The value of plant genetic diversity to resource-poor farmers in Nepal and Vietnam

doi:10.3763/ijas.2007.0291

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166© 2008 Earthscan. ISSN: 1473-5903 (print), 1747-762X (online). www.earthscanjournals.com

The value of plant genetic diversity to resource-poor farmers in Nepal and Vietnam

Bhuwon Sthapit1, Ram Rana2, Pablo Eyzaguirre3 and Devra Jarvis3

1Bioversity International (formally International Plant Genetic Resources Institute), Regional Offi ce for Asia, the Pacifi c and Oceania, 3–10 Dharmashila Buddha Marg, Nadipur Patan, Kaski, Pokhara-3, Nepal; 2Local Initiatives for Biodiversity, Research and Development (LIBIRD), PO Box 324, Pokhara, Nepal; and 3Bioversity International (IPGRI), Diversity for Livelihoods Programme, Via del Tre Denari 472/a, 00057 Maccarese, Rome, Italy

Genetic resources for food and agriculture are the biological basis of world food and nutrition security; and they directly or indirectly support the livelihoods of over 2.5 billion people. Genetic diversity gives a species or a population the ability to adapt to changing environments. For resource-poor farmers, adaptive animal breeds, crop varieties and cultivars adapted to particular micro-niches, stresses or uses are the main resources available to maintain or increase production and provide a secure liveli-hood. The economic value of genetic diversity for productivity and yield traits is discussed in the litera-ture. However, it is diffi cult to value many other aspects of agricultural biodiversity as these have both direct and indirect values in terms of qualitative traits such as food, nutrition and environmental uses that include adaptation to low input conditions, co-adaptive complexes, yield stability and the conse-quent reduction of risk, specifi c niche adaptation, and in meeting socio-cultural needs. Together, the direct and indirect values of genetic resources for resource-poor farmers are expressed in a range of options in the form of the crop varieties and species they use for managing changing environments.

The value of genetic diversity to resource-poor farmers is seldom captured by markets or addressed by the international research agenda. This paper presents lessons learned from our work over 5–10 years in the Asia and Pacifi c Ocean (APO) region on participatory crop improvement, home gardens and on-farm management of agricultural biodiversity. The lessons illustrate how farmers adapt genetic resources to suit local environmental conditions. The paper focuses on the value of genetic diversity of selected crop species to meet people’s food and other needs. Genetic diversity valued by resource-poor farmers is often maintained, selected and exchanged by local social seed networks. Identifi cation of such genetic resources and their custodians is important if international agricultural research is to contribute to the reduction of poverty. The paper highlights some good practices from case studies that illustrate how such genetic resources could be exploited by informal research and development strategies or participatory plant breeding or for marketing value-added products.

Keywords: agricultural biodiversity, plant genetic diversity, wild foods, home gardens, dietary diversity, on-farm conservation, Nepal, Vietnam

Introduction

Agricultural biodiversity in farming systems delivers food and nutrition, fi bre, fuel and services that

contribute to people’s livelihoods, health and well-being, and helps to conserve habitats. It is the fruit of thousands of years of observations, selection, exchange and breeding. The value of genetic diversity is apparent in agriculture at all levels for meeting both short-term needs and achieving long-term *Corresponding author. Email: [email protected]

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 149

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

sustainability. Within the agricultural sciences, a common justifi cation for preserving genetic diversity is the need to be prepared for a potential outbreak of disease and pests, and their use as raw materials for breeding improved varieties.

The importance of agricultural biodiversity is increasingly recognized due in part to recent inter-national agreements such as the Convention of Biological Diversity (CBD) and the work of the FAO Commission on Genetic Resources for Food and Agriculture that have highlighted the issues over the last decade (Jarvis et al., 2004b). Genetic resources for food and agriculture are the biological basis of world food security and directly or indirectly, support the livelihoods of over 2.5 billion people (FAO, 1998). The genetic diversity contained in traditional farmers’ crop varieties and animal breeds are also the raw materials for the production of modern cultivars and commercial breeds – either through animal/plant breeding or through biotech-nology. Furthermore, modern biotechnology has increased the value of biodiversity both within crop species and among their wild relatives as genes can now be moved from related or completely unre-lated species into new crop varieties (CAST, 1999; Tanksley & McCouch, 1997). There has been considerable interest in the economic valuation of biodiversity in recent years as it allows policy makers to provide economic justifi cation for conser-vation goals (Evenson et al., 1998; Smale, 2006). This paper primarily focuses on the social, economic, cultural, biomedical and aesthetical value of crop genetic diversity as it is used directly by poor farmers to meet their multiple needs and how it contributes to livelihood security. This new focus can provide a better understanding of how research and development institutions can integrate biodiver-sity into community development.

Measuring the value of biodiversity

The value of genetic diversity is extensively discussed in literature (Brush & Meng, 1998; Evenson et al., 1998; Gollin & Evenson, 1998; Rao & Evenson, 1998; Simpson and Sedjo, 1998; Smale, 2006; Swanson, 1998), however, the economic valuation of many aspects of agricultural biodiversity remains problematic as these not only have direct value in terms of food and nutrition, but also have indirect uses which include adaptation to low input

conditions, co-adaptive complexes, yield stability (reduction of risk), aesthetic value and meeting reli-gious and socio-cultural needs (Figure 1).

For crop varieties, three different types of value are distinguished: direct, indirect and option value (Brown, 1990, Brush, 2000, OECD, 2002; Swanson, 1996). Direct or use value is the simplest and most obvious one that refers to the harvest and uses of crop varieties by farmers (Smale et al., 2004). Indirect value refers to the environmental services or ecological health the crop varieties contribute to, but which farmers may not observe or notice (Hajjar et al., 2007). Option value refers to the future use of crop varieties (Krutilla, 1967). From the farmers’ perspective, the latter two values of crop varieties are secondary, whereas for conser-vationists the option value is of paramount impor-tance. In general terms, as illustrated in Figure 1, agricultural biodiversity provides many goods and services of environmental, economic, social and cultural importance; these environmental goods and services also contribute to sustainable liveli-hoods in a number of ways (Cromwell et al., 2001). The economic value of such goods and services is not well captured by market prices because they are not traded (Brown, 1990) but are valued by local communities often in marginal areas where markets are weak or not present (Smale, 2006).

A growing body of empirical studies have begun to assess the economic bases of farmers’ decisions and benefi ts when using local crop varieties (Smale et al., 2004). These studies provide a more concrete understanding of the public and private values that farmers’ crop varieties embody. They are: (1) ‘private’ values in the harvest the farmer enjoys, either directly as food or feed, or indirectly through the cash obtained by selling the produce and purchasing other items; and (2) ‘public’ values in its contribution to the genetic diversity from which future generations of farmers and consumers will also benefi t. The genetic diversity attributes of crop diversity are not fully captured by markets (Brown, 1990) and gener-ally require public investments to provide farmers enough economic incentives to continue growing them. Although the economic value is important in each context, there are trade-offs, and the value system varies within the local context and culture, which is why understanding local culture is essential. In the following sections we highlight how crop genetic diversity provides direct use benefi ts to resource-poor farmers and vulnerable groups.

150 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Figure 1 Agricultural biodiversity provides goods with: (1) option value (Brush et al., 1992; Rao & Evenson, 1998); (2) direct use value (Johns & Sthapit, 2004); and (3) exploration value (Wilson, 1988). The services offered by agricultural biodiversity can also be categorized into three values: (1) option value (Swanson, 1996); (2) direct use value (Smale, 2006); and (3) indirect use value (Hajjar et al., 2007)

Farmers’ perceptions of the value of genetic diversity

Farming communities view the landscape as a source of natural resources for their sustainable liveli-hoods. Such landscapes in areas of high agricultural

biodiversity typically include common lands, protected areas, forests, watersheds, larger crop fi elds, water bodies, home gardens and patches where uncultivated foods are found. In any given ecosystem, biological diversity is linked to the cultural diversity of the region as it provides both goods and services

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 151

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

to the specifi c culture and people. It is important to understand how communities perceive the value of biodiversity at the agro- ecosystem, species and genetic levels and how their interaction with it affects the livelihoods and quality of people’s lives.

Three case studies are discussed below in respect to three typical livelihood scenarios: (1) uncultivated and wild food; (2) home gardens; and (3) diversity within species in larger ecosystems. In reality, there are many more scenarios, from ‘simple’ ones such as those where communities totally depend upon wild and uncultivated food systems to complex situations such as the integrated system of all three farming systems at landscape level to meet household needs. From the above case scenarios, the value of genetic diversity can be illustrated from the perspectives of the following disciplines and themes:

● Ecology● Economics● Risk management● Food culture and dietary diversity

These experiences are mostly drawn from partici-patory research, on-farm conservation and home gardens studies in Asia with particular focuses in Nepal and Vietnam (Bajracharya, 2003; Eyzaguirre & Linares, 2004; Gauchan, 2004; Jarvis et al., 2000; Rana, 2004; Sthapit et al., 2001, 2003a, b, c; Trinh et al., 2004; Tuan et al., 2003; Watson & Eyzaguirre, 2002). The case studies can help clarify hidden assumptions in alternative defi nitions and approaches to sustainability.

