"Just 15 crops account for 90% of the world’s energy intake"
But climate change threatens to make growing them more difficult
The solution might be to produce some less well-known foods
Names are steeped in meaning in Uganda. They reflect parents' hopes and aspirations for their children, as well as ties to their culture and environment.
Traditionally, among the Banyoro and Batooro communities in western Uganda, clan members hold special ceremonies when they bestow a name to a baby. At these ceremonies, known as okuruka amabara, villagers examine the baby for family features and distinctive qualities in order to pick the name befitting what they believe is the child's character.
Towards the climax of the naming ritual, those present are given millet bread, served fresh from the fire in wicker baskets called endiiro, alongside pots of steaming smoked beef or pigeon peas and peanut butter stew. The fresh millet bread is also a signifier of the change of season, releasing a scent like that of clean air and rain falling on dry ground.
Historically, every family would cultivate their own plot of millet and harvesting the crop was a communal activity. Towards the harvest season, children would patrol millet fields, banging empty tins with sticks to scare away the insatiable quelea birds. Then in November and December, groups of women armed with baskets and knives would harvest millet. Wooden granaries, raised off the ground on stilts close to the homes, would heave with the grain by Christmas.
But millet, a major crop in both Africa and Asia and one of the world's most nutritious cereals, is now under threat. Production is decreasing and many families have flattened the wooden granaries where they used to store the crop, using them as firewood. A dish of millet bread and pigeon peas-groundnut stew is no longer a common traditional meal in many households.
Climate change and declining soil fertility have facilitated this decline in the grain. With it, time-honoured traditions like okuruka amabara are also under threat, says Patrick Byakagaba, a natural resource and environmental governance researcher at Makerere University in Kampala, Uganda.
It is just one of many common food crops that are being endangered by changes in the climate, farming practices and consumer fashions. Even hugely popular luxury foods such as coffee, chocolate and avocados are among those at risk.
You don't have to look too far for evidence of how tasty plant produce might disappear. Millet was a major crop on the slopes of Kilimanjaro in Tanzania for thousands of years, but this is no longer the case.
"Millet yields are low these days," says Yesero Businge, 46, a farmer in Hoima, western Uganda. "It no longer grows to the expected height, sometimes not even more than 2ft (60cm). And today's farmers find growing, weeding and harvesting millet labour-intensive."
Millet was previously a major source of food in Businge's household. In the 1980s, Businge says his father would let part of their family's land lie fallow over one or two seasons to allow the soil quality to improve before planting millet again.
But as his family grew and his land became overworked, he noticed a drop in millet yields in the late 1990s. "You need land that has not been cultivated for years to grow millet. [The] population has increased and there is no such land now," Businge says.
Nearly one million plant and animal species are threatened with extinction, including the closely related wild relatives of domesticated crops such as maize, avocado, common bean, cotton, potato, vanilla, chilli pepper, squash and husk tomato.
The loss of wild varieties represents a grave risk to global food security, as they are a key source of genetic diversity, which can be used to reintroduce desirable traits such as drought and disease resistance to crops through breeding. According to the Royal Botanic Gardens at Kew, UK, we now rely on just 15 crops for 90% of the world's energy intake
In Uganda, the wet and dry seasons are becoming more intense and lasting longer, while human lives and crops are now lost to floods nearly every year. Erratic rains and floods have led to the failure of pearl millet at various times – the world's most common millet type.
When it comes to finger millet – the most popular type in Uganda, Kenya and Tanzania – excessive rains result in poor germination, while severe drought can lead to total crop failure. Pigeon pea crops are also experiencing significant yield loss as heat stress disrupts the bloom stage by damaging the pods.
"Seasons have changed [so much] that we now have rain at Christmas, which was not the case in the 1990s, when it used to be a dry season," says Byakagaba. "It's around this time that people harvest millet. Due to losses from rains, farmers have abandoned millet. Excessive rain is responsible for high rates of abandonment in crops."
In Kenya, traditional crops like yam, cassava, sweet potato and pumpkin have slowly disappeared from the diets of many households. "We have lost them as cultural foods. They used to feature a lot previously," says Wanjira Mathai, regional Africa director at the World Resources Institute.
Kenyan farmers have suffered successive drops in yields of crops like millet, dolichos lablab bean and pigeon pea due to climate change, according to the Kenya Climate Change Working Group (KCCWG) and Women's Climate Centers International. "These are the traditional crops which were suitable in these semi-arid areas and contributed to food security and incomes," says KCCWG's chairman, John Kioli.
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Climate variability and extremes like floods, storms and droughts were a key driver of global hunger and malnutrition in 2021. The proportion of low- and middle-income countries exposed to climate extremes has increased from 76% to 98% between 2000 and 2020, according to the UN Food and Agriculture Organization.
Some 52% of these countries experienced three or four types of extreme climate events like floods and droughts between 2015 and 2020, up from 11% during the 2000-2004 period.
Food systems might become more vulnerable to these climatic events unless they are strengthened and traditional crops preserved.
Despite its declining use, millet has been identified as a currently underutilised crop that might help to make food systems more diverse and resilient in the future. It's drought resistant and has a long storage life – which allows it to be locked up in granaries for long periods without insect damage, and makes it an ideal crop for fighting famine and malnutrition.
"Finger millet seeds can resist pests for as long as 10 years, ensuring around-the-year food supply," says Rosemary Atieno, Kenya project lead at Women's Climate Centers International.
