Abstracts on Sustainable Agriculture (GTZ, 1992, 423 p.)[edit | edit source]
Abstracts on homegardens[edit | edit source]
Acknowledgements[edit | edit source]
1180 92 - 8/41
Asia, proceedings, workshop, household gardens, sustainable development, nutrition, projects, failures, successes, AVRDC
MIDMORE, D.J. et al.
1. Household gardening projects in asia: past experience and future directions[edit | edit source]
AVRDC Technical Bulletin No. 19; Workshop Report, Bangkok, Thailand, Mai 1991; price developing countries USD 3.50, elsewhere USD 5.00
Food production near human settlements has been a major food security and survival strategy, particularly in the developing world. Since household gardens have been around almost since the beginning of agriculture, they have been taken for granted and their benefits sometimes go unnoticed.
At AVRDC the household garden concept is receiving renewed attention because of its considerable potential as a development tool. Such food gardens contribute substantially to the nutritional and economic status of the poor.
The benefits and advantages of household garden projects as well as the constraints and implementation strategies were among the issues discussed in a 3-day workshop organized by AVRDC, the Users Perspective with Agricultural and Rural Development (UPWARD) and the International
Development Research Centre (IDRC) for practioners in Asia and elsewhere on 12-15 May in Bangkok.
Participants came from Bangladesh, Indonesia, the Philippines, Sri Lanka, Taiwan, Thailand and the USA.
The participants discussed the constraints and factors that have contributed to the success and failure of particular garden projects.
Too often, homestead or underutilized marginal land is the only resource available to the landless and near-landless groups and urban slum dwellers. Intensive gardening can turn this space into a productive source of food and economic security. The technology requires little capital investment and risk.
Household gardens are efficient users of soil, water, sunlight and household wastes, and therefore present an ecologically sound land management system. As a multiple cropping system, they prevent depletion of soil nutrients and represent repositories of diverse plant genetic resources. They also do not use toxic chemicals in contrast to field-based agriculture.
Household gardens are also an efficient way of using limited resources such as time, energy, money and land among the low-income groups. They offer women, who are usually the providers of family meals, with an important means of earning income without overtly challenging cultural and social restrictions on their activities. In addition, other family members such as the children and the elderly can provide labor.
One of the glaring reasons identified by the participants for the failure of garden projects was the lack of a long-term commitment of development and funding agencies and project personnel. This can be attributed to the perception that household food production is easy to promote, which is hardly the case.
Reaching the poorest segments of the population is actually more difficult than getting through to the large-scale commercially-oriented farmers due to psychological, educational, social, motivational and behavioral barriers.
Promoting household food production requires qualified and committed project personnel who understand the local situation. Furthermore, there is a need to develop technologies that are compatible with household needs and resources.
To ensure the long-term success of this development intervention, integrated support for family gardens within the existing national agricultural development framework must be promoted.
A summary of the recommendations of the participants for successful implementation of garden projects follows below:
- Build upon user needs from the beginning of the project.
- Use secondary information and cost-effective appraisal techniques to assess the limiting constraints in the project.
- Formulate clear and achievable objectives.
- Use already available potential solutions to constraints faced in household production.
- Offer complete technology packages to promote household gardens since marginal households are selective and adaptive in their adoption and use of recommended practices and technologies.
- Emphasize locally-adapted species, but not to the complete exclusion of commercially exotic species.
- Direct training at users, through community-based garden promoters and the judicious siting of demonstration plots.
- Employ social marketing techniques to build up motivation and provide nutrition education.
- Exercise caution in evaluating the difficult-to-assess social benefits of garden projects.
- Motivate project participants to take up household production for its own intrinsic value rather than for free inputs which distort incentives and affect the sustainability of results.
1181 92 - 8/42
Developing countries, Asia, Africa, Latin America, strategic plan, vegetables, economic value, agroecological zones, production systems, research, training, technology, transfer, monitoring, international cooperation
2. Vegetables research and development in the 1990s - a strategic plan[edit | edit source]
AVRDC Publication No. 91-362; AVRDC, P.O.B. 205, Taipei 10099; ISBN 92-9058-050-x, 1991, 61 p.
This 10-year strategic plan outlines the nature of the challenge and describes AVRDC's vision of the future. It reviews AVRDC's current status as an institution and analyzes the choices it has made in revising its strategy and planning its future activities and programs.
