- Frafra potato is having a moment: an indigenous West African tuber, adored locally and mostly ignored by science, out looking for its big commercial break.
- Speaking of breakthroughs, this bus driver found his own, swapping the wheel for seed multiplication and turning five acres into a livelihood, proof that sometimes the missing link in a seed system is just someone willing to do the unglamorous middle bit well.
- Which is, per Farming First, precisely Africa’s problem at scale: only 2.5% of smallholder seed in Sub-Saharan Africa comes from formal seed companies, so a few million more bus-driver-style multipliers wouldn’t hurt.
- Meanwhile in the Balearics, the opposite direction of travel: the local seed bank is expanding to rescue tomatoes, onions and broad beans, and is looking for farmers willing to take them back.
- Indigenous fruit trees in Malawi turn out to fight malnutrition and biodiversity loss at once. Happy coincidence?
- Getting those trees into the ground well needs the same unglamorous groundwork as any good crop seed system: a Mongabay commentary argues that restoration campaigns skipping Indigenous and local seed knowledge are optimising for trees planted, not trees that survive.
- And once you’ve got the saplings in the ground, you might want to monitor how they’re doing: enter Bruno, a pushcart rigged with mobile phones that can collect field data. And not just for breeders.
- Finally, proof that not all genetic-resource hunting needs a genebank: Brussels brewers are getting people to comb the city for wild yeast, because the raw materials for a proper lambic turns is hanging around in urban trees.
Brainfood: Tree conservation from assisted migration to cryo
- The potential effect of megafaunal extinctions on modern conservation of horse chestnut Aesculus hippocastanum. The extinction of large seed-dispersing mammals (i.e. elephants) may explain why horse chestnut failed to recolonise Europe after the last ice age, pointing to assisted migration as a conservation option.
- Mapping melliferous tree species in Kenya via one-class classification with hyperspectral unsupervised domain adaptation. Hyperspectral remote imagery and fancy maths can accurately identify and locate Kenya’s honey trees, potentially supporting both conservation and beekeeping. Brave new world. Elephants not involved.
- Everyday agroecologies in the Mixteca Alta, Mexico: gendered knowledge and practices in homegarden agroecosystem management. Women’s knowledge helps sustain homegardens as reservoirs of agrobiodiversity and climate-adaptation spaces, embedding many interesting wild and cultivated trees, along with much else, in wider systems of knowledge and resource management.
- Integrative DNA barcoding and multimethod species delimitation reveal marker performance in the genus Ficus L. (Moraceae). Takes on the old taxonomic problem of where one fig species ends and another begins. Ficus is an especially resonant group for today’s tree-themed roundup: taxonomically challenging, ecologically consequential, economically and culturally important, tied to famously specialised pollination relationships. “Integrative” means the usefulness of a DNA marker must be tested against other evidence and against the particular boundaries one is trying to recognise.
- Chloroplast phylogeographic analysis guides the source tracing and conservation strategies of the endangered Magnolia kwangsiensis Moving down one biodiversity level, mapping maternal genetic structure helps identify appropriate seed sources for conservation and restoration, rather than treating all populations as genetically equivalent. Next comes feeding the seeds to passing elephants.
- Development of a simple and easily interpretable cultivar identification system using 18 insertion/deletion (InDel) markers in Japanese pummelo (Citrus maxima). Really simple markers can identify Japanese pummelo cultivars, and even reveal clues about their parentage.
- К 100-летию отдела генетических ресурсов плодовых культур ВИР. (On the 100th Anniversary of the Fruit Crop Genetic Resources Department of VIR). A century-long institutional case study in tree (ok, and shrub) conservation at scale: some 19,000 fruit, nut and berry accessions now held in field genebanks across ten Russian field stations, each sited in the climate zone that suits what it conserves.
- Cryopreservation strategies for trees: Leveraging organogenesis and somatic embryogenesis for effective conservation. Combining ultra-low-temperature storage with making shoots or roots from an explant tissue and making embryo-like structures from non-reproductive cells offers ways to emulate seeds when the real things cannot be easily stored in the usual way, field genebanks cannot be guaranteed to last 100 years, and there are no elephants around.
When farming worlds collide
When we think about crops moving around the world — and we often do around here — the Columbian Exchange is the canonical example, and why not? The transatlantic movement of maize, potatoes, tomatoes, cassava, and chili peppers to Europe, Africa and Asia, and of wheat, sugar, coffee, and livestock to the Americas, was profoundly transformative. It reshaped global agriculture and diets more dramatically than any single event in human history after the Neolithic.
But similar, if maybe smaller-scale, “exchanges” happened long before 1492. The deep history of agriculture features several ancient “mixing bowls,” let’s call them, where traditions from different geographic origins met and interacted in fascinating ways. These are natural experiments in how new crops become part of diversified farming systems, and I think they can be especially useful in thinking about “opportunity crops.”
Usually, by opportunity crops we mean local or regional crops that were perhaps once more important, and then declined. Or, even if they were never very important, they could still do more, given the chance, whether for diets or incomes, or resilience: indigenous fruits and vegetables, forgotten grains, traditional tubers, you know the kind of thing. Their local resurgence is a crucial path to diversification, for sure. But those agricultural mixing bowls suggest that crops from the outside also have a role in enriching local farming.
There are no opportunity crops
At least, not in any biological sense.
No plant is born an “opportunity crop.” It becomes one when somebody finds a way to make its particular combination of characteristics valuable, in a particular context.
That does not make the term useless. It can be a convenient way to describe crops whose potential seems underdeveloped, or whose qualities come to matter more under changing climates, diets and markets. But the phrase can also mislead. It can make opportunity sound like something that resides in a species or variety.
But consider the Georgia peach. Today, the US state of Georgia is almost synonymous with peaches, at least to Americans. But it was not always so. The fruit arrived in North America with the Spanish in the mid-1500s1, spreading rapidly through the Southeast from seed, almost weed-like. For generations, peaches were mostly a local resource, made into pies, fed to livestock or turned into brandy.
As William Thomas Okie recounts in a recent piece in Smithsonian Magazine, it took deliberate selection and breeding, better production practices, research, transport and access to distant markets to turn the peach into a commercial industry — and eventually the icon it is today.
The lesson is not that peaches are in any way special. It’s almost the opposite.
When we talk about “opportunity crops” in the Global South, we often seem to be looking for crops that already possess a particular combination of characteristics: nutritious, climate resilient, locally adapted, culturally valued and perhaps capable of generating income.
But why should opportunity be an intrinsic property of a crop?
All crops contain genetic variation. Some of that variation may become valuable because of a new breeding objective, a new processing technology, a change in consumer preferences, a new market or simply changing environmental conditions.
We cannot know all of those opportunities in advance. Nobody knew in advance that the peach presented an opportunity in the American South.
The Georgia peach story also reminds us that an opportunity is not necessarily an opportunity for all. That industry developed within a society shaped by slavery and racial inequality, and its commercial success depended on agricultural labourers who didn’t much share in the value they helped create. If a neglected African crop becomes commercially valuable, who controls the breeding, seed, processing and markets. Who gets paid?
This does not mean that every crop deserves the same investment. Resources are limited, and choices have to be made. But it does suggest that the most useful question may not be “Which crops are opportunity crops?” but rather “Where is there diversity from which new opportunities could be created?”
This is why we need genebanks. They preserve options, not predictions. A crop or variety that looks unremarkable today may contain a characteristic that becomes valuable tomorrow.
Perhaps, then, we should stop thinking of opportunity crops as a special category of crops, waiting to be discovered. The real opportunity lies in maintaining enough diversity across all crops to keep our options open for whatever the future may bring.
What is maize good for?
Two pieces of work on maize I recently came across are unconnected as to aim and place, but nevertheless make for an interesting combined story. One asks how far maize yield can actually be pushed by the environment; the other, how far we should define its success by yield anyway.
The first study is a systematic analysis of more than 14,000 yield observations across sub-Saharan Africa. It finds that maize generally produces more grain than pearl millet, even in relatively dry environments. That complicates the familiar story that the traditional, hardy millet simply “beats” the relative newcomer, more pernickety maize in marginal conditions. And you know how much we love complicating a conventional story here.
But, heaping complication upon complication, there is a catch: maize’s performance is much less consistent. Its high yields are associated in part with hybrids and the input packages that accompany them, whereas pearl millet produces yields that are lower, sure, but also more stable. And grain weight leaves quite a lot out anyway: millet brings higher levels of iron, zinc and protein. The authors therefore argue that comparing cereal crops by yield alone can obscure their actual advantage to farmers, under their own conditions. That’s been a recurrent theme with us here, actually, come to think of it.
The Philippine experience described in the second study makes a similar point from the farmer’s side of the equation. In Laguna, farmers evaluating maize varieties did not rank them simply by how many tonnes they produced. They cared about taste, culinary uses, familiarity, nutritional value, market prospects and climate resilience as well as yield. The authors recommend involving farmers in local testing and breeding efforts, rather than treating them as merely the final recipients of fancy new varieties.
Put together, the two stories suggest a useful way of thinking about the potential, and the limits, of maize — and indeed any other crop for that matter. Maize is remarkably productive and adaptable, and the evidence does not support writing it off completely in dry conditions. But its apparent superiority depends strongly on what we measure, where we grow it, and what we put into the system.
A tonne of maize produced with expensive hybrid seed and inputs is not necessarily a better outcome than a more modest but more dependable harvest of millet; nor is a variety that comes out on top in a yield trial necessarily the variety a farmer most wants to eat, sell or grow next year.
Maize can do a great deal, but its real potential emerges only when yield is considered alongside stability, inputs, nutrition, markets and, ultimately, what the people growing and consuming it really want.
Sometimes, in some places, even maize can be an opportunity crop. Other times, not so much. And that goes for millet too.