Conservation and use of traditional vegetables in Ethiopia

Zemede Asfaw
Faculty of Science, Addis Abeba University, Addis Abeba, Ethiopia

Abstract

Ethiopia is well known for its diversity of indigenous food plants, including vegetables. The cultivated vegetables are mainly grown by traditional farmers in home gardens, although some are grown in fields and along field margins. About 27% of the crop species cultivated in home gardens in Ethiopia, many of them indigenous, are used as vegetables. Non-cultivated species sporadically used as vegetables are estimated to comprise about 29% of the total wild food plants of the country, most of these being indigenous. Traditional Ethiopian vegetables do not figure very prominently in modern crop research and conservation programmes. Traditional vegetable crops are marginalized in modern agriculture while the wild and weedy vegetable species receive no special attention. The vegetable resources of Ethiopia can be developed through a strategy of complementing and augmenting traditional practices with modern scientific approaches. The vegetable industry could benefit from tapping the potential of the indigenous taxa as this would improve local and national food security, augment farmers' incomes and help surmount some health problems associated with nutrient deficiency.

Introduction

Food plants are often classified into different types according to the way they are grown and the way their produce is used (Tindal 1983; National Research Council 1989; Prosea 1993). Vegetables are generally succulent plants grown mainly in gardens and consumed as a side dish with starchy staples. They are of special nutritional importance as sources of vitamins (being especially rich in vitamins A and C), minerals, trace elements, dietary fibre and protein. They also increase variety and add flavour and zest to diets (National Research Council 1989). Widespread malnutrition in many tropical countries is often partly ascribed to the insufficiency of vegetables in the diet (Tindal 1983). This paper is a brief treatment of the food plants - cultivated, weedy and wild -that can be classified as traditional Ethiopian vegetables.

History and current status of vegetables in Ethiopia

Three main agro-ecological zones are recognized in Ethiopia, based on altitude: Dega (2300-3200 m), Weyna Dega (1500-2500 m) and Kolla (500-1500 m). Within these zones vegetables are cultivated in varying intensities (Harlan 1969; Westphal 1975; see Appendix I). In traditional farming systems practised around the homestead and other suitable places, cultivated vegetables have always appeared as a major plant category. Some of these cultivated vegetables can be considered traditional since their use in Ethiopia is known from very ancient times. Sporadic consumption of non-cultivated species, including many vegetables, is also well documented in Ethiopia's past (Amare Getahun 1974; Edwards 1991; Zemede Asfaw 1992). Plants used as leafy vegetables constitute a major group of wild edible plants in Ethiopia (Amare Getahun 1974; Edwards 1991).

Limited archaeological findings have shown that grain harvesting from natural stands in Ethiopia dates from 15 000 years before present (Clark and Williams 1978), which could have been antedated by the earliest use of indigenous vegetables (e.g. Ensete ventricosum, Brassica carinata, Plectranthus edulis) as food. Crop cultivation started early in Ethiopian civilization, with the domestication of new and unique crops from the fields and forests (Harlan 1969; Brandt 1984). Later, various crops were introduced from other regions at different times (Harlan 1969). The tradition of eating a high proportion of plant products was strengthened with the adoption of Coptic Christianity by a large section of the population early in the history of the country, which forbids the eating of animal products during the Lent period and other holidays. Ordinary followers of Coptic Christianity fast for about 140 days during the year, while ardent believers like the clergy and the elderly will subsist entirely on plant foods for even longer periods. In addition, there is an annual cycle of shortage of grains in some localities in Ethiopia, where families exhaust their grain supply before the next harvest and then heavily supplement their food intake with leafy vegetables (Edwards 1991; Zemede Asfaw 1992). This happens during the rainy period, the time when leafy vegetables flourish in the fields and compounds. Traditional/as well as modern, Ethiopian foods thus make considerable use of vegetables.

Wild vegetables have rescued thousands of hungry Ethiopians, even in recent years, as it takes much less time for the leaves and young shoots of these plants to become good for eating compared with grains. Vegetable consumption probably served as an important means of survival during famine periods. It is known that E. ventricosum is mostly consumed as a vegetable during periods of grain shortage when younger plants of sweet varieties are harvested as emergency rations (Kefale Alemu and Sandford 1991).

This long-standing tradition of vegetables in the diet will aid efforts to increase the use of fresh indigenous vegetables by the population. The frequent use of leafy vegetable foods in times of grain shortages in some localities may have led to the tendency to associate eating of leafy vegetables with famine, but their nutritional significance is being increasingly appreciated. Vegetable production for home consumption had suffered in many places when rural families were resettled through the villagization programme, since they were unable to closely monitor and work on backyard plots. In urban and semi-urban settings, production and use of vegetables have grown in recent years, as have external demands.

The traditional vegetable crops of Ethiopia

What qualifies as a traditional vegetable needs to be defined. This is of particular importance for Ethiopia as it has a long tradition of plant cultivation, including both domestication and introduction. It is rather difficult to exclude from the list of traditional vegetables some crops assumed to have a different centre of domestication, despite being biologically diverse in the country and deep-rooted in local tradition. Crops like the hot pepper and shallot are popularly considered traditional, although they originated elsewhere (Harlan 1969). An indigenous plant consumed as a vegetable by a given ethnic group in Ethiopia for a considerable time is considered here a traditional vegetable. The traditional vegetables of Ethiopia include both cultivated species and non-cultivated wild/weedy plants. Although a full list of such plants has not yet been compiled, the more important species are well known.

In a recent study (Zemede Asfaw 1992), 27% of the species recorded from home gardens in Ethiopia were consumed as raw or cooked/boiled vegetables (Appendix I). Some of these species, considered traditional in the narrow sense, as they are also believed to have their origins in Ethiopia (PGRPS 1993), are listed in Table 1. These traditional vegetables are largely maintained in home gardens by family labour, mainly women and children.

Table 1. Some cultivated traditional Ethiopian vegetables.

1. Leafy vegetable crops	3. Leguminous vegetable crops
Allium sp. (ursinum?)	Cajanus cajan p
Brassica carinata p, g	Vigna unguiculata p, g
Brassica nigra p, g
Moringa stenopetala p, g	4. Fruit vegetable crops
	Abelmoschus esculentus p, g
2. Root and tuber vegetable crops
Amorphophallus abyssinicus p, g
Coccinia abyssinica p, g
Colocasia spp. p
Dioscorea spp. p, g
Ensete ventricosum p, g
Plectranthus edulis p, g
Sphenostylis stenocarpa p, g

p= collections at PGRC/E (PGRC/E database), g = important genepool in Ethiopia (Edwards 1991).

The bulk of the plant species consumed in Ethiopia since ancient times are still in the wild state (Zemede Asfaw 1992). Out of 170 species of non-cultivated angiosperms for which clear evidence of consumption by Ethiopians exists, 29% are consumed as vegetables (Zemede Asfaw 1992). Most of these have been consumed in some areas since antiquity. The list of non-cultivated traditional vegetables will increase with further botanical and ethnobotanical documentation. Some common non-cultivated plants used as vegetables are listed in Appendix II.

Although the traditional vegetable resources of Ethiopia are diverse with respect to number of species, only a few of the cultivated taxa are widely used in the country. The use of most of the cultivated and all of the non-cultivated taxa is restricted to some areas and some groups of people. Because of this localization, promotional efforts, including appraisal of nutritional values, should be part of production ventures. Some of the species given as non-cultivated can in fact be considered semi-cultivated because they are tolerated, or even encouraged, among other crops. For example, farmers in Welaita do not weed out Solarium nigrum plants that grow spontaneously in their gardens since they cook the leaves.

Uses and potential

The use of vegetables varies within Ethiopia, being most developed in the south and southwest of the country, where root and tuber vegetables are widely cultivated and consumed. In general, the habit of eating vegetables is concentrated around the nuclear zone of the crops' production and use, but the spread of such localized vegetables to parts of the country where the diet is more cereal-based would be advantageous from a nutritional standpoint. The use of traditional foods by indigenous populations has been implicated in the prevention of diabetes (Brand et al. 1978), and sufficient amounts of vegetables in the diet prevent a number of deficiency diseases as they provide essential vitamins and minerals.

Leafy vegetables are consumed more during the rainy season, when they grow in abundance and when grains are in short supply. Leafy and other vegetables are also eaten more during Lent. Greater production of vegetables is needed to cover consumption needs during such periods. Production during the off-season requires supplementary irrigation. Since some people tend to consider leafy vegetables very secondary as food sources, promotional methods should be integral parts of traditional vegetable enhancement schemes to forge wider public acceptance.

The traditional vegetables of Ethiopia have the potential for increased production and expansion of use to areas where they are less popular or not known at all. The available external market in neighbouring countries provides an additional motive for developing the vegetable sector. The sector's development would also help to recruit some possible future crops from among the promising non-cultivated indigenous vegetables, which can be used as sources of genes to improve the cultivated taxa as some are relatives of crops (Edwards 1991). The overall potential of the indigenous vegetables is estimated to be considerable. Future efforts should strive to develop the traditional systems and practices connected with vegetable production and use, together with modern innovations. Vegetable production in polythene-covered greenhouses and the nethouse system of production practised elsewhere (Watts 1978) could be considered. The full realization of the potential of the vegetables of Ethiopia requires among other things an emphasis on research on traditional vegetables. This serves important national goals, cutting across the economy, health and conservation.

Research

Crop research in Ethiopia has largely concentrated on the more important cereal, oil and industrial crops. The rather localized importance of indigenous vegetables seems to be part of the reason for the lack of national research focus. Most of the traditional vegetable crops of Ethiopia are produced by small farmers following traditional practices. There is no direct attention paid to non-cultivated species. They are not fully documented and no programmes are currently aimed at their development and production. Some of these species are already at risk owing to land degradation and habitat destruction. Most of Ethiopia's important traditional vegetable plants have thus far been out of the main stream of scientific research, together with their main traditional repositories, i.e. home gardens.

The need for research in various aspects of vegetable production has been stressed (Zelleke and Mariam 1991; Lemma Dessalegne et al. 1994), and the need for work on traditional vegetables should be stressed in particular. Modern production of vegetables in Ethiopia has thus far concentrated on non-indigenous species.

Research and modernization of production of indigenous vegetables must be taken more seriously. The indigenous vegetables of Ethiopia are in need of enhanced research programmes if they are to contribute to national food security and farmers' well-being.

Conservation

Efforts to conserve the traditional vegetables of the country are short of what is desirable. The genetic resources of traditional vegetables are to a large extent left to traditional practices and natural processes, although crops presumed to be of high potential (e.g. Ensete, Coccinia, Brassica, Plectranthus, Abelmoschus, Amorphophallus, Amaranthus) are being collected and preserved in the Ethiopian national genebank (Plant Genetic Resources Center/Ethiopia, PGRC/E)¹. Sixteen species of traditional vegetables (most of them cultivated) are included in the programme of seed preservation at PGRC/E. Some field genebanks also conserve traditional vegetable crops (Dawit Tadesse 1994). However, more collecting is required as present holdings include few accessions in many cases. Conservation of the other species is to be seen in the context of efforts directed to the in situ conservation of natural ecosystems, habitats and vegetation types.

¹ Now the Biodiversity Institute.

Traditional farming systems

The traditional farming systems which can contribute to the conservation of cultivated and non-cultivated vegetables in Ethiopia include the specialized systems in use in the high-altitude forests, where root crops and coffee are cultivated under the canopy of forest trees, various kinds of intercropped field systems and the species-diverse home gardens - traditional agroforestry systems which maintain a high proportion of vegetables. These farming systems are able to maintain a rich diversity of genetic diversity of vegetables and other crops as the people who use them have developed sophisticated mechanisms of selection, transfer, exchange and conservation (Berg 1992). The indigenous knowledge and practices need to be studied and supported.

Conservation in sacred places and places of worship

Sacred places and places of worship - like the compounds of churches and mosques, graveyards and monasteries - have been important sites for the protection of the indigenous flora. The conservation of non-cultivated vegetables can be enhanced in such areas through increased awareness on the part of the users of the areas, including both those responsible for their maintenance and the general public.

Conservation in protected areas

Areas such as state forests, community forests and grazing lands, and national parks and reserves where the wild flora has been afforded a degree of statutory protection could be used to specifically safeguard wild species used as vegetables by local people.

Other traditional conservation practices

The traditional practices of allowing some large trees to grow in the vicinity of living quarters, regulating access to grazing land near villages and protecting the natural vegetation found along riverbanks and rural roadsides by not removing trees and shrubs, have contributed to the conservation of non-cultivated vegetables growing in such microhabitats.

These practices should be studied and strengthened. These systems by which the plants of Ethiopia have been protected in situ can be used not just for the mere preservation of what is now left behind but also for their enhancement, with backing from modern methods. Classical ex situ seed and field genebank conservation and the new initiative of PGRC/E in on-farm landrace conservation and enhancement (PGRPS 1993) can positively complement the traditional practices. In such efforts the collaboration of local communities with researchers in government and non-government organizations will be crucial.

Conclusion

Vegetables are a significant component of the Ethiopian diet, and traditional vegetable species are particularly important. These traditional vegetables have been relatively neglected, and their potential remains to be fulfilled. The enhancement of some traditional systems, in conjunction with modern scientific approaches, can contribute to the growth of the vegetable industry, thereby augmenting the national economy and improving people's health and standard of living. Increased attention needs to be focused nationally on traditional Ethiopian vegetables through research, conservation and promotion of use.

References

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Appendix I. Cultivated indigenous vegetables of Ethiopia.

Species (Family)	Vernacular name†	Habit	Parts consumed	Mode of preparation	Major nutrients	Origin	Distribution (m asl)	Cultivated	Research	Conservation	Use (extent and potential)
Allium sp. (Alliaceae)	Alangele (O)	Annual herb	Bulbs and leaves	Cooked with other foods	Vit. A, phosphorus	Ethiopia	1500-2500	Home gardens	?	?	Localized, could be developed
Brassica carinata (Brassicaceae)	Yabesha gomen (A)	Annual herb	Young leaves and shoots	Cooked	Vit. A, P, Ca, K	Ethiopia	1500-2600	Home gardens, fields, margin of other crops	IAR	PGRC/E	Widely used and could be developed more
Brassica nigra (Brassicaceae)	Senafitch (A)	Annual herb	Young shoots and leaves	Cooked	Protein, vit. A, P, Fe, Ca	Horn of Africa	1500-2600 (Shewa, Harar, Gonder)	Home gardens, fields, margins of crops, also weed	?	PGRC/E	Widely used, also as a spice
Amorphophallus abyssinicus (Araceae)	Bagana (S)	Herb	Root tuber	Prolonged cooking (coalescent)	Carbohydrate	Ethiopia	1300-2000 (Gojam, Gamo, Gofa, Konso)	Home gardens	?	PGRC/E	Limited
Coccinia abyssinica (Cucurbitaceae)	Anchote (A, O)	Climbing perennial herb	Tuberous roots	Cooked	Carbohydrate, Ca	Ethiopia	1400-2400 (Gonder, Gojam, Bale, Welega)	Home gardens	?	PGRC/E	Limited, could be developed
Ensete ventricosum (Musaceae)	Enset, Koba (A), Worke (O)	Large perennial herb	Pseudocorm	Cooked, fermented	Carbohydrate, Ca	Ethiopia	1500-3000 (S, SW)	Home gardens	Some research	Well conserved within trad. farming system	Widely used staple, potential high
Plectranthus edulis (Lamiaceae)	Welaita dinich (A)	Annual herb	Tuber, leaves	Cooked (leaves used in kefa)	Carbohydrate, P	Ethiopia	1600-3000	Home gardens and fields	Observations, preliminary studies	PGRC/E	Not widespread, but can be developed
Cajanus cajan (Fabaceae)	Yewof ater (A)	Perennial herb	Young shoots, leaves, pods	Cooked	Protein	India?	500-2000	Home gardens and field	Small programme	PGRC/E	Limited use, potential high
Vigna unguiculata (Fabaceae)	Adenguare (A)	Annual herb	Young leaves and pods	Cooked	Protein, carbohydrate, K, P, vit. A	Africa	500-2000 (Shewa)	Field crop, also home gardens	Research programme underway	PGRC/E	Use as pulse wide, potential high
Abelmoschus esculentus (Malvaceae)	Bamia (A)	Annual herb	Young fruits	Cooked	K, vit. A	Africa	500-700	Home gardens	Observations	PGRC/E	Limited
Moringa stenopetala (Moringaceae)	Aleku (A)	Tree	Young leaves	Boiled	?	?	1000-1800	Field/garden margins, conservation sites	Some research on medicinal and other properties	PGRC/E	Considerable, potential high

^† A = Amharic; O = Oromo; S = Sidama.

Species	Parts used
Allium alibile	leaves and bulbs
Amaranthus caudatus, A. hybridus	young shoots
Arisaema schimperianum	tubers
Bauhinia purpurea	leaves
Campanula edulis	roots
Commelina benghalensis	roots and tubers
Commelina latifolia	tubers
Corchorus olitorius	leaf
Corchorus tridens	shoots and leaves
Cyperus bulbosus, C. esculentus	tubers
Cyphia glandulosa	young shoots and bulbs
Cyphostema adenocaulis	leaves and tuberous roots
Dioscorea quartiniana, D. schimperiana	tubers
Diplophophium abyssinicus	fresh stems
Embelia schimperi	leaves
Eriosema cordifolium	tuberous roots
Eruca sativa	young shoots
Erucastrum abyssinica, E. arabicum	young shoots and leaves
Girardinia diversifolia	leaves
Hypoxis obtusa, H. villosa	corms
Launaea taraxifolia	leaves
Luffa cylindrica	fruits and young leaves
Momordica foetida	leaves and young shoots
Oxalis corniculata	leaves
Portulaca quadrifida	shoots
Portulaca oleraceae	shoots
Pterocarpus lucens	leaves
Rumex abyssinicus	leaves
Rumex nervosus	leaves and stems
Sisymbrium irio, S. officinale	young shoots
Solanum nigrum	leaves
Urtica simensis	young shoots and leaves
Vicia hirsuta, V. sativa	young shoots
Vicia villosa	flowers