Local Crop Development:
an annotated bibliography

1. Farmers' Knowledge and Practices

Local crop development is based on farmers' knowledge of local crop varieties, farmers' skills in adapting those varieties to their environmental and socio-economic conditions, and the contributions of local seed systems. The literature presented in this chapter focuses on: the varietal characteristics that are important to farmers; the ways in which farmers observe, select and experiment with crop varieties; and the techniques they employ for storing and distributing seed.

There are a number of studies available that document the range of local crop varieties, and some of these also explain why farmers prefer crop varieties with particular characteristics. Farmers select varieties based on a wide range of criteria. Varieties must have agronomic characteristics compatible with the soils, climatic conditions, resources, and cropping patterns of local farming systems. In addition, varieties may be preferred for particular culinary or food-preparation characteristics. Varieties are often grown to meet local market demands as well. Many farming communities have well-developed classification systems for crop varieties. Information on these characteristics is drawn from anthropological and ethnobotanical studies, farming systems research, and studies of indigenous technical knowledge (ITK).

Information on farmer varietal preference is also available in some studies of the adoption of modern varieties. Much of the vast adoption literature treats farmers as passive recipients of technology, and examines characteristics such as education or farm size that might make farmers more or less receptive to technology. In this chapter, however, we concentrate on those studies that show farmers not as 'adopters' or 'non-adopters' but rather as participants in the active evaluation of new varieties in the context of complex farming systems.

In contrast to this general understanding of the varietal characteristics that are of potential interest to farmers, there is less information available on how farmers actually select and improve their own varieties. A few detailed examples are included in the review, but more research is certainly warranted on this important topic. This is part of a more general deficiency in the literature regarding the ways that farmers experiment with agricultural innovations. There are hardly any studies available that link sociological or anthropological descriptions of farmers' varietal selection to biological assessment of their selection practices, and there is obviously much scope for increasing interdisciplinary collaboration to further our understanding of local crop development.

Lack of information about farmer varietal management techniques and outcomes is matched by deficiencies in our knowledge of local seed systems. We have relatively little information about seed storage practices, for instance. Although it is often believed that the seed of local crop varieties is well distributed within communities, there is as yet little empirical evidence to support this assumption. Indeed, some of the studies reviewed here indicate that the patterns of local seed distribution and exchange are more complex, and at times more limited, than is generally imagined. More research is required on the way seed, and knowledge of varieties, moves from farmer to farmer.

1 Andrade­Aguilar, J. F. & E. Hernandez­Xolocotzi, 1991. 'Diversity of common beans (Phaseolus vulgaris, Fabaceae) and conditions of production in Aguascalientes, Mexico'. Economic Botany 45 (3): 339-344.

This study analyses the regional diversity of common beans (Phaseolus vulgaris, Fabaceae) in Aguascalientes, Mexico, in relation to local physical, biological, cultural, and socio­economic factors. Greater bean diversity was found in areas under rainfed conditions with low­input traditional agriculture. Farmers cultivate up to 12 bean varieties per year to ensure some production for home use in spite of environmental stress factors. Most of the bean varieties are cultivated in plots of less than 1 ha, because of the high variability in topography, soil fertility, drainage and rockiness. Early­maturing varieties are mostly used under uncertain rainfed conditions. Reduced bean diversity is cultivated under irrigated conditions with high­input modern agriculture where high­income farmers grow a few uniform improved cultivars to obtain high yields for commercial purposes. The relatively short time (1-5 years) of continuous use of most bean varieties is mainly due to (i) long and frequent droughts, (ii) national agricultural credit programmes, which oblige farmers to use one class of seed, (iii) lack of market demand for many local bean varieties and (iv) national warranty prices of beans which cover only those few bean varieties wanted in urban areas.

Keywords: genetic diversity, genetic erosion, variety turnover

2 Ashby, J. A., 1982. 'Technology and ecology: implication for innovation research in peasant agriculture'. Rural Sociology 47 (2): 234-250.

This paper uses data from three farming systems in Nepal to make two points about the study of the adoption of innovations. First, adoption must be studied by relating specific characteristics of the technology to specific aspects of the physical, biological and social environment of the farmer. Second, the characteristics that influence early diffusion of an innovation may be different from those that influence later diffusion. These points are related to data on the adoption of rice and maize modern varieties (MVs), which show very different diffusion patterns depending on farming system and farm type (subsistence, part­time, small livestock commercial, and large crop commercial). Although fertilizer is used on MVs, rates of diffusion of chemical fertilizer are equivalent for the three farming systems, and so MV diffusion is not apparently related to fertilizer diffusion. The most important farming system characteristics in the adoption of the maize MV are the length of the variety's growing season, its compatibility with rotations and relay crops, and the labour requirements of the different cropping patterns. The principal farming system characteristic determining adoption of the rice MV was its suitability for different temperature patterns. The rice MV was adopted more by farmers with abundant labour relative to land, while the maize MV was adopted by larger farmers with a scarcity of labour. A number of factors are considered as influencing a farmer's decision to experiment with a new variety. Early adopters of the maize and rice MVs tended to be larger farmers, with more extension contacts. Education and schooling had no influence on early adoption, and involvement in off­farm labour had a negative effect. It is emphasized, however, that these factors do not necessarily influence the behaviour of those farmers who adopt the variety at a later stage.

Keywords: farmer experimentation, fertilizer, labour, marketability, maturity, MV adoption, relay cropping, rotations

3 Barnett, M. L., 1969. 'Subsistence and transition in agricultural development among the Ibaloi in the Philippines'. In C. R. Wharton. Subsistance agriculture and economic development. pp. 284-295, Adline Publication Cooperation. Chicago.

This study describes the agricultural practices of the Igorot of northern Luzon, the Philippines. The description concentrates on one village where subsistence farming is the predominant pattern. Rice is the principal crop, and most farmers can get only one crop per year. A number of rice varieties are grown, and some of their important characteristics are discussed. Because rice is stored in bundles and not threshed until needed for consumption, farmers prefer varieties that do not shatter easily. Specific varieties may be chosen because of their high yield, cooking qualities, or maturity. Variety choice usually involves compromise. An early­maturing variety is useful in periods of water shortage, but is difficult to pound and its taste is not highly appreciated. Glutinous rice is appreciated for consumption but is more susceptible to attack by birds and rats. About a quarter of the rice planted is glutinous rice, even though these varieties are lower yielding, principally because of its importance in religious ceremonies. A variety's ease of harvesting is also a major consideration. Stalk quality is also important; smooth stalks are difficult to bind at harvest, while tough stalks cannot be fed to livestock. Farmers try to select varieties of similar maturities to those of neighbours, because animals graze the fields after harvest and can destroy a late­maturing crop. Several modern varieties were tested with farmers in the village. The favourable qualities of the new varieties were balanced against less desirable attributes, such as that the shorter varieties were more difficult to harvest, had smooth, hard stalks, and tended to shatter easily.

Keywords: ceremonial use, cooking quality, farmer selection criteria, fodder, maturity, yield

4 Bedigian, D. & J. R. Harlan, 1983. 'Nuba Agriculture and Ethnobotany, with particular reference to sesame and sorghum'. Economic Botany 37 (4): 384-395.

There is a remarkably high level of variation within cultivated sesame and sorghum in the Nuba Mountains of Sudan, although the region is relatively small. The Nuba people are geographically isolated and culturally diverse in religion, language, material inventory, agricultural practices and in their rituals involving crop plants, and this contributes to the diversity in their cultivars. Nuba crop management is sophisticated and is extensively described. The genetic diversity of sesame and sorghum is promoted by their many different uses, the cultural diversity of the Nuba and the different micro­environments. The Nuba identify specific cultivars of sorghum and sesame by their particular oil content, seed colour, and resistance to locust attack or disease. At Tebeldiko, red and white sesame cultivars are cultivated separately, while in southern areas several landraces of sesame are grown intermixed, sometimes with sorghum. Relatives of sesame grow as weeds in farmers' fields. At the end of the paper an extensive description is given of the different uses of sesame.

Keywords: crop management, farmer selection criteria, genetic diversity

5 Bellon, M. R. & S. B. Brush, 1994. 'Keepers of maize in Chiapas'. Economic Botany 48 (2): 196-209.

This paper examines how maize farmers in southern Mexico manage their fields in order to control variability, how they acquire new genotypes, and how they maintain known types of maize. The farmers studied grow maize as their principal crop, with quite high levels of inputs, and much of the maize is marketed. Fifteen maize varieties are grown in the community, representing 9 landraces or landrace combinations, and these are described. On average, each farmer plants 3 varieties, and selection criteria include performance on different soils, tolerance of weeds, fertilizer requirements, and risks from wind damage. These criteria are applied to the three most important varieties, and it is emphasized that no variety satisfies all of the farmers' concerns. The question of variety maintenance is also addressed. Farmers in the community have an average of four fields, often dispersed among different soil types. Different varieties or races are not isolated from each other and there would seem to be ample opportunity for hybridization. Different planting times and different growing cycles may serve to reduce cross­pollination, but this would not be sufficient to provide complete isolation. Seed selection is thought to be more important for variety maintenance. Ears for seed are selected on the basis of the ideal type for the variety in terms of kernel colour and size, density and shape, cob length, and number of seed rows. There would still seem to be considerable hybridization taking place, however. Six of the varieties grown are intermediate between two races, for instance. The most common modern variety (MV) is the dominant variety, but there is ample opportunity for it to hybridize with other varieties. Indeed, farmers may be in the process of transforming this to a local variety as they have done with several other introduced varieties. Concerns about genetic erosion are not misplaced, however, and it is pointed out that the local maize is dominated by only two landraces. The research questions the conception of the simple replacement of local varieties by MVs, and suggests that it is likely to be a much more complex process.

Keywords: farmer selection criteria, landraces, MV adoption, recombination, seed selection, variety maintenance

6 Bellon, M. & J. Taylor, 1993. '"Folk" soil taxonomy and the partial adoption of new seed varieties'. Economic Development and Cultural Change 41 (4): 763-786.

This study examines the use of three maize varieties in a community in the state of Chiapas, Mexico. The three varieties include a local landrace, an advanced generation of an improved variety that had been introduced previously, and an open pollinated modern variety (MV). Each was seen by the farmers to have particular advantages. The MV was earlier­maturing and more resistant to lodging. The intermediate type was felt to be better yielding, and the local variety was more productive on poorer quality soils. Local soil taxonomy was also elicited and included five soil types, which were seen as having distinct attributes with respect to maize growing. Soil samples collected following the local taxonomy were analysed in the laboratory and showed significant differences in a number of parameters. An econometric analysis was done for data on variety use by plot for a sample of farmers. The results showed that the local variety is favoured over improved varieties on poorer quality soils. Land fragmentation and off­farm labour are negatively associated with area planted to MVs, which are more labour­intensive.

Keywords: adaptation, fertilizer, maturity, MV adoption, soil type, yield

7 Benz, B. F., L. R. Sanchez­Velazques, F. J. Santana Michel, 1990. 'Ecology and ethnology of Zea diploperennis: preliminary investigations'. Maydica 35: 85-99.

Zea diploperennis is an endemic diploid perennial teosinte. Investigations in the Laboratoria Natural Las Joyas, Mexico indicate that the occurrence of Zea diploperennis is intimately associated with disturbed and anthropogenic environments. Populations of this species appear to be healthier under conditions of active maize cultivation, suggesting that its survival requires human­managed environments. In abandoned fields, Z. diploperennis dominated the early successional stages, giving way to other species in the later stages of successions. The largest population exists under conditions of active maize cultivation, where Z. diploperennis behaves as an integral part of a traditional agroecosystem in which hybridization, and perhaps introgression, takes place, and in which the plant also serves as an important source of fodder. According to the local people, the process of hybridization may increase yield, makes the maize less susceptible to disease and results in a harder grain. The study calls attention to the importance of humans in the apparent fitness of the species, as well as its association with prehistorically human­modified environments. This implies the need to conserve the existing system of traditional land use and management.

Keywords: disease resistance, farmer breeding, farmer selection criteria, fodder, grain type, in-situ conservation, introgression, recombination, yield

8 Benzing, A., 1989. 'Andean potato peasants are seed bankers'. ILEIA Newsletter 5 (4): 12-13.

This article tells the story of a peasant family in Ecuador, who returned to their former way of farming after trying 'modern' potato production. The inputs necessary for the modern varieties became more expensive every year, the modern varieties (MVs) were more susceptible to diseases and their taste was bitter, according to the farmer. The entire farming system is concentrated on the maintenance of the greatest possible diversification. The farmer and his wife have a detailed knowledge about soils, climates, crops and the potato varieties they grow. Due to the introduction of MVs, the diversity of species and varieties in Andean potato farming is declining. Diversity on the farmers' fields is maintained by establishing a small centre for the production of certified seed from indigenous potato varieties. Giving the peasant families access to high­yielding local seed avoids the farmers becoming dependent on the introduced high­input agriculture.

Keywords: community conservation, MV adoption, seed production

9 Berlin, B., 1992. Ethnobiological classification. Principles of categorization of plants and animals in traditional societies. Princeton University Press, Princeton.

This book presents evidence in support of a number of widespread regularities in the classification and naming of plants and animals among peoples of traditional, non­literate societies, regularities that persist across local environments, cultures, societies, and languages. These patterns can best be explained by the similarity of human beings' largely unconscious appreciation of the natural affinities among groupings of plants and animals. People recognize and name a grouping independently of its actual or potential usefulness or symbolic significance in human society. Berlin's claims challenge those anthropologists who see reality as a 'set of culturally constructed, often unique and idiosyncratic images, little constrained by parameters of an outside world'. Part 1 of this book focuses primarily on the structure of ethnobiological classification inferred from an analysis of descriptions of individual systems. Part 2 focuses on the underlying processes in the functioning and evolution of ethnobiological systems in general.

Keywords: folk taxonomy

10 Boster, J. S., 1984. 'Classification, cultivation, and selection of Aguaruna cultivars of Manihot esculenta (Euphorbiaceae)'. Advances in Economic Botany 1: 34-47.

This paper describes how Aguaruna cassava cultivars are lost, found, and maintained. Boster distinguishes three types of cultivar selection: perceptual, cultural and natural. The most intense selection is during the planting of a new garden. The women cultivators keep a good mix of cultivars in the garden. Women are making planting decisions on the basis of the properties of the taxonomic categories which they recognize. Selection criteria are: yield, suitability for eating or beer­making, storage qualities and rate of growth. The community of cultivators is inherently heterogeneous in motivation, experience and skill in the maintenance of genetic diversity. The author concludes that, although cultivars differ in response to environmental factors, the Aguaruna are generally unaware of or unconcerned with these differences. The greatest loss of manioc cultivars is through wholesale abandonment, either directly through loss of the planting material itself or indirectly through loss of local knowledge. Introduction of new material is mainly by exchange and is limited by the nurturing of seedlings, which appear after a period of secondary forest succession. Some women experiment with these volunteer seedlings. Finally the paper describes the ways in which this dynamic system is reflected in Aguaruna manioc nomenclature.

Keywords: cooking quality, farmer experimentation, farmer selection criteria, folk taxonomy, gender, local knowledge, seed exchange, storage, yield

11 Boster, J. S., 1985. 'Selection for perceptual distinctiveness: evidence from Aguaruna cultivars of Manihot esculenta'. Economic Botany 39 (3): 310-325.

This paper presents evidence that cultivars of manioc (Manihot esculenta) have been selected for combinations of characters that allow them to be perceptually distinguished and maintained by humans. This mode of selection is put forward to explain why cultivars are so variable in perceptually salient taxonomic characters unrelated to the use or survival of the plant. The paper reanalyses published material on manioc and presents new evidence from the inventory of manioc cultivars maintained by the Aguaruna Jivaro of northern Peru. The model of selection for perceptual distinctiveness suggests that farmers identify cultivars on the basis of characters that show the greatest range of variation and perceptual salience. In Aguaruna manioc cultivars this means leaf shape, petiole colour, and stem colour. Perceptual distinctiveness is a necessary condition for cultivar maintenance; cultivars must be distinguishable before they can be selected on the basis of utility. By maintaining the cultivars which are most peculiar in appearance, the farmer increases the variation that could serve to distinguish them. The proposed model is supported by biological and anthropological evidence. The evidence suggests that procedures used by farmers to identify cultivars leave their imprint on the plants; crops show the effect of the cultivator's eye as well as hand.

Keywords: farmer selection criteria, folk taxonomy

12 Boster, J. S., 1986. 'Exchange of varieties and information between Aguaruna manioc cultivators. ' American Anthropologist 88: 428-436.

This study is concerned with intracultural variation in the knowledge of cassava varieties and with the relationship between the pattern of the transmission of knowledge about cassava and the pattern of exchange of cassava varieties. It was carried out with the Aguaruna Jivaro who occupy the humid tropical forest in northern Peru. Exchange of cassava varieties in Aguaruna society takes place between women and seems to have more of a social than an economic function. Close kin are more likely to exchange varieties, but considerable exchange occurs among unrelated women as well. The study involved two cassava gardens planted by the researcher, one which contained 15 common varieties and the other which contained 61 different varieties. A sample of 31 women were asked to visit the gardens and identify the varieties. Information was also collected on their participation in variety exchange and their kinship relations. The analysis concludes that women who are more involved with variety exchange tend to represent the consensus on variety names better, and that the majority of deviations in variety naming are due to alternative names applied by particular kin groups. Exchange with others in the community outside the immediate kin group allows women to learn the cultural consensus regarding cassava varieties.

Keywords: folk taxonomy, local knowledge, seed exchange

13 Box, L., 1989. 'Knowledge, networks and cultivators: cassava in the Dominican Republic'. in N. Long. Encounters at the interface: a perspective on social discontinuities in rural development, pp. 165-182. Wageningen Agricultural University, Wageningen Studies in Sociology.

This chapter examines the lack of communication among farmers, extensionists, researchers and traders in the Dominican Republic. Some cultivators maintained collections of up to 25 varieties of cassava which they tested under various conditions. Approximately half the cassava cultivators surveyed had tested a new variety within the past five years. Cassava cultivators were motivated by four main characteristics in their search for better cassava varieties: marketability (including processing); early maturity; yield under declining soil fertility; and resistance to a type of root deterioration. Examples are given of popular cassava varieties that had been introduced by traders. Contributions by the formal research and extension systems were less in evidence, however.

Keywords: disease resistance, farmer experimentation, marketability, maturity, yield

14 Brammer, H., 1980. 'Some innovations don't wait for experts: a report on applied research by Bangladesh farmers'. Ceres 13 (2): 24-28.

This article discusses various farmer innovations, mostly related to crop management. With respect to crop varieties, a wide range of rice cultivars is grown in Bangladesh. Small differences in flooding depth and duration can lead to selection of different varieties. There are several cases where farmers have made their own selections from the modern variety IR­8 for greater plant height.

Keywords: crop management, farmer breeding, MVs

15 Brush, S. B., 1992. 'Reconsidering the Green Revolution: diversity and stability in cradle areas of crop domestication'. Human Ecology 20 (2): 145-167.

This paper reconsiders two widely held hypotheses about the effects of the Green Revolution namely, that it led to (i) biological simplification and (ii) instability. The hypothesis of biological simplification (genetic erosion) is tested with evidence from Andean potato agriculture. Two valleys in Peru with a different degree of modernization and commercialization are compared. In the more modernized valley, farmers maintain greater diversity on less land. While there has not been deletion of genotypes or alleles, the population structure of local potato varieties has been greatly altered by the adoption of modern varieties and heightened involvement in the market economy. The hypothesis of increased instability is tested with evidence of rice and wheat data from Asia. Agricultural instability, defined as fluctuations in production or yield over time, may be exacerbated by the adoption of modern crops and the use of purchased inputs in two ways: genetic vulnerability and input supply problems. The data from Asia show no general pattern of increased instability. It is suggested that the conventional wisdom about the Green Revolution should be reconsidered, with emphasis on resilience and variation in modernizing farming systems.

Keywords: commercialization, genetic erosion, MV adoption, yield stability

16 Brush, S. B., M. Bellon & E. Schmidt, 1988. 'Agricultural development and maize diversity in Mexico'. Human Ecology 16: 307-328.

A summary is given of changes in maize cultivation in Mexico over the past several decades. Yields have tended to increase, while the real price of maize has decreased. These changes have not been associated with high adoption of maize modern varieties (MVs), however, but are due more to subsidized prices for credit and fertilizer and guaranteed prices for maize. A study was carried out in two communities of the ecological transition zone between the highlands and lowlands of the state of Chiapas. Hillside fields tended to be intercropped and farmed with hand tools, and were predominantly planted to tall, local maize varieties. Fields on flat land were monocropped, prepared by ox or tractor plough, received chemical inputs, and were planted more to short­stature MVs. Ten different varieties were reported for the flat land system and nine varieties for the hillsides (five were found in both systems). In the flat lands, the most important variety is an MV that is particularly appreciated because of its resistance to lodging. The seed is renewed every 3-4 years because farmers report that it tends to become taller (probably from mixing with other varieties). 40% of the flat area is planted to varieties that are considered as landraces; some are advanced generations of improved varieties, but are managed as landraces. In the hillside system, the most important variety is more drought­tolerant than others. 46% of the MV seed is purchased (half from seed suppliers and half from other farmers), while 16% of the seed of local varieties is purchased, all from other farmers. It is emphasized that no clear distinction is made by farmers between improved maize types and landraces. Because advanced generations of MVs are managed as landraces, and several cultivars may co­exist in one field, it is suggested that the introduction of new varieties enhances diversity.

Keywords: drought tolerance, fertilizer, landraces, MV adoption, seed purchase, variety maintenance

17 Brush, S. B., H. J. Carney & Z. Huaman, 1981. 'Dynamics of Andean potato agriculture'. Economic Botany 35 (1): 70-88.

This article describes the maintenance of native potato varieties in two areas of Peru where modern varieties (MVs) have been introduced over the past three decades. The diversity and classification of Andean potatoes are first reviewed. For the study, tuber samples were collected and planted, and stem, flower and tuber characteristics were recorded; field mapping was done; tubers were described and scored against a standard; and tubers with the same local name were compared visually and electrophoretically. The folk taxonomy is described. Potatoes are distinguished from all other Andean tubers. Four folk species of potato are distinguished on the basis of cultivation, edibility, processing, and frost resistance. Below this level there are many named varieties, based on tuber characteristics; the average farmer can name about 35 varieties. Tuber colour is further used to distinguish within named varieties. Like­named tubers from the same locality were judged to be morphologically and electrophoretically identical, but like­named tubers from different localities tend to be electrophoretically dissimilar. Reasons for variation in native classification are discussed, including the possibility of inter­ and intra­ploidy hybridization producing new clones. Farmers in one village generally know which households have certain named varieties, and exchange of varieties takes place based on the native names. Non­bitter potatoes are usually grown separately from bitter potatoes. For native, non­bitter varieties, some fields are planted with a mixture of varieties; 'seed' for this type of field is selected on the basis of quality rather than variety. This mixture of species and genotypes promotes hybridization and crossing between ploidy levels and among clones. There are also fields with more uniform plantings of native potatoes, often planted by farmers who market native cultivars or who are involved in seed distribution networks of native varieties. Seed selection for these fields usually occurs at harvest. Seed­producing areas on the eastern slopes of the Andes export seed tubers westward. This traditional movement of seed has resulted in the planting of a relatively small number of cosmopolitan varieties by most households over large areas, in addition to the planting of other native varieties by small proportions of households. Native potato varieties are distinguished from MVs, which are selected and grown separately, usually as a cash crop. The MVs need to have their seed replenished every 1-3 years, which is not the case for the native varieties.

Keywords: biochemical markers, folk taxonomy, landraces, MVs, recombination, seed exchange, seed selection, variety maintenance

18 Brush, S. B., J. E. Taylor & M. R. Bellon, 1992. 'Technology adoption and biological diversity in Andean potato agriculture'. Journal of Development Economics 39: 365-387.

This study examines the problem of loss of biological diversity ('genetic erosion') in areas of crop origin with the introduction of modern varieties (MVs). The data are drawn from a study of potato variety adoption in two valleys of eastern Peru, where 297 and 227 names, respectively, of native potato varieties have been recorded. Random samples of 200 households were studied in each valley in 1985-86. In one valley farmers have longer experience with MV potatoes, which account for nearly half their potato acreage. In the other valley, experience with MVs is more recent and they account for about 12% of the potato area. Econometric analysis is used to examine MV adoption and changes in farm­level diversity. MV adoption is related to farm size; the larger the farm, the larger the absolute (but not relative) area under MVs. Both valleys include production zones at different altitudes, and the MVs have largely replaced local varieties in the intermediate altitude zone (3,000 to 3,800 m), where early maturing MVs under irrigation can be brought to market at a time of relative scarcity. Farmers also maintain several native varieties that are uniformly selected and produced commercially, as well as a large number of mixed native varieties. The latter are generally stored and planted unsorted, although certain farmers keep a large number of varieties and deliberately maintain and expand their collection. The analysis supports the hypothesis that the expansion of land under MVs reduces diversity (at the farm level) in the early stages but not in the late stages of adoption. In the valley with longer experience of MVs, there is no relation between area under MVs and diversity, while in the valley with more recent experience, there is such a relation. In both valleys off­farm occupations are negatively associated with diversity. It is more difficult, however, to make a link between farm­level diversity and aggregate diversity in a region. This is partly because of inconsistency among households in naming local varieties. Elimination is most likely for varieties that are currently found at very low frequencies. Households may be able to replenish the seed of particular varieties, and data are presented showing considerable purchase and exchange of native seed among sample households. The study concludes that considerable diversity remains in Andean potato cultivation despite the wide diffusion of new varieties, but encourages more research on the subject.

Keywords: commercialization, folk taxonomy, genetic erosion, MV adoption, seed exchange

19 Byerlee, D., K. Khan & M. Saleem, 1991. 'Revealing the rationality of farmers' strategies: on farm maize research in the Swat Valley, Northern Pakistan'. In R. Tripp. Planned change in farming systems: progress in on­farm research, pp. 169-190. John Wiley, Chichester.

A research programme identified appropriate maize varieties for cropping systems in the upper Swat Valley of northern Pakistan. Farmers grew mid­ to full­season white maize varieties. They were particularly interested in earlier maturing varieties, to be compatible with cropping patterns or to address irrigation water shortages. The rationality of local maize management, which began with very high planting densities and then continuously removed plants throughout the growing cycle, was demonstrated through field measurements. The high value of maize fodder justified the management methods. On­farm trials with a medium maturity maize variety (Azam) showed that it yielded about 10% more than the local variety. Farmers said that they preferred Azam for its higher yield, but considered that the local variety yielded more stover. Trial results showed, however, that Azam's stover yield was also higher; it is hypothesised that farmers' perceptions of stover yield were affected by the fact that Azam is shorter and less leafy. Pilot seed multiplication programmes were established in two villages, where certified seed was provided to key farmers who were then asked to produce and distribute seed to their neighbours. A subsequent survey showed high rates of adoption. Many farmers growing Azam noted, however, that it had become mixed with the local variety, highlighting the problem of introducing open­pollinated varieties in a single infusion of new seed.

Keywords: crop management, fodder, MV adoption, on­farm trials, seed programmes, variety maintenance

20 Chand, S. P., 1988. 'Exploration of local resources: the experience of Pakhribas Agricultural Centre with local germplasm evaluation.' Paper presented at the first national working group meeting on Plant Exploration and Related Activities, Kathmandu, 28-30 September 1988.

This study describes the performance and status of indigenous crop varieties commonly grown in the Koshi hills of Nepal. Farmers adopt local varieties not only for their yield potential, but also for their taste, market value, cooking quality, disease resistance, toleration of moisture stress and other selection criteria. Screening of such germplasm in other areas may lead however, to omision of region­specific characters (hail tolerance in non­hail areas). Screening of indigenous cultivars in their native environment and where farmers understand and prefer the type, would be a better policy. The Pakhribas Agricultural Centre has observed that a yield increase of up to 20% can be obtained through some local varieties. Local germplasm may be improved through selection or through disease­free planting material (in the case of potatoes, virus­free seed potatoes). Exchange of materials among similar agro­climatic regions should be encouraged. Adequate seed production is essential for the variety testing of local material. Until recently, seed farms were not allowed to produce seed of local varieties. This policy should be changed.

Keywords: disease resistance, farmer selection criteria, landraces, plant breeding methodologies, seed production, variety testing

21 Clawson, D., 1985. 'Harvest security and intraspecific diversity in traditional tropical agriculture'. Economic Botany 39 (1): 56-67.

This paper reviews farmer rationale for planting several varieties of one crop. Cultivars are often distinguished on the basis of colour, and varieties of different colour may have different cooking qualities, resistance to stresses or maturities. The review concentrates on the relation of colour to maturation period. Data are presented for one area of highland Mexico where four kernel colours of maize are found: yellow, white, blue­purple, and red. Their maturities and yields vary in that order (yellow being the latest and highest yielding). For millet, the literature on the use of varieties of differing maturities in Africa is reviewed. Several references are cited on the use of rice varieties of differing maturities in Africa and Asia. The literature on the diversity of potato varieties in the Andes and on the utilization of varieties of sweet potato differentiated by both external and internal root colours in Asia and Latin America is also reviewed. Studies on cassava are also reviewed; not only is difference in maturity an important characteristic for distinguishing varieties, but also the ability to store well in the ground. Studies on the yam are also reviewed. The author's data from Jamaica show yellow, white, and purple­fleshed varieties of the cush­cush yam, which are distinguished by cooking quality and maturity. Jamaican farmers also grow two colours of cocoyam (Xanthosoma) which have the same maturity but different storage characteristics. Studies on beans are also reviewed. Multicoloured varieties are often sown; in cooler, highland zones one advantage is that these varieties have different germination rates and since early rains are erratic this is a way of reducing risk.

Keywords: cooking quality, farmer selection criteria, maturity

22 Clawson, D. L. & D. R. Hoy, 1979. 'Nealtican, Mexico: a peasant community that rejected the Green Revolution'. American Journal of Economics and Sociology 38 (4): 371-387.

In the highland villages in the state of Puebla in Mexico maize and beans are the principal crops. Maize types are distinguished by kernel colour and 90% of the maize grown is white. The Plan Pueblo project of CIMMYT (International Maize and Wheat Improvement Center) promoted hybrid maize, but the hybrid varieties were unacceptable to the farmers. The short stalk of the hybrid maize did not suit their fodder needs, was more susceptible to corn worm infestation, and had a disagreeable taste and texture. Unlike their own landraces, the hybrid seeds need the same length of growing season and so have to be sown at the same time. The hybrid maize was characterized by large cobs and small kernels, which farmers perceived as a disadvantage, as they felt that the yield per cob was lower than that of their own local maize varieties. The farmers prefer their own open­pollinated landraces, and this enables them to select and continuously adapt their own seed stock without dependence on outsiders.

Keywords: cooking quality, farmer selection criteria, fodder, grain type, maturity, MV adoption, pest resistance

23 Colfer, C. J. P., 1991. 'Indigenous rice production and the subtleties of culture change: an example from Borneo'. Agriculture and Human Values 8 (1&2): 67-84.

Rice production in two Kenyah Dayak communities in East Kalimantan is described. Yields in one community (Long Segar), where most of the fields were planted in areas cleared from old growth forest, were much higher than those of the other community (Long Ampung) which used fields cleared from secondary forest. It was found that women's role in rice production in Long Segar was less than that of Long Ampung; the Long Segar community also had access to markets for its rice production. In Long Ampung 21 types of rice (average 3.2 per family) were recorded, while in Long Segar 23 types (average 2.9 per family) were recorded. Farmers in Long Segar placed more reliance on one variety (31% of variety use) which was preferred because it made a good price, was well adapted to hard, rocky soil, and was drought­tolerant. Farmers in Long Ampung, on the other hand, tended to use a wider range of varieties to suit their more varied soils and topography.

