Home gardens and their role in the conservation of Taro diversity in Vietnam

Transcription

1 Home gardens and their role in the conservation of Taro diversity in Vietnam Nguyen Thi Ngoc Hue 1, Luu Ngoc Trinh 1 and Nguyen Van Minh 2 1. Plant Genetic Resources Centre, Vietnam Agricultural Science Institute, Van Dien, Thanh Tri, Hanoi, Vietnam. ntngochue@hn.vnn.vn 2.Plant oil and perfumes research Institute, Ham nghi street, Ho Chi Minh City, Vietnam. Abstract Home gardens, known in Vietnamese as vuon nha, reflect complex layers of meaning to the farmers who create them. In Vietnam, home gardens are patches of land of varying dimensions surrounding rural houses that are commonly planted with fruits, vegetables and root crops. Better understanding of home gardens in Vietnam and the ways that they can serve as conservation sites for taro and other indigenous crops is essential. This study was conducted primarily to determine the nature of home gardens; the activities of garden custodians, and the role home gardens may have in conserving Taro genetic resources. Surveys of home gardens and interviews of garden custodians were made in four locations in the country: the Red River Delta (Nho Quan), the Northern Midlands (Nghia Dan), suburban Ho Chi Minh City (Thuan An), and the Mekong River Delta near Cantho (Chau Thanh). Participatory approaches, focus group discussion were used to collect data. The home gardens in different zones generally differed in their size, structure, and the manner in which they were maintained. Taro was selected as a key home garden species because it is present in home gardens from the North to the South of Vietnam, as well as in the larger agro ecosystem. Taro is important in household food security because it is a crop that is often used and maintained by rural women. Study results indicate that during the long history of taro cultivation, local people in Vietnam have accumulated rich indigenous knowledge and experience in the use and management of taro resources. Different varieties of taro are grown for different purposes and under different maintenance regimes depending on the farmer making the selections. The fact that a number of discrete varieties of taro were found in home gardens and were not present in the larger fields and paddies suggests that home gardens are good avenues by which to conserve the genetic diversity of taro. Key words: Taro, Colocasia spp., Xanthosoma spp., garden custodian, indigenous knowledge, insitu conservation Introduction Taro is one of the common root crops in Vietnam where it is used in various ways not only by the people in the rural area but those in urban places, as well. Its corm or cormel of a common variety is used for food while the stem is fed to pigs, the stolon of another variety is chopped and boiled to make a medicine for constipation. There is another kind producing a tasty new leaf and petiole which are stir-fried with garlic to make a special dish eaten on Festival days or cooked special soups as lau ; bun moc. Some varieties with particularly tasty corms can be grown on a large- scale for commercial production. Truong Van Ho et al (1996) and Nguyen Ngoc Hue (2) noted that taro plays an important part in the culture of the people in some parts of the country. Freshly harvested corms are a preferred gift by rural people to relatives in the towns or cities in special occasions. In Vietnamese homegardens, taro in commonly grown with other vegetable plants in an orderly or random fashion. The level of genetic variation in garden-planted taro appears higher in places where its importance is greater than in areas where the crop is not highly regarded. Eyzaguirse (1996) mentioned that the genetic diversity present in Home garden is closely linked to the multiple and varied uses of the plants by traditional households. In other hand, Taro crop generally faces various threats in Vietnam ( Nguyen Thi Ngoc Hue et al 2). In the global science, taro is one of the crops considered as neglected. In view of this, the role of Home garden in the conservation of taro have to be seriously evaluated especially that the local. This paper presents the role of the Home garden and garden custodians in the conservation of Taro genetic resources.

2 Materials and methods PRA Surveys were conducted in 4 ecological regions in the country: The Red River Delta (Nhoquan), the Northern Midlands (Nghiadan) suburban HochiMinh City (Thuan An) and the Mekong River Delta near Can Tho (ChauThanh). The survey was done to locate home garden of any dimension, which induce taro as one of its component crops. This aimed to gather the information on Home garden structure, size, the measure instituted by householders to protect the garden plants, determining the number of taro varieties present in the garden and the manner in which taro is being kept in the garden in association with the other vegetable or crop plants. Sixty, thirty, sixty and thirty home gardens were point of the survey in Nho quan, Nghia dan, Thuan an and Chau thanh, respectively.the interview involved the home garden owners in which the man and women was the preferred informant. The interview intended to know the family member incharge of taking care of the garden, purpose of maintaining the garden, reason for including taro as one of the crop in their garden, name given to the taro varieties and their use value present in the garden and length of time the crop has been planted in the garden. Results and discussions Description of the home gardens structure and composition Vietnam home garden links closely with the livelihood of Vietnamese farmers, especially with those are poor. Today home garden receive increasing importance for generating income and for improving material and cultural living standard of the rural people. Actually, the total area of Home garden in Vietnam was estimated at approximately 2. ha, which covers around 4,% of the agricultural cultivated area. Area of home gardens is lowest in the RRD with the average size 15m2 and largest in the Central Platen (West Highland) with the average size,5ha. Majority of the home gardens surveyed in Vietnam were located less than 1m from the residence of the garden owner. Reasons are to make the garden easily accessible by any member of their household to pick vegetable from quickly, easterly watching over the garden and driving away foraging animals like pigs and poultry and the plants in the garden can contribute in beatifying the landscape immediately surrounding the house. Throughout Vietnam, a bare dirt or paved area opens directly in front of the house, with ornamentals bordering the open space or lining a walkway, including flower species such as the Hue lily (Polianthes tuberosa) and the Hibiscus (Abelmoschus moschatus tuberosus), whose flowers are often placed daily on the household shrine. Medicinal and herb species are often located on the edge of the open porch area, for easy access. Fruit trees are mostly located behind the house, with a few choice species in the front, often the bigger fruit trees (>5m tall) such as eggfruit (Lucuma mammosa) that also provide shade to the cleared house yard. Gardens in lowland areas may have canals that are dug to create raised beds of land, providing good drainage in the rainy season and maintaining water supply in the dry season. In this way, diverse types of crop species can be accommodated into small niches. Fruit trees are planted on the higher ground and interspersed with lower-story crops such as Colocasia esculenta, Xanthosoma sagittifolia, Capsicum sp., or Mentha sp. The ditches are either used for drainage or irrigation depending on the region of Vietnam (primarily drainage in the Mekong Delta) and the season of the year. Ditches or ponds can accommodate crops that need more moisture, such as Ipomoea aquatica, Eichhornia crassipes, and Sagittaria sagittifolia (Hodel & Gessler, 1999). There is usually a more open area of the home garden where vegetables requiring lighter such as Solanum undatum or Brassica oleracea are grown. Bamboo (Bambusa multiplex) often provides a side or back border, with cacti commonly used as a lower fence for the front of the yard. Home garden in Vietnam can be classified in to general categories based on primary production system, crop composition and structure of home garden: Home garden with fruit tree (South Vietnam) with pond and covered livestock area (RRD and Central Vietnam) or with some vegetables. But almost are Home garden with mixed planting of crops: Fruit, Medicinal, vegetable, spice, root crop 2

