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.
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.
Wine from the ashes
I’ve been following the vineyards of Pompeii for quite a while, it turns out. Maybe because archaeology and wine are two of my favourite things. As part of our anniversary celebrations, here’s a recap of the story, as it has unfolded on the blog over the past ten years and more. It was prompted by a recent piece by renowned wine writer Jancis Robinson. It’s unfortunately paywalled, but I found another source.
In 2013, I wrote about the vines I encountered growing among the ruins, planted where archaeologists had found evidence of ancient vineyards: casts of vine roots and the supports on which they had grown. The idea was to reconstruct not just a Roman vineyard, but something of the agricultural landscape that disappeared when Vesuvius erupted in AD 79.
By 2016, the experiment had progressed from vines to wine, and we duly Nibbled about it. The Mastroberardino winery was using archaeological evidence, ancient texts and surviving local grape varieties to recreate aspects of Pompeian viticulture. Some of the varieties thought to have been grown in antiquity were still being cultivated around Vesuvius. The reconstructed vineyards were producing wine too, although the winemaking was sensibly not being reconstructed quite as faithfully as the viticulture.
By 2020, the vineyards had become part of the experience of Pompeii itself, with harvesting and winemaking incorporated into the archaeological site’s interpretation of its ancient gardens and agriculture.
And now, in 2026, the project is entering a new phase. A new partnership aims to expand vineyard production within Pompeii, with around 30,000 bottles a year envisaged. The scale is very different from the experimental 1,500 bottles of a decade ago, but the basic idea remains: use archaeology, surviving agricultural biodiversity and modern expertise to recover something of Pompeii’s lost viticultural heritage.
Pompeii died two thousand years ago. It’s rather wonderful that its vineyards have come back to life.
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.
Eat this ravioli
Jeremy’s latest Eat This Newsletter tackles cassava, the chestnut, rice and pears. But his coolest find is a website called Flavour Lines, that allows you to find out, among other things, how far you are from a restaurant whose sign outside advertises biryani as opposed to pulao, or ravioli as opposed to pierogi.