Charlie Pye-Smith, New Scientist 10 Nov 09;
IF YOU had come here 10 years ago, says Thaddeus Salah as he shows us round his tree nursery in north-west Cameroon, you would have seen real hunger and poverty. "In those times," he says, "we didn't have enough chop to eat." It wasn't just food - "chop" in the local dialect - that his family lacked. They couldn't afford school fees, healthcare or even chairs for their dilapidated grass-thatch house.
Salah's fortunes changed in 2000 when he and his neighbours learned how to identify the best wild fruit trees and propagate them in a nursery. "Domesticating wild fruit like bush mango has changed our lives," he says. His family now has "plenty chop", as he puts it. He is also earning enough from the sale of indigenous fruit trees to pay school fees for four of his children. He has been able to re-roof his house with zinc sheets and buy goods he could only dream of owning before. He even has a mobile phone.
From Salah's farm we gaze across the intensively cultivated hills which roll away towards the Nigerian border. "Ten years ago, you'd hardly see any safou [African plum, Dacryodes edulis] in this area," says Zachary Tchoundjeu, a botanist at the World Agroforestry Centre's regional office in the Cameroonian capital Yaoundé. "Now you see them growing everywhere."
The spread of African plum through these hills is one small part of a bigger movement that could change the lives of millions of Africans. The continent is home to some 3000 species of wild fruit tree, many of which are ripe for domestication. Chocolate berries, gingerbread plums, monkey oranges, gumvines, tree grapes and a host of others could soon play a role in ensuring dependable food supplies in areas now plagued by malnutrition (see "Future fruits of the forest").
One of the architects of the programme is Roger Leakey, a former director of research at the World Agroforestry Centre. He calls these fruit trees "Cinderella species": their attributes may have gone unrecognised by science and big business, but the time has come for them to step into the limelight.
"The last great round of crop domestication took place during the green revolution [in the mid-20th century], which developed high-yielding varieties of starchy staples such as rice, maize and wheat," says Leakey. "This new round could scarcely be more different." Sparsely funded and largely ignored by agribusiness, high-tech labs and policy-makers, it is a peasant revolution taking place in the fields of Africa's smallholders.
The revolution has its roots in the mid-1990s, when researchers from the World Agroforestry Centre conducted a series of surveys in west Africa, southern Africa and the Sahel to establish which indigenous trees were most valued by local people. "We were startled by the results," says Tchoundjeu. "We were expecting people to point to commercially important timber species, but what they valued most were indigenous fruit trees."
In response to this unexpected finding, the World Agroforestry Centre launched a fruit tree domestication programme in 1998. It began by focusing on a handful of species, including bush mango (Irvingia gabonensis), an indigenous African species unrelated to the Indian mango, African plum - not actually a plum but a savoury, avocado-like fruit sometimes called an afrocado - and a nut tree known locally as njansan (Ricinodendron heudelotii). Though common in the forests and as wild trees on farms, they were almost unknown to science. "We knew their biological names, but that was about all," says Ebenezar Asaah, a tree specialist at the World Agroforestry Centre. "We had no idea how long it took for them to reach maturity and produce fruit, and we knew nothing about their reproductive behaviour." Local people, in contrast, knew a good deal about them, as the trees' fruits have long been part of their diet.
Rural Africans consume an enormous variety of wild foodstuffs. In Cameroon, fruits and seeds from around 300 indigenous trees are eaten, according to a study by researchers at Cameroon's University of Dschang. A similar survey in Malawi and Zambia found that up to 40 per cent of rural households rely on indigenous fruits to sustain them during the "hungry months", particularly January and February, when supplies in their granaries are exhausted and they are waiting for their next harvest (Acta Horticulturae, vol 632, p 15).
Some of these so called "famine foods" have already been domesticated by accident, says ethnoecologist Anthony Cunningham of People and Plants International, an NGO based in Essex Junction, Vermont. He cites the example of marula (Sclerocarya birrea), a southern African tree in the cashew family with edible nutty seeds encased in a tart, turpentine-flavoured fruit. "Long before the development of agricultural crops, hunter-gatherers were eating marula fruit," he says. "They'd pick the best fruit, then scatter the seeds around their camps." These would eventually germinate and mature into fruit-bearing trees, ensuring, in evolutionary terms, the survival of the tastiest. Marula is now fully domesticated and the fruit is used to make juice, a liqueur called Amarula Cream and cosmetic oils.
Hard graft
Likewise, generations of farmers in west Africa have selected and eaten the tastiest varieties of African plum and bush mango, planted their seeds and traded the seedlings - to such an extent that these trees are now widely grown. However, this is a haphazard and unscientific way to domesticate plants.
The planned domestication programme in Cameroon, initially led by Leakey and Kate Schreckenberg of the Overseas Development Institute in London, began with an analysis of the traits most appreciated in the villages. Unsurprisingly, farmers wanted trees that produce lots of large, sweet fruit as quickly as possible. So the researchers asked the farmers to show them their favourite wild trees, and took samples so they could propagate their own. Farmers also received training in horticultural techniques, such as grafting, used to propagate superior varieties.
Initially, many villagers viewed the techniques with suspicion. "People said this was white man's witchcraft, and at first they didn't want anything to do with it," says Florence Ayire, a member of a women's group in Widikum, Northwest Province. They changed their tune, however, once they saw how her grafted fruit trees - created by splicing material from a superior tree onto one which lacks the desired traits - flourished. Now they all want to learn, she says.
This isn't the only technique farmers are learning. They are also being trained how to clone superior trees by taking cuttings - one of the best ways of producing large numbers of genetically identical plants - and how to do marcotting, which involves peeling away bark from a branch and tricking it into producing roots while it is still attached to the parent plant. Once the roots appear, the branch can be cut down and planted in the soil.
