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1 AIZEN (MUKHEIT) The aizen or mukheit (Boscia senegalensis (Pers.) Lam. ex Poiret) occurs across the very area that in recent decades has faced more hunger than any other in the world—the vast swath of Sahel and Sahara savannas stretching from Mauritania, Senegal, and Mali all the way to southeastern Egypt, Sudan, Ethiopia, Somalia, and Kenya. This highly stressed and unforgiving region provides some of the most daunting conditions ever faced by higher plant life. Yet this is the aizen’s territory. In extreme aridity it shrinks to a scrawny shrub less than 2 m tall, but in favorable environments it soars several times that height and becomes almost treelike with a rounded, spreading crown. Having survived thousands of years of recurrent drought without horticultural help, this wild species holds the potential to make life more bearable under the desiccating conditions in which millions of Africa’s most destitute are increasingly forced to exist. For this, there are at least three reasons. First, aizen is adaptable, resilient and, of course, capable of handling extreme drought and heat. Second, it yields an array of useful products. And third, it provides year-round shade in areas where even slight relief from the sun seems merciful. Aizens are not fruit crops in the normal sense. It is the combination of foods and useful qualities that makes them important. The species produces enough different products to sustain human life almost by itself. In at least a dozen countries, at times people virtually live off aizen fruits, aizen seeds, aizen roots, and aizen leaves. In eastern Sudan, for example, men and women sometimes spend 8 hours a day seeking aizens, carrying the branches and fruits home to ease their hunger or sell along the roadsides to other hungry people. For them, these plants are crucial to existence, allaying hunger and earning cash. Also, the foliage keeps their animals alive during the dry months when little remains to sustain a herbivore. And certain peoples use various parts of the plant for cooking food, controlling pests and parasites, and clarifying water to render it safer for drinking. Although not unpleasant on the palate, the fruits are most notable for being on hand when little else edible remains. The foliage’s very unpalatability is key here: livestock and wildlife leave aizen alone for most of the year. Thus the human users have no worries that their trees will be 221

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LOST CROPS OF AFRICA 222 Zinder, Niger Republic. Aizen occupies some of the hottest, driest locations ever faced by plant life in the modern era. Yet it not only survives, it yields enough useful products to sustain human life almost by itself. In at least a dozen countries, people virtually live off aizen fruits, seeds, roots, and leaves. The bushes typically give a lot of fruits, which mostly ripen at once. The fruits shown here are unripe, and would normally be collected only after they turn yellow. But because of the food shortage, people are often unable to wait that long. (Eden Foundation) destroyed by the desert or devoured by goats or gazelles. For this double security alone, aizen is promising for establishing famine-food reserves, for protecting erodible soil, for stabilizing dunes, for windbreaks, and for other utilitarian purposes in the harshest of harsh sites—ones where people need every last bit of help in the struggle to survive. This plant’s endurance is remarkable. It tolerates shade temperatures as high as 45°C, a level not rare in its habitat. It occupies most types of arid- land environment: stony slopes, sand dunes, and cracking-clay plains, just for starters. It often occurs in desiccated, barren, hard, and even fire- scorched sites. As to soils, they are usually poor, sandy, rocky, worn-out laterite, or clay. Commonly it sprouts directly out of termite mounds. And it survives in areas receiving as little as 100 mm annual rainfall, although it grows best where there is at least 250 mm. Contributing to the plant’s built- in drought tolerance is its remarkable leaf structure: the cuticle is up to 20 microns thick, the stomata are sunk in deep cavities, and each stomate has thickened walls and a protective armoring of papillae.1 1 Killian, C. 1937. Contribution à l’étude écologique des végétaux du Sahara et du Soudan tropical. Bull. Soc. Hist. Nat. Afrique du Nord 28:12-18.

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AIZEN (MUKHEIT) 223 For all such reasons, this nondescript “ugly duckling” is in humanitarian terms one of the most admired of all trees. When in recent years researchers surveyed local food and forage species, aizen proved to be the most popular food source among all the indigenous trees in Niger.2 During the 1984-1985 famine in Sudan it was by far the most widely used famine food.3 According to one analysis, 94 percent of people in northern Darfur who had access to aizen (mukheit) during the famine consumed it.4 In fact, during the famine a market developed in which it effectively replaced sorghum and millet (esh) as the staple and those normally basic grains became luxury foods. Perhaps it is not so surprising that people like aizen fruits. At least six parts of it can be put to use, and most of those can be lifesavers. Further, aizen trees are used in at least four ways that relate indirectly to food production. All these are mentioned below. Fruits The yellow cherry-sized berries (up to 1.5 cm in diameter) are borne in clusters. When newly ripe, their rather sweet pulp is translucent and jelly-like. However, in the desiccating air it quickly dries out, turning into something not unlike caramel before ending up a brittle, brown, and quite sugary solid. Despite its good taste, this toffee-like treat is difficult to separate from the seed. Although the fruit is a seasonal food, its season differs from the norm and comes at the beginning of the rains, a time when farm crops are just being planted and anything to eat is usually difficult to find. This alone makes aizen a lifesaver.5 In the better-watered zones, where there are many edible plants to choose from, aizens serve mainly as supplementary, rather than staple, foods. But still, these fruits remain inestimably valuable backups for the devastating drought emergencies that arise almost routinely every decade or two. Besides being eaten fresh, the ripe fruits are often boiled. Furthermore, sometimes juice is extracted, filtered, and boiled down into “aizen butter,” a semisolid commonly mixed with millet and curdled milk to make “cakes.”6 2 Information from Timothy J. Johnson and Michele Rodrick. 3 Salih, O.M., Nour, A.M. and Harper, D.B. (1991) Chemical and nutritional composition of two famine food sources used in Sudan, mukheit (Boscia senegalensis) and maikah (Dobera roxburghi). J. Sci. Food. Agric. 57 367-377. Also, Omar Mohamed Salih Abdelmuti (1991) Biochemical and Nutritional Evaluation of Famine Foods in the Sudan, PhD thesis, University of Khartoum. 4 de Waal, Alex. 1989. Famine That Kills: Darfur, Sudan, 1984-1985. Clarendon Press, Oxford. 5 As contributor Paul Beckman wrote: “The fruits are usually ripe in the area around Eden’s field station near Tânout, Niger, for two months during July-August. This is in the rainy season but it is a critical period when food stocks from the previous harvest are at their lowest.” 6 Sometimes the juice is extracted by loading a pile of aizen fruits into the panniers carried by donkeys. The jolting does the job.

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LOST CROPS OF AFRICA 224 Detailed nutritional analyses seem unavailable, but the fruits are reportedly rich in calcium, phosphorus, iron, and B vitamins.7 They are also said to contain a little protein. Seeds Each fruit usually has one or two greenish seeds, which look like peas and are used like peas. They are in fact the more important foodstuff. Throughout the Saharo-Sahelian zone they are such common items of diet they are sometimes described as desert dwellers’ staples. They, too, are important famine-time foods. And roasted, they also substitute for coffee. After extracting the juice from the fruit, people typically separate the seeds from the pithy residue, dry them in the sun, and put them aside for safekeeping. In times of scarcity, such as at the bitter end of the dry season, these dried seeds substitute for millet or lentils. They require lengthy preparation and must be eaten cooked. The traditional procedure involves soaking the seeds for a week (changing the water daily) to remove bitter components. Less commonly, they are boiled 3 hours (and rinsed at least twice with new water). In either case, they are subsequently dried and ground into flour. This aizen-seed flour commonly replaces sorghum, millet, or lentils in making porridge. Nutritionally speaking, the seeds are satisfactory. Starch and soluble carbohydrate content compares favorably with local staples (sorghum and millet). The protein content is high relative to those cereals and the protein quality (chemical score 33) is similar to that of sorghum (chemical score 36). As to minerals, the seed has exceptional amounts of sulfur and zinc.8 Roots Young roots, scraped of bark, may be ground, sieved, mixed with cereals, and boiled into a thin gruel or thick porridge. They are very sweet. Some are dried in the sun and kept on hand for hungry times. Root tissues are also boiled slowly for several hours to make syrup. Leaves The leaves, although just about the most leathery and least appealing foodstuffs on earth, are also consumed. Most are dropped into soups or boiled and mixed into cereal products such as gruel or couscous. The plant is particularly useful this way because it is an evergreen and provides food and nutrients when other plants are bare. Flowers The flowers provide bee forage, often in areas where little else capable of sustaining honeybees is available. 7 Wickens, G.E. , J.R. Goodin, and D.V. Field, eds. 1984. Plants for Arid Lands. George Allen and Unwin, London. 8 Information from D.B. Harper. The protein quality mentioned was for seeds that had undergone a soaking treatment. The boiling process improved the quality of protein (to a chemical score of 49), but reduced the overall protein content. Assuming the bulk of the sulfur is present as sulfate, the seeds contain about 6 percent sulfate on a dry-matter basis.

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AIZEN (MUKHEIT) 225 Zinder, Niger Republic. A food security gem, this fruit has been a proven lifesaver during famines from ancient times right up to recent days. Within recent memory it has preserved many lives in the Sahel as well as during the subsequent famines in Sudan and Ethiopia. The fact that livestock and wildlife ignore aizen for most of the year removes one of the hazards of wild foods. And the trees resist destruction even by the desert. For this multi-layer security, alone, aizen is extremely promising for establishing famine-food reserves. (Eden Foundation) Wood Aizen wood is cut for poles, notably those holding up houses. Although smoky and stinky, it is used as cooking fuel when nothing better is at hand (which in the harshest areas is all too often). Forage Unpalatable as the fresh foliage is, aizen is nonetheless a vital feedstuff. There is a strange paradox in the fact it is good because it is unpalatable. In fact, its very repulsiveness is its strength: When all else has been eaten up, aizen keeps cattle, sheep, goats, camels, and donkeys (not to mention gazelles and other wild creatures) alive. It is what might be termed “famine forage.” Although the need for such a fallback-forage may be brief, it may be vital. Livestock cannot be dried and stored on the shelf like fruits; they must of course be fed year-round. A few scrawny aizen bushes providing sustenance for a few weeks or perhaps a few days may be all that stands between the animals and death.

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LOST CROPS OF AFRICA 226 Pest Repellent In some parts of the Sahel, aizen leaves are added to granaries to protect stored foods against pests. This long-standing traditional process seems to work. Given some study, it might prove to be yet another way this plant can contribute to food supplies and food security. Water Clarification Aizen contains natural coagulants. In Sudan, Niger, and Nigeria, for example, bark, twigs, leaves, and roots are used to scavenge suspended and colloidal compounds from unclean water (such as that from ponds churned up by storms or from baobab-tree cisterns contaminated with soil). Normally the plant parts are sliced up and placed on the water surface. Compounds leach out and catch the clay and other particulates like magnets, causing them to clump and settle to the bottom. It is reported that truly turbid water can be safely drunk after just a day of such treatment. For even faster results, aizen branches are swirled in the water. Indeed, certain Tuareg groups in the Sahara region fill sacks with aizen leaves and dunk them into the muddy pools that comprise their only source for drinking. Following a rare desert downpour they may also place these giant tea bags across ditches so that the runoff clarifies itself as it oozes through.9 NEXT STEPS Considering the desperate international efforts to feed people in the area where aizen grows, this plant deserves much greater support than it presently receives. Although it has not yet been subjected to horticultural attention, it is promising wherever in Africa desertification is a threat or a reality. Having a reliable backup on hand for the worst of hungry times would be a step toward stability for that part of the world that has absorbed billions of dollars of food aid during recent decades, and yet still lacks a reliable food base. Despite all this promise, however, much fundamental research remains to be done before aizen projects can be launched with confidence. Some practical steps and basic fact-finding endeavors are the following. Build Up Wild Stands One direct approach toward improving food security for Africa’s most vulnerable regions is to rescue, revive, and redevelop the individual trees and existing stands of aizen. Farmers tend to respect areas carrying this species, and their bred-in-the-bone interest can be harnessed to solidify thousands of local stands. This is a good endeavor to start an aizen program with: 1) it avoids the delay of waiting for the trees to grow and mature; 2) aizen’s presence shows that at least the terrain, soil, and moisture are not in doubt; and 3) probably, the site will not be overgrazed. Hence restoration programs are more likely to be immediately successful than new plantings. 9 Although water clarification is an important feature, moringa (see companion report on African vegetables) does better. However, aizen thrives where moringa cannot survive.

