and as part of our climate change work we are collecting varieties that can withstand conditions such as drought, salinity and water-logging.

We are working to ensure fair use and ready access of these resources and, in June 2009, our collection was placed in the Multilateral System of the International Treaty on Plant Genetic Resources for Food and Agriculture. Around the same time, agreement was made with the Global Crop Diversity Trust to safeguard our collection of taro and yam, two of our most important food crops in this region.