3 and ornamental, 85.8, 93,3%, 91.4, % and 5% being percentage of Home garden with mixed planting of crops were found in Nho Quan, Nghia Dan, Thuan An and Chau Thanh respectively ( Table 1). Maintenance of the Home garden. A high proportion( 8%) of the Fruit homegardens inspected in Chau Thanh are systematically maintained. Their components plants regardless of species are appropriately spaced in fitly arrange rows. The plants of the same species are usually planted together in one part of the garden. The manner of maintaining the plants in most gardens in midlands and mountain is mixed planting of crops without proper planting distance and arrangement. The plant grows at random in a strictly mixed semblance without regular spacing. In many home gardens of Nho Quan and Nghia Dan districts some the disorganized garden were surveyed due to lack of labor resource. As far as the security of the plants in the garden from foraging animals is concerned in NhoQuan and Nghia Dan. A significant number of the Home garden is only being watched over by the owners. More than 5% Home garden in Vietnam inspected is fenced around garden custodians. Some of the gardens needed no watching and facing because their custodians have their pigs, cow and poultry kept in pens. Taro as garden plant One hundred of the total number of gardens in Nghia dan and Thuan an contain two or more taro varieties. 1% gardens in Chau thanh contain two taro varieties. In Nhoquan proportion of gardens with one, two, three or more taro varieties is 46.7%, 13.3%, and 4.% respectively of the total gardens (Table 3). In home garden at all study sites, the taro is made to occupy the shaded or moisture portion of the garden. In 1% homegarden in Chauthanh and 5% of HG in Nghiadan, where the Taro that do not tolerance soil moisture occupy the drier portion of the gardens. Feral taro is in fact grown even along household drainage, canals or artificial waterways. Garden keepers know very well the adaptability of Taro with natural condition of homegarden. With the long history of homegarden farming, different local names of the Taro varieties varied from one region to another. In Nhoquan, some varieties are named according to their special characteristics. For instance, variety name "Docmung" which means petiole utilization. The farmers explained that this variety is so named because it s petioles are excellent vegetable item and can be cooked together with some other vegetable and fish or meat making in special food (Lau). Bac ha is other name of taro cultivar referring with its name to the silver color of petiole. "Khoai nuoc" or Ngua is common name of feral type of taro that is made to plant along drainage canals. " Sap" meaning nice sticky corm with yellow waxy color of the root flesh, is another local name given to a native taro variety. "Tamdaoxanh" is named according to their original place, where this variety firstly introduced from France. Moncao is named for high yielding corm variety. Sen refers with its name to the lotus plant. A local name however, is not understood by gardeners themselves as Tau". This name is simply adopted from the ancestors. In Nhoquan, 6 discrete varieties of taro were found. Garden custodians using vernacular names can readily identify all of them. Similarly in Nghiadan, Thuanan and Chauthanh, the number of taro varieties is 4, 6 and 5 were observed respectively. Some of discrete varieties of taro were found in homegardens and were not present in the larger fields and paddies (Table 2). The garden plants planted in HG are different and vary from one garden to another in the four sites. In Nhoquan, the commonly observed plants grown with taro are Luffa (Luffa cylindrica) sweet potato (Ipomea batatas), Lablab (Dolichos lablab), watercress (Ipomea aquatic) and Ginger (Zingiber officinale). In Nghiadan, Yam (Dioscorea alata) and sweet potato, Alpinia tonkinensis were the most prevalently planted crops together with taro. In both sites of the North, the lemon(citrus aurantifolia), Pherynium parviflorum Roxb, eggplant (Solanum melogena) and Chili (Capsicum annum) are also common. In Thuanan and Chauthanh, taro is always to be grown under shade of fruit trees with 3

