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| Registros recuperados: 71 | |
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| Smale, Melinda; Byerlee, Derek R.; Jayne, Thomas S.. |
| 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... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Sub-Saharan Africa; Maize; Seed; Agricultural and Food Policy; Production Economics. |
| Ano: 2011 |
URL: http://purl.umn.edu/113651 |
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| Smale, Melinda; Cohen, Marc J.; Nagarajan, Latha. |
| In-depth field research—undertaken by IFPRI with the Food and Agriculture Organization of the United Nations (FAO) and other partners in India, Kenya, and Mali—brings to light new evidence about farmers’ access to seed and the role of village markets in supplying it, with a focus on semi-arid environments.1 The findings point to several policy options aimed at improving the effectiveness of these markets, which can be crucial for reducing the potential negative impacts of high food prices. Such options might be considered in tandem with those recommended for more favorable environments, where seed systems already function more effectively. This brief introduces the issues that drove this research project, relevant concepts, and methods. The accompanying... |
| Tipo: Report |
Palavras-chave: Crop Production/Industries. |
| Ano: 2009 |
URL: http://purl.umn.edu/49998 |
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| Brennan, John P.; Godden, David P.; Smale, Melinda; Meng, Erika C.H.. |
| As part of an ACIAR-funded project on genetic diversity in wheat in Australia and China, Australian wheat breeders were surveyed to assess the importance of genetic diversity to breeders. This paper reports the findings of that survey, and identifies the key issues that concern wheat breeders. The issues addressed include the breeders’ attitude to diversity and the diversity available in their current gene pool. The sources of materials that breeders use to maintain and/or increase diversity in their programs are identified, and ways in which diversity influences breeding decisions are also examined. More importantly from the policy view point, survey responses identify changes over time in the environment in which breeders operate that affect the extent... |
| Tipo: Presentation |
Palavras-chave: Genetic/diversity/wheat/breeder/survey; Crop Production/Industries. |
| Ano: 1999 |
URL: http://purl.umn.edu/123776 |
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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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| Benin, Samuel; Gebremedhin, Berhanu; Smale, Melinda; Pender, John L.; Ehui, Simeon K.. |
| On farm conservation of crop diversity poses obvious policy challenges in terms of the design of appropriate incentive mechanisms and possible trade-offs between conservation and productivity. This paper compares factors explaining the inter-specific diversity (diversity among species) and infra-specific diversity (diversity among varieties within a species) of cereal crops grown in communities and on individual farms in the northern Ethiopian highlands. Using named varieties and ecological indices of spatial diversity (richness, evenness, and inverse dominance), we find that a combination of factors related to the agro-ecology of a community, its access to markets, and the characteristics of its households and farms significantly affect both the inter-... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Household Farms; Communities; Ethiopia; Agrobiodiversity; On Farm Conservation; Crop Production/Industries. |
| Ano: 2003 |
URL: http://purl.umn.edu/16101 |
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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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| 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; 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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| Rice, Elizabeth; Smale, Melinda; Blanco, Jose-Luis. |
| The principal advantage of in situ conservation is that it allows adