- A 2023 study was recently awarded the Cozzarelli Prize from the Proceedings of the National Academy of Sciences for its work identifying “forgotten” food crops in sub-Saharan Africa that may be more resilient to climate change than the region’s current staple crops: maize, rice, cassava and yams.
- The study found that West Africa and Central Africa would experience the greatest decline in suitability for current staple crops by 2070, with maize being the most vulnerable staple crop.
- In addition to identifying 52 food crops that are likely to be better suited to the region’s future climate and have greater nutritional value than staple crops, these researchers have also already succeeded in introducing some of the overlooked crops to local communities.
For many people in Sub-Saharan Africa, Cleome-gyandrabetter known as the spider plant, is not a food: it’s a weed. The spider plant is a tall, lanky plant with stars of almond-shaped leaves and clusters of white flowers. It is most common in countries in southern and eastern Africa. Until recently, however, it has been a ‘forgotten’ crop: occasionally eaten by rural people for subsistence, but largely neglected in larger food systems. This is despite the fact that its peppery, mustardy leaves and stems are rich in vitamins, minerals and nutrients – and the fact that it may be more resilient than other staples in a region rapidly changing due to climate change.
The spider plant is one of 52 crops identified in a 2023 study that recently won the prestigious Cozzarelli Prize from the Proceedings of the National Academy of Sciences (PNAS). The research examined “forgotten” crops that could help make sub-Saharan food systems more resilient and nutritious as climate change makes it harder to grow the corn, rice, cassava and yams the region currently relies on.
“The changing environment, coupled with the need to diversify the food system and eliminate some of the health problems we have now, should drive us to change the way we grow things and the way we eat,” said co-author Enoch Achigan-Dako, director of the Genetics, Biotechnology & Seed Sciences Laboratory at the University of Abomey-Calavi in Benin. “The diversity we need is already available.”
The researchers began by looking at the current and future bioclimatic ranges, including temperature, rainfall and soil type, of current staple crops. Using models of predicted climate for the year 2070, the coauthors identified several regions where climate change is likely to make it more difficult to grow these current staple crops over the next 50 years.
Suitable ranges for these crops are likely to shrink the most in West Africa, with a 17.7 percent decline, the study found. The researchers predicted that Central Africa’s staple crops would see a 14.5 percent decline in their ranges. Of all staple crops, maize was predicted to be the most vulnerable to climate change. The study predicted that more than a quarter of current cropping sites in West Africa and a third of those sites in Central Africa would experience “novel” conditions outside of maize’s basic bioclimatic niche.
The researchers then compared these future scenarios to the environmental ranges of 138 candidate crops native to sub-Saharan Africa, found in genebanks and in fields. According to the study, these were food crops that were “relatively underexplored, underutilized, or underpromoted in an African context,” but which have the nutritional value and growing stability to support healthy diets and local economies in the region.
“Often, ‘forgotten’ crops have always been part of the continent’s food systems,” Achigan-Dako says. “But no one is promoting those crops and no one is generating additional knowledge on the information that farmers have already gathered about those resources.”
The researchers found that the current ranges of many of these plants suggested that they could thrive under new, expected climate conditions. From this group, the researchers then narrowed their list down to only crops with high nutritional value.
“If you look at larger patterns, not just in Africa but globally, there is a kind of tendency to homogenize diets, which affects not only our nutrition but also the resilience of food production systems,” said co-author Maarten van Zonneveld, the genebank manager at the World Vegetable Center in Taiwan. “Yet we know that there is a nutritional gap all over the world. We want to determine to what extent we can use this [plants] to achieve this double win, to tackle climate change, but also to contribute to providing people with access to healthier diets.”
For this team, the work isn’t just theoretical. This collaboration has come about in part because the researchers involved have all worked on the ground in Africa, with breeders and seed banks, collecting and studying underutilized plant species and devising the best strategies for introducing them into local diets.
