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| Registros recuperados: 71 | |
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| Gauchan, Devendra; Van Dusen, M. Eric; Smale, Melinda. |
| This paper presents an empirical case study about farmer management of rice genetic resources in two communities of Nepal, drawing on interdisciplinary, participatory research that involved farmers, rice geneticists, and social scientists. The decision-making process of farm households is modelled and estimated in order to provide information for the design of community-based conservation programs. A bivariate model with sample selection treats the simultaneous process of whether farmers decide to plant landraces or modern varieties, and whether the landraces they choose to plant constitute genetic diversity of interest for future crop improvement. Findings show that the two landrace choices are affected by different social and economic factors. The... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Genetic resources; Rice; Farmers; Nepal; Landraces; Crop diversity; Crop Production/Industries. |
| Ano: 2005 |
URL: http://purl.umn.edu/58589 |
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| Smale, Melinda; Meng, Erika C.H.; Brennan, John P.; Hu, Ruifa. |
| Spatial diversity indicators may serve policymakers as they seek to manage crop genetic diversity and externalities associated with diffusion of some genetically modified crops. This paper adapts ecological indices of spatial diversity to area distributions of modern wheat varieties in contrasting production systems of Australia and China. The variation in three concepts of spatial diversity—richness, abundance, and evenness—is explained using Zellner’s seemingly unrelated regression (SUR). Determinants of wheat diversity differ by concept, but include variety traits other than yield potential, environmental factors, and policies affecting the supply of varieties, research spill-ins, and market liberalization. |
| Tipo: Presentation |
Palavras-chave: Agricultural and Food Policy; Crop Production/Industries. |
| Ano: 2000 |
URL: http://purl.umn.edu/123732 |
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| Smale, Melinda; Diakite, Lamissa; Sidibe, Amadou; Grum, Mikkel; Jones, Hannah; Traore, Issa Seni; Guindo, Hamidou. |
| Malian farmers have been cultivating millet and sorghum for millennia, but they are slow to adopt and develop modern varieties because it is difficult to observe the difference in yields in their fields, given the challenging local growing conditions. Farmer participatory approaches are therefore recommended. This paper applies an instrumental variables method to survey data from Mali to evaluate the impacts of Diversity Field Fora, a type of farmer field school which aims to boost millet and sorghum yields by showing farmers how to manage diverse varieties. Impact indicators are expected and recalled millet and sorghum yields, the total number of unique attributes of millet and sorghum varieties stocked as seed, and the relative deprivation of the... |
| Tipo: Journal Article |
Palavras-chave: Farmer field school; Sorghum; Millet; Landraces; Participatory crop improvement; Mali; Crop Production/Industries. |
| Ano: 2010 |
URL: http://purl.umn.edu/93879 |
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| Gomez, Jose Alfonso Aguirre; Bellon, Mauricio R.; Smale, Melinda. |
| Four environments with contrasting potential for agricultural productivity and infrastructure development were identified in Guanajuato State, Mexico, to test hypotheses about the relationship 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. The maize samples were classified by race, racial mixture, or type of 'creolized' or improved variety. 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... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Crop Production/Industries. |
| Ano: 1998 |
URL: http://purl.umn.edu/7671 |
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| Smale, Melinda; Bellon, Mauricio R.; Gomez, Jose Alfonso Aguirre. |
| This study uses an approach derived from models of the private and public characteristics of goods to illustrate (1) the overriding importance of variety attributes in farmers' decisions to allocate area among varieties of maize landraces and (2) the significance of farmers' perceptions of changes in the maize germplasm base in the surrounding community in their choices. Diversity indices and the concept of 'scale', as understood in ecology, are adapted and employed to test hypotheses empirically. Though a case study of maize farmers in Southeastern Guanajuato, the research raises methodological issues for models of variety choice and has policy implications for the potential to conserve maize genetic diversity on farms in Mexico. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Crop Production/Industries. |
| Ano: 1999 |
URL: http://purl.umn.edu/7669 |
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| Katungi, Enid; Smale, Melinda. |
| Changing agricultural research and extension systems mean that informal mechanisms of information diffusion are often the primary source of information about improved seed and practices for farmers in sub-Saharan Africa. This paper investigates the interactions between gender, social capital and information exchange in rural Uganda. Within the framework of farmer-to-farmer models, we conceptualize the informal information diffusion process to comprise social capital accumulation and information exchange. We assume that each agent participates in information exchange with a fixed (predetermined) level of social capital and examine how endowments of social capital influence information exchange, paying close attention to gender differences. A multinomial... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Gender; Social capital; Information exchange; Informal mechanisms; Uganda; Labor and Human Capital. |
| Ano: 2006 |
URL: http://purl.umn.edu/50070 |
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| Meng, Erika C.H.; Smale, Melinda; Ruifa, Hu; Brennan, John P.; Godden, David P.. |
| In recent years, output on genetic diversity in the economic literature has included conceptual pieces on the definition and measurement of crop genetic diversity, methodologies for estimating its value, and efforts to analyze its contribution to productivity and stability. However, because biological diversity refers in general to a broad area of scientific inquiry, the growing quantity of literature has also generated some confusion over the definition, measurement, and interpretation of genetic diversity in the context of economic analysis. This paper addresses some of the measurement issues encountered in incorporating genetic diversity into economic analysis by presenting a synthesis of several of the relevant concepts and tools. Using data collected... |