4 different kind of spices and tropical vegetables as eggplant (Solanum sp.), Chilles (Capsicum sp.) and Bitter gourd (Momordica charantia) Role of home garden custodians Preliminary results show that men make most decision relating to cultivation of fruits and ornamental (Luu Ngoc Trinh et al.2). In contract, spices, vegetable and root and tuber crops seem to be the work domain of women. Their crop species in no doubt are most important for home consumption and seem to be closely related to daily meal preparation works of women. In our research results, this can demonstrate by higher percent of mother, who originally planted taro in HG in both four sites. In Nhoquan almost (95,4) of households obtained their first planting materials of taro from relatives, the rest got from market. Contract; in Nghiadan half of garden owners had taro source from relatives, the 5% rest acquired taro from relatives and market. In HG, different types of taro are cultivated for the use of different part. Different ethnic groups have their own way of preparing taro and there are special occasions and festival, when the products of taro are relished (Table 2). The extent and distribution of taro cultivars may vary with natural ecology, farmer's specific preferences, socioeconomic conditions, market forces and cultural values. One hundred percent of the gardens in Nhoquan, Nghiadan, Thuanan, include taro for food and feed purposes, but in Chauthanh 9% HG, where mainly taro is grown for income, only 1% for food and feed. In Nhoquan all of gardens have taro for five years or more. In Nghiadan 2% of home garden have taro for just about a year, 5 % have the plant for 2-5 years already, the rest 3% of home garden are maintaining taro for more 5 years. In Thuan an most of home garden have taro for 5 or more years. The rest are taro having less 5 years (Table 3) Majority of home garden custodies in three sites claimed that they do not have problem with taro as a garden plant because it is easy to grow, propagate and maintain. Those that expressed other problem are drought. In contract, in Chauthanh the custodies complain that they have problem with pest and Leaf blight disease with taro growing. In Nghiadan and Nhoquan a great majority of the garden owners do have preferred variety, where as in Thuan an about 65,7% of the gardeners do not have any preferred ones. The taro qualities, with garden and owners in both sites Nhoquan and Nghiadan, Thuanan and Chau thanh prefer are ease in cook, delicious taste of corm and stolons and big corms. When used as vegetables, majority of the garden owners in Nhoquan and Thuanan use petiole and stolons weakly, where in Nghiadan, 3% of gardens owners harvest petiole and stolon every weakly (Table 3). Conclusion Home garden types in Vietnam are numerous and diversified. Depending on the agro ecology, market forces and traditional culture specific to an area, the composition and structure of Vietnamese homegarden vary markedly. In throughout country, the taro is commonly grown in HG. The area under taro in HG is small but sustainable and taro plays a significant role in household food security as every household maintains and gowns at least a variety of taro. The custodies preparation, choice of variety, cooking style and eating time vary with ethnicity and ecological distribution. During the long history of taro cultivation, local people in Vietnam have accumulated rich indigenous knowledge and experience in the use and management of taro resources. Different varieties of taro are grown for different purposes and under different maintenance regimes depending on the farmer making the selections. In aspect of genetic diversity, taro diversity in home garden, is practically rare of genetic erosion. The fact that a number of discrete varieties of taro were found in home gardens and were not present in the larger fields and paddies suggests that home gardens are good avenues by which to conserve the genetic diversity of taro and home garden can play complement role by in situ conservation for taro genetic resources. 4

5 Table 1. Feature of the home gardens in Vietnam Features Distance from the owner's residence (m) 1. Less than More than 2 Approximate areas (m2) 1. Less than More than 4 Condition of the HG 1. Area is shaded by tree 2. Soil is moisture 3. Soil is well drained 4. Area not shaded by tree Safety measures provided 1. With fence all around 2. Animal nearby are tied 3. Owners watch the garden 4. Others Nho quan 1 6,7 73, Total number of Home gardens (%) Nghia dan Thuan an Chau thanh Planting pattern 1. Mixed planting of crops without proper planting distance and arrangement. 2. Systematically planted with proper planting distance and arrangement 3. Others 93,3 6, Home garden composition 1. With fruit tree 2. With pond and covered livestock areas 3. With vegetables 4. With forest tree 5. Mixed planting of crops Portion where taro is planted 1.. Shaded 2. Moist area 4. Others, dry part

