Category: History

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Not too early for an early warning system for PGRFA

It turns out that if you keep a blog going long enough, you start to notice that you’re not so much writing new posts as filing updates to old ones. Looking back over two decades of the blog, a few obsessions definitely surface again and again, some healthy, others not so much. One of my main ones has been: Why do we still not have a proper early warning system for genetic erosion? You tell me if it’s healthy or not.

I first raised the question in 2009, in a post cheekily titled “Reporting threats to agrobiodiversity: A modest proposal”. I was inspired by ProMED, the disease-outbreak reporting system, and by a participatory mapping tool called pestMapper. Oh, and by Jonathan Swift.

The analogy seemed obvious. If a new pathogen appears somewhere, people can report it, someone can assess the information, and the reports can be aggregated to give us a picture of where the threat is spreading, or indeed where there are multiple threats. So why not do something similar for genetic erosion? What if losing a crop or variety in a particular place triggered the same kind of alarm as the outbreak of a new pathogen?

I even sketched out what a putative…wait, what shall we call it? The Global Agrobiodiversity Surveillance Programme — GASP for short? Yes, let’s go with that. What might GASP look like? Well, for a start: a way for people to report diversity that was disappearing, being replaced or becoming difficult to find; a system capable of dealing, somehow, with the inconvenient fact that the same variety might have several names, and similar issues; and maps and other visuals that could reveal trouble before it became irreversible.

And perhaps, I suggested, we could bundle in something contributors to the system might actually directly benefit from — like a way to get seeds, for example — so that it didn’t become another worthy database that nobody visited.

Worthy indeed. Seventeen years on, nobody has built the thing. Yet.

It has, however, been mildly gratifying, in a slightly irritating told-you-so sort of way, to see the idea keep resurfacing in other people’s work, dressed up in new technology each time.

For example, at one point I got excited about a Slow Food appeal for information on Italian vineyards under threat of destruction. Could crowdsourced alarm-raising like that be the closest thing yet to the system I had been going on about?

I don’t think I blogged about it, but there was also a project in Puglia that used Open Data Kit and Google Fusion Tables to collect information, including GPS readings and photographs, on vegetable crops at risk, then map and share it. Well, that sounds a bit familiar.

But there was kind of a fundamental problem. Before you can warn about genetic erosion, you need to know what genetic erosion looks like. And that’s not always easy.

This is where the notorious “75% of crop diversity has been lost” statistic comes in. I spent a lot of time on the blog — maybe too much time? — taking that claim apart, because we didn’t seem to know what the 75% was 75% of, or how either the starting point or the loss had been measured. We can’t build an early warning system out of made-up numbers. As I put it at the time, we should admit that we don’t know how much crop diversity has been lost overall, and go out and get better numbers. Fifteen years later, we do have some better numbers, indeed we have a review of all the numbers, I’m still “100% sure that 75% is incorrect”. But I still don’t know what headline number for the crop diversity we have lost to give to a journalist.

Yes, genetic erosion is annoyingly slippery. A farmer can stop growing a variety without losing the seed. A variety can survive in one village after disappearing from ten others. Two varieties can acquire the same name. One variety can acquire several names. A new variety can replace an old one without reducing the total number of varieties. The number of varieties can stay constant while their genetic complement and composition changes.

An example of this comes from two studies of sorghum in Ethiopia I blogged about in 2008. One found that farmers had stopped growing some varieties, but that the number of distinct variety names in the area had actually increased. Another found important varieties disappearing or becoming marginalised, while overall phenotypic diversity did not show a decline. The picture was one of “tremendous dynamism”: local losses, but also gains and turnover.

A snapshot tells you what exists. You need a time series to tell you what is changing.

And because farmers’ diversity doesn’t exist in isolation, monitoring those changes would need to connect with the processes that actually make diversity move. In other words, we shouldn’t just monitor the plants. We should monitor the systems that determine which plants get grown.

More recently, the technology for doing that has become rather tantalising. Satellite data on global human modification of ecosystems had me daydreaming yet again about a real-time version focused specifically on farming landscapes — “a perennial favourite here,” as I put it at the time, by which point I wasn’t even pretending to have an original idea anymore.