Keywords: drought tolerance, farmer selection criteria, gender, marketability, soil type

24 Collins, G. N., 1914. 'Pueblo Indian maize breeding. Varieties specially adapted to regions developed by Hopis and Navajos - their work not sufficiently appreciated - probably much yet to be learned from them'. Journal of Heredity 5: 255-268.

Indians of the Southwest of America have preserved from pre­Colombian times a type of maize which is able to produce fair crops in regions where other varieties fail for lack of sufficient water. The article begins with the description of a ceremony using the first ripened maize cobs. In the field the farmer selects for the earliest­maturing ears. When all the harvest has been gathered, dried, sorted and corded up, the finest ears of each variety are selected and set aside for special storage treatment. The article then goes on to describe the special features of Indian maize varieties. The Hopi and Navajo varieties have a mesocotyl which can grow to over 10 inches, thus bringing the coleoptyle to the soil surface when planted very deep (up to 12 inches). These varieties also produce only a primary seminal root and no secondary ones. The primary seminal root is very long, making water absorption from deep soil layers possible. Both characteristics allow deep planting under very dry conditions. Under extreme drought or other unfavourable conditions, the persistent tendency of this type of maize to produce seed is very striking. The importance of the unconscious pioneering agricultural work of the American Indians has not been adequately appreciated.

Keywords: adaptation, crop management, drought tolerance, farmer selection criteria, maturity, seed selection, seed storage

25 Conklin, H. C., 1957. Hanunoo agriculture in the Philippines. Forestry Development Paper No. 12, Food and Agriculture Organization of the United Nations, Rome.

This book is an important historical case study of the agriculture of the Hanunoo people, an ethnic group in Mindoro (the Philippines). Their system of shifting cultivation is primarily concerned with the production of food for local consumption. Grains, bananas and root crops provide about 90% of the annual diet. Rice is the most highly valued food and the Hanunoo people distinguish 92 varieties. In addition to rice, they grow over 300 specific food­crop types in their swidden, at least several dozen of which are regularly cropped together with rice. The Hanunoo distinguish plant types according to the habits of stem growth: ligneous, herbaceous and vine­like. Classification at lower levels is based on leaf shape, colour, habitat, length of growing period, taste, smell, etc. and 1,600 plant types are named. More than 90% of these plant types are of significance in terms of food provision, medicines, rituals or general technology. The ritual crop, rice, is cultivated in a complex sequence of rituals and cultivation practices. The report describes the various aspects of the different stages of the cultivation cycle: site selection, cutting, burning, cropping and fallowing. Some aspects of seed production and selection are described. Each type of rice seed is planted, harvested and stored separately. On average four to five varieties are planted in every swidden. Rice is classified by length of growing time, specific characteristics of the grain, and whether or not it can be grown in lowland wet fields as well as in swiddens.

Keywords: crop management, farmer experimentation, folk taxonomy

26 Coughenor, C. M. & S. M. Nazhat, 1985. Recent change in villages and rainfed agriculture in North Central Kordofan: communication process and constraints. Institute of Agriculture and Natural Resources, Nebraska Report No. 4, International Sorghum/Millet CRSP. University of Nebraska, Lincoln.

This report deals with the communication of agricultural information among farmers in Kordofan, Sudan. One section is devoted to local knowledge about sorghum and millet. Names of 51 sorghum varieties and 6 millet varieties are presented. The sorghum varieties include both traditional and recently introduced varieties. Both male and female farmers were asked to name the best variety for various purposes, and the results of this analysis are presented. One important aspect which farmers associate with each sorghum variety is the type of soil on which it grows best. Seed is saved by selecting the best heads; these are threshed separately and the seed is stored in a tin with a tight fitting lid or in a burlap sack. Merchants and markets, as well as kinship ties, are discussed as important sources of information about new varieties. More than half the farmers said that they would not discuss a new variety they were planting with other farmers until after it was harvested, in order to be sure that it was worthwhile, to avoid requests for seed from neighbours, or to be able to avoid competition and gain a commercial advantage. Other farmers, however, said that social obligations would cause them to discuss new varieties they were testing, especially with kin.

Keywords: farmer selection criteria, local knowledge, seed exchange, seed storage, soil type

27 Crissman, C. & J. Uquillas, 1989. Seed potato systems in Ecuador: a case study. International Potato Center, Lima.

This report focuses on the formal seed potato sector in Ecuador, and concludes that official seed production programmes have had relatively little impact. One section of the report describes the potato seed systems of local farmers. Potatoes are a commercial crop in Ecuador, even among small farmers, and a high level of chemical inputs is used. Potato farmers are generally able to maintain their own seed, and the most common reasons for buying seed in the market are to obtain a new variety or because high prices at harvest have caused the farmer to sell potatoes that would otherwise have been used for seed. The usual source of seed is neighbours or the market, and there is relatively little interregional flow of potato seed in Ecuador. There are, however, several areas that have the reputation of being producers of good quality seed, and producers in more tropical environments obtain their seed from producers at higher altitudes. Seed of new varieties is often obtained by gift, loan or purchase from relatives or friends. Farmers obtain small quantities of seed of a new variety and multiply it themselves. In seed selection, farmers do not consider the characteristics of the plant, nor is there evidence that they remove diseased or off­type plants. Seed tubers are stored on­farm and there is little storage loss. In preparing seed for planting, the longer sprouts are removed.

Keywords: seed exchange, seed purchase, seed selection, seed storage

28 Cromwell, E., 1990. Seed diffusion mechanisms in small farmer communities: lessons from Asia, Africa and Latin America. Agricultural Administration Research and Extension Network, Network Paper No. 21, Overseas Development Institute, London.

This paper reviews studies from Nepal, Pakistan, Kenya, and Peru that document farmer seed systems. The Nepal case concerns the diffusion of a rice variety (of unknown origin) which had been included in extension minikits distributed to farmers. The variety was found to have several attractive characteristics and spread rapidly, mostly through seed exchange, and usually among farmers of the same ethnic group. A relatively small number of farmers played the major role as sources of seed. The Pakistan case discusses the problem of the slow turnover of modern varieties of wheat among farmers in the Punjab and Northwest Frontier Province. Most of the seed used is retained from the farmer's previous harvest. When another source of seed is used, it is more likely to be other farmers rather than the formal sector. About half the farmers interviewed knew the location of the nearest seed depot, but only a minority had ever visited it. The Kenya study describes the distribution of new varieties of a number of crops. The farmers carefully tested the varieties before deciding whether to incorporate them in their farming system, and the adoption of many of the new varieties was quite low. In cases where a variety spread, there was evidence that farmer­to­farmer diffusion mechanisms functioned well. The Peruvian case concerns a project where eight farmers were selected to multiply and sell clean potato seed. Farmers obtain fresh seed periodically from neighbours (40% of the cases), from commercial seed growers (11%), or from village markets and other sources. The eight farmers who participated in the experiment distributed seed to a total of 35 other farmers. Several conclusions are drawn from these studies. Farmer seed diffusion mechanisms function to distribute new varieties, without compromising the quality of the seed. The extension system was often useful for providing initial information, but its role needs to shift from the control of access to seed to facilitating informal seed exchange mechanisms. With respect to agricultural research, it is suggested that more attention needs to be given to developing varieties appropriate for small farm conditions and for involving farmers in the testing process.

Keywords: extension, seed exchange, seed purchase, variety diffusion

29 Dennis, J. V. Jr., 1987. 'Farmer management of rice diversity in northern Thailand'. Ph. D. thesis, Cornell University. Ithaca, New York.

This thesis shows that farmers in northern Thailand maintain a considerable genetic variation of rice landraces. In the introductory chapter the author provides a review on the literature on ecology and genetic diversity and presents two models to account for the genetic diversity found in the study area. According to the relict diversity model, high diversity is an historical by­product of the cultural and geographic heterogeneity of the region. The diversity management model argues that farmers, by maintaining varietal diversity at the village level, have achieved higher and more stable yields. The villages studied presented different ethnic groups, and differences in agroecosystems, distance from the urban centre and integration into the national economy. The management of diversity is investigated at village level, farm level and within­field level. Farmers in central irrigated areas and in remote irrigated and upland rice areas maintain more genetic diversity than those in rainfed agroecosystems. Exchange of varieties between different villages is active. Hmong and Karen communities are more reluctant to discard their existing varieties, while lowland Thai farmers change varieties every three years. Adoption of modern varieties (MVs) increased dramatically in both irrigated and rainfed agroecosystems. At the farm level 'innovative' farmers, early adopters of MVs, were often 'contrarians', farmers who retained unpopular traditional varieties well after their neighbours had discarded them or who shifted away from new varieties before they were in widespread use. Operators of larger farms were innovators more frequently than those of smaller farms. The short­term effect of MV adoption has been to increase genetic diversity in the landscape as measured by the Shannon­Weaver diversity index and by isozyme analysis. Fertilizer use was inversely related to the number of varieties used and to the evenness of variety use. Variety turnover and the persistence of traditional varieties in the irrigated areas, in contrast to their complete erosion of traditional varieties in the rainfed areas, were explained by the interaction of three factors: i) harshness of the environment, ii) uneven efficiency on the part of farmers in water control and iii) the belief in irrigated areas that yields fall if the same variety is planted in the same area for more than three years. The research shows that the maintenance of varietal diversity was the result of conscious decisions by farmers who recognized the utility of this diversity. In Thailand, the Ministry of Agriculture should increase the number of varieties made available to farmers. Complexity and diversity in farming systems should be viewed as a resource rather than an obstacle.

Keywords: biochemical markers, farmer breeding, folk taxonomy, genetic diversity, genetic erosion, MV adoption, seed exchange, variety turnover

30 Dorp, M. van, T. Rulkens, 1993. 'Farmer crop­selection criteria and genebank collections in Indonesia' in W. de Boef, K. Amanor & K. Wellard with A. Bebbington Cultivating knowledge. Genetic diversity, farmer experimentation and crop research., pp. 119-127. Intermediate Technology Publications, London.