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AIZEN (MUKHEIT) 227 Food Security Rescuing aizen stands provide excellent opportunities for relief programs among the destitute. Again, locals should see a lot of self- interest in the work, and will likely participate with enthusiasm, not to mention skill and care. According to a Sudanese famine-food specialist, aizen was the “number one” famine food during the horrific 1984 famine in the western Sudan. “It proved to be people’s lifesaver,” he reports, “and it saved more lives than all the food aid that was given.”10 Given an experience like that, aizen should be not only preserved and protected, it should be planted out in big blocks throughout the drought- threatened regions of the Sahel, Sudan, Somalia, and Ethiopia. Not only would these plantings protect the land, they would provide famine reserves for the future droughts to come. Global reforestation activities today largely focus on rainforest regions and temperate zones, but reforesting the drylands might bring the greater benefit, at least in humanitarian terms. Though aizen is today very far from any forester’s ideal, it could be a key for opening the reforestation activities across Africa’s hungry drylands. The trees may look terrible to a forester, but their benefits could nonetheless be sublime. Although the seeds germinate readily, the seedlings have so far proved difficult to transplant from nursery to field. Thus, it is recommended that direct-seeding trials be established to find out how to establish healthy populations in situ.11 Aizen is of course important to the natural environment, providing wildlife with a last-ditch forage supply. It is sometimes all that animals can find to eat; everything else being dead, dying, dormant, or too desiccated to digest. Expanded plantings will therefore bring benefits beyond purely humanitarian ones. Gather Germplasm No scientific authority has reported on the genetic diversity in Boscia senegalensis. At present, the variability is dispersed and known only to local individuals. This traditional knowledge could point to immensely valuable variants relating to fruit size, sweetness, and at least a dozen other features. The key is to assess this decentralized wisdom and to locate the best individual plants. Contests and cash prizes would likely winkle out surprising genetic variants. Seeds from these could be collected and made available especially for use in these self-same regions threatened by disastrous drought, including the Horn of Africa and the Sahara’s sharp southern edge. This is a big undertaking but their own knowledge–coupled with science–could make one of the greatest contributions to these same peoples, among the most vulnerable in the world. 10 Information from O.M. Salih Abdelmuti. 11 Direct seeding is already being advanced by the Eden Foundation (eden- foundation.org), a Norway-based charity operating out of Zinder, Niger.