Then a Brainfood roundup mentioned remote monitoring of drought stress. If satellites can give us early warnings of drought, why shouldn’t we eventually be able to detect environmental and other changes that put crop diversity at risk? At this point, any spatial dataset that smells vaguely of early warning gets roped into the running list.

And it isn’t only satellites. Just a few weeks ago I pointed to FAO’s work on tools for capturing wild foods in dietary surveys: local inventories, market surveys, harvest calendars and identification aids. Why not adapt those methods to crop diversity? If they get widely adopted, you just need to mine the resulting information and aggregate it.

In “Listening for genetic erosion”, I wrote about a longitudinal study in which researchers returned to the same Australian livestock producers and landscapes after about fifteen years, using repeat photographs and interviews to understand what had changed. I was particularly taken by their use of “I-Poems”: first-person statements assembled from interviews to capture how people themselves experienced change. Why not do something similar with crop diversity? And feed the poems into the system.

A variety doesn’t usually go from “important” to “extinct” in a single bound. There is a story in between, and those stories may provide some of our best early warnings.

Put all this together and, after twenty years, I think I have a better idea of what GASP might actually look like. Not one giant database, and not a map with little red flashing lights, but a collection of imperfect sensors: threat reports, repeated field surveys, seed-system information, farmer interviews, spatial data, genebank records, remote sensing, all monitored in real time — presumably by Skynet — helping to identify places where the probability of important diversity being lost is increasing.

We keep half-finding the tool. Someone builds a citizen science app. Someone else maps a global index of something or other. Someone develops a new way of surveying crops from space. Someone puts a clever machine-learning model on top of a mountain of data. Someone creates a fancy dashboard.

And I write a post going: “Ooh. Is this it?”

It never quite is, and I go back to waiting for the next piece of the puzzle.

It’s like Twain said. Making predictions is always difficult, particularly about the future. Spotting genetic erosion is genuinely hard, especially before it happens. But I’m pretty sure we’ll eventually crack it. The technology will get better, the datasets will start talking to each other and someone will finally build something that truly deserves to be called GASP.

And then, of course, we’ll have a new problem.

Because knowing that crop diversity is in danger of disappearing is not the same as doing something about it. An early warning system can tell us that a landrace is becoming rare, that a landscape is changing, or that some other signal deserves attention. It can tell us where to look and perhaps even how urgent the situation is. But then someone has to decide what happens next.

Is the diversity already safely conserved somewhere? Should it be collected? Should farmers be supported to keep growing it? Does the seed system need strengthening? Is there someone who needs to be told about it? Or is this actually a perfectly normal bit of turnover that doesn’t require a conservation response at all?

In other words, once we finally solve the problem of seeing genetic erosion coming, we’ll have to get good at responding to it.

Which is probably the chief lesson of twenty years of discussing this on the blog. The problem keeps moving one step further downstream. First we needed to know what had been lost. Then we needed to know what was in danger of being lost. Now we need to work out how to turn a warning into a solution.

I’m quite looking forward to that problem, though. It seems like a healthier one to have.

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There’s gold in that thar rice story

Carolina Gold is another one of those stories that we kept coming back to, and that I now want to recap as part of our anniversary celebrations.

Before the U.S. Civil War, Carolina Gold was the dominant rice of the South Carolina Lowcountry, grown on vast plantations by enslaved Africans and generating much of Charleston’s wealth. The war, emancipation and a series of hurricanes then shattered that cruel system; commercial plantings dwindled and the last U.S. harvest is usually dated to 1927. But that wasn’t the end of the story, as it turns out.

I first wrote about the variety in 2007, asking where it had actually come from. New genetic evidence from a USDA study complicated the conventional story that it had arrived from Madagascar, pointing instead toward a West African source that fit rather better with the history of the transatlantic slave trade. Check out the string of comments on the post too.

I came back to the story in 2010, linking to an IRRI piece about how cultivation was revived in Carolina thanks to — wait for it — genebank samples. In 2016, there was an update on the revival. And then friend-of-the-blog Mike Jackson picked up the thread in 2017 with an account of “Civil War destruction … genebank redemption”.