This paper describes research carried out on the Indonesian islands of Lombok and Sumbawa, in which local varieties of soya bean, maize, cassava and sweet potato were collected for inclusion in the national genebank. Collecting germplasm was combined with an investigation of farmers' knowledge of the local varieties. The research was based on rapid rural appraisal techniques, combining a study of existing documentation with informal interviewing. A multidisciplinary research team carried out field observations and informal interviews, held with individual male and female farmers and farmer groups as well as with key persons such as traders, retailers and agro­processors. Data were collected on the agronomic and product quality aspects of varieties, and the changing patterns of variety selection over time. Farmers' selection criteria involve a complex interaction of agronomic, consumer preference, and socio­economic and changing market factors. An awareness of the division of labour and the dynamics of the household is important in understanding factors influencing the criteria people use in evaluating crops as well as the change from subsistence to commercial farming. As evaluation is a major bottleneck in many genebanks, farmers' information can function as a first indication of characteristics present in the germplasm collection. A method needs now to be developed for systematically classifying and storing farmers' information on genetic material in a databank parallel to passport data. A better understanding of the processes of crop selection by farmers can also be used in formal breeding programmes to reflect more fully the requirements of farmers.

Keywords: farmer selection criteria, local knowledge

31 Dove, M. R., 1985. Swidden agriculture in Indonesia. The subsistence strategies of the Kalimantu Kantu', Studies in the social sciences No. 43. Mouton Publishers, Berlin, New Babylon.

This book presents an analysis of the swidden agriculture of the Kantu people of West Kalimantan. The Kantu continously modify their swidden system to deal with uncertainty, diversity and the constantly changing environment. The first chapter describes the social structures and the physical environment of the study area, followed by chapters desribing the rice cultivation practices in chronological order. This abstract is a projection of the information given in the first part of Chapter 5. During 1975 and 1976 44 different rice varieties were planted at the village of Tikul Batu, an average of 17 varieties by each household each year, all of which are classified and named by one system which provides six different levels of contrast. The Kantu plant multiple rice varieties in order to maximize this exploitation of the environment, and this is supported by certain ritual rules which prescribe the use of multiple varieties. When the size of the swidden and the importance of economies of scale increase, the average number of varieties per swidden decrease. Acquisition of rice stocks is by gift, exchange, wage and 'theft', the first two sources being more important within longhouses, while the last two are more important between longhouses. New varieties are planted in mixed stands and monitored. Favourable growing varieties are planted in a larger monovarietal stand during the next cropping season. Unfavourable varieties continue to be harvested and planted in a mixture. Intravarietal selection is practised when selecting the finest grains on visible characteristics from each stand of each variety for use as seed for the following year. Farmers prefer a full, whole grain. Other selecting criterion are the number of grains per panicle, the number of panicles per plant, and the threshing and husking qualities of the grain. Because the last two are not visible in the swidden, varieties with husking and threshing problems will be entirely eliminated.

Keywords: crop management, farmer experimentation, farmer selection criteria, folk taxonomy, grain type, seed exchange

32 Duvick, D. N., 1984. 'Genetic diversity in major farm crops on the farm and in reserve'. Economic Botany 38 (2): 161-178.

Genetic vulnerability does not present a major threat to the production of United States field crops at this time, according to a 1981 survey by US crop breeding directors. But plant breeders do regard genetic vulnerability as an important and potentially dangerous problem. The author of this paper foresees little change in the uniformity within cultivars, the small number of widely grown cultivars, and the phenotypic similarity and high degree of pedigree relationships among cultivars. Genetic diversity in modern plant breeding programmes is provided in other ways, namely, through genetic diversity in time (high variety turnover), diversity in reserves (cultivars planted for production and in advanced and preliminary trials), diversity through anticipation and transportable genetic diversity. However, the author emphasizes that the number of cultivars in each crop and the genetic diversity among these cultivars have to be increased to improve the margin of safety.

Keywords: genetic diversity, MVs, plant breeding programmes, variety turnover

33 Ferguson, A., 1992. '"So the grandparents may survive": farmer participation in bean improvement in Malawi'. In J. B. Smithson, Progress in Improvement of Common Bean in Eastern and Southern Africa. Proceedings of the 9th SUA/CRSP and 2nd SADCC/CIAT Bean Research Workshop, pp. 379-391. Sokoine University of Agriculture Morogoro, Tanzania.

Participatory research techniques for bean improvement in the Dedza Hills Rural Development Project in the Central Region of Malawi are described. Researchers examined the bean varieties grown by each household in the sample of 18 farmers. Farmers maintained an average of 13 different bean varieties. A range of varieties was maintained for several reasons. First, this diversity in maturities and disease and insect resistance helped to avoid risk. The range in maturities also allowed a steady supply of bean leaves, fresh and dry beans over the season. Secondly, the different bean types had different end uses. Finally, some less­preferred types were grown because seed of other types was not available. Other research in Malawi has shown that bean diversity is lowest on farms in the south of the country, followed by the Central region and the North. When farmers acquired new bean varieties they usually planted them in separate plots to observe their performance. Because farmers have a number of criteria for planting bean varieties, and these are sometimes negatively correlated (e. g., yield and maturity), it is suggested that a 'component breeding programme' be developed which releases a relatively large number of varieties, each with one or more characteristics of interest to farmers. The improvement programme could be based on local, regional and exotic sources. The materials would be tested by farmers, under their management conditions, and in comparison with varieties that have similar characteristics.

Keywords: farmer experimentation, farmer selection criteria, gender, maturity, plant breeding programmes, risk avoidance

34 Fernandez, P. G., 1994. 'Indigenous seed practices for sustainable agriculture'. Indigenous Knowledge and Development Monitor 2 (2): 9-12.

A shift to sustainable agriculture requires fundamental changes to the seed production paradigm. It is important for farmers, particularly those in the Third World, to have control over their seed. This requires a knowledge and appreciation of alternative technologies for crop and seed production, genetic conservation, and crop improvement, as well as a thorough understanding of related issues. A seed production system along the lines of a sustainable agriculture framework would be based on holistic and integrative farming principles and a greater participation on the part of farmers in all aspects of the seed industry. The author of this paper gives some results of her informal study of the indigenous seed practices of tribal communities in the Philippines. Indigenous seed practices encompass practically all aspects of crop production. The local farmers prepare the seed for planting in different ways, select the seed for the next season's crop and have various methods for storing their seed. Seed quality is an important aspect. Some communities have developed specialized practices in gene conservation, not only for food security and general survival, but also for posterity. Indigenous systems provide a rich source of alternatives. However, these too have been misused, not only for profit but also to gain a monopoly of the means of production, and to perpetuate the dominant but unsatisfactory development paradigm.

Keywords: local knowledge, seed production, seed quality, seed selection, seed storage

35 Freeman, J. D., 1955. Iban agriculture: a report on the shifting cultivation of hill rice by the Iban of Sarawak. Colonial Research Station Paper No. 18, Her Majesty's Stationary Office, London.

This book provides an outline of all aspects of the shifting system of hill rice cultivation by the Iban of Sarawak, East Malaysia. The opening chapters describethe social organization of the Iban and their land tenure system. Chapter 3 covers the agronomic aspects of Iban agriculture. The cultivation of rice is entangled with many ritual ceremonies. The Iban distinguish glutinous varieties, quick­ripening varieties, varieties for ordinary everyday diet and ritual and sacred varieties. The glutinous and quick­ripening varieties are planted first and the ritual varieties last. Most households grow 10 to 15 varieties. The senior woman in the family is responsible for selecting the seeds and their storage. In general, she picks the most perfectly formed panicles, and these are treated and stored separately. In reaping the panicles for seed for the next year, it is required, that she should not break her continuity, while the spirits are following her; otherwise they would miss their way and get lost. The Iban take great interest in new or uncommon varieties; they will deliberately travel considerable distances to obtain or exchange varieties. Although men take part in the actual cultivation, they do not have an accurate knowledge of the selection of the varieties. Chapter 4 describes the economics of agriculture and Chapter 5 touches on Iban methods of land usage. The final chapter deals with the problems of shifting cultivation.

Keywords: ceremonial use, crop management, gender, seed exchange, seed selection

36 Friis­Hansen, E., 1989. Seeds of wealth - seeds of risk. The vulnerability of hybrid maize production in the Southern Highlands of Tanzania. Centre for Development Research, Copenhagen.

Field work was carried out in 1987 in Njombe District, Tanzania, including villages in both the high­potential upper plateau agroecological zone and the low­potential medium­dry intermediate agroecological zone. A description of local maize varieties is given. Maize seed is selected from the central portion of the larger cobs for all of these varieties. The characteristics of mass selection are reviewed, together with the characteristics and history of six varieties. All the local varieties tend to be earlier­maturing than the Tanzanian hybrids available. The ability to harvest green maize during the growing season is important for maintaining household food supplies. Local varieties are also more resistant to pest damage than the hybrids, apparently because of their harder grain texture. Local varieties have specific uses, but little information is given on this. Most households cultivate no more than 2 or 3 maize varieties, and varieties may differ from village to village. Some households mix local varieties in storage and in seed selection, while others maintain separate varieties. Hybrid maize is grown by farmers who are more commercially oriented. Three Tanzanian hybrids are available, and some hybrid seed is imported as well. Demand for hybrid seed exceeds supply, and problems with the parastatal TANSEED are discussed. The hybrids tend to be grown with fertilizer. They outyield the locals in high­potential areas when the rainfall is adequate. The lack of hybrid varieties of shorter maturity is highlighted. The possibility is explored that cross­pollination from hybrids to local varieties is changing the characteristics of the local maize. Only a few farmers are aware of the nature of cross­pollination. Some farmers do not plant local maize close to hybrid maize in order to maintain its isolation, but for many this is impossible because of the shortage of land. The concluding chapter outlines a proposal for local­level multiplication of improved open­pollinated maize.

Keywords: farmer selection criteria, maturity, MVs, seed marketing, seed selection, variety maintenance

37 Friis­Hansen, E., 1992. Seeds for African peasants. A case study from Zimbabwe. Centre for Development Research, Copenhagen.

This study provides a description of agriculture in Zimbabwe, a review of the theory of African peasantry, a history of plant breeding in Zimbabwe, a case study of agricultural patterns in one area of the country, and conclusions regarding the future of the seed sector in Zimbabwe. The case study was carried out in Silobela communal area in Kwekwe District. The area is subject to seasonal droughts and severe dry spells. The principal crop is maize, which is used for subsistence and marketing; sorghum, sunflower, groundnuts, Bambara nuts, finger millet, pearl millet, and other crops are also grown. Sources of seed vary for the different crops. Almost all the maize planted is hybrid; the survey found farmers using 5 different hybrids. Although many farmers depend on local retailers for maize seed, these merchants do not always have an adequate supply, as they wait to estimate farmer demand for different hybrids before renewing their stocks. Most of the seed of other crops is retained from the farmers' own harvest, although about 10% of sorghum, groundnut and sunflower seed is purchased from retailers in the towns. For drought­tolerant crops such as millet most households store more than one year's supply of seed. Seed is often stored in the ceiling of the kitchen hut. Descriptions are given of the major crop varieties and their origins. Some 'local' varieties exist, although these are often derived from earlier government releases. Farmers' choice of varieties is analysed. For maize, early­maturing varieties predominate. This is especially true for households without access to draught power. If the rains are early, farmers may purchase seed of medium­maturity maize; if the rains are late, they will purchase earlier­maturing seed. Only households with access to draught power are able to plant the groundnut variety Valencia, which requires early planting. Similarly, the hybrid sunflower variety Masasa is planted by those farmers who can undertake winter ploughing and early planting. The concluding chapter presents suggestions for improving the effectiveness of both farmer and scientific plant breeding, and an integrated plant breeding system is proposed which includes the two sectors.