They’ve already had some success, including with the spider plant: the former weed is now a common sight at farmers markets in Kenya, and Achigan-Dako is working with farmers to sell it directly to consumers in Benin. His lab has also had success introducing the mung bean (Vigna radiata) to Benin by sharing seeds from the World Vegetable Center with farmers.
In Eswatini, Van Zonneveld and the World Vegetable Center are working with schools to introduce hardy, underutilized vegetables into their gardens, where normally only beans and corn grow.
“These programs seem like a promising way to engage young people, provide them with more nutritious meals and also introduce them to these types of vegetables,” says van Zonneveld. “These are going to be our future champions and they are going to take these vegetables with them. That is really part of a long-term solution.”
The work is far from over, however. One problem is that there is still much to learn about the diversity of indigenous crops; van Zonneveld pointed to a significant knowledge gap in terms of historical crop records in the Congo Basin in particular.
“It’s one of the least researched areas on the continent in terms of vegetable diversity,” he says. This is partly because these countries rely on imports for their food. In many parts of the region, eating Western food is also seen as a sign of wealth, while indigenous peoples and cultures still experience discrimination. In addition, poor infrastructure and ongoing armed conflict in some countries can make it difficult and expensive to conduct research.
Moreover, says Josué Aruna, director of the Congo Basin Conservation Society (CBCS) in the Democratic Republic of Congo, most scientific interest in the region focuses on “improved” crops bred for yield and productivity, rather than nutrition or resilience.
“Communities have abandoned their cultural practices around food systems, which has led to less attention being paid to it,” says Aruna. “Academic researchers are focusing on [improved] seeds, have set aside the nutritional, cultural and economic values of ancestral seeds.”
Yet the Congo Basin is not only one of the most climate-vulnerable regions, it is also an area of exceptional biodiversity, potentially home to many more ‘forgotten’ crops that could help boost resilience.
Change is starting to happen. According to Famara Diédhiou, a program officer at the Alliance for Food Sovereignty in Africa (AFSA), supply chain disruptions caused by the COVID-19 pandemic and Russia’s war in Ukraine have led many African countries to shift their focus from food security, which focuses on access to food, to food sovereignty: “Not just access, but diversification and choice,” he says.
AFSA has worked with several countries, including those in the Congo Basin, to implement the My Food is African campaign, which promotes indigenous and traditional foods. They also advocate for more local food policies and a greater focus on agroecology within the African Union.
Achigan-Dako, van Zonneveld and their colleagues also provide information and seed resources to the U.S. State Department’s Vision for Adapted Crops and Soils (VACS) program, which provides funding to improve the resilience and sustainability of global food systems. VACS even used the list of crops from the PNAS study to select its focus crops. The World Vegetable Center also is conducting “rescue missions” to study native crops in Benin, Tanzania, Madagascar and Eswatini, four hotspots of plant biodiversity, with the goal of continuing the search for useful plants.
“I think that is an important message now, because if you don’t know what you have, you can’t keep it and you can’t use it,” says van Zonneveld.
The final piece of the puzzle is identifying the most effective ways to mainstream these crops. One aspect of this is working closely with farmers to figure out which crops do well in different areas. The other is making sure that newly introduced foods taste good in local kitchens. The World Vegetable Center has been working on this, using mobile kitchens in clinics, shopping malls and supermarkets to test dishes using some of these once “forgotten” ingredients, including black nightshade, leaf amaranth, pumpkin leaves, okra, jute mallow and leaf kowpea — all served, says van Zonneveld, “with peanut sauce: very important.”
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Banner image: WorldVeg and staff from the Ministry of Agriculture admire a superior variety of okra in the country of Eswatini. Photo courtesy of WorldVeg.
Quote:
van Zonneveld, M., Kindt, R., McCullin, S., Achigan-Dako, EG, N’Danikou, S., Hsieh, W., … Dawson, IK (2023). Forgotten food crops in sub-Saharan Africa for healthy diets in a changing climate. Proceedings of the National Academy of Sciences, 120(14) doi:10.1073/pnas.2205794120