Vegetables are important foods and vegetable production, marketing and processing are significant contributors to income. Population growth and urbanization are creating increased demand for food, and concerns are rising about malnutrition, especially in peri-urban areas. There is also growing concern that unenlightened methods of vegetable production are having adverse effects on the environment.
Economic trends suggest that vegetables will increasingly contribute to improved diets in the developing countries in the future. The adoption of improved varieties and efficient methods of vegetable production has the potential both to raise incomes and give greater equity in their distribution, while improved cultural practices will help to protect the quality of the environment and conserve natural resources. But several obstacles - technical, economic, and institutional - stand in the way of achieving this potential.
Increased production and improved handling of vegetables have great potential to enhance the nutrition of the rural and urban poor in the developing countries, as well as to increase their incomes and provide greater opportunities for employment. Unfortunately, the national institutions charged with the responsibility for vegetables have, for the most part, only limited capacity to solve the problems and accelerate progress. Consequently, there is tremendous scope for international collaboration to meet these needs for vegetables in ways that have already proved successful with the cereals and other staple food crops.
In its evolving program strategies, AVRDC will position itself to exploit the special strengths of an international center. It will help accelerate capacity building of its national partners and promote synergy and complementation among them and with its own efforts. It will move progressively towards greater emphasis on strategic research, forging new links with advanced research laboratories to keep abreast of the rapidly advancing frontiers of science and technology. It will strengthen its activities in all aspects of the conservation and distribution of genetic resources; expand its information services; and reorient its training program to focus on research training at headquarters and conduct most of the production training in its regional programs.
While retaining its emphasis on crop improvement as the most cost-effective means of increasing productivity, AVRDC will support an integrated set of research activities aimed at improving both the crop and the environment in which it is grown. It will restructure its programs to give a more comprehensive coverage of problems in vegetable production - from seed production to postharvest handling and distribution.
1182 92 - 8/43
Tropics, vegetables, biotechnology methods, clonal propagation, disease elimination, plant breeding, axillary branching, adventitious shoot formation, crops, analysis of the situation
3. Biotechnology developments in tropical vegetables.[edit | edit source]
In: AVRDC Publ. No. 90-331, ISBN 92-9058-043-7, 1990, 194 p.
This paper gives an overview of recent developments in biotechnology in vegetables, where plant tissue and cell culture techniques have been most effectively used.
The primary goals of the in vitro propagation of vegetable crops include production of large numbers of plantlets from species in which plant development from seed is difficult, clonal propagation of a large number of genetically identical plantlets, production of virus-free materials, crop improvement through various techniques of genetic modification, enhanced axillary branching using stem tips and lateral buds as the explants, an adventitious shoot formation.
Biotechnological methods are applied in the following way:
- Clonal propagation:
It is possible by conventional breeding to produce one whole shoot from one cutting under perfect natural conditions. Thus the asexual multiplication of rare and elite varieties of crops has to be handled with great care. It is possible through tissue culture techniques to produce millions of identical shoots from one portion of a plant within a very short span of time. Thus, rare genotypes can be multiplied and conserved.
- Disease elimination:
A reasonable assumption is that all plants that are propagated asexually by traditional methods (e.g. by cuttings, grafting, bulbs, tubers, etc.) are often infected with one or more pathogens, particularly viruses and other agents. Plant tissue culture is also an asexual method of breeding plants. The superiority of the technique is warranted by the fact that perfectly healthy clones could be produced by the technique of meristem culture. The philosophy of the methodology is that the terminal 2-3 mm portion of plants (meristems) are almost free from viruses, because cell divisions in such parts are very rapid and active. Virus particles, on the other hand, divide comparatively slowly after heat treatment and lag behind. Such meristems could be made to grow into complete healthy shoots, on nutrient media, under controlled environmental conditions.
- Plant breeding:
Plant breeding by tissue culture could save time, space and money.
These techniques can be used to aid traditional means of breeding.
Embryo culture can be used to overcome incompatibility barriers that exist in nature, while ovule, ovary, pollen and anther culture are being employed to reduce the breeding cycle by producing homozygous lines in the first or second generation. Cell and protoplast culture are new developments for an efficient screening system for mutations.
Homozygous mutations can occur even in somatic tissue culture giving this technique an edge over conventional mutation breeding.