Keywords: farmer selection criteria, maturity, MVs, plant breeding programmes, seed purchase, seed storage

38 Fujisaka, S., P. Elliot, E. Jayson & A. Dapusala, 1993. 'Where there has been no "Green Revolution": farmers' upland rices and related knowledge in Mindanao, Philippines'. In Indigenous Knowledge and Sustainable Development, pp.96-110. International Institute of Rural Reconstruction, Silang.

This paper describes surveys of 67 farmers in Bukidnon Province and 35 farmers in Misamis Oriental Province regarding their preferences and use of upland rice cultivars. The farmers in Bukidnon planted only traditional cultivars. A total of 18 cultivars were recorded, although one cultivar, Dinorado, was predominant, being grown by 57% of the farmers. Farmers also provided names of several cultivars that used to be grown but have now been replaced by Dinorado and others. Several upland rice cultivars were described by the farmers in Misamis Oriental as well, although two cultivars (one modern variety (MV) and one traditional) were predominant. Many farmers there had planted Dinorado, but had abandoned it because of high losses to birds. Many positive and negative characteristics are listed that influence farmers' preferences, but the most common priorities mentioned in both areas were high yield, early maturity, good palatability, and lodging and disease resistance. It is pointed out that many of the criteria used by farmers in selecting cultivars are the same as those used by breeders, but in some cases farmers can contribute criteria about which breeders know little, particularly those related to cooking qualities and palatability. It is also pointed out that farmers' selection criteria are scientifically sound. Examples include the selection for resistance to bird damage; the relation between plant architecture and weed competitiveness; the fact that aromatic cultivars may be more susceptible to certain insect pests; and that certain cultivars are better adapted to poorer soil conditions.

Keywords: cooking quality, farmer selection criteria, local knowledge, maturity, pest resistance, yield

39 Goland, C., 1993. 'Agricultural risk management through diversity: field scattering in Cuyo Cuyo, Peru'. Culture and Agriculture 45­46: 8-13.

In this article the hypothesis that field scattering is an effective risk­buffering strategy in Cuyo­Cuyo is evaluated. Data on agricultural production were collected during two agricultural cycles with the assistance of ten families in each of two communities. The sectorial fallowing system, termed manda, is primary in the conceptual and practical organization of agriculture in Cuyo­Cuyo. Relative to land area, agriculture is input­ (labour, fertilizer) intensive and the average family's landholding is small. Most of the high degree of variance in productivity cannot be statistically explained by the input factors under the control of households, such as labour, fertilizer quantity and proximity to the community. The evaluation of the effectiveness of field scattering was carried out for potato production and required three steps. The first was to establish the yield below which households experience a serious deficit. The second step was to show the reduction in variance gained by planting scattered fields. Third, the costs of field scattering was established. The author demonstrates with empirical data that field scattering effectively helps families avoid distrastrously poor levels of production, while acquiring a minimum cost in terms of reduced yield due to additional travel and transport. Because the fields are differentially exposed to stochastic factors that enhance or reduce the production of each, pooling the harvest of several fields reduces the variance experiences of households relative to what would occur if they were to rely on a single consolidated field.

Keywords: farmer experimentation, risk avoidance

40 Green, T., 1987. Farmer­to­farmer seed exchange in the Eastern hills of Nepal: the case of 'Pokhreli Masino' rice. PAC Working Paper 05/87. Pahribas Agricultural Centre, Kathmandu.

In 1986 it was found that a large number of farmers in Terhathum District, eastern Nepal, were using the rice variety 'Pokhreli Masino' which had been included in some minikits (packages of seed of one or two improved varieties) that had been distributed by the extension service. A study was undertaken to: trace the pattern of seed movement in Terhathum District; find out how farmers obtained Pokhreli Masino seed; understand farmers' criteria for accepting or rejecting the variety; and make recommendations to the research station on future seed activities. The study found a steady increase in the number of farmers growing Pokhreli Masino, although the total area grown is relatively small. Pokhreli Masino is of unknown origin but is grown widely in the Kathmandu valley. A large number of local cultivars are grown in the area. Most farmers obtained the seed in exchange for other seed or grain. Only about 40% of farmers included in the study exchanged seed, and a few played a preponderant role in the spread of the variety. The majority of seed exchange was carried out between neighbours and often within the same ethnic group. Adoption of the variety tended to be higher among relatively larger farmers, and was influenced by particular characteristics: good straw yield for large ruminants; soft cooking quality, good for several food preparations (but not acceptable to poorer consumers); good lodging resistance; and farmer experience in planting the variety on relatively better quality land. Farmers adjusted their seeding rates for Pokhreli Masino to take account of the variety's higher tillering capacity. The study makes a number of recommendations. It points out that the minikit technique is potentially useful, but suffers from mixed objectives; research sees it as a way of obtaining data on variety performance, while extension sees it as a way of diffusing new varieties. In addition, the minikits need to be better targeted to reach all classes of farmers and a broader geographical range. It is suggested that future seed activities should take more advantage of the existence of farmer­to­farmer seed exchange traditions.

Keywords: cooking quality, extension, farmer selection criteria, seed exchange, variety diffusion, variety testing

41 Gunadi, N. & M. J. Potts, R. Sinung­Basuki & G. A. Watson, 1992. 'On­farm development of potato production from true seed in Indonesia'. Experimental Agriculture 28: 31-39.

Lack of adequate and timely supplies of good quality seed is a major constraint to potato production in Indonesia. Seed growers' land is increasingly infested by pests or diseases. This article describes an on­farm experiment during three seasons to develop potato production from botanical or true potato seed (TPS) under fertile conditions in West Java, Indonesia. 23 farmers experimented with two production systems: the use of transplants, and the use of seedling tubers produced in nursery beds. Seedling tubers and field transplanted seedlings of 12 progenies were compared with seedling tubers of the cultivar Granola, which currently accounts for about 80% of the potato area in Indonesia. All the progenies were superior to Granola in canopy sturdiness and resistance to late blight. There was little yield difference between the systems, but an apparent progeny x system x season interaction was observed. Appropriate matching of progeny and system gave seed of comparable quality with, but total yields slightly less than, certified imported seed (=seedling tubers) of the cultivar Granola. Farmers showed a strong preference for producing seed tubers from transplanted seedlings, since transplants allow greater flexibility in planting time than seedling tubers, which have to be produced and stored so as to be in the correct physiological condition at planting. The farmers can maintain tuber seed stocks derived from true potato seed for six to eight multiplications, as opposed to one or two under the old system. The initial investment for transplanted true potato seed is less, and the potential profit greater than that for imported certified seed.

Keywords: farmer evaluation methods, on­farm trials, seed production, seed quality

42 Haugerud, A. & M. Collinson, 1990. 'Plants, genes and people: improving the relevance of plant breeding in Africa'. Experimental Agriculture 26: 341-362.

The argument is made that plant breeding will be more successful if it pays closer attention to farmers' preferences. Examples are given based on research in Africa on maize and potato. It is emphasized that African farmers use several cultivars to meet multiple objectives. In Rwanda, most farmers plant three to eight potato cultivars. Planting a mixture of potato cultivars of different maturities allows farmers to stagger their harvests and enjoy an extended period of availability. Potatoes have only been grown in Rwanda for about a century, and the distinction between modern and traditional varieties becomes blurred. Farmers were interviewed about the four most commonly grown varieties and expressed opinions on the following characteristics: growth cycle, dormancy, taste, starch content, cooking time, storability, yield under good and poor rainfall, late blight resistance, bacterial wilt tolerance, market acceptability, and suitability for intercropping. Examples are also given of diversity in maize cultivars in Zambia, Zimbabwe and Kenya. This diversity is related to factors such as different end uses, disease and pest resistance, and performance under moisture stress. The relative economic value of maize stover is also becoming a criterion for variety selection in several countries. Much emphasis is placed on the importance of early maturity, and balancing early maturity with yield, for both maize and potatoes. Later­maturing varieties may yield more, but may not be compatible with local labour patterns. In addition, in areas of bi­modal rainfall, late varieties may restrict the possibility of planting a second crop. For both crops it is concluded that farmers prefer short­duration cultivars or a mixture of long and short, rather than relying solely on long­duration ones. Suggestions are given for testing new cultivars under farmers' management. Farmer participation in germplasm screening is also suggested.

Keywords: farmer selection criteria, fodder, intercropping, maturity, variety testing

43 Hernandez­Xolocotzi, E., 1985. 'Maize and man in the Greater Southwest.' Economic Botany 39 (4): 416-430.

In northwest Mexico, more than 20 racial types of maize have been collected. This diversity is related to the variation in climate and soil conditions, to human migration from the Meso­american centre to the Greater Southwest area, and to differential selection by the ethnic groups in the region. The agricultural practices of the farmers are reviewed in order to illustrate how different aspects of the environment, food preferences, and the manner of utilization constitute continuing factors in selection and motivation for the introduction of varieties from other areas. Important criteria in farmer selection are texture and colour of the grain, and maturity rate. In isolated communities, the floury, pop and sweet types are cultivated in rows separate from the main varieties (flint and dents types), but out­crossing is prevented. Also varieties with different maturity dates are planted in such a way that genetic isolation is taken care of. Farmers are aware of cross­pollination, and in selecting seed of the colour and texture varieties, they select grains which fully express the desired character. A phenotypic analysis of more than 600 collections from the area indicates the occurrence of constant intercrossing among maize populations.

Keywords: farmer selection criteria, grain type, maturity, seed selection, variety maintenance

44 Jackson, M. T., J. G. Hawkes & P. R. Rowe, 1980. 'An ethnobotanical field study of primitive potato varieties in Peru'. Euphytica 29: 107-113.