Marcotting overcomes an important barrier to domestication for many species: the time it takes a tree to reach maturity and bear fruit. "There's a saying round here that if you plant the nut of a kola tree, you'll die before the first harvest," says Kuh Emmanuel, who helped to establish the centre where Salah was trained. It is still not known how long it takes for a wild kola tree to reach maturity - probably 20 years or more. Using marcots, however, farmers can raise kola trees that fruit after just four years. What's more, says Emmanuel, it results in a dwarf tree, which is important when you consider how many people fall to their death when harvesting fruit.
There's nothing new about the horticultural techniques being used to develop superior varieties of fruit tree in Africa. "What distinguishes this from most crop development programmes is the way it's being implemented," says Leakey. The traditional model involves the development by agribusiness companies of new varieties which can be grown as monocultures in vast plantations. "What's happening with the domestication programme in Cameroon is completely different," he says. "Local farmers play a key role in developing and testing new varieties, and they're the ones who stand to benefit most."
The programme has been a huge success: in 1998, there were just two farmer-run nurseries in Cameroon; now there are several hundred. Many are independent businesses, making significant profits and providing enough trees to transform the lives of tens of thousands of rural families.
Many farmers have increased their income by a factor of three or more, and their spending priorities are nearly always the same: more and better-quality food, school fees, decent healthcare, and zinc sheets to replace leaking thatch. Many also use their new-found wealth to buy land or livestock. One of the most exciting things about the domestication programme, says Tchoundjeu, is the way it is encouraging young people to stay in their villages rather than head to the cities to look for work.
Some projects are evolving into big business. Leakey is particularly impressed by Project Novella, a public-private partnership involving, among others, Unilever, the World Agroforestry Centre and the International Union for Conservation of Nature (IUCN). The project is promoting the domestication of Allanblackia, a group of trees whose seeds contain oil perfect for making margarine. Some 10,000 farmers in Ghana and Tanzania already grow the trees. If all goes to plan, this will rise to 200,000 farmers growing 25 million Allanblackia trees in a decade's time, earning them a total of $2 billion a year - half the annual value of west Africa's most important agricultural export, cocoa.
All of this chimes well with the findings of a recent analysis of the problems facing agriculture worldwide. The latest report by the International Assessment of Agricultural Knowledge, Science and Technology for Development suggests that business as usual is not an option. Instead, it argues, agriculture must do far more than simply produce food: it should focus on issues of social, economic and environmental sustainability, concentrating on the needs of the world's smallholders. The report also suggests that more attention should be paid to utilise wild species.
Better than cocoa
A glimpse of how such a future could look can be seen at Christophe Misse's smallholding, an hour's drive north of Yaoundé. In the 1990s, his main crop, cocoa, yielded an income for just three months a year; even with the extra cash he earned as a part-time teacher he struggled to make ends meet. Then, in 1999, he attended a training session held by the World Agroforestry Centre.
Two years later he set up a fruit tree nursery with three neighbours, and they now sell over 7000 trees a year. Their own farms are also much more profitable since they began growing indigenous trees. Some of Misse's most fruitful African plum trees earn 10,000 CFA francs (about $20) a year each, five times as much as his individual cocoa bushes. "I've built a new house," he says proudly, "and I'm making enough money to pay for two of my children to go to private school."
Misse still has some old timber trees shading his cocoa, but these are gradually being replaced by fruit trees, which will provide not just shade but a significant income and a habitat for wildlife. There is another benefit, too. Trees are much more capable of resisting droughts and other climatic shifts than annual crops such as cassava and maize. By planting a range of different tree species, farmers like Misse are taking out an insurance policy for the future.
As he sips a glass of Misse's home-made palm wine, Tchoundjeu muses on the changing landscape. "If you come back here in 10 years' time, I hope - I'm sure - you'll see improved varieties of indigenous fruit tree on every smallholding," he says. "I think you'll see a great diversity of different tree crops and a much more complex, more sustainable environment. And the people will be healthier and better off." It's a story, he believes, that could be repeated across Africa.
Future fruits of the forest
Last year, the US National Research Council published an exhaustive study of the wild fruits of Africa. Drawing on the knowledge of hundreds of scientists, the authors selected 24 species that could improve nutrition and food supplies.
Ten of these species have undergone a degree of domestication, including African plum, tamarind and marula. Of the 14 completely wild species - "essentially untouched by the almost magic hand of modern horticulture" - they identified seven with outstanding potential for domestication.
Given how many tropical fruits have already made their way into western supermarkets, here are some African staples that shoppers may soon find in their shopping cart.
Chocolate berries (Vitex spp)
Scattered across tropical Africa, these trees produce an abundance of blackish fruit with a chocolate flavour.
Aizen (Boscia senegalensis)
A scrawny scrub in the hottest and driest regions, its fruits, seeds, roots and leaves are eaten by desert-dwellers. The yellow, cherry-sized berries are sweet and pulpy when ripe, and harden into a sweet caramel-like substance when dried.
Ebony fruit (Diospyros spp)
Best known for their valuable, jet-black wood, ebony trees also produce large, succulent persimmon-like fruit with a delicate sweet taste.
Gingerbread plums (several genera of the family Chrysobalanaceae)
Distributed throughout sub-Saharan Africa, the plums this tree produces have the crunch of an apple and the flavour of a strawberry.
Medlars (Vangueria spp)
These trees grow well in arid areas and produce fruits that, when dried, have the flavour and smell of dried apples.
Sugar plums (Uapaca spp)
Found in woodlands, this tree bears juicy fruit with a honey-like taste.
Sweet detar (Detarium senegalense)
A leguminous tree of savannahs, its pods contain a sweet-and-sour pulp which can be eaten fresh or dried.
Charlie Pye-Smith is a freelance writer