| Tipo: Presentation |
Palavras-chave: Genetic/diversity/wheat/variety/measurement; Crop Production/Industries. |
| Ano: 1999 |
URL: http://purl.umn.edu/124089 |
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| Horna, J. Daniela; Smale, Melinda; Al-Hassan, Ramatu M.; Falck-Zepeda, Jose Benjamin; Timpo, Samuel E.. |
| Tomato, cabbage and garden egg (African eggplant, or Solanum Aethiopicum) are important crops for small-scale farmers and migrants in the rural and peri-urban areas of Ghana. Genetic modification (GM) has the potential to alleviate poverty through combating yield losses from pests and diseases in these crops, while reducing health risks from application of hazardous chemicals. This ex-ante study uses farm survey data to gauge the potential for adoption of genetically-engineered varieties, estimate the potential impact of adoption on farm profits, and highlight economic differences among the three crops. Farmer's expenditures on insecticides are below the economic optimum in all three crops, and the estimated function for damage abatement shows that... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries; Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2008 |
URL: http://purl.umn.edu/6506 |
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| Rejesus, Roderick M.; Heisey, Paul W.; Smale, Melinda. |
| Sources of yield growth in wheat are investigated based on a stylized framework of technical change. Evidence suggests that the relative contribution of input intensification to yield growth has diminished in recent years and is likely to continue to decline in the future. One potential source of yield growth in wheat during the medium to long term is improved efficiency of input use, rather than input intensification, through sustainable wheat production practices rather than pure input increases. Other large gains could be made with continuous adoption of newer and better modern varieties based on advances in wheat breeding. Wide crossing and biotechnology could improve the stability of wheat yields in the intermediate term; their long-term impact on... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Crop Production/Industries. |
| Ano: 1999 |
URL: http://purl.umn.edu/7693 |
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| Birol, Ekin; Villalba, Eric Rayn; Smale, Melinda. |
| Maize, the second most globally important staple crop after wheat, originated in Mexico, where it is typically grown as part of a set of associated crops and practices called the milpa system. This ancient mode of production is practiced today in ways that vary by cultural context and agro-environment. Milpas generate private economic value, in terms of food security, diet quality and livelihoods, for the two-million farm households who manage them. Furthermore, milpas generate public economic value by conserving agrobiodiversity, especially that of maize landraces, which have the potential to contribute unique traits needed by plant breeders for future crop improvement. In this way, milpas contribute to global food security in maize. However, the... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Mexico; Maize; Genetically modified crops; Conservation; Crop Production/Industries. |
| Ano: 2007 |
URL: http://purl.umn.edu/42373 |
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| Nagarajan, Latha; Smale, Melinda; Glewwe, Paul. |
| The purpose of the research paper is to characterize biological diversity related to millets in the semi-arid regions of India at various spatial scales of analysis (e.g., farm household versus community levels) and place that evidence in a broader seed systems (includes both formal and informal) context. An important finding of this research is that producer access to millet genetic resources is affected by the extent to which seed is traded via formal markets or through other social institutions, along with farm and household characteristics. Findings also underscore the need for an enhanced theoretical understanding of local seed markets in analyzing crop variety choices and the diversity of materials grown in less favored environments. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Millet diversity; Seed systems; Local markets; Crop diversity; Biological diversity; Crop Production/Industries. |
| Ano: 2005 |
URL: http://purl.umn.edu/59235 |
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| Gollin, Douglas; Smale, Melinda; Skovmand, Bent. |
| This paper develops a theoretical model for analyzing gene bank management decisions regarding the search for traits of economic value in ex situ collections of wheat. The model is applied to data on the probability of finding useful sources of resistance to Russian wheat aphid (Diuraphis noxia) and septoria tritici leaf blotch, using Monte Carlo simulations for sampling distributions, simulations of varietal diffusion paths, and actual cost data from searches. Three specific questions are posed and answered: (1) what is the optimal size of search among genetic resources of a given type for a trait of economic value? (2) what is the value of specialized knowledge about which genetic resources are most likely to display resistance? and (3) how should search... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Crop Production/Industries. |
| Ano: 1998 |
URL: http://purl.umn.edu/7695 |
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| Edmeades, Svetlana; Smale, Melinda; Renkow, Mitch; Phaneuf, Daniel J.. |
| Ugandan smallholder farmers produce the nation's major food crop using numerous banana varieties with distinctive attributes, while coping with important biotic constraints and imperfect markets. This empirical context motivates a trait-based model of the agricultural household that establishes the economic association between household preferences for specific variety attributes (yield, disease and pest resistance, and taste), among other exogenous factors, and variety demand, or the extent of cultivation. Six variety demands are estimated in reduced form, each in terms of both plant counts ("absolute" or levels demand) and plant shares ("relative" demand). Two salient findings emerge from the analysis: 1) the determinants of both absolute and relative... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Variety demand; Variety attributes; Agricultural household model; Bananas; Uganda; Crop Production/Industries; Food Security and Poverty. |
| Ano: 2004 |
URL: http://purl.umn.edu/60323 |
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| Registros recuperados: 71 | |
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