- Axillary branching:
The advantage of this type of micropropagation is that very little callus is formed and the degree of genetic abnormalities is often reduced. Once the explants are established and axillary bud development enhanced, the cultures can be subcultured for many generations, resulting in increased shoot formation. Shoots, can be excised after elongation and generally rooted either in vitro or in a growth chamber or greenhouse environment. Vegetable crops that have been micropropagated using these techniques include asparagus, broccoli, brussels sprouts and sweet potato.
- Adventitious shoot formation:
Adventitious shoot formation has also been used to propagate vegetable crops in vitro. Lettuce and cabbage are examples of vegetable crops in which adventitious plantlets have originated directly from the primary explant. Adventitious plantlet formation from callus has been reported with asparagus, broccoli, brussels sprouts, chives, cabbage, carrot, garlic, kale, lettuce, pepper, potato, tomato and sweet potato. The disadvantage of adventitious plantlet formation is that genetic variability often increases, especially when the plantlets are derived from callus. The genetic variability generally tends to increase as the length of time the callus remains in culture increases. The genetic variability commonly observed in these cultures includes variation in phenotypic expression, yield variability and loss of organic potential, and is generally the result of chromosome abnormalities and/or ploidy changes in chromosome number.
A state of the art report regarding the various methods used in vegetable production is outlined in this article.
Concluding it can be said that biotechnology offers considerable scope for the improvement of most tropical vegetables. Such techniques can be safely used in conjunction with conventional breeding practices to boost vegetable production.
1183 92 - 8/44
Asia, Philippines, China, developing countries, food production, sustainability, small-scale households, low-input system, recycling, space-intensive, labour-intensive, water conservation, appropriate technology, nutrition, pest control, genetic resources, ecology
4. Characteristics of the bio-intensive approach to small-scale household food production.[edit | edit source]
AVRDC Publ. No. 87-273, Proc. of the Vegetable Improvement Gardening
Workshop; AVRDC, Shanhua, Tainan, Taiwan, ISBN 92-9058-028-3, 1988, pp. 93-99
The bio-intensive approach, as the name suggests, is a biological (as opposed to chemical) form of agriculture in which a small area of land is intensively cultivated with the use of nature's own ingredients to rebuild and then maintain the soil's productivity.
At the heart of the approach is the effort to improve the soils capability to nurture and sustain plant life. What a bio-intensive gardener tries to do on his small plot is to stimulate or replicate a natural forest (with the constant recycling of nutrients and maintenance of soil, moisture, and microbial conditions). Many countries of the world (and China is particularly notable) have farmed biologically for thousands of years and have been able to sustain output levels over those years. In sharp contrast the "efficient" but short-sighted approaches being used in many Western and Third World countries have often been disruptive of the natural resource base.
Farmers in many parts of the world are experiencing the fact that they have to use steadily increasing quantities of fertilizers and pesticides to sustain previous yield levels.
In the bio-intensive approach being recommended here for small-scale plots, the soil is gradually enhanced and the composition of beneficial microbial life actually improves from season to season. The soil structure and humus content is also supported. The nutrient content of the soil is built up, rather than depleted, after each crop. A healthy soil means a healthy stand of plants, and that means less insects and diseases. In the bio-intensive approach, yields continue to rise for the first few years and then tend to stabilize at an overall higher yield.
Such systems and the outputs (i.e. yields) are easily sustained at that level for many years with unchanging or even reduced levels of material and labour inputs.
The bio-intensive system is characterized by a greatly reduced dependence on expensive inputs that are generally used in conventional food production approaches. Many of these nonrenewable inputs, such as chemical fertilizers and pesticides, are produced at high energy costs (usually petroleum-based). Instead of chemicals, plant and animal wastes and natural mineral substitutes are used. In the methods being advocated here, the inputs required are bones, wood ash, eggshells, compost, ipil-ipil leaf meal or fish meal.
Locally available seeds are advocated rather than hybrid and other imported substitutes. Experience suggests that it is feasible to achieve a 100% self-reliance in recurring input needs. Other than hand tools, all material inputs are usually available locally or within easy access.
This reduces significantly or eliminates the need for cash outlays. It also provides the producers with a sense of control over the required production resources. Finally, by emphasizing the use of local and biological resources, rather than energy-intensive, fossil-fuel-based chemical imports, a small step is being made in the direction of conserving the world's nonrenewable resources.
The bio-intensive approach to food production at the household level differs considerably from the conventionally introduced gardening systems because of its stress on deep-bed preparation, nutrient recycling, building up of the soil's biological base, diversified cropping, and a balanced and integrated ecosystem.