If finger millet – so-called because the seeds grow on finger-like spikes – disappears, it's not only a single variety that will be lost, but several genetically diverse varieties of the same crop, called landraces.
Each village that grows this crop in Busia in Uganda and Kisii in Kenya, for instance, has a combination of millet varieties. Each variety is different in terms of colour, shape, number of fingers, maturing period and taste. There are varieties with three to six fingers, and some with folded or straight fingers.
Some varieties yield tastier beer, porridge or bread than others. It's this genetic diversity in millet and other underutilised foods that researchers at the Royal Botanic Gardens are hoping to preserve before it's lost.
There are over 2,000 overlooked native grains and fruits in Africa, including finger millet, African rice, pearl millet and sorghum, which constitute a huge food resource for the growing population.
For farmers battling falling millet yields from dry spells, irrigation holds part of the answer. For instance, the average millet yield on dry lands is 1.8 tonnes per hectare (0.73 tonnes per acre) in Uganda and one tonne per hectare (0.4 tonnes per acre) in India. But on irrigated lands, yields can go up to six tonnes per hectare.
Increasing yields of traditional crops is part of the agenda at the Kenya Agricultural and Livestock Research Organisation. Here, researchers have developed six improved varieties of finger and pearl millet adapted to varying climate conditions and different soil types.
The three pearl millet varieties, which are said to be high-yielding, coupled with a recently approved genetically modified cassava variety, are part of Kenya's efforts to combat food insecurity. On top of these, the Kenyan researchers have developed four drought-resistant sorghum varieties which mature within two to three months of planting.
Some of these crops, such as pearl and finger millet, are descended from grasses in Africa that were domesticated thousands of years ago. The modern varieties could borrow genes for tolerance to heat, cold, drought, water logging and the ability to mobilise nutrients from their wild relatives.
It is an approach that will be necessary to ensure the survival of a wide range of crops – some of which are hugely important commodities at the centre of global industries.
Elsewhere, farmers and scientists are turning to overlooked crop varieties to see if they can strengthen popular varieties against climate change. At Symington Family Estates, a major wine producing farm in Portugal, scientists are now experimenting with neglected wine grape varieties in search of climate-resilient types.
Of the 1,100 existing wine grape varieties, only about 12 are used to make the most popular wines. If successful, these experiments and others like them could prevent a projected drop in wine production, estimated in some areas to be as high as 85% over the next 50 years and thus save many parts of the £300bn ($397bn) industry.
"Every generation has faced its challenge and we are going to have to adapt to climate change," says Victoria Symington, the estate's brand marketing manager. "We need to have the most information available so we make the right decisions now for the future generations."
The estate uses technology to gauge water levels in the wine grape fields by monitoring leaf temperature, which allows scientists to understand climate impacts, like heat and water stress, on the crop and make timely interventions. Technologies like this might help keep wineries running.
Meanwhile, in the cocoa-producing Bahia region of Brazil, farmers facing dwindling crop yields have turned to a traditional method of agroforestry, called cabruca, in which cocoa is grown in dense forests. Cocoa plants thrive in shady conditions, so Brazilian growers hope that a return to cabruca might keep chocolate from disappearing.
"Cocoa is our only income source in the region. Without cocoa, we cannot have a job and we have nothing to harvest," says Carlos Jose Dos Santos, a farmer in Bahia.
Meanwhile in North America, the University of California, Riverside is leading an effort to develop avocado varieties with enhanced abilities to fight diseases and withstand droughts and increased soil salinity. The research might help keep farmers like Chris Sayer, an avocado farmer at Petty Ranch in California, in business.
In the video below, you can see Sayer explain how his crop has been adapted to drought to keep it from decimating his livelihood.
Researchers hope to retain genetic diversity by preserving natural habitats where wild varieties and landraces thrive. But, as an insurance policy, genetic materials can also be conserved outside the natural environment in seed banks.
Gayle Volk, a research plant physiologist at the National Laboratory for Genetic Research Preservation (NLGRP), a US seed bank with 550,000 samples, says the diverse genetic resources held in the facility are accessible to breeders and researchers.
But not all crops can be kept in seed banks, which means we need alternatives, too. Wild coffee plants, already threatened with extinction, cannot be preserved indefinitely in a cold, dry facility – which is how seeds are stored at the bank. Nevertheless, there's another way of conserving coffee – cryopreservation, an ideal method for preserving plants with limited seed storage capability.
Ashley Shepherd, a lab technician at NLGRP, explains that shoot tips are harvested from coffee plants and frozen in liquid nitrogen, halting the metabolic processes.
Technology can help to preserve genetic material, but we also need to use a greater variety of crops in the field. Traditional crops like millet – once so important in parts of Africa – are often overlooked in Western diets (though millet is predicted to increase in demand in Europe over the next few years).
Even if the granary where Businge used to keep millet all year round is no more and the crop's traditional function and naming custom are coming under greater threat than ever before, he hopes that one day millet will get the same research attention as crops like rice and maize.
"Millet has been a major source of food for our family and a key part of our traditions like naming for many years," he says. "Losing millet is not only loss of traditional food, but some of our customs as well. My family will continue to grow it for its unique traditional and nutritional benefits regardless of the reducing yields."
For now, Businge will rely on his traditional hand-hoe farming tool to grow the crop in the hope that his worn out land will continue to yield this delicious and nutritious grain so it doesn't become a thing of the past in his family.