The Quechua Indians in Cuyo­Cuyo in southern Peru, an area of traditional agriculture, grow their potatoes on terraces. In this study two fields are examined to determine the varietal and ploidy richness of these potato fields. Farmers distinguish their potato varieties on the basis of tuber morphology and in the field on vegetative characteristics. A total of 25 varieties were found in the two fields. Tetraploids were the most common plants in both fields, representing over 95% in each. New genotypes may enter the genepool following the sexual process. In the year following the cultivation of potatoes, oca is grown on the same fields, and it is likely that potato tubers derived from seedlings will be harvested along with the oca tubers. This is expected to happen more often at the tetraploid level, following self­pollination, than at the diploid and triploid level, where cross­pollination is necessary. Farmers were asked to evaluate each variety and assign a quality rate. Flavour and dry matter content were the most important quality factors. Three varieties which were classed as poor were grown at a higher frequency than some of those which were considered good or intermediate. The clonal reproduction of potatoes allows farmers to modify their cultivar population and retain both superior and inferior genotypes, which may remain stabilized in the population for a long time.

Keywords: cooking quality, farmer evaluation methods, farmer selection criteria, recombination

45 Janssen, W., C. A. Luna & M. C. Duque, 1992. 'Small­farmer behaviour towards bean seed; evidence from Colombia'. Journal of Applied Seed Production 10: 43-51.

Surveys were conducted with farmers growing beans in the department of Santander, Colombia. Bean production is increasing in the area, and the most popular variety is of uncertain origin. Most farmers try to use their own saved seed. Seed selection began in the field for 31% of the farmers, who selected from parts of the field with abundant foliage and low incidence of disease. The rest of the farmers did all their seed selection after the harvest. Most farmers applied chemicals or other products to stored seed to prevent weevil attack. On average, farmers purchased fresh seed every two years (four cycles). Two cooperatives in the area produced and sold seed. The principal reasons for purchasing seed were: the perception that saved seed had become discoloured, seed storage problems, the poor quality of the previous harvest, or the desire to plant a larger area. Experiments showed that purchased seed did not yield more than saved seed. The paper includes a review of a number of previous studies, the majority of which conclude that 'clean seed' for beans offers little or no yield advantage over farmer­saved seed.

Keywords: seed purchase, seed quality, seed selection, seed storage

46 Johannessen, C. L., 1982. 'Domestication process of maize continues in Guatemala' Economic Botany 36 (1): 84-99.

Fieldwork was carried out among Amerindians of Alta Verapaz, an area of traditional maize farming in Guatemala. Although little knowledge of genetic processes is extant among the Indians, they did perceive many varieties for different uses. Varietal changes in a given family corn crop do occur through the loss of a variety, almost always due to insect problems during storage. The Indians try to select varieties that will grow in their ecological niche. Ear selection is done in the dwelling. The selection criteria are the longest, fullest ears, and the most disease­ and insect­free ears with a consistent colour, shape and starch type. The selected seed ears are hung above the kitchen cooking hearth for a time, to be smoked and made more insect­resistant. Seeds are mainly selected from the central part of the cob and less from the butt. Maintenance of the desired and selected features of varieties is obtained by isolation in time and space and by semi­magical storage practices. The several colour and starch types of corn have distinct maturation times. Very few new varieties are brought into the villages from outside. Dispersal of selected and maintained maize seeds mainly occurs among relatives. The author concludes that the higher the number of spurious activities, the greater the difficulty in selection and maintenance that the ancient cultivators experienced during the domestication process. Other more easily maintainable plants were cultivated in the world prior to the modification of a wind­pollinated plant like maize. Vegetatively planted, selfing, or perhaps apomictic seed plants were certainly first. No wind­pollinated plant other than maize has been modified continually over such a long time and now has such extreme variability.

Keywords: domestication, farmer breeding, farmer selection criteria, grain type, maturity, seed exchange, seed selection, seed storage

47 Johns, T. & S. L. Keen, 1986. 'On­going evolution of the potato on the Antiplano of Western Bolivia'. Economic Botany 40 (4): 409-424.

This article reports on an investigation of the biological and cultural factors determining the evolution of the potato in the Andes. The study was carried out in the valley of Ajawiri Marka where abundant weedy and cultivated forms of Solanum x ajunhuiri grow in close association. Three species of bee visitors and two fly species were the likely pollinators of potato flowers in altiplano fields. The farming practices of Aymara subsistence cultivators facilitate recombination between wild and cultivated gene pools. Wild species are growing in and along the borders of the farmers' fields. When seedlings germinate under favourable conditions, their tubers are harvested along with volunteer potatoes growing from tubers not harvested the previous year. During seed potato selection by the farmers a passive introduction of new types into cultivated potatoes was observed. Farmers maintain potato varieties and distinguish various cultivars, varying from 10 to 32 cultivars per household. In general, altiplano farmers are disposed to experiment with new varieties, which are grown for two years and evaluated for survivability, yield and culinary quality and then either accepted or discarded. Finally, the authors present the case of one farmer practising a form of potato breeding through the maintenance of true potato seeds and testing the seedlings. In the second year of propagation the tubers yielded comparatively well as against the yield from seed tubers.

Keywords: farmer breeding, farmer experimentation, introgression, recombination, seed production

48 Johnson, A. W., 1972. 'Individuality and experimentation in traditional agriculture'. Human Ecology 1 (2): 148-159.

Traditional agriculture has often been portrayed as a set of uniform practices, but this is far from the truth. An earlier study in Guatemala is cited to show significant differences among farmers in field management practices. Variation among farmers is due to: environmental differences, economic differences, and differences of opinion and experience among farmers. Several cases are quoted of farmers conducting their own experiments, such as farmers in Brazil trying out small quantities of new manioc or rice varieties. Other examples from the literature are given of experimentation with new varieties.

Keywords: farmer experimentation

49 Kashyap, R. K. & J. C. Duhan, 1994. 'Health status of farmers' saved wheat seed in Haryana, India - a case study'. Seed Science and Technology 22: 619-628.

In India, 93% of the total wheat acreage is sown by farmers' own saved seed or seed from neighbouring farmers. Surveys were carried out for three years (1990-92) to find out the health status of farmers' saved wheat seed in Haryana State, India. The samples were found to be infested with seven species of insects, both primary and secondary seed feeders. Only 13.2% of the samples were free from insect­pest infestation over the period. Depending upon the life cycle/feeding behaviour of the insect, the seed embryo or endosperm was damaged, resulting in the rejection of 67.6% of the samples on the basis of Indian Minimum Seed Certification Standards. While storing the seed for the following year, 72.2% of the farmers did not distinguish between seed and grain. The majority of the farmers (54.8%) did nothing to save the seed from insect damage or to improve the quality of the insect­infested seed before sowing. The incidence and range of seed infection due to seed­borne diseases, i. e. Karnal bunt (Neovossia indica), loose smut (Ustilago segetum) and black point (Helminthosporium, Alternaria; Curvularia spp.) were greater in the humid than in the dry zones of Haryana. More samples were rejected due to Karnal bunt (25.5%) and loose smut (70.8%) from the humid zone than from the dry zone (respectively 3.1% and 16.2%). The study clearly reveals that the farmers' saved wheat seed is of poor health status. Educating farmers about seed health, i.e. the use of disease­free/certified seed; fungicide seed treatment before sowing; storing seed with proper moisture content separately from grain in metallic bins; phosphine fumigation or at least sieving; or increasing the seed rate at sowing etc. in relation to seed quality would help to increase wheat yields in tropical and subtropical areas of the world.

Keywords: seed quality, seed storage

50 Kirkby, R., 1981. The study of agronomic practices and maize varieties appropriate to the circumstances of small farmers in highland Ecuador. Cornell University, Ithaca.

This study was carried out within the Quimiag­Penipe Integrated Agricultural Development Project in Chimborazo Province, Ecuador. It included the study of farmers' production practices, and on­farm experimentation with rotations involving early maturing maize and pea varieties and with fodder management of different maize varieties. Maize (usually intercropped with beans), potatoes, and barley are the most important crops in the area. Farmers grow up to seven types of local maize, although there are usually three types that are predominant in any one area. There are three main climbing bean varieties. Several varieties of potato are grown, with the traditional varieties being more common in indigenous communities. The poorest farmers prefer a potato variety ('chaucha') that requires less time for cooking, and is earlier maturing. Farmers are often found doing their own experiments, such as planting maize at different times of the year or in new environments. Part of the research involved on­farm experiments to test the feasibility of a new early­maturing maize planted in rotation with peas, or local maize planted in rotation with new early­maturing pea varieties. Other experiments involved the common farmer practice of 'topping' the maize, cutting the tassel and top leaves for fodder. It was found that the defoliation practices (the removal of tassel and entire stem above the ear) used by poorer farmers resulted in a considerable loss of grain yield, but an improvement in fodder supply. Less drastic practices used by more commercial farmers had little effect on grain production. It was also found that the local maize varieties tolerated defoliation better than the experimental varieties. The importance of fodder is emphasized as a selection criterion for developing acceptable maize varieties.

Keywords: cooking quality, farmer experimentation, fodder, maturity, on­farm trials

51 Kurin, R., 1983. 'Indigenous agronomics and agricultural development in the Indus Basin'. Human Organization 42: 283-294.

This study was carried out in a village in Sahiwal District, Punjab, Pakistan where the main staples are rice and wheat and the principal cash crops are cotton and sugarcane. A humoral classification system for agriculture is described in which the farmers classify crops (and varieties), soils, and inputs along two dimensions: hot - cold and wet - dry. With respect to varieties, traditional wheat and rice are both classified as cold and wet, while modern variety (MV) wheat is considered hot and dry and MV rice is thought to be of moderate temperature and dry. Farmers make their classifications based on how crops grow in different weather conditions and how they respond in different soil types and fertilizer levels. They consider that certain crops prosper with soils and inputs that are similar, while other crops require a clash of humoral properties. This classification system is reflected in the differences in management between MV and traditional rice and wheat varieties. MV rice receives more fertilizer than the traditional varieties, and MV wheat more fertilizer (and less manure) and tubewell irrigation rather than canal irrigation.

Keywords: crop management, fertilizer, folk taxonomy, MVs

52 Lambert, D. H., 1985. Swamp rice farming: the indigenous Pahang Malay agriculture system. Westview Press, Boulder.

In the village of Pesagi, Peninsular Malaysia, the farmers present a complex example of diversification in indigenous agriculture. A wide range of rice varieties and habitats helps the Pesagi swamp farmers to continue their farming system given, the uncertainties of ecological conditions, water, weather, diseases and pests. A general introduction on the indigenous agriculture, is followed by a description of the history of Pahang and Pesagi and their natural setting. Chapter 4 describes the rice varieties of the Pesagi farmers. Over 40 varieties are recognized and planted. The varieties are distinguished by the grain texture (vitreous, glutinous and viscous), the colour of the husk and pericarp, and by the size and shape of the grain. Varieties are adapted to the 4 distinct swampfield habitats, which differ in the mean water depth. Vitreous rice is grown together with glutinous rice, because the latter has a higher tolerance of weeds, pests and drought. Farmers harvest ear by ear. Each variety is maintained over time by seed selection and is constantly improved. Superior seed selectors are recognized within the village and their households operate as selectors for many generations and are the custodians of a basic seed collection. The seeds of different households, while bearing the same name and exhibiting the recognized characteristics, are certainly very different in terms of genetic constitution. Varieties are exchanged within the village, but also outside the village, among close kin and friends. Farmers experiment with newly received varieties and with off­types isolated in the field. Chapter 5 gives a description of the swamp rice agriculture system practised by the Pesagi. The book ends with an outline of the prospects for the Pesagi farmers.