1184 92 - 8/45
Asia, Africa, feed garden, fodder production, legume trees, shrubs, grasses, marginal lands, livestock, integrated systems
5. Sustainable agriculture intensive feed garden.[edit | edit source]
Sustainable Agriculture, 3, No. 1, 1991, 14-16
The concept of an Intensive Feed Garden (IFG) was adapted and tested in the Philippines by the International Institute of Rural Reconstruction (IIRR), based on a design originally developed by the International Livestock Centre for Africa in Ethiopia. IFG aims at maximizing the cultivation of fodder production per hectare through intensive cultivation of leguminous trees/shrubs and grasses on a small area (10m x 20m). This technology is recommended for marginal lands, areas where land is scarce, areas where it is compulsory to confine livestock and is most appropriate for areas where feed is not readily available for a cut-and-carry system.
An IFG provides renewable sources of nutritious and palatable fodder, fuel and green manure; curbs soil erosion, conserves soil moisture and increases soil fertility; increases the productivity of a given piece of land by interplanting diverse species of fodder trees, shrubs and grasses; provides a stable agricultural system for the semi-arid tropics; and reduces the danger of toxicity problems from noxious weeds and contaminated poisonous fodder.
An intensive fodder garden is usually established on a small piece of land (10m x 20m). Larger plots may, however, be used, depending on the number of animals to be maintained. One of the recommended designs of an IFG (yield: 20 tons dry matter/ha) incorporates legume trees, shrubs and grasses. A spacing of four meters between rows of trees is maintained.
The space between trees in the row is one meter. The grasses are spaced 75 cm, between rows and 30-40 cm between hills. While grasses and leguminous shrubs/vines are mature for cutting in six to eight weeks, they should be cut on a 10-12 week cycle for optimum productivity. More frequent cutting will reduce total productivity.
The land should be cleared of all weeds before land preparation and planting. Since forage grass (i.e., Panicum) seeds are small, they require a fine seedbed. If vegetative planting materials are used, a rough seedbed is tolerated. Flamengia, Rensonni and Gliricidia can be planted either on a flat or ridged land and must be planted ahead of the forage grass to minimize shading for the first six weeks. Forage trees may be planted by direct seeding or by nursery seedlings. Direct seeding is easier, cheaper and feasible in areas where annual rainfall is 1,200 mm or more with a minimum growing season of about 200 days. Planting of seedlings is recommended at the start of the rainy seasons. If irrigation is available, planting can be done anytime of the year. The ideal depth of planting should be about 2.0 cm, with two to three seeds per hill.
The following fodder trees, grasses and legumes are recommended:
- Fodder trees: Gliricidia sepium, Leucaena leucocephala, Cajanus cajan, Sesbania grandiflora.
- Grasses: Pennisetum purpureum, Panicum maximum, Brachiaria mutica, Cynodon plectostachyus, Digitaria decumbens, Pennisetum clandistinum, Dicanthium aristatum, Bracharia decumbens, Chloris gayana.
On fertile land, fertilizer may not be necessary; however, on moderate to low fertility soils, decomposed animal manure could be incorporated in the soil at least two weeks before planting. If manure is not available, a side dressing of 15-15-15 fertilizer (in the initial year of establishment only) at about 150 kg per hectare (four to six weeks after planting) can boost the initial growth of tree seedlings and forage grasses. After one to one-and-a half year of establishment, the fertilizer requirements of the grasses can be met by returning 50 to 70 percent of the cut leaves from the tree species back to the soil in the form of mulch. All the grasses and one-half to one-third of the tree leaves can then be used as animal feed.
In the first year, IFG production in a plot measuring 200 square meters would be sufficient to supply 25 percent of the daily intake of 3.6 small ruminants (goats or sheep). Foliage yields in the first year range from 9 to 20 tons/ha dry matter. Increased yields can be expected during subsequent years. To maintain a cattle fattener, there is a need to develop 400 meters of intensive feed garden area.
1185 92 - 8/46
Africa, Latin America, study, cowpea, leafy vegetable, grain legume, post harvest, quality loss, handling, storage
6. Handling and storage of cowpea vigna unguiculata (l.) Walp. As a leaf vegetable.[edit | edit source]
Trop. Agric. (Trinidad), 69, No. 2, 1992, p. 197-199
This study examines the effects of temperature and package ventilation on the storage life of fresh cowpea leaves.
Cowpea, Vigna unguiculata (L.) Walp., is a popular leaf vegetable and grain legume in many parts of Africa.