Results: three scenarios

Scenario 1: diversity in uncultivated food for health, nutrition and medicine

Resource-poor farmers constitute over half of the world’s farmers and produce 15–20% of the world’s food (Francis, 1986). In many societies uncultivated food or food collected from the wild fi nds its way into people’s diets and contributes signifi cantly to overall food security and micro nutrient intakes (preventing ‘hidden hunger’). In Bangladesh, uncul-tivated food items such as leafy greens, fi sh and tubers collected from ponds, farmers’ fi elds, road-sides and common lands comprise a large proportion of the daily diet of the rural poor. At least 40% of

the food consumed by the poor in Bangladesh comes from uncultivated sources (UBINIG, 2000). This scenario is very common in many African and Asian countries too. In Nepal, the harvest from forests or the wild is a major source of medicine, food and nutrition for ethnic communities like Chepang, Rai, Sherpa and Gurung (Table 1). The indigenous knowledge of the Rai and Sherpa communities indi-cate that they use 47 wild species for household consumption, 38 for fodder, 19 for medicine, fi ve for religious and ceremonial purposes, 11 to make household implements, and 11 for trade as raw and processed materials (Daniggelis, 2003).

In remote areas of Western and Central Nepal, the Chepang communities depend on gathering, hunting and fi shing for food as well as some slash and burn cultivation. During periods of food defi -cit, the livelihoods of the Chepang community depend upon uncultivated wild foods like githha (D. bulbifora), bhaykur and bharlang (D. daltoides), types of aerial yam; sisnu (Artica dioca; Urtica napus; Girardinia spp.), wild mushrooms; and niuro, wild edible ferns. The Chepang people are well acquainted with edible roots and tubers, and can identify various species of roots and tubers by distinguishing traits of leaves or creepers. The most commonly used tubers and roots are lak (gittha), goi (yam), hung (bharlang), pas (Vhyakur) and gli (Tyagun) (Regmi et al., 2003, 2005). Chepangs place great cultural value on the chiuri butter tree (Bassia butyracea), known locally as yosi – a distinc-tive feature in Chepang food culture and considered as an indicator tree for the Chepang community.

In rural communities of Nepal, all wild and uncul-tivated foods have a role to play in the culture and diets of local people (Table 1). Plants that grow natu-rally in uncultivated plots, along the fences of home gardens, arable lands and in forests are important food for poor people because they cost nothing; they are fresh, often free from pesticides and have an appealing taste. They are valuable sources of nutri-tion, have many medicinal properties and are avail-able in times of scarcity and food defi cit. The contribution of such biodiversity as a source of minerals, vitamins and amino acids at the household food security level is often under estimated. The importance of uncultivated food is universally deval-ued or at least not recognized by mainstream research and development sectors because they are viewed as easily accessible (free) and associated with poverty

152 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Table 1 Culturally associated uncultivated foods of ethnic communities in Nepal and their contribution to livelihoods of marginal and poor people

Ethnic group Locations Descriptions of culturally linked biodiversity Reference

Chepang Chitwan, Makawanpur, Dhading, Gorkha and Tanahun district, Nepal

One of the most underprivileged groups in Nepal, 85% suffer from malnutrition 3–9 months a year. Main subsistence relies upon: • seven species of root crops; • six types of leafy vegetables; • nine types of fruit.Main sources of protein are: bats, birds, crabs, larva and pupae of bees and hornetsChiuri (Aesandra butyracea L.) is a native tree with great importance in their livelihoods: • wedding gift to a daughter on her marriage; • the fruit is eaten as a sweet fruit; • kernel oils are extracted for ghee; • by-products of processed kernels are used as poison

baits for fi shing.

Regmi et al., 2003, 2005

Mushar Dhanusa, Siraha, Saptari, Morang, Eastern Terai

An ethnic group in the Terai between Nepal and India.Basically landless, their livelihoods depend on off-farm employment and gathering uncultivated foods from farmlands and canals.Diet includes: snails, wild fi sh (summer) fi eld rats (winter), uncultivated leafy greens such as Amaranthus, lahare palungo or red vine spinach (Basella rubra L.) and Chenopodium.

Shrestha, pers. comm., 2002

Rai/Limbu/Sherpa

Eastern Nepal Tibeto-Burmese people of the Eastern mountains of Nepal. Livelihood extensively depends upon wild plants such as: • common leafy vegetables (Sag), young chayote shoots,

pumpkin (Cucurbita spp.). Sisnu (Urtica napu: Girardinia diversifolia: G. palmata), rayo (Brassica juncea), mula (Raphanus sativus), taro (Colocasia esculenta), Niguro (Dryopteris cochleata; Diplazium spp.) and Bhurmang (wild leafy green);

• types of yam (Dioscorea versicolor: D. deltoidea: D. bulbifera. D. alata) harvested for Maghe Sankranti festival;

• bamboo shoots of Trewia nudifl ora and Arundinaria falcate;

• Kalo chwache (black pig) – cultural uses as a wedding gift from the groom to his in-laws;

• a special variety of malted-fi nger-millet used to brew Tongba (fermented beer);

• products of high altitude yaks; • forest based wild yams, niuro (Thelyopteris spp.),

sisnu (Urtica dica) and buckwheat, potatoes and barley.

Daniggelis et al., 2003

Gurung Western Nepal Ethnically related to Magars, Thakalis and Kiratis of eastern Nepal, they are considered the oldest ethnic group. Mostly settled along the Annapurna areas and along the Kali Gandaki river above the Baglung district. Common food culture of Gurung includes three daily meals of staples (millet/maize /rice/potatoes/ soyabean), broad leaf mustard (Rayo), buffalo meat and milk products, and uncultivated foods such as tama bans (Dendrocalmus hamiltonii), nigalo, niuro and tree tomato.

Gurung & Vaidya, 1998

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 153

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

(Wilken, 1970; Scoones et al., 1992). Unfortunately, such ecosystems are being polluted by commercial farming practices which abuse the traditional food sovereignty of poor farmers (Mazhar et al., 2007).

Scenario 2: species diversity in home gardens

The second scenario, home gardens, refl ects the greater appreciation of the multiple goods and services provided by biodiversity in agricultural ecosystems (Figure 1). Home gardens are typically cultivated with a wide range of annual and peren-nial plants that can be harvested on a daily or seasonal basis (Nair, 2001; Shrestha et al., 2002). These gardens are microenvironments within larger farming systems and contain high levels of species and genetic diversity (Eyzaguirre & Linares, 2004). A single home garden has ranges of 56–602 species in West Java, Indonesia (Abdoellah et al., 2002), 23–54 species in Vietnam (Trinh et al., 2003b) and 123–131 species in Western Nepal (Sunwar, 2003) (Table 2). These gardens have not only been impor-tant sources of food, fodder, fuel, medicines, spices, construction materials and income but have also been an important means for on-farm management of a wide range of plant genetic resources. Farmers

reduce risk by planting different crops as well as planting different varieties to spread harvesting time. They also rear small livestock around the homestead. Home gardens, with their intensive and multiple uses, provide an insurance against risk and uncertainty for these households. The diverse species used as condiments, medicine and ornamen-tals contribute to the overall sense of well-being in a household, and support the culinary traditions and cultures of local communities.

Typically home gardens are valued for the following specifi c uses: (1) food security, nutrition and cash income; (2) fodder, fi rewood and timber; (3) spices, herbs and medicinal plants; (4) green manures and pesticide crops; and (5) cultural and religious uses (Shrestha et al., 2002). Farmers main-tain rich local crop diversity in home gardens for the following reasons: (1) to meet household needs and preferences; (2) to meet the specifi c need of local ethnic food culture; (3) to increase the options of availability of fresh leafy vegetables, herbs, spices, fruits, and so on, at the household level; (4) easy access to fresh food as refrigerators are an uncom-mon option for preservation; (5) to save money by reducing expenses on daily needs; (6) to improve self-reliance as access to markets is diffi cult in remote areas; (7) to improve access to the source of

Table 2 Comparative characteristics of common home gardens in Asian countries

Country A typical range of species per home garden

Categories of plants Structure and composition Reference

Nepal 123–131 Vegetables, crops, fodder species, fruits, fuelwood, medicinal plants, ornamental, pesticides and green manure plants and shade providing trees

Mixed farming with fodder, vegetables and crops; integrated with livestock and small ruminants and poultry;Vegetables around compost pit or water source; Trees around boundary with climbers

Sunwar, 2003Subedi et al., 2005a

Indonesia 56–602 Ornamentals, vegetables, fodder species, fruits, fuelwood, medicinal plants, building materials

Typically three layers of perennial fruits

Abdoellah et al., 2002

Vietnam 16–12612–103

Annual food crops, vegetables, herbs and spices, perennial fruits, medicinal plants, tea, ornamental and industrial crops

Multistoried fruit and herb based system integrated with fi sh culture and pig farming

Hodel et al., 1999Trinh et al., 2003b

154 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

low-cost vitamins and minerals; (8) to increase the variety of vegetables, fruits, and so on. for ensuring nutrition, functional/health value (e.g. antioxidant, phyto-chemical, hypoglycemic, carotenoids, lutein, zeaxanthin, lycopene, phenolics, dietary fi bre).