He did us all a great service by telling the whole story in detail all in one place: the decline of rice cultivation after the Civil War, Carolina Gold’s near-disappearance, and its rescue when Savannah doctor Richard Schulze discovered seed in the USDA collection. Fourteen pounds supplied to Schulze eventually became 10,000 pounds by 1988. Mike checked Genesys and found 19 accessions carrying the Carolina Gold name, raising the next questions: how different are they, and which one was actually used for the rescue?

Along the way, I actually tasted the stuff! And Jeremy found a film featuring it.

By 2018, Carolina Gold had become the precedent for the comeback of another “lost” rice, this time in Trinidad.

For a blog about agricultural biodiversity, Carolina Gold, with its origin debates, near‑extinction, and then real‑world use of what genebanks kept alive, really is a near‑perfect subject. Can you find others in our archive?

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Not so plain vanilla

There’s a great interview on the History Extra podcast with Prof. Eric T. Jennings about his book Vanilla: The History of an Extraordinary Bean. It really is a fascinating story, and you get quite a lot of it in the half hour of the pod. If it whets your appetite, as it were, you could do worse than follow it with the global conservation strategy for the crop. One quibble, though. The source of vanilla is definitely not the only edible orchid, as anyone who has had saleb will know full well.

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Cassava, revisited, and revisited again

Cassava has been a persistent thread through this blog since the beginning. It first appears as a staple with a dark side: capable of keeping people fed, but also of causing a nasty disease under some conditions. Over time, it resurfaced repeatedly, showing how one crop can illuminate many of the key issues in agrobiodiversity conservation and use. As part of our anniversary celebrations, let’s pull some posts out and see how that might work…

An early post we called Detoxifying cassava looked at the complex ways konzo epidemics in Africa are linked to the consumption of bitter cassava. A later Nibble pointed to a very digestible (sic) introduction to cassava and cyanide. And Manihot esculenta, I presume? widened the lens historically, drawing on Dr Livingstone’s Zambesi Expedition papers to show how he understood cassava’s diversity, its promise and its danger back in the day.

Several posts over the years have looked at how well we now know and conserve the diversity of the crop. Gaps in cassava collection in Africa highlighted sounded an alarm: eastern and southern Africa seemed to be under‑represented in international genebanks. Later, More on cassava germplasm from Brazil and an earlier post compared the geographic distribution of CIAT’s genebank holdings with the that of both accessions and cultivation in Brazil, illustrating how national and international collections overlap — and where they don’t.

A post on safety duplicating germplasm collections explained the mechanics of backing up diversity, using Embrapa’s genebank as a concrete example. It also included a reference to the global cassava conservation strategy, during the development of which I got schooled on the diversity of the crop. And a paper on sources of pest resistance in cassava we included in a Brainfood showed the value of genebank holdings, identifying landraces in CIAT’s global collection with resistance to thrips, mites, and whiteflies.

This particular arc culminates in a summary of two papers on 50 years of cassava conservation at CIAT, which looks at that genebank from both ends: what went in over five decades, and what actually came out in breeding. A recent Nibble notes that cassava’s diversity is spread across multiple genebanks, and why that’s a good thing, up to a point.

Then came the TME 419 saga: Is there more than one TME 419 cassava? unpacked confusion around an IITA genebank accession number; I say TME 419, you say TMe‑419 revisited the same named clone in Nigerian fields years later. Another intricate tale centred around how some modern varieties got their resistance to post-harvest rotting. Spoiler alert: a wild relative was involved.

Genebanks, however, are not the full story. Cassava’s diversity also has to survive in farmers’ fields, where diseases constantly test its resilience. An early post, Ho hum … another deadly disease, placed cassava brown streak virus (CBSV) alongside then emerging threats like Ug99 wheat rust. CBSV was duly much in the news a few years later in 2011, and we were of course all over it, though not always one hundred percent correct in our judgements. That’s what the comments are for.