Most commonly, leaves are served boiled to accompany a starchy porridge; fried and fresh in relish are other popular methods.
The cowpea has many desirable horticultural characteristics not usually associated with leaf vegetables. It is an efficient nitrogen-fixing, heat- and drought-tolerant legume. A single planting yields leaves, immature pods, and immature and mature seeds. Cooked leaves contain two-thirds the protein, seven times the calcium, three times the iron, half the phosphorus, eight times the riboflavin, five times the niacin and several hundred times the asorbic acid and beta-carotene of the cooked seed. Amino acid composition indicates that cowpea leaf protein is superior to seed protein.
Drying boiled or blanched cowpea leaves is a widespread method of preservation.
"Vita 7", a erect cowpea cultivar with short trailing vines was selected for the study.
It was released by the International Institute for Tropical Agriculture, Ibadan, Nigeria, for its high yields and adaptability throughout Africa and Brazil.
Storing cowpea leaves in shaded, closed polythene bags or any container with minimal ventilation at ambient temperature increases storage life of cowpea leaves compared with open storage. Minimal cooling lengthens the period of storage, but temperatures below 15 C will induce chilling injury. If leaves are cooked immediately after removal from cold storage as would be expected if leaves were stored in the home, chilling injury might not be detrimental. Leaves in cold storage below 15 C at the whole sale or retail level would not remain edible after purchase.
Additional research should determine if ventilation greater than the closed bag but less than the next level tested (25 times greater) can extend the storage life and reduce the development of off-odours at high temperatures due to reduced oxygen levels.
1186 92 - 8/47
Africa, Niger, dry season, gardening projects, Lutheran World Relief
7. Dry-season gardening projects, Niger[edit | edit source]
In: The Greening of Aid; Ed. Czech Conroy and Miles Litvinoff; Earthscan Publ. Ltd. and IIED, London, 1988, pp. 69-73
The Lutheran World Relief (LWR) programme in Niger started in 1974 a project. This project was designed to truck seeds from Nigeria to the southern parts of Niger and Chad.
The villagers' immediate need was for vegetable seeds. While tomato and okra seeds could be dried and collected, and manioc cuttings could be replanted, other vegetables which would broaden the diet and nutritional base were generally not available. Composting was almost unheard of and difficult in dry areas, and with the loss of livestock and their manure these people were left to grow a few food items in low-quality soil.
These factors generated the first few modest project attempts. The larger amounts of food grown using chemical fertilizer gave encouragement to the men and women involved, but success was short-lived.
Insecticides in small amounts were imported to control the nematodes.
Villagers were encouraged to hand-exterminate external pests, while the Nigerian agriculture services demonstrated the safe use of insecticides and distributed them. It was rediscovered that nitrogen-fixing legumes (chickpeas) not only provided nutritional vegetables for additional food but were easy to dry, store and replant. If intercropped with other vegetables they provide nitrogen to the needy soil and cut down on nematode infestation.
Strong, hot wind caused erosion and sand dunes and sapped the life out of vegetables struggling to survive the intense heat. In response, a number of indigenous trees and bushes were planted on pond perimeters and around garden plots. These local varieties of hedges became a simple, effective way to keep out livestock and counter the relentless winds. The effect was to reduce water consumption, to add the new colour of green on vegetables and to strengthen wilting varieties of legumes; the shade given to the earth in the gardens greatly lowered ground temperatures.
Traditional well problems took longest to solve. Work was begun on designing a simple technology to meet the requirements of local replicability and durability.
This technology solved well cave-in and dirty water problems and had the advantages of low cost, simplicity and ease of maintenance.
The most easily measured economic impact is the increased availability of garden vegetables. People have increased food for themselves, which was the primary goal, but most gardeners have surplus vegetables to sell.
Less easily measurable economic benefits are increased production of animal feed from the use of windbreaks and live fencing.
Environmental effects are positive. Live fencing utilizing indigenous species is possible and within the capabilities of local people. Its use has reduced pressure for the use of live and dead thorn-tree branches.
Twelve years' experience in Niger has shown that these dry-season gardens are self-sustaining. People are aware that rain-fed agriculture may never be as it was in past years because of the decline in rainfall.
Dry season garden projects and wells have been replicated in more than 20 areas of Niger with the same success as in the original 8. Burkina Faso, Mali, Senegal and Western Sudan were surveyed for areas with water tables that would allow replication of most of the components of these dry-season gardens.