Keywords: farmer breeding, farmer experimentation, folk taxonomy, grain type, seed exchange, seed production, seed selection, variety maintenance

53 Lando, R. P. & S. Mak, 1994. Cambodian farmers' decision making in the choice of traditional rainfed lowland rice varieties. IRRI Research Paper Series No. 154 International Rice Research Institute, Los Baños.

Many factors influence Cambodian farmers of rainfed lowland rice in choosing the varieties they will cultivate. Data collected through interviews with farmers in three Cambodian provinces and through crop cuts taken in their fields during the 1989-90 and 1990-91 wet season rice harvest helped to identify these factors and clarified their relative influences on the farmers' choices. Cambodian farmers base their choices of varieties to plant on a combination of factors: field characteristics (elevation, soil type and water regime), varietal maturity, eating quality, and yield potential. Early­maturing varieties are usually planted in high fields, medium­ and some late­maturing varieties in middle fields, and late­maturing varieties in low fields. Cambodian farmers prefer varieties that have white, long/slender grains and are aromatic and soft when cooked. However, no correspondence was found between farmers' ratings of grain shape and texture and the results of laboratory analyses. Survival characteristics, such as drought and flood tolerance, are considered equally with yield and culinary preferences when choosing early­ and late­maturing varieties. Yield and sale price are more important in choosing medium varieties, because the fields to which these varieties are best suited are less prone to environmental stress. Cambodian cultural practices, particularly the order of sowing, the density of transplanting, and the application of fertilizer, are also examined. Rice breeders have their own priorities for improving the plant type, yield potential, and survival characteristics of rainfed lowland rice varieties in order to intensify rice production in Cambodia. They, and other agricultural scientists working to change and improve rice varieties and farming practices, need to understand how farmers choose varieties and manage crops, if their efforts are to be effective.

Keywords: cooking quality, drought tolerance, farmer selection criteria, flooding tolerance, grain type, maturity, soil type, yield

54 Lightfoot, C., 1987. 'Indigenous research and on­farm trials'. Agricultural Administration and Extension 24: 79-89.

Two examples of indigenous research by farmers in the Philippines are described. In the first case, the farmers' lowland bunded rice crop was destroyed by flash flooding, leaving them with no seed of lowland varieties. A number of farmers used the seed of an upland modern variety that had been demonstrated in the area (but had not performed well) in their lowland plots. A summary is given of each farmer's management of the crop. The farmers used plant populations more than twice those typical of upland rice management. They were in general satisfied with the results of the adaptation and many of them continued to grow the upland variety in part of their lowland fields. The second case involves farmers' evaluation of sweet potato varieties. They evaluated a total of 16 varieties, although most farmers grew only 6 of them. The varieties were evaluated on the basis of: taste (sweetness and dryness preferred), storage qualities in the soil, maturity (earliness preferred), yield, pest and disease tolerance, rapid vining (in order to suppress weeds and control erosion), and capacity for sequential harvesting. It is pointed out that some of the farmers' objectives are not addressed by conventional breeding objectives.

Keywords: farmer experimentation, farmer selection criteria

55 Longley, C. & P. Richards, 1993. 'Selection strategies of rice farmers in Sierra Leone'. In W. de Boef, K. Amanor & K. Wellard with A. Bebbington, Cultivating knowledge. Genetic diversity, farmer experimentation and crop research, pp.51-63. Intermediate Technology Publications, London.

This paper examines the cultural and socio­economic factors underlying farming strategies, seed selection, and farmer experimentation, drawing on two case studies in Sierra Leone. In the Mende case, panicle harvesting has allowed farmers to select rices for characteristics of short, medium and long duration. Social differentation is evident in the ownership and control of rices belonging to each of the duration classes. Long­duration, flood­tolerant types are planted in valley­bottom wetlands by young men and older women after the main tasks on the family farm have been carried out. While long­duration types have a low status in Mende society, short­duration types are important to reduce the pre­harvest period and offer a durable solution to the social evil of indebtedness. In the Susu case, all farmers are aware of the contrasting characteristics of two rice varieties related to drought tolerance, duration, height, yield, taste, texture and nutritional bulk, but only a few farmers grow the two varieties mixed. This example demonstrates that indigenous technical knowledge is not a single coherent body of knowledge shared by all members of the community. The paper draws attention to the importance of understanding the local technical knowledge within its social and cultural context, before it can be decoded and incorporated into appropriate conservation and development programmes.

Keywords: farmer selection criteria, intercropping, local knowledge, maturity, seed selection

56 Marten, G. G., 1990. 'Small­scale agriculture in South East Asia'. In M. A. Altieri, & S. B. Hecht Agroecology and small farm development, pp. 183-200. CRC Press, Boston.

In South­east Asia many traditional farmers maintain dozens of local rice varieties. A farmer may plant a half dozen different varieties in one season, with a monoculture of each variety in different paddies. Similar varietal diversity exists for many other crops in the region, but little of this has been documented. The chapter provides descriptions of three agroecosystems: the Philippine Cordillera, the Uplands of West Java, and the Chiangmai Valley in Thailand. The Bontok of the Philippine Cordillera grow rice as their major crop. Different varieties are selected for different fields, depending on factors such as soil moisture. After the main harvest, about half the fields are planted to a second crop. If it is rice, farmers use varieties that are earlier­maturing than those used in the main season. In the Chiangmai Valley, a traditional rice variety that matures quickly is planted before the early cool­season crops, while late­maturing rice varieties are cultivated before a crop of soybean. The diversity of traditional rice varieties in the valley is diminishing.

Keywords: crop management, genetic diversity, maturity, rotations

57 Martin, G. & M. W. Adams, 1987. 'Landraces of Phaseolus vulgaris (Fabaceae) in Northern Malawi. I. Regional variation'. Economic Botany 41 (2): 190-203.

Common bean germplasm collections in northern Malawi revealed the existence of diverse landraces, which have probably been maintained by local farmers as heterogeneous mixtures since the pre­colonial introduction of Phaseolus vulgaris in eastern Africa. In this paper the term 'landrace' is used to refer to a genotypic mixture of predominantly self­pollinating species that is maintained by a subsistence farmer at a particular farm site. 25 lines were randomly selected from each landrace collection of seeds gathered at 15 farm sites in 5 different areas. Principal component analysis of morphological, phenological and agronomical metritical traits for the 375 lines showed a clinal pattern and indicated a greater variability between areas than within areas. The various seed types comprising these mixtures are known by an array of local names, reflecting farmer perceptions of seed colour and pattern, eating quality, plant structure, origin and other characteristics. The seed characteristcs varied in a broad north­south line due to environmental and/or consumer preference factors. Climbing beans predominate in the northern region where the vast majority of farmers grow their beans in association with maize. Beans and maize form the primary carbohydrate and protein sources in Malawi. While farmers desire and succeed in maintaining a uniform maize variety, they prefer a great diversity in their bean varieties. Heterogeneous bean mixtures may have advantages in northern Malawi due to intrapopulation buffering which may enhance disease and insect tolerance or a differential response to drought or light stress. Malawian farmers may also maintain their bean diversity for aesthetic purposes. Bean landrace diversity in Malawi is probably the result of a complex interplay among forces that generate variability, such as outcrossing and human and environmental selection.

Keywords: farmer selection criteria, genetic diversity, landraces, variety diffusion

58 Martin, G. & M. W. Adams, 1987. 'Landraces of Phaseolus vulgaris (Fabaceae) in Northern Malawi. II. Generation and maintenance of variability'. Economic Botany 41 (2): 204-215.

Common bean landraces in northern Malawi are found to be very diverse for many quantitative and qualitative traits. An earlier 21­character evaluation of 25 lines in 15 landraces found significant differences in all characters among lines and among landraces. The present study has concentrated on two factors involved in the generation and maintenance of this heterogeneity: seed­handling practices and outcrossing. Seed­handling practices during harvest, storage, and marketing at the village, local market, and national levels were found to result in physical and usually non­selective mixing of many seed types. Station experiments determined that outcrossing does occur at a low level (average rate 0.81%) and results in the generation of many new seed phenotypes. Principal component analysis of three landraces show that individual bean landraces range from relatively simple physical mixtures of unrelated types to biologically dynamic populations of great heterogeneity involving parental components, their intercross hybrids, and recombinant derivates. A scenario of bean landrace development integrating seed­handling practices and outcrossing was developed to understand the generation and maintenance of variability in these landraces. Understanding the process whereby landrace heterogeneity arises, and the way it is maintained, should assist plant breeders in the development of improved germplasm for subsistence farmers.

Keywords: landraces, recombination, seed exchange

59 Maurya, D. M., 1989. 'The innovative approach of Indian farmers'. In R. Chambers, A. Pacey & L. A. Thrupp, Farmer first. Farmer innovation and agricultural research., pp. 9-13. Intermediate Technology Publications, London.

Even in the absence of formal research, farmers regularly innovate and choose their own technology. A number of examples are given from India. A rice variety introduced from Malaysia, and rejected by breeders because of lodging, was taken by farmers and multiplied. It spread widely and is now the third most popular variety because of high tillering and good grain and milling qualities. The government has been forced to notify the variety under the Seeds Act. Similarly, a rice breeding line (IR24) was shown to be susceptible to low temperature, but a few plants that survived trials were taken by farmers and multiplied. It has now spread under the name Indrasan and proved to be particularly resistant during an outbreak of plant hopper in 1985 in Haryana. Examples are also given of a rice variety and a sugarcane variety that have been officially withdrawn but are widely used by farmers. In another case, a farmer selected an earlier­maturing plant from a late­maturing cotton variety, multiplied it and began to grow it as a distinct variety, which is now widely used by farmers. Other farmer innovations in machinery, pest control and fertilization are discussed. The implications for farmer participation in experimentation are pointed out.

Keywords: farmer breeding, farmer participatory research

60 McArthur­Crissman, L., 1989. Evaluation, choice and use of potato varieties in Kenya