6 Table 2 Local name Nuoc tia Nuoc xanh Bac ha Tam Dao xanh Tam dao tia Mon do Cao Mon Sap Doc mung Mon ngot Khoai So Tim Ngua Sen Tau Main morphological characteristics and use value of some discrete Taro varieties observed in Home Garden in Vietnam. Morphological characters Distribution Uses Plant Height 1-12 cm, Dark purple petiole, dark green leaf, yellow junction color, Ellipse corm, Itches, Some and very short stolon 8-95cm, Green petiole, green leaf, pink margin leaf, Small oval corm, very itches, Many and long stolon 5-1cm, Round, light green leaf, White-Green Petiole with glaucous, Very small corm, itches, Rare and Short stolon, 7-13cm, Glaucous green petiole, big green leaf, Corm with cylinder shape, white flesh and white apex, Not stolon, 7-1cm, Cup-shaped dark green leaf, dark purple glaucous petiole, Oval corm, long oval cormel with purple fiber flesh, Not stolon 8-1cm, Dark green leaf with purple junction, red purple petiole, Very small oval corm, Not stolon, 1-14cm,Green leaf and petiole, Round corm 7-1cm, Green leaf, green petiole, Round corm with many oval cormels, 8-1, Green leaf, Green with purple stripe petiole, Purple junction, Small corm, itches, 8-11cm, Green leaf, Red junction and top petiole color, big round corm. 8-1cm, Green leaf, Green with purple Stripe, Small round corm 9-11cm, Big, long, lumpy corm, purple flesh color, 12-14cm, Small leaves, Purple junction color, oval corm very itches, Long stolon, 9-1cm, Large leaves Green light violet towards upper end, Big oval tuber, Glutinous 9-1cm, Glaucous green petiole, Big and green leaf, Oval corm, Drainage canals. Drainage canals, moisture area Shade area, along lower fence for the back of the house. Uplands, under fruit trees Drainage canals near well Near well Uplands with fruit tree Dry area with fruit tree Drainage canals near well Under shade of fruits Intercropping with sweet potato Shade area Drainage canals, Beside ponds Intercropping with spices Under shade of fruits Pig feed Pig feed, Stolon used for cuisine bup khoai so kho tuong and khoai nau me Petiole used as vegetable for Lau, Bun moc Food and Fodder Petiole used as Vegetable and pig feed, Cormel for soup Medicine for stomach ill and dysentery Food and Pig feed Food and feed Food and Feed Food, cake Boiled eat, soup Food, cake Animal feed Sweet soup, Sweeten soup 6

7 elliptical cormel, Yellow flesh Table 3. Facts about of the home garden with taro in Vietnam Facts Person responsible in the care of the garden 1. Husband 2. Wife 3. Other, parents Gender distribution in decision making for Taro crop (%) 1. Female 2. Male 3. Both Purpose in planting taro 1. For food and feed 2. For income 3. Other Person who originally planted taro in home garden 1.Father 2.Mother 3.Other household member Source of original taro planting materials 1. Other taro grower 2. Relatives 3. Market Total number of homegarden (%) Nho quan Nghia Dan Thuan an Chau thanh , Years of maintaining taro in garden 1. About 1 year 2. Less than 5 year 3. Five years or more Number of taro maintaining in garden 1. One 2. Two 3. More two Frequency of harvesting taro for vegetable Almost daily Weekly Monthly Yearly Have not harvested yet

8 Acknowledgement Dinh Van Dao from VASI, Nguyen Hong Tin from Cantho University and Phan Thi Chu from Phuqui fruit research center are duly acknowledged for data collecting. We are also indebted to the donors who made the study possible through their financial support, Germany s GTZ/BMZ (Deutsche Gesellschaft fur Technische Zusammenarbeit/German Federal Ministry for Economic Cooperation and Development). References 1.Eyzaguirre, P. (1996). IPGRI work on the ethnobotany and economics of the conservation and use of plant genetic resources. IPGRI-APO Newsletter 2: 1-2(1996) 2. Hodel, U., Gessler, M. et al.(1999). Hodel, U., Gessler, M., Cai, H.H., Thoan, V.V., Ha, N.V., Thu, N.X., and Ba, T., In situ conservation of plant genetic resources in home gardens of southern Vietnam. IPGRI, Rome. 3.Luu Ngoc Trinh et al. (2) Technical report of In situ Project LoA98/18 for 2 year. 4.Nguyen Thi Ngoc Hue. (2). Taro diversity and use in Vietnam. In: Ethnobotany and genetic diversity of Asian taro: focus on China.IPGRI-CSHS, 2, p Truong Van Ho, et al. (1994) Root and tuber crop Genetic Resources in Vietnam. P in Proceedings of the International workshop on Plant Genetic resources, 15-17March, MAFF Research Council, Japan. 8