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LOST CROPS OF AFRICA 228 Horticultural Development At this point aizen’s ultimate contribution as a resource is anyone’s guess. It is hard to assess the potential of any food crop when there exists neither agricultural trials nor any estimate of yield. One certainty, however, is that the much abused specimens now populating the dry zones around the Sahara are poor indicators of the species’ potential. Indeed, considering that the species has not been domesticated, there should exist opportunities for improving everything from yields to palatability. Once superior types are identified and mass propagation worked out those improvements can occur with a rush. Although details are uncertain, there are claims that root and shoot cuttings have been used to propagate aizen. This could be a vital lead because with them superior plants can be replicated. Also grafting should be explored, because it would allow elite aizen types to be grafted onto the wild trees now so prevalent and widespread. That in turn would ensure rapid quality-fruit production. Also, it would provide lasting benefits because of the rootstock’s obvious adaptability to the site. Analyze Current Usage Aizen offers much potential for anthropological studies, especially in the hunger-prone regions. There have been studies already, of course, but those were sweeping assessments of all the so-called famine plants. Now is the time to focus specifically on this particular plant. It is clearly a leader, and the specifics awaiting documentation are likely to be surprising. Nutrition and Food Science A major immediate need is for toxicological tests. Toxicity in the fruits seems unlikely considering that they are such a common food. But the seeds are certainly bitter and may prove unsafe. Given the fact that poorer families rely on the flour from dried aizen seeds, researchers should investigate and determine what (if any) toxic compounds are present. Helpful here, also, would be public health surveys of possible harmful effects on the people who eat aizen fruits in quantity. Analyses should also be made of the various processes used to remove bitterness. This would clarify whether or not such lengthy preparations (or even more lengthy ones) are needed to make the seeds edible. Similar toxicological tests should be performed on leaves. This will settle (or confirm) doubts about their use for feeding both people and animals. Pest Control The aforesaid fact that aizen leaves are used to protect grain against pests deserves at least preliminary investigation. This is exactly how neem is used in rural India. Over the past few decades researchers have followed up that lead and their work has led to the use of neem in countries as far away as the United States, where the seed-extracts have environmental approval and are now considered a wonderful new organic pesticide.

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AIZEN (MUKHEIT) 229 FAMINE FOOD In famine times, people in rural Sudan rely on aizen. Typically, they collect the fruits, sun-dry them, separate the pea-sized seeds, and remove the hard outer seed coat. Seeds are then subjected to “sweetening” to remove bitter and possibly toxic components. The traditional procedure involves soaking for a week, changing the water every day. Sometimes “kambo,” a local potash prepared from plant ash, is added to aid the debittering. Less commonly, sweetening is conducted by boiling for 3 hours, with the water changed hourly. After such treatment, the sun-dried “sweet” seeds are stored until required, at which time they are boiled until soft, changing the water once during the process. The resulting food is usually eaten with oil and salt. Alternatively, seeds are ground to a flour which is consumed in the form of kisra, a flat thin bread popular in Sudan or asida, a local form of porridge. The taste of the final product can be improved by blending with millet or sorghum flour. (D.B. Harper, Eden Foundation) Anti-Desertification Trials As already noted, aizen’s helps people survive in some of the most desolate, dry, and infinitely difficult regions.12 Preserving aizen along the Sahara margins could be a first practical step in 12 For instance, when crops failed in the western Sudan (Kordofan) way back in 1900, aizen fruits were fed to the people and apparently this is what kept them alive in that era before rock stars and airlifts could rush in support from the world outside.

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LOST CROPS OF AFRICA 230 AIZEN BY ANY OTHER NAME This plant goes by innumerable common names. Aizen (sometimes spelled ayzen) is a Berber word and is the one most commonly used in the literature dealing with West Africa. Other names include mandiarha (Berber); mokheit, mukheit, umkheit (all Arabic), bere (Bambara); ngigili (Fulani). Other common names for the fruit include dilo (Hausa); bokkhelli and kursan (Arabic); gigile (Fulani); tadahant, tadent, tadomet (Tamachek); harrenya (Sonrai); nabedega (More); and nkiandam and diendoum (Wolof). The genus is named for a French biologist, Louis Bosc (1759-1828). During the French Revolution he was rendered destitute and imprisoned for the obvious crime of possessing a father who’d been King Louis XIV’s doctor. In 1796, however, he was reinstated and sent to the United States as his country’s consul. There (particularly in North Carolina), he did most of his botany, eventually naming some 600 North American species. Later, when the Swedish botanist Carl Peter Thunberg—today recognized as the “Father of South African Botany”—discovered a new genus of plants at the Cape of Good Hope, he named it Boscia in tribute. reversing the destitution caused by desertification. And the power of this plant is not just stopping expansion of desert conditions; aizen could be a prime offensive weapon for active reclamation of lands that now seem lost. In this regard, trials with planting seeds and/or cuttings into sand dunes should be carried out. Aizen is commonly the last vegetation left before the desert takes over, so there is hope that it could be the first vegetation in the process of taking the land back from the desert’s grasp. AIZEN RELATIVES The genus Boscia includes almost a dozen species bearing edible fruits of reasonable size in Africa. Various of these species are to be found across the continent. Most of them populate open savanna, but can also form a thick understory in woodlands and dry forests. Possibly all have merits as future foods, but now is the time to focus on the few showing immediate promise. Research to clarify the genetic differences, as well as test plantings to identify different ecological requirements, are particularly suggested. Perhaps cross-pollinations between species will yield useful hybrid products, such as seedless fruits or extra-vigorous trees that grow fast and yield above- average fruit harvests.

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AIZEN (MUKHEIT) 231 Below we highlight two of the better-known aizen relatives. Boscia angustifolia A. Rich This species, too, is found in the huge belt stretching from Senegal to northern Nigeria, but it occupies an area just to the southward of aizen. It also extends at least as far south as Malawi. In many places it is more common than aizen, and the two are often confused. Although its roots are inedible, people often dig them up in the mistaken belief that they are aizen roots. Although quite edible, the fruits are bitter. The seeds are cooked and then eaten. Even the bark is supposedly edible. Powdered and mixed with millet flour, it is added to soups or cereals. The plant is browsed by herbivores, although somewhat reluctantly. Nevertheless, it is a very important browse plant for livestock, notably for goats, sometimes sheep. Trees are heavily lopped, especially at the end of the dry season, as a way to keep the herds from starving. Boscia albitrunca (Burch.) Gilg & Gilg-Ben. (Shepherd’s Tree) Perhaps Africa’s second-best known Boscia species, the shepherd’s tree or witgat is widespread in drier sections of southern Africa. It is found, for example, throughout Namibia and South Africa, as well as in parts of Angola, Zambia, Zimbabwe, and Mozambique. It mainly occurs in savannas and bushveld. Dubbed a “tree of life,” it provides nourishing fodder for game and livestock and water for people. The San, for example, seek out its old hollow trunks for the water they hold. Many African groups regard this tree so highly they forbid anyone destroying it. In times of drought, herdsmen cut off the branches or bend them within reach of grazing stock; hence the name “shepherd’s tree.” The smooth-skinned, cherry-sized fruits are orange-yellow when ripe. They are rather acrid in taste and have slimy flesh, but are nevertheless widely and eagerly eaten. Although having a short shelf life, they are easily preserved in the form of a tasty jam or syrup. Soaked in water, they produce a sweet drink. Some are also crushed in fresh milk to make a pleasant treat. Surprisingly, the roots contain sugar…a lot of sugar. In Botswana, they are widely used to make sweet drinks. The bark is scraped off, the inner tissues are pounded to separate the coarsest fibers, and the resulting cassava- like pith dried in the sun. When needed, this white solid is pounded to a powder and boiled with water until it resembles syrup; on cooling and diluting it is ready to drink. The young roots are also roasted, ground, and used as a coffee or chicory substitute. This attractive plant produces an abundance of small, sweet-smelling flowers. The flower buds may be pickled in vinegar and used like capers. For this reason it is also known as caper bush.13 13 Both it and the capers plant belong to the same family, Capparaceae.

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LOST CROPS OF AFRICA 232 South African research (carried out by the CSIR’s Division of Food Science and Technology) has shown that the root kills fungi well enough to be used to preserve food. Local people have long known this; the use of root slices to keep butter and other foods from molding is of long tradition. This small tree is important to the lives of millions of domestic and wild animals, especially in drier areas. Cattle, goats, birds, monkeys, antelopes, and even elephants devour the fruits and leaves, which are said to be exceptionally high in protein and vitamin A. The shepherd’s tree might prove useful for supplementing the aizen in the Sudano-Sahelian zone.

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