Melinda Smale

Land Allocation in HYV Adoption Models: An Investigation of Alternative Explanations

Microeconomic theory provides four competing explanations for partial land allocation to new and traditional seed varieties in HYV adoption decisions: input fixity, portfolio selection, safety-first behavior, and learning. Testing a general model that contains each as a special case suggests that they are jointly most likely to explain land allocation in the HYV adoption decisions of Malawian smallholders. Yet when each explanation is tested to the exclusion of the others (as is usually the case in the literature), competing hypotheses are individually significant. Results suggest that employing approaches based on single explanations may lead to inappropriately narrow conclusions.

Valuing crop biodiversity: on-farm genetic resources and economic change.

Preface - J von Braun and E Frison Part I: Introduction Concepts, Metrics, and Plan of the Book - M Smale Part II: Private Value: Stated Preferences of Farmers Crop valuation and farmer response to change: Implications for in situ conservation of maize in Mexico - G Dyer, CIECO, Mexico Farmer demand for agricultural biodiversity in Hungarys transition economy: A Choice experiment approach - E Birol and A Kontoleon, University of Cambridge, UK, and M Smale Demand for attributes and on farm conservation of coffee in Ethiopia - E Wale, Alemaya University, Ethiopia and J Mburu, University of Bonn, Germany Part III: Private Value: Revealed Preferences of Farmers Missing markets, migration and crop biodiversity in the Mexican milpa system: A household farm model - M E Van Dusen, Berkeley, California, USA Determinants of cereal diversity on household farms in the highlands of northern Ethiopia - S Benin, IFPRI, Uganda, M Smale and J Pender, IFPRI, Washington DC, USA Demand for cultivar attributes and the biodiversity of bananas in Uganda - S Edmeades, IFPRI, Washington DC, USA, M Smale, and D Karamura, INIBAP, Uganda Farmer management of agricultural biodiversity in Hungarys transition economy - E Birol, M Smale and A Gyovai, Institute for Agrobotany, Hungary Rural development and the diversity of potatoes on farms in Cajamarca, Peru - P Winters, American University, USA, L H Hintze, Inter-American Development Bank, USA, and O Ortiz, International Potato Center, Peru Part IV: Public Values, Villages and Institutions Managing rice biodiversity on farms: The choices of farmers and breeders in Nepal - D Gauchan, Nepal Agricultural Research Council, Nepal, M Smale, N Maxted and M Cole, University of Birmingham, UK Determinants of cereal diversity in villages of Northern Ethiopia - B Gebremedhin, International Livestock Research Institute (ILRI), Ethiopia, M Smale and J Pender Social institutions and seed systems: the diversity of fruits and nuts in Uzbekistan - E Van Dusen, E Dennis, Indiana University, USA, M Lee, J Ilyasov, S Treshkin IPGRI-CWANA, Uzbekistan, and M Smale Village seed systems and the biological diversity of millet crops in southern India - L Nagarajan, IFPRI, Washington DC, USA, and M Smale Seeds supply and on farm demand for diversity: a case study of Eastern Ethiopia - L Lipper, R Cavatassi, FAO, Rome, Italy and P Winters Institutions, stakeholders, and the management of crop genetic sources on Hungarian family farms - G Bela, B Balazs, Institute of Environmental and Landscape Management, Hungary, and G Pataki, St Istvan University, Hungary Cooperatives, wheat diversity and crop productivity in southern Italy - S Di Falco, IFPRI, Washington DC, USA and C Perrings, University of York, UK Part V: Conclusions Scope, limitations and future directions - M Smale, L Lipper and P Koundouri, University of Piraeus, Greece An annotated bibliography of published literature about the economics of conserving crop biological diversity on farms - P Zambrano, IFPRI, Washington DC, USA, and M Smale.

The Demand for Crop Genetic Resources: International Use of the US National Plant Germplasm System

In contrast to a perception that ex situ collections of germplasm are rarely used, this empirical case study reveals large quantities of germplasm samples distributed by the U.S. National Germplasm System to many types of scientific institutions located in numerous countries around the world. Distributions favor developing countries in several ways including the numbers of samples shipped, utilization rates in crop breeding programs, and the secondary benefits brought about through sharing this germplasm with other scientists. Expected future demand is also greater among scientists in developing countries. These findings underscore the importance to global science and technology of retaining such resources in the public domain.

Farmer preferences for milpa diversity and genetically modified maize in Mexico: a latent class approach

Mexico is the centre of origin of maize. Maize is Typically grown as part of a set of associated crops and practices called the milpa system, an ancient mode of production that is practiced today in ways that vary by cultural context and agro-environment. We use a choice experiment to estimate the farmers’ valuation of three components of agrobiodiversity: crop species richness, maize variety richness and maize landraces. We include the option to cultivate genetically modified (GM) maize. Data were collected from 420 farm households across three states of Mexico. We analyze the heterogeneity of farmer preferences with a latent class model, which enables us to identify the characteristics of farmers who are most Likely to continue growing maize landraces, as well as those least likely to accept GM maize. Findings have implications for debates concerning the use of GM maize in Mexico and the design of on-farm conservation programmes.