Farmers’ attachment to the local food culture is often cited as a reason for growing diverse crops at the household level (Trinh et al., 2003b). Traditional cultures often see food, medicine and health as inter-related. In home gardens in Vietnam, diverse herbs and spices are grown for preparing traditional dishes. In rural areas of Vietnam, male farmers eat dog meat as a delicacy and they use at least 14 different kinds of herbs in order to prepare this special food.

The rhizomes of rieng (Alpinia spp.) and leaves of mo long (Paederia tomentosa Bl.) and mo lang (Paederia consimilis Pierre) are basic spices needed to prepare dog meat dishes to mask its strong smell. Since these herbs need to be used fresh, they are often found in home gardens near the kitchen. Similarly, in Vietnam, the leaves of another common home garden plant Pherynium paravilfl orum are used to wrap around a traditional sticky rice cake and give the cake its characteristic green coating when unwrapped (Hodel et al., 1999).

Various festivals and feasts are associated with seasonal agricultural biodiversity and local cuisine in South Asia. In India and Nepal, a wide range of spices, leafy vegetables and legumes are grown in home gardens because they are essential for local curry-based cuisine. For example, we can fi nd three to nine types of taro cultivars in each home garden and about 24 varieties in a community because of farmers’ preferences for specifi c varieties for prepar-ing special dishes. It was found, for example, that among many other varieties and uses (Rijal et al., 2003) farmers in Kaski in Nepal used the petioles of Dudhe karkalo, Kalo karkalo and Lahure pindalu for making a kind of pickle (achar), the young shoots of Khujere, Khujure kalo and Thagne as a green vegetable (siura), and the dried corms of Panchmukhe seto, Bhainsikhutte and Lahure pindalu as an off-season dried vegetable (koresho). In Vietnam, the silver colour petiole of the Bac ha variety of taro is specially maintained to prepare sweet and sour fi sh and vegetable soup (lau) whereas the Phuoc hom variety is preferred for breakfast cake (Banh khoai) as it has a good aroma (Hue et al., 2003). In Eastern Asia, a large number of herbs, medicinal plants and leafy vegetables are used

as salad ingredients and therefore, home gardens are generally kept pesticide-free and harvested fresh when needed. The above-mentioned cases are a few examples that illustrate the complex valuation of diverse genetic resources by farmers for their own consumption as food.

Furthermore, the diversity of plants in home gardens also increases dietary diversity and serves as a source of vitamins, minerals, antioxidants and other nutritional requirements (Johns & Sthapit, 2004; Ogle et al., 2001). Ogle et al. (2001) reported that high dietary diversity and food variety of Vietnamese people in both the lowland Mekong delta (182–320 vegetable species including wild vegetables) and Central Highlands (234–248 species) are associated with the local food culture. A large variety of vege-tables are used in Vietnam but only half of the vege-tables species are cultivated. It was discovered that wild vegetables contribute signifi cantly to the over-all micronutrient intakes.

In some communities’ cultural and ethnic trad i-tions, biodiversity has cultural, religious and spirit-ual values (Gurung & Vaidya, 1998) and these values play a major role in their life. For example during the Vietnamese Tet festival, fi ve kinds of fruit,1 symboli-zing iron, wood, water, fi re and soil, are required to worship at the household shrine of a Vietnamese family (Trinh et al., 2003b). During the Tet festival in Vietnam a large red fruit with spikes (Momordica cochinchinensis, a cucurbit) is in high demand for cooking sticky rice cakes with a red colour, indicat-ing that it is also a rich source of B-carotene.

In Nepal some specifi c crops are associated with specifi c ethnic food. Shrestha et al. (2002) reported that Newars (a dominant ethnic group in Kathmandu valley, Nepal) specifi cally maintain cholecha (Allium spp.), black soybean (Glycine max), shallot (Allium ascalonicum), chamsur (Lepidium sativum) and red turnip (Brassica rapa) in their home garden as these are commonly used in cultural ceremonies and feasts. Just after transplanting rice in the monsoon season, Jyapu farmers consume a nutritious soup made of nine different etiolated grain legumes (locally known as qwati) which is rich in vitamin E and a source of protein. Hill people in Eastern and Western Nepal tend to keep broad leaf mustard (Brassica juncea var. rayo), bhote lasun garlic (Allium sativum), tree tomato (Cyphomendra betacea), cherry tomatoes (Lycopersicon spp.), chayote (Sechium edule) and radish (Raphanus

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 155

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

sativus) in their home gardens as these are culturally associated with their food preparation. On the other hand, oal (Amorphophallus campanculatus), leafy vegetables lapha sag (Malva verticillata), patuwa sag (Corchorus spp.) and drumstick (Moringa oleifera) are delicacies eaten by Terai people. The indigenous drumstick vegetable is reported to have multiple medicinal properties.

Amongst the Hindu Brahmin caste, it is a trad-ition to worship and water the Tulsi (Ocimum sanctum) plant as it is believed to have 52 properties of medicinal value. In the Yunnan province of China, Chinese Buddhists offer fi ve fi ngers citruses to the shrine of Budhha. These specifi c cultural values help the community to conserve a variety of unique crops and cultivars in home gardens as people see that biodiversity is closely linked to cultural diversity.

Home gardens in Asia are also valued for their aesthetic value, cooling effect and are regarded as a symbol of wealth and social prestige. In South Vietnam, where the weather is always hot, broad leaf and shading trees are dominant tree species around home gardens for their cooling effects whereas in the middle hills of Nepal, fodder trees are found around the home garden to provide multiple uses: fodder for animals, branches for fuel, support for climbers such as chayote (Schium edule), sponge gourds (Luffa cylindrica), cucumber, chattel (Momordica cochinchinensis), yams, peren-nial beans, and so on. Besides the above-mentioned direct values, farmers keep a diversity of crops and varieties to ensure stable yields by managing pests and diseases, weather-related vulnerability, labour availability and market forces. This strategy is commonly seen in multiple layers of species in agro-forestry and home garden systems in contrast to the mixed/intercropping, which is common practice in larger ecosystem farming systems.

These experiences from a wide range of countries suggest that home gardens can provide an ideal setting in which to understand and develop local gardening practices appropriate to the environmen-tal conditions and food cultures of local communi-ties. Because of the small size of home gardens, most governments have never identifi ed home gardens as an important unit of conservation and food production and so they remain neglected by research and development programmes. However, at the household level, the system is very important as it is an important source of quality food and

nutrition for the rural poor and, therefore, home gardens are important contributors to the household food security and sustainable livelihoods of farming communities in Nepal and other countries.

Scenario 3: diversity within crop species in larger agroecosystems

The third scenario is to understand why small communities of farmers maintain a large number of crop cultivars in an agroecosystem. We have taken the examples of rice from in situ conservation sites in Nepal to illustrate the farmers’ ration ale for main-taining diverse cultivars within the species. For instance in Begnas village, about 900 households have maintained a total of 63 landraces and six modern cultivars. At the household level, fi ve rice cultivars per household are grown on average of which usually four are local and one is a modern cultivar (Rana et al., 2007). However, we found that one person (Mrs Tara Tiwari from the Archalthar hamlet at Begnas) maintained as many as 22 rice cultivars. But no one landrace covers more than 17% of the total rice land planted with rice.

About two-thirds of the number of land races and varieties (n � 48) are grown by only a few (fewer than fi ve households). Using molecular anal-ysis, Bajracharya (2003) also reported that Begnas village is rich in rice genetic diversity (0.37 measured as Polymorphic Information Content value) and shows a high average number of alleles per primer (2.4) using 39 primers in the same sample set from the site using microsatellite (SSR) markers. Farmers maintain multiple varieties on farm because no single crop/variety could satisfy all the requirements of a farmer’s many, varied needs (Rana, 2004). It has been found that farmers maintain a range of cultivars for the following reasons:

● economic traits (yield, quality-aroma, taste, soft-ness, post-harvest-milling recovery, disease/pest resistance, etc.);

● ‘best-fi t’ to ecology (adapted land types-low/high altitude, rainfed/irrigated, poor/fertile soil, open/shade, cold/warm water source, upland /lowland, dry/swampy);

● a mix of cultivars with different phenology to spread labour demands and timing of harvests;

● socio-cultural value (preference for food culture, and religious needs).

156 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

These three scenarios illustrate the value of genetic diversity at different levels to resource-poor farmers. Enhanced understanding of the benefi ts of agricultural biodiversity is crucial to promoting a wider use of agricultural biodiversity to advance the well-being of the poor. Nutrition, income and sustainability can all be improved, and clear demonstrations of these benefi ts, with better management of the resources, will result in improved conservation as well as increased use. The classic use of genetic diversity is to improve livestock breeds and crop varieties through scientifi c breeding. The challenge is to fi nd simple and innovative methods to maximize the use of the genetic diversity that belongs to poor, marginal areas, neglected by inter-national and national research programmes. The above three scenarios also help us to understand how farmers use local knowledge of biodiversity assets to manage and use the potential of landscape and agroecosystems. These examples offer unparal-leled opportunities not only through breeding but also by delivering a raft of far-reaching diverse benefi ts, which will be discussed below.

Discussion: what use values are valued?

Ecosystems and co-adapted complexes

Landraces are reservoirs of adaptive variation in crops. Farmers have a good understanding of the qualitative and adaptive traits of their landraces and the interaction between ecosystems and landraces. In Nepal, local rice varieties are valued, especially in the remote mountain areas where they are adapted to diverse ecosystems, including cold stress, water scarcity, fl ood conditions and poor soils. In Begnas village, eight landraces are common, cultivated on large areas by many households as the best fi t to the prevalent land types. For example, the Mansara rice variety is locally adapted to the ‘poor’ rice fi elds where no other rice varieties perform well. The Mansara landrace is grown mainly by resource poor farmers and therefore, considered a valuable resource as it supports the livelihoods of poor households who do not usually have access to fertile land or high inputs. Of the 209 households sampled, 14.3% of farmers grew this landrace despite its poor taste, low yield and poor market value. So, Mansara is still

competitive with modern varieties and is, therefore, conserved by farmers (Rana, 2004). However, this variety would be easily replaced by better varieties (in terms of taste and quality) if available for such growing conditions. These special adaptive traits of land races are not being utilized to develop better varieties for marginal environments by public sector plant breeding because of the focus on conventional types of crop improvement. Recently participatory plant breeding combined with in situ conservation in Nepal has successfully added value to the Mansara landrace by improving quality and productivity by crossing it with a locally adapted modern variety (Khumal-4) and the impact of these new farmer varieties is being monitored (Gyawali et al., 2006; Sthapit et al., 2001).

In contrast, the Naltume rice landrace is main-tained by only one household because the variety grows well in the shade of fodder trees. Farmers will value a specifi c variety as long as their circum-stances demand the adaptive traits it offers. There are several such examples in Nepal. The study suggests that land use and farming systems basically determine the genetic diversity of rice in Nepal (Bajracharya, 2003; Rana, 2004). Farmers use different varieties to manage the ecological diversity present in their farms, however, the varietal choices available for marginal and diffi cult environments are limited compared to the choice of varieties suit-able for more favourable growing environments (Table 3). Rana et al. (2007) illustrated that depen-dence on farmers’ varieties for food security is signifi cantly higher in marginal growing conditions than in high yield production systems in Nepal. Of the 600 households surveyed on the most commonly used rice cultivars in three contrasting communities of Nepal, it emerged that 100% of mountain people depend solely upon local varieties followed by hill (73%) and Terai (below 300 m asl) (17%). In many developing countries, farmers still rely largely on local seed sources for their staple crops. Over 95% of rice cultivated in Nepal, 85% of durum wheat in Morocco, 98% of barley in Morocco and 50% of maize seeds in Mexico still come from local farmer sources (Jarvis et al., 2004a). Farmers’ appreciate the easy access to locally adapted materials.

Households grow Ekle, Madise and Gurdi in large areas for good yield stability over seasons, which is the most valued trait for subsistence needs. Modern variety Mansuli is also grown on a large

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 157

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Table 3 Relative perceived values of rice varietal diversity in Nepal and Vietnam

Types of direct value by farmers

Country Valued trait Name of rice cultivars

Market and economic trait

Nepal Premium price for softness and aroma Jetho Buddho, Basmati, Pahele

Nepal Moth tolerance Sano gurdi

Nepal High milling recovery Sano gurdi; Some populations of Jetho Budho (70% recovery)

Vietnam High quality from Red river delta Lua Tam Xoan

Vietnam Pest and disease resistance in fi eld and storage Khau khinh

Adaptive value Nepal Adapted to snow-melt cold irrigation water at seedling stage (2500 m asl)

Jumli marshi

Nepal Cold tolerance at anthesis and blast/ShBR resistance

Chhomrong

Nepal Adapted to poor soil, moisture and nutrient stresses

Mansara

Nepal Adapted to waterlogged marshy condition Anga, Jerneli, Bhatti

Nepal Adapted to submerged and ponds Bhatti, Silhat

Nepal Adapted dry seeded upland rainfed conditions Ghaiya

Nepal Shade tolerant under agroforestry system Naltume

Vietnam Adapted to low input upland Khau cam pi, Khau lao, Moc tuyen

Vietnam Adapted to acid sulphate and salinity prone areas of Mekong coastal areas

Trang Tep

Nutritional, medicinal and health value

Nepal Backache and maternity diet for women Kalo bayerni, Rato anadi

Nepal Subside fever Ghaiya

Nepal Heat stroke treatment for animal and humans Aaga

Vietnam Multipurpose Khau cam pi

Vietnam Medicine for pregnant women; violet coloured rice rich in iron

Beo khau leng from ChodonKhao nep cam from Dabac

Food culture and culinary value

Nepal Selroti (a doughnut shaped popular bread) and rice pudding

Bayerni, Jetho Budho, Jhinuwa

Nepal Preferred for Latte (sweeten sticky rice by slow steamed cooking) eaten during Push pandra festival

Anadi-rato and seto (sticky rice)

Nepal Preferred for beaten rice used for snacks with pickle and gravy curry

Marshi, Jerneli, Taichung and Thapachini

Nepal Preferred for pulao-soaked rice fried in ghee, spices, condiments and nuts prepared for marriage party

Pahele, Jetho budho

Nepal Preferred for cooked quality rice for softness, aroma and separateness

Jetho budho, bayerni, basmati

(Continued)

158 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

scale because of its high productivity and market-ing ease. A recent study on cost–benefi t analysis of growing landraces from Bara ecosite in Nepal (Gauchan & Smale, 2003) revealed that certain landraces in particular niches such as Bhathi in swampy land and Mutmur in poor upland soils are highly valued by the farmers who have land types that suit the varieties and they can be profi tably grown in these poor environments. No modern vari-eties currently available can compete with them.

Although land use systems determine rice diver-sity, favourable market prices or inherent quality traits in certain varieties may attract farmers to grow these varieties outside their ‘best fi t’ ecosystems (Rana, 2004). Rana found that competition between varieties for space primarily occurs within the ecosystem and there is a lot of competition in favourable ecosystems compared to marginal ecosys-tems owing to the presence of a higher number of varieties in favourable ecosystems (Table 4). The majority of landraces are only grown in small patches by a few households in each village and can be considered as uncommon (rare) types of landraces or alleles. Such diversity is often main-tained, selected and exchanged by few farmers, and it is essential to strengthen their seed networks for continued management of such diversity in situ or otherwise preserve the seeds ex situ.

In Begnas village, no single variety covers more than 17% of the land planted with rice and therefore,

the mosaic of rice diversity in the ecosystem may provide a genetic diversity that contributes resistance to diseases, pests and stresses. Bajracharya’s (2003) study using principal component analyses (PCA) grouped landraces according to ecosystems using DNA markers on rice landraces collected from the study sites. Varieties falling within the same ecosys-tem are more likely to be similar in their genetic composition compared to varieties from dissimilar ecosystems. The logic underpinning the argument is that landraces have been conditioned over years by their continued cultivation and selection over time in specifi c ecosystems. As a result, it can be expected that they have developed adaptive traits, which are unique to landraces in that ecosystem. The results also support the idea that the varieties grown in small areas by few households are more diverse as they may have been selected for micro-niches and the seed system is often closed compared to the more common varieties (Bajracharya, 2003).

Thus, the farmers’ practice of allocating different varieties to different growing environments affects the genetic diversity of the farmers’ repertoire of varieties maintained on-farm (Cleveland & Soleri, 2002). Resource-poor farmers value diverse variet-ies as they provide cheaper options for managing variable environments. The use of locally adapted materials can help ecosystem health by reducing the need for fertilizer and pesticides and thus providing indirect benefi ts to society.

Table 3 Continued

Types of direct value by farmers

Country Valued trait Name of rice cultivars

Nepal Preferred for bhuja-puffed rice eaten as snacks with meat and vegetables

Seto anadi

Vietnam Good quality rice wine Nep Thai binh, Beo veng tram, Beo khau ken, Nep hao vang, Moc Tuyen

Vietnam Sticky rice for cake Nep Hoa vang, Beo xem, Nep cai goa vang

Vietnam Best glutinous rice Khao khinh

Vietnam Good taste with aroma Lua tam xoan, Tang san nieu

Vietnam Rice noodle (Pho) CL8; Ham Trau (OM576)

Specifi c use value

Nepal Preferred for straw mat making and fodder value

Jetho Budho, gurdi

Source: compiled from Sthapit et al., 2001; Pant, 2002; Tuan et al., 2003; Rana, 2004; Bajracharya, 2003; Gauchan, 2004

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 159

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Economic value

Economic value is the common way of describing the overall value of traditional varieties and relates to the direct use value of goods and service provided by agricultural biodiversity (Figure 1). The value of biodiversity is often expressed in economic terms because people and societies derive benefi t from the use of goods and services that intraspecifi c diversity provides. Landraces having economically valued traits are grown in large areas by many households as Rana (2004) reported in the case of Jetho Budho, Pahele and Ekle landraces in Begnas village. Farmers consider Jetho Budho and Pahele to be the best landraces for cultivation in large areas because of multiple traits. Besides being a good and stable yielder (both grain and straw), farmers consider Jetho budho and Pahele to be of good quality for cooked rice because of its aroma, good taste and soft texture. This is verifi ed by the high demand of both varieties by consumers and the premium price they receive in local markets. Therefore, farmers enjoy the private value of the varieties either directly, as consuming quality rice or indirectly, receiving cash from sales at a higher price.