A Nibble on cassava pests questioned the crop’s “indestructible,” Rambo-like image as new problems appeared in Southeast Asia and elsewhere. An experiment on cassava degeneration, Twitter‑style focused on what to do about the widespread viral infection of cassava planting material across Africa, which badly affects performance. And a Nibbles roundup on cassava bad and good news captured an apparent mismatch between FAO worry and CGIAR optimism back in 2011. Maybe we should do an update on that, now I think about it.

Another theme has been how the crop is promoted, produced, and woven into everyday food systems today. In Cassava on a roll? I traced production ups and downs in Kenya, intrigued by seeing new products in supermarkets on my return to the country. I followed that up with The flour of Kenyan agrobiodiversity marketing, which shows cassava (with finger millet) being used to diversify staple flour, connecting conservation to real products and diets. And a Nibble on Ugandan cassava from a couple of years back highlights local innovation in value chains, if you interpret it charitably. No doubt all part of the African cassava revolution touted by Forbes in a 2023 Nibble.

I hope this roundup of our past encounters with cassava, incomplete as it inevitably is, has given you a little taste of what twenty years of this blog have been about: following stories as they unfold, picking up old threads, occasionally digging really deep, other times not deep enough. Do search for your favourite crop in the archive, and tell us what you come up with.

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Then. Now. Next.

Twenty years ago this month, the Agricultural Biodiversity Weblog was born. Typically, the first thing we wrote about was a genebank in crisis.

In October 2006, Typhoon Xangsane — known locally as Milenyo — tore through the Philippines. It damaged the National Plant Genetic Resources Laboratory, with mud everywhere. The genebank at the International Rice Research Institute (IRRI), just down the road, luckily came through largely unscathed, and IRRI offered its facilities to help the Philippine national system recover.

Reading that little post twenty years later is pretty sobering. The underlying problem hasn’t gone away. Genebanks may be grandily described as custodians of crop diversity, but they are also buildings — dependent on staff, electricity, equipment, roads and functioning institutions. A typhoon or prolonged power outage can turn a well-run collection into one that’s in trouble almost overnight.

But it’s not all bad news. Something has changed. I think the crop diversity conservation community now thinks much more explicitly about risk and recovery. Safety duplication, backup equipment and disaster preparedness are a much bigger part of the way we plan long-term conservation. The growth of the Svalbard Global Seed Vault and the fact that safety-duplication arrangements are embedded in standard operating procedures and performance metrics reflect a recognition that no genebank, however well managed, can be assumed to be permanently secure.

The Philippines story also points to something else that has become increasingly clear over the past two decades: genebank resilience is a property of a network, not just an individual institution. IRRI was able to help because it was nearby, unaffected and connected to the national system. But mutual support on that scale only works when institutions have relationships, systems for sharing material and experience and, crucially, reserves of goodwill and trust.

Since that first year, we’ve written about a daunting range of threats to agricultural biodiversity — droughts, floods, wars, political upheavals, budget cuts, pests, diseases, climate change and, inevitably, the occasional freezer failure. We’ve also written about the success stories though — the people and institutions rescuing and nurturing crop diversity, often with limited resources, putting it to work, and making the case for its importance.

A lot has changed since 2006. The technologies are fancier. The vocabulary is different. We have vastly more data, better tools and a deeper understanding of crop diversity and the systems needed to conserve it.

But some of the fundamental challenges remain stubbornly familiar.

Perhaps that’s one of the unexpected pleasures of an archive such as this blog provides. It is of course a record of what we thought was important at the time. But it is also a way of discovering that some of the problems we think are new today have been sitting there, quietly and not so quietly, for a while.

The blog has changed too, of course. In the early days, we were largely pointing to interesting things we had found. Over time, that has gradually turned into something maybe a tad more analytical. We now spend more time connecting the dots between different kinds of diversity, questioning claims that don’t quite stand up, and asking what new research actually means, especially for farmers.

So, as we celebrate twenty years of the evolution of the Agricultural Biodiversity Weblog, let’s remember that there is still much to discover — and quite a lot to rediscover. Do delve into our archive. You never know: the answer to a question you are asking today may already be there, in a discussion we had last week, or 20 years ago.

And if it’s not, we hope you at least have as much fun looking for it as we had writing about it.