Maize revolutions in Sub-Saharan Africa

There have been numerous episodes of widespread adoption of improved seed and long-term achievements in the development of the maize seed industry in Sub-Saharan Africa. This summary takes a circumspect view of technical change in maize production. Adoption of improved seed has continued to rise gradually, now representing an estimated 44 percent of maize area in Eastern and Southern Africa (outside South Africa), and 60 percent of maize area in West and Central Africa. Use of fertilizer and restorative crop management practices remains relatively low and inefficient. An array of extension models has been tested and a combination of approaches will be needed to reach maize producers in heterogeneous agricultural environments. Yield growth overall has been 1 percent over the past half-century, although this figure masks the high variability in maize yields, as well as improvements in resistance to disease and abiotic pressures that would have caused yield decline in the absence of maize breeding progress. The authors argue that conducive policies are equally, if not more, important for maize productivity in the region than the development of new technology and techniques. Currently popular, voucher-based subsidies can “crowd out” the private sector and could be fiscally unsustainable.

Participatory landrace selection for on-farm conservation: an example from the central valleys of Oaxaca México

On-farm conservation is recognized as a key component of a comprehensive strategy to conserve crop genetic resources. A fundamental problem faced by any on-farm conservation project is the identification of crop populations on which efforts should be focused. This paper describes a method to identify a subset of landraces for further conservation efforts from a larger collection representing the diversity found in the Central Valleys of Oaxaca, Mexico. Mexico is a center of origin and diversity for maize (Zea mays L.). The 17 landraces selected from an initial collection of 152 satisfy two criteria. First, they represent the diversity present in the larger collection. Second, they appear to serve the interests of farmers in the region. Data for applying the method were elicited through participatory as well as conventional techniques. They incorporate the complementary perspectives of both men and women members of farm households, and of plant breeders and social scientists.

Wheat Rusts and the Costs of Genetic Diversity in the Punjab of Pakistan

The theory of impure public goods is used to demonstrate why farmers may not grow wheat cultivars with the socially desirable level of rust resistance. First, they may grow cultivars that are high yielding though susceptible to rust. Second, many farmers may grow cultivars with a similar genetic basis of resistance. Expected rust losses can be reduced by (a) more diversified genetic background in released wheat cultivars; (b) greater spatial diversity in planted cultivars; or (c) use of a temporally changing list of cultivars known to be rust resistant. Yield trade-offs associated with these policies illustrate potential costs of increasing genetic diversity. Copyright 1997, Oxford University Press.

A regional analysis of maize biological diversity in Southeastern Guanajuato, Mexico

Four environments with contrasting potential for agricultural productivity and infrastructure development were identified in Guanajuato State, México, to test hypotheses about the relaciónship of maize biological diversity to the region’s potential for agricultural productivity and infrastructure development. Samples of all types of maize grown by a random sample of farmers were collected from each environment. Landraces were the dominant maize class in all four environments; the use of improved varieties was negligible. Several diversity indices were calculated, and no statistically significant differences were apparent between the environments with the most contrasting agroecological and infrastructural conditions. Statistical differences in diversity are apparent when the development of infrastructure interacts with agroecological factors in an environment. Qualitative data suggest that the richness of maize populations may be associated with maize yield potential in a geographical area, whereas the evenness of maize populations may be associated with the presence of infrastructure. These findings suggest further hypotheses about regional patterns of maize diversity.RésuméMéXICO. Este estudio examina la relación entre la diversidad biológica del maíz presente en una región con su potential de productividad agrícola y el grado de desarrollo de su infraestructura. Con el propósito de poner a prueba ciertas hipótesis acerca de esta relación, se identificaron cuatro ambientes con caracteristicas contrastantes de productividad potential e infraestructura en el sureste del estado de Guanajuato, México. En coda uno de estos ambientes, se colectaron muestras de maéz de todas las variedades sembradas por una muestra aleatoria de agricultores. Las variedades criollas fueron dominantes en los cuatro ambientes, y el uso de variedades mejoradas es muy limitado. Varios índices de diversidad fueron calculados con los datos recabados. No se encontraron diferencias estadísticamente significativas entre los ambientes más contrastantes en ninguno de los índices de diversidad. Sin embargo, si se encontraron para un ambiente, donde el desarrollo de la infrastructura y el potential productivo parecen interactuar. El patrón en los datos cualitativos sugiere que la riqueza de las poblaciones de maíz puede estar asociada con el potential productivo de un área, mientras que la equidad en la distributión de las muestras parece estarlo con la presencia de infraestructura. Los resultados de este estudio sugieren algunas hipótesis sobre los patrones regionales de la diversidad biológica del maíz.

Unequal Exchange? Recent Transfers of Agricultural Resources and their Implications for Developing Countries

Plant genetic resources constitute the biological basis for plant breeding and future agricultural development. Their transfer from developing to developed countries over centuries has sometimes been viewed as an example of exploitation, if not ‘biopiracy’. Modern gene flows are different in character and magnitude from historic exchanges, however. This article examines current patterns and finds that developing countries are major net recipients of germplasm samples from CGIAR centres, particularly if ‘improved materials’ are considered. Potentially problematic, intellectual property rights do not currently present major barriers to the availability and use of genetic resources by developing countries. Proposals to restrict flows and redress perceived injustices may reduce the benefits accruing at present to developing countries from germplasm exchanges.

Searching an Ex Situ Collection of Wheat Genetic Resources

A theoretical model is developed and applied to the search for disease and pest resistance in ex situ collections of wheat genetic resources, employing actual data on frequency distributions, disease losses, and search costs. Experiments developed from case studies clarify several misperceptions about the value of gene banks and their utilization by breeders. The observation that wheat breeders “use” gene banks rarely does not imply that marginal accessions have low value. High costs of transferring genes with conventional breeding techniques mean that it may be efficient to store certain categories of genetic resources (such as landraces) “unused” for many years. Copyright 2000, Oxford University Press.