We found that resource-poor farmers have allo-cated a large portion of their fi elds to these high quality rices because they are easy to sell at the farm gate for a high price, and that they then buy modern cultivars for home consumption.

Food culture and local cuisines

Pant (2002) reported that food traditions and dietary habits provide a strong incentive for conserving specifi c crop and varieties within a crop. In Begnas village, it is a common trend that the majority of farmers allocate small parcels of land for special varieties that are valued for taste, local cuisines and food festivals. For example, consum-ers prefer Bayerni, Jerneli and Jhinuwa for its especially high quality such as softness, aroma and taste of cooked rice. These high quality landraces are often low yielding and therefore grown by resource-rich farmers in small areas for their own use during festivals and when entertaining special guests (Rana, 2004). It makes economic sense to allocate a small area to high-quality rice with low-yield potential. Such specifi c landraces are valued for local food culture and special occasions for social prestige and quality of life. Table 3 illustrates selected examples from Nepal and Vietnam show-ing how consumers prefer different rice varieties for preparations of special local dishes (Pant, 2002; Rana, 2004; Trinh et al., 2003a).

Farmers often prefer Bayarni or Jhinuwa for the smooth and soft texture of selroti (a kind of Nepali donought). Latte (sticky rice cooked with sweetener) is only made from Rato Anadi (glutinous rice) land-race since no other landrace has the required char-acteristics. Latte is also becoming a common snack

Table 4 Choice of rice diversity available for the specifi c land use systems in Nepal

Indigenous rice domains

Inherent fertility of soil for rice cultivation*

Most valued landraces for the domain†

Total number of local varieties

Total number of modern varieties

Pakho tari (upland bari)

Poor Rato ghaiya, Seto ghaiya, Jire ghaiya

12 0

Tari khet (rainfed) Very poor Mansara, Anga, Kathe gurdi 10 1

Kule khet (irrigated) Good Jhinuwa, Bayerni, Ekle, Jetho budho, Pahele, Kanchi mansuli, Mansuli, Radha-7

27 4

Dhab (marshy) Very good Rato anadi, Seto anadi, Gauriya, Tunde jhinuwa, Mansuli

14 2

*Inherent fertility of soil is considered to be highest for marshy plots and lowest for rainfed tari plots. In terms of productivity potential, farmers identifi ed irrigated ecosystem has the highest potential followed by marshy ecosystem. †Name in bold indicates the variety is best adapted to that ecosystem though grown in other ecosystems as well.Source: Rana, 2004.

160 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

apart from its mandatory consumption during special festivals. Normally coarse grain varieties are considered to make good beaten rice, and among the landraces Marshi is the preferred grain for this purpose. Beaten rice is very popular amongst city dwellers as a regular snack mixed with meat and vegetables. Another popular item is puffed rice, which is primarily consumed as a snack and also consumed during special ceremonies. Seto Anadi is the preferred landrace for making puffed rice. For preparing pulao (steamed cooked rice with ghee and condiments), Pahele is the preferred landrace because its grains are aromatic, slender and non-sticky when cooked.

In Vietnam, the situation is similar. The local food culture determines the distribution of rice diversity. For example, rice noodle soups commonly eaten for breakfast (locally known as ‘Com Pho’) are prepared from both modern (CL8) and local (Ham Trau OM576), non-glutinous rice varieties. Varieties such as Nep hoa vang and Beo xem are valued for sticky rice cakes whereas upland rices such as Nep thai binh and Beo veng tram are appreciated for their home-made rice wine qualities (Trinh et al., 2003a) (Table 3). In summary, we found that culturally valued or nutri-tionally valued landraces (e.g. Anadi and Bayerni) tend to be grown by many households but in a small area because of low productivity. Such culturally associated traditional varieties are under great threat with changing food habits and the globalization of the food chain in biodiversity rich countries.

Medicinal and health value

The health value is also considered a direct use value and is another way for farmers to describe the overall value of traditional varieties. Of the 69 rice varieties found in Begnas, Nepal, four landraces are known to have some medicinal and health values (Rana, 2004). The Kalo Bayarni landrace is consid-ered to be nutritious so it is provided to women after childbirth to recover their strength. It is also consumed for relief from pain resulting from physi-cal exertion. Besides being used for consumption, Anadi rice is used for plastering fractured bones due to its adhesive (glutinous) nature, and as a base for mixing other medicinal herbs to cure fractures. This landrace is also eaten as a pre-meal appetiser in small quantities, to relieve backache. Farmers believe that the consumption of Ghaiya upland landraces

gives relief from fever. Finally, the Aanga landrace is classifi ed as ‘Chiso’ (cool) for human and animal consumption to overcome heat-stroke problems. Rice soaked in water is provided for consumption to animals suffering from heat; this practice is more common for animals than for human beings.

In Vietnam, a black rice called Beo khau leng is popular for its nutritious and medicinal value for pregnant women whereas in Bangladesh, local rice varieties were found to possess signifi cant nutrient levels; local varieties having higher iron and zinc content than modern ones (Kennedy & Burlingame, 2003). Taiwan’s Agricultural Research Institute (TARI) reported that Chinese farmers maintained a dozen non-genetically modifi ed coloured rice cultivars, including black, red and yellow, which are enriched with nutrients such as beta-carotene, antioxidants and anthocyanins (TARI, 2003). The new strains of rice could have a high economic value if farmers go further to commercialize such varieties.

Specifi c use value

Of the 69 rice cultivars found in Begnas, Nepal, 70% of farmer-named varieties are grown by fewer than six households in a small area of 0.5 ha. It is important to understand why farmers need so many rice varieties for such a small area. Local knowledge of the farmers’ circumstances and needs revealed that they are very specifi c to household needs and special varieties are selected to suit their specifi c needs (Rana, 2004). For example, Sano gurdi is valued not only for moth tolerance in stor-age in low altitudes but its high milling recovery. Naltume is a niche specifi c variety adapted to shaded areas of the agroforestry system. Furthermore, farm-ers need special rice varieties for fodder and other uses. In Begnas, Jetho Budho, Bayerni and Gurdi rice varieties are valuable for making traditional straw mats and also valued for animal feed and for religious offerings. Inferior types of rice (usually upland rice) are considered ‘impure’ and are not offered to the gods (Rana, 2004). Similar results were reported on taro crop diversity in Nepal (Rijal et al., 2003) and in Vietnam (Hue et al., 2003). Farmers consider these specifi c use values which have direct or indirect use value for their circum-stances and they trade off high yielding varieties for traits of such specifi c varieties.

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 161

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Implications

Consolidating the role of the community in biodiversity management

Resource-poor farmers consider agricultural bio-diversity to be an important livelihood asset for managing their natural and socio-economic circum-stances. The genetic diversity valued by resource-poor farmers is often maintained, selected and exchanged through one farmer and his/her social seed networks (Subedi et al., 2004). The identifi ca-tion of these genetic resources and their custodians is important if the global research programme aims to reduce poverty for such vulnerable communities.

These individual farmers, referred to as ‘nodal farmers’, occupy a relatively central position in the formal network of agrobiodiversity management on-farm: they grow more diverse crops and main-tain more diversity; they constantly search for new diversity from within the village or outside it, selecting for variable environments, and they main-tain and exchange the materials within and outside their networks. These networks of nodal farmers are considered as ‘local institutions’ for plant genetic resource management and have been used for ‘community seed exchange’. They can play a signifi cant role in conservation efforts as they manage the majority of genetic resources present at the community level.

At present, local institutions for community biodiversity management are under threat with seri-ous implications for the sustainable livelihoods and food security for the poor. In order to recognize and strengthen the capacity of these community-based institutions, the Bioversity on-farm conservation project in Nepal has developed good practices to develop options with social, economic and environ-mental benefi ts to the community. The project has played a role in strengthening the capacity of local institutions and farmers in order to improve:

● access to knowledge, information and education;● access to fi nancial capital;● access to natural capital – choice of genetic

diversity;● access to markets and consumers;● access to physical capital.

It has been found that the local community institu-tions can be strengthened through the management

of community-based knowledge systems to identify, conserve, manage, add value and exchange on-farm local diversity through community actions. These community actions include:

(1) Community actions: biodiversity fairs, diversity blocks, diversity kits for locating diversity, under-standing its value and deploying it for the benefi t of the community (Sthapit et al., 2003a).

(2) Capacity building of community knowledge centre: Community Biodiversity Registers (Subedi et al., 2005a), community seed banks (Shrestha et al., 2006), biodiversity fairs (Sthapit et al., 2003b), diversity fi eld fora/farmers’ fi eld schools (SEARICE, 2003).

(3) Value addition of local crop diversity by partic-ipatory plant breeding (Sthapit et al., 2003c) and non-breeding approach (Rijal et al., 1999; Sthapit et al., 2000).

The above-mentioned conservation actions are an integral part of community biodiversity manage-ment and several good practices have been learned to implement these activities most effectively aiming at capitalizing the value of genetic resources and enhancing the benefi ts to local communities (Table 5). To be effective, good practices must be practical, cost-effective, sustainable and have the potential for scaling up to wider geographic, insti-tutional and socio-cultural contexts. Some exam-ples of the on-farm projects in Nepal and Vietnam are beginning to shed light on how the community can gain the greatest social, economic and environ-mental benefi ts from the on-farm conservation of agricultural biodiversity.

Participatory plant breeding

Within traditional crop production systems, the direct use value of local crop diversity is well recog-nized by farmers; however farming communities may often not fully recognize the breeding value of gene and genetic traits inherent in farmers’ varieties or landraces. Sthapit et al. (1996) have shown that by utilizing farmers’ knowledge, and in situ genetic resources, the value of local diversity has been increased by participatory plant breeding. For exam-ple, participatory plant breeding (PPB) programmes using local landraces have enhanced desirable traits such as cold tolerance, disease resistance and adap-tive traits while modifying grain colour and quality

162 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Table 5 Good practices of community biodiversity management in Nepal

Good practices Examples-crops and products Methods and approaches

(1) Improved access to unique and valuable crops and landraces

Bhatti landrace for swampy areas in Terai; Jetho Budho rice for quality rice in middle hills; Basaune ghiraula (aromatic sponge gourd) seeds

Diversity kits (small packets of seed) distributed through CBOs/farmer groups for informal research and development

(2) Value additions to culturally important landraces

Better packaging and marketing of quality Anadi rice in Pokhara, Nepal (e.g. Gunilo Brand)

Link and promote rural–urban market by improved processing, packaging and quality control

(3) Increase consumer demand by creating new markets for local crops and providing value added information

Millet breads, rolls, cookies, sweet rolls;Masura (vegetable dish made from chopped taro petioles and black gram fl our);Black gahat (horse gram) marketed for patients with kidney stone problems;Basaune ghiraula marketed as sponge gourd with better aroma and taste.

Identifying interested private entrepreneurs in action research and training to develop new products (e.g. Madhv café and Taja Bakery);marketing local products;nutrition and quality information provided on packaging

(4) Promoting geographic trademark of origin for local economically valuable landraces

Jetho Budho rice is recognized as premium price aromatic rice from Pokhara valley

Two populations of Jetho Budho were developed from germplasm enhancement of 338 populations of Jetho Budho from 7 major production sites. Improved cooking quality, milling recovery, plant height, disease resistance and community-based seed marketing

(5) Quality seed production for market incentives

Multiplication and marketing of locally adapted cultivars through extension agents and CBOs: Jetho Budho, Anadi, Kariya Kamod, Panchmukhe, Dudhe karkalo

Community seed production for farmers

(6) Improvement of landraces through PPB to make them competitive

PPB products of Mansara × Khumal –four cross

Participatory plant breeding by resource poor farmers to improve taste and productivity of Mansara (locally adapted variety)

(7) Links to markets Shorea robusta leaves from community forest;many local products of taro;condensed citrus juice (chuk);non-timber forest products.

E.g. Urban demand for biodegradable plates (tapari), essential for traditional Hindu offerings, worships and parties, contributes to livelihoods of Pratigya women groups, who make them from Shorea robusta leaves harvested from community forest

(8) Strengthening capacity of local institution as community resource centre

Diversity fairs;Diversity blocks;Diversity kits;Community biodiversity fairs (CBR);Community awareness programmes.

Local institutions, nodal farmers and farmers’ groups were trained to organize fairs, blocks, CBR and awareness programmes so that community manage local diversity for community benefi ts

Compiled from various sources: Sthapit et al., 2001, 2003a, b, c; Gauchan et al., 2004; Rijal et al., 2003b, c.

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 163

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

to suit local preferences (Joshi et al., 2002; Sthapit et al., 1995, 1996). Similarly, through PPB, Mansara rice, which is valued for better adaptation in poor fi elds, has been hybridized with a locally released, high-quality modern cultivar viz. Khumal-4 to improve the quality and yield of the Mansara variety, while still maintaining the trait adapted to low-input agriculture conditions (Sthapit et al., 2001). The involvement of farmers in the breeding process not only adds value to the conservation of local crop diversity but also helps maintain and enhance farm-ers’ knowledge about how to select and manage local crop populations, and manage seed supply systems through social seed networks. At the same time, diverse farmer preferences, agro-ecological niches and local farming systems help to conserve a reservoir of genetic diversity on-farm.

Conclusion

We found that there is a common pattern of how farmers valued genetic diversity. The results illustrate the rationale of managing a large number of cultivars at household levels: (1) varieties grown for food security or for the market tend to be cultivated in large areas by many households; (2) landraces culti-vated for socio-cultural (traditions, religious rituals) purposes are grown in small areas by many house-holds; (3) varieties with specifi c abiotic co-adaptive traits (such as being adapted to swamp soils, poor soils, drought) are grown in large areas by few house-holds; and (4) varieties with specifi c use values to particular families are grown in small areas by few households. The degree to which genetic diversity is used and valued by farmers can be measured in the proportion and size of the population planted within the fi elds of households in a community.

Biodiversity is a crucial asset available to resource-poor farmers for managing vulnerability, uncer-tainty, shocks and stresses and therefore, access to and control over such resources are a critical policy issue. The genetic diversity found within individual crops is also of value to ensure options as well as exploration value. Genetic diversity is needed to provide the raw materials with which farmers and plant breeders produce new varieties for changing contexts. Such diversity within crops is also essential to maximize yields and use options.

We also found that cultural identity shapes the preferences and tastes for a crop species and/or

for the traits of food prepared from a crop. Home gardens and uncultivated food from wild areas/forests are equally important for households in supplementing family nutrition and meeting other household health and cultural needs. In larger ecosystems, multiple farmer concerns (e.g. yield stability, risk and quality), environmental heteroge-neity, and the absence or presence of markets contribute to the persistence or prevalence of land-races. Social, cultural and religious uses are also important value systems for promoting conservation besides economic valuation. The indirect benefi ts offered by the diversity of plants are appreciated by local communities and these genetic resources will be sustainably used if the role of the community in blending traditional with scientifi c knowledge is institutionalized to promote collective actions for local innovation and for the commercial farming of locally available biodiversity assets.

To meet the need for more food, it will be necessary to make better use of a broader range of the world’s genetic diversity. Plant breeders, using biotechnology-based breeding methods, will need to consider, and in some cases work alongside, farmers where primary concerns are to continue the selection and use of the genetic diversity that is already available within their production systems.

Biodiversity assets relevant to poor people are being lost or not used optimally because they are not understood, valued or managed properly, either by research and development institutions or by policy makers and donor communities.

The studies revealed that genetic resources are one of the few resources available to resource-poor farmers to ensure their livelihoods and income. The world global community has an ethical respon-sibility to ensure these genetic resources are made available to future generations. With the improved opportunity to access such genetic resources and knowledge, farmers can improve their ability to meet food, nutrition and livelihood needs by grow-ing an assortment of crop varieties.

Acknowledgements

The work was supported by grants from the Swiss Agency for Development and Cooperation (SDC), The Netherlands Directorate-General for Interna-tional Cooperation (DGIS), International Develop-ment and Research Center (IDRC) Canada. The

164 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

authors are grateful to Dr Coosje Hoogendoorn, and Dr Geoff Hawtin for encouraging me to pres-ent this paper at the Tri-societies conference in Denver in 2003. I would also thank Dr V. Ramanatha Rao, Mr B. Regmi, LI-BIRD, Mr Resham Gautam, LI-BIRD, Dr Jwala Bajracharya, NARC, Dr D Gauchan, NARC, Mr Nguyen Ngoc De, Cantho University, and Dr Nguyen Ngoc Hue, Vietnam Agricultural Science Institute and Sajal Sthapit the College of Wooster for providing criti-cal comments, suggestions and information. I am also thankful to Ms Anne Huie and Ms Arwen Bailey for language editing.

Note

1. Green banana (Musa spp.), red orange kumquats (Citrofortnella microcarpa), yellow pomelo (Citrus grandis), purple colour chilli (Capsicum spp.) and pears (Pyrus pyrifolia).

References

Abdoellah, O.S., Parikesit, G.B. and Hadikusumah, H.Y. (2002) Home gardens in the Upper Citarum Watershed, West Java: A challenge for in situ conservation of plant genetic resources. In J.M. Watson, and P.B. Eyzaguirre (eds) Home Gardens and In Situ Conservation of Plant Genetic Resources in Farming Systems. IPGRI, DSE and GTZ, Proc of the Second International Home Garden Workshop, 17–19 July 2001, Witzenhausen, Germany, 140–147.

Bajracharya, J. (2003) Genetic diversity study in land-

races of rice (Oryza sativa L.) by agromorphological characters and microsatellite DNA markers. PhD thesis, University of Wales, Bangor, UK.

Brown, G.M. (1990) Valuing genetic resources. In G.H. Orians, G.M. Brown, W.E. Kunin, and J.E. Swierzbinski, (eds) Preservation and Valuation of Biological Resources (pp. 203–226). Seattle: University of Washington Press.

Brush, S.B., Taylor, J.E. and Bellon, M.R. (1992) Techno-logy adoption and biological diversity in Andean potato agriculture. Journal of Development Economics 39, 365–387.

Brush, S.B. and Meng, E. (1998) Farmers’ valuation and conservation of crop genetic resources. Genetic Resources and Crop Evolution 45, 139–150.

Brush, S.B. (2000) Genes in the Field: On-Farm Conser-vation of Crop Diversity (pp. 3–26). Canada: IDRC; Rome: IPGRI.

CAST (1999) Value of biodiversity in crop plants and animals. In Benefi ts of Biodiversity, Task Force Report No. 133, Centre for Agricultural Science and Technology (CAST), Ames, USA, 10–12.

Cleveland, D.A. and Soleri, D. (eds) (2002) Farmers, Scientists and Plant Breeding. Integrating Knowledge and Practice. Wallingford, UK: CABI Publishing.

Cromwell, E., Cooper, D. and Mulvany, P. (2001) Agri-culture, biodiversity and livelihoods: Issues and entry points for development agencies. In I. Koziell, and J. Saunders (eds) Living off Biodiversity: Exploring Livelihoods and Biodiversity Issues in Natural Resources Management. (pp. 79–112) London, UK: International Institute for Environment and Development.

Daniggelis, E. (2003) Women and wild foods: Nutrition and household security among Rai and Sherpa forager-farmers in Eastern Nepal. In P.L. Howard (ed.) Women and Plants: Gender Relations in Biodiversity Manage-ment and Conservation (pp. 83–95). London and New York: Zed Books.

Evenson, R.E., Gollin, D. and Santaniello, V. (1998) Agricultural Values of Plant Genetic Resources (pp. 1–25). Wallingford, UK: FAO and CAB.

Eyzaguirre, P. and Linares, O. (eds) (2004) Home Gardens and Agrobiodiversity (pp. 254). Washington, DC: Smithsonian Institution Press.

FAO (1998) The State of The World’s Plant Genetic Resources for Food and Agriculture. Rome: FAO.

Francis, C.A. (1986) Multiple Cropping Systems. New York: Macmillan.

Gauchan, D. and Smale, M. (2003) Choosing the “Right tools” to assess the economic costs and benefi ts of growing landraces. An illustrative example from Bara District, Central Terai, Nepal. Plant Genetic Resources Newsletter 134, 41–44.

Gauchan, D. (2004) Conserving crop genetic resources on-farm: The case of rice in Nepal. PhD thesis, University of Birmingham, UK.

Gollin, D. and Evenson, R.E. (1998) Breeding values of rice genetic resources. In R.E. Evenson, D. Gollin, and V. Santaniello (eds) Agricultural Values of Plant Genetic Resources (pp. 179–196). Wallingford, UK: FAO and CAB.

Gyawali, S., Sthapit, B.R., Bhandari, B., Shrestha, P., Joshi, B.K., Mudwori, A., Bajracharya, J. and Shrestha, P.K. (2006) Participatory plant breeding: A strategy of on-farm conservation and improvement of landraces. In B.R. Sthapit and D. Gauchan (eds) Proceedings of a National Symposium, 18–19 July 2006, Kathmandu, Nepal. On-farm Management of Agricultural Bio diver-sity in Nepal: Lessons Learned (pp. 164–173). Nepal Agricultural Research Council, LI-BIRD, Bioversity and IDRC.

Gurung, J.B. and Vaidya, A. (1998) The benefi ts to agrobiodiversity of the wide range of food culture in Nepal. In Tej Pratap and B. Sthapit (eds) Managing Agrobiodiversity; Farmers’ Changing Perspectives and Institutional Responses in the Hindu Kush Himalayan Region (pp. 55–62). Kathmandu: IPGRI/ICIMOD.

Hajjar, R., Jarvis D.I. and Gemmill-Herren, B. (2007) The utility of crop genetic diversity in maintaining ecosystem services. Agriculture, Ecosystems and Environ-ment 123 (4), 261–270.

Hodel, U. Gessler, M., Cai, H.H., Thoan, V.V., Ha, N.V., Thu, N.X. and Ba, T. (1999) In situ Conservation of

VALUE OF PLANT GENETIC DIVERSITY TO RESOURCE-POOR FARMERS 165

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Plant Genetic Resources in Home Gardens of Southern Vietnam. Rome: IPGRI.

Hue, N.N., Trinh, L.N., Ha, N.P., Sthapit, B.R. and Jarvis, D. (2003) Taro cultivar diversity in three ecosites of North Vietnam. In H.D. Tuan, N.N. Hue, B.R. Sthapit and D.I. Jarvis (eds) On-Farm Management of Agricultural Biodiversity in Vietnam (pp. 58–62). Rome: IPGRI.

Jarvis, D., Sthapit, B. and Sears, L. (eds) (2000) Conserving agricultural biodiversity in situ: A scientifi c basis for sustainable agriculture. Proceedings of a Workshop, Strengthening the Scientifi c Basis of in situ Conservation of Agricultural Biodiversity On-farm, 5–12 July 1999, Pokhara, Nepal; IPGRI, Rome.

Jarvis, D.I., Sevilla-Panizo, R., Chavez, J.L. and Hodgkin, T. (eds) (2004a) Seed systems and crop genetic diversity on-farm. Proceedings of a Workshop, Strengthening the Scientifi c Basis of in situ Conservation of Agricultural Biodiversity On-farm; Seed Systems and Crop Genetic Diversity On-farm, 16–20 September 2003, Pucallpa, Peru: IPGRI, Italy.

Jarvis, D.I., Zoes, V., Nares, D. and Hodgkin, T. (2004b) On-farm management of crop genetic diversity and the convention on biological diversity programme. Plant Genetic Resources Newsletter 138, 5–17.

Johns, T. and Sthapit, B.R. (2004) Biocultural diversity in the sustainability of developing country food systems. Food and Nutrition Bulletin 25 (2), 143–155.

Joshi, K.D., Sthapit, B.R., Subedi, M. and Witcombe, J.R. (2002) Participatory plant breeding in rice in Nepal. In D.A. Cleveland and D. Soleri (eds) Farmers, Scientists and Plant Breeding Integrating Knowledge and Practice (pp. 239–268). UK: CABI Publishing.

Kennedy, G. and Burlingame, B. (2003) Analysis of food composition data on rice from a plant genetic resources perspective. Food Chemistry 80, 589–596.

Krutilla, J.V. (1967) Conservation reconsidered. American Economic Review 57, 777–786.

Mazhar, F., Buckles, D., Satheesh, P.V. and Akhter, F. (2007) Food Sovereignty and Uncultivated Biodiversity in South Asia. Essays on the Poverty of Food Policy and the Wealth of the Social Landscape. New Delhi: IDRC, Academic Foundation.

Nair, P.K. (2001) Do tropical home gardens elude science, or is it the other way round? Agroforestry Systems 53, 239–245.

OECD (2002) Handbook of Biodiversity Valuation. A Guide for Policy Makers. Paris, France: Organization for Economic Cooperation and Development.

Ogle, B.M., Hung, P.H. and Tuyet Ho Thi (2001) Signifi cance of wild vegetables in micronutrient intakes of women in Vietnam: An analysis of food variety. Asia Pacifi c Journal of Clinical Nutrition 10 (1), 21–30.

Pant, L.P. (2002) Linking crop diversity with food tradi-tions and food security in the hills of Nepal. NORAGRC MSc thesis, NLH Agricultural University of Norway, Norway.

Rana, R.B., Garforth, C., Jarvis, D. and Sthapit, B.R. (2007) Infl uence of socio-economic and cultural factors in rice varietal diversity management on-farm in Nepal. Agriculture and Human Values 24 (4), 461–472.

Rana, R.B. (2004) Infl uence of socio-economic and cultural factors on agrobiodiversity conservation on-farm in Nepal. PhD thesis, The University of Reading, UK.

Rao, K.P.C. and Evenson, R.E. (1998) Varietal trait values for rice in India. In R.E. Evenson, D. Gollin and V. Santaniello (eds) Agricultural Values of Plant Genetic Resources (pp. 151–156). Wallingford, UK: FAO and CAB.

Regmi, B.R., Aryal, K., Tamang, B. and Shrestha, P.K. (2005) Home gardens: An opportunity to minimize pressure on slash and burn system and option for improving dietary diversity of Chepang households. In Home Gardens in Nepal. Proceedings of a Workshop, 6–7 August 2005, Pokhara, Nepal. IPGRI/LI-BIRD.

Regmi, B.R., Subedi, A., Aryal, K.P., Shrestha, P.K., Sthapit, B.R. and Tamang, B.B. (2003) Looking into the life of Chepang. Discussion Paper, LI-BIRD, Pokhara, Nepal (unpublished).

Rijal, D.K., Sthapit, B.R., Rana, R.B., Tiwari, P.R., Chaudhary, P., Pandey, Y.R., Poudel, C.L. and Subedi, A. (1999) Options for adding benefi ts of local crop diver-sity through a non-breeding approach: Experiences of Jumla, Kaski and Bara sites in Nepal. In B.R. Sthapit, M.P. Upadhyay and A. Subedi (eds) A Scientifi c Basis of In-Situ Conservation of Agricultural Biodiversity in Nepal. NP Working Paper No. 1/99, pp. 100–110.

Rijal, D.K., Sthapit, B.R. Rana, R.B., and Jarvis, D.I. (2003) Adaptation and uses of taro diversity in agro-ecosystem of Nepal. In B.R. Sthapit, M.P. Upadhyaya, B.K. Baniya, A. Subedi and B.K. Joshi (eds) On-Farm Management of Agricultural Biodiversity in Nepal. Proceedings of a National Workshop, 24–26 April 2001, Lumle, Nepal, 29–36.

Scoones, I., Melnyk, M. and Pretty, J. (eds) (1992) The Hidden Harvest – Wild Foods and Agricultural Systems. A Literature Review and Annotated Bibliography. London: IIED.

SEARICE (2003) Strengthening farmers’ agricultural biodiversity management systems. In Conservation and Sustainable Use of Agricultural Biodiversity: A Source Book. Vol. III. Ensuring an Enabling Environment for Agricultural Biodiversity. Philippines: CIP-UPWARD, GTZ, IDRC, IPGRI, SEARICE.

Shrestha, P., Gautam, R., Rana, R.B. and Sthapit, B.R. (2002) Home gardens in Nepal: Status and scope for research and development. In J.W. Watson and P.B. Eyzaguirre (eds) Home Gardens and In Situ Conservation of Plant Genetic Resources in Farming Systems, 17–19 July 2001, Witzenhausen, Germany/IPGRI, Rome, pp. 105–124.

Shrestha, P., Subedi, A., Sthapit, S., Rijal, D., Gupta, S.K. and Sthapit, B. (2006) Community seed bank: Reliable and effective option for agricultural biodiversity conservation. In B.R. Sthapit, P.K. Shrestha and M.P. Upadhyay (eds) Good Practices: On-Farm Management of Agricultural Biodiversity in Nepal. NARC, LI-BIRD, IPGRI and IDRC.

Simpson, R.D. and Sedjo, R.A. (1998) The value of genetic resources for use in agricultural improvement. In R.E. Evenson, D. Gollin, and V. Santaniello (eds)

166 B. STHAPIT ET AL.

INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY 6(2) 2008, PAGES 148–166

Agricultural Values of Plant Genetic Resources (pp. 55–66). Wallingford, UK: FAO and CAB.

Smale, M., Bellon, M., Jarvis, D. and Sthapit, B. (2004) Economic concepts for designing policies to conserve crop genetic resources on-farms. Genetic Resources and Crop Evolution 51, 121–135.

Smale, M. (2006) Valuing Crop Biodiversity On-Farm Genetic Resources and Economic Change. UK: CABI Publishing.

Sthapit, B.R., Pradhanang, P.M. and Witcombe, J.R. (1995) Inheritance and selection of fi eld resistance to sheath brown rot disease in rice. Plant Disease 79 (11), 1140–1144.

Sthapit, B.R., Joshi, K.D. and Witcombe, J.R. (1996) Farmer participatory crop improvement. III. Partici-patory plant breeding, a case study for rice in Nepal. Experimental Agriculture 32, 479–496.

Sthapit, B.R., Sajise, P. and Jarvis, D. (2000) Strength-ening scientifi c basis of in situ conservation on-farm: Learning experiences from Nepal and Vietnam. In J. Xu (ed.) Links Between Cultures and Biodiversity (pp. 338–357). Proc of the Cultures and Biodiversity Congress 2000, 20–30 July 2000, Yunnan, China. China: Yunnan Science and Technology Press.

Sthapit, B.R., Joshi, K.D., Rana, R.B., Upadhyay, M.P., Eyzaguirre, P. and Jarvis, D. (2001) Enhancing biodi-versity and production through participatory plant breeding: Setting breeding goals. In An Exchange of Experiences from South and South East Asia: Proceedings of the International Symposium on PPB and Participatory Plant Genetic Resource Enhance-ment, Pokhara, Nepal, 1–5 May 2000, PRGA, CIAT, CA, 29–54.

Sthapit, B.R., Rijal, C., De, N.N. and Jarvis, D. (2003a) A role for diversity fairs: Experiences from Nepal and Vietnam. In Conservation and Sustainable Use of Agricultural Biodiversity: A Source Book, Volume II: Strengthening Local Management of Agricultural Biodiversity (pp. 271–276). Los Banos, Philippines: International Potato Centre (CIP) and User’s Perspec-tives with Agricultural Research and Development (UPWARD).

Sthapit, B.R., Subedi, A., Rijal, D., Rana, R. and Jarvis. D. (2003b) Strengthening community-based on-farm conser-vation of agricultural biodiversity: Experiences from Nepal. In Conservation and Sustainable Use of Agricul-tural Biodiversity: A Source Book Volume II: Strength-ening Local Management of Agricultural Biodiversity (pp. 344–354). Los Banos, Philippines: International Potato Centre (CIP) and User’s Perspec tives with Agricultural Research and Develop ment (UPWARD).

Sthapit, B.R., Subedi, A., Gyawali, S., Jarvis, D. and Upadhyaya, M.P. (2003c) In situ conservation of agri-cultural biodiversity through participatory plant breeding in Nepal. In Conservation and Sustainable Use of Agricul-tural Biodiversity: A Source Book, Vol II: Strengthening Local Management of Agricultural Biodiversity (pp. 311–321). Los Banos, Philippines: International Potato Centre (CIP) and User’s Per spec tives with Agricultural Research and Development (UPWARD).

Subedi, A., Chaudhary, P., Baniya, B.K., Rana, R.B., Tiwari, R.K., Rijal, D.R., Sthapit, B.R. and Jarvis, D.I. (2004) Who maintains genetic diversity and how: Implications for on-farm conservation and utilization. Culture and Agriculture 25 (2), 41–50.

Subedi, Av., Suwal, R., Gautam, R., Sunwar, S. and Shrestha, P. (2005a) Plant diversity in home gardens of two different eco-geographical regions of Nepal. In R. Gautam, B.R. Sthapit, and P. Shrestha (eds) Home Gardens in Nepal. Proceedings of a Workshop, 6–7 August 2005, Pokhara, Nepal. Nepal: IPGRI/LI-BIRD.

Subedi, Av., Sthapit, B., Upadhyay, M.P. and Gauchan, D. (eds) (2005b) Learning from community biodiversity register in Nepal. Proceedings of the National Workshop, 27–28 Oct 2005, Khumaltar, Nepal.

Sunwar, S. (2003) Understanding the plant diversity and its contribution to on-farm conservation of plant genetic resources in home gardens of nepalese farming systems. MSc thesis, The Swedish Biodiversity Centre (CBM), Uppsala, Sweden.

Swanson, T. (1996) Global values of biological diversity. Plant Genetic Resources Newsletter 105, 1–7.

Swanson, T. (1998) The sources of genetic resource values and the reasons for their management. In R.E. Evenson, D. Gollin, and V. Santaniello (eds) Agricultural Values of Plant Genetic Resources (pp. 67–84). Wallingford, UK: FAO and CAB.

Tanksley, S.D. and McCouch, S.R. (1997) Seed banks and molecular maps: Unlocking genetic potential from the wild. Science 277, 1113–1116.

TARI (2003) Taiwan creates new rice strains. The Nation 28, 50116, 11 July 2003, Taiwanese Agricultural Research Institute (TARI), Taiwan.

Trinh, L.N., Cuong, P.H., Hue, N.N., Ha, N.P. and Nien, D.V. (2003a) Genetic diversity within farmers’ rice varieties in three eco-regions of north Vietnam over time. In H.D. Tuan, N.N. Hue, B.R. Sthapit and D.I. Jarvis (eds) On-Farm Management of Agri cultural Biodiversity in Vietnam (pp. 6–19). Rome: IPGRI.

Trinh, L.N., Watson, J.M., Hue, N.N., De, N.N., Minh, M.V., Chu, P., Sthapit, B.R. and Eyzaguirre, P.B. (2003b) Agrobiodiversity conservation and development in Vietnamese home gardens. Agriculture, Ecosystems and Environment 2033, 1–28.

Tuan, H.D., Hue, N.N., Sthapit, B.R. and Jarvis, D.I. (eds) (2003) On-Farm Management of Agricultural Biodiversity in Vietnam. Proceedings of a Symposium, 6–12 Dec 2001, Hanoi, Vietnam; Rome: IPGRI.

UBINIG (2000) Proceeding of South Asian Workshop on Uncultivated Food and Plants, 2–4 October 1999, Tangail, Bangladesh.

Watson, J.W. and Eyzaguirre, P.B. (eds) (2002) Proceeding of the Second International Workshop: Home Gardens and In Situ Conservation of Plant Genetic Resources in Farming Systems, 17–19 July 2001, Germany. Rome: IPGRI.

Wilken, G. (1970) The ecology of gathering in a Mexican farming region. Economic Botany 24, 286–295.

Wilson, E.O. (1988) Biodiversity. Washington, DC: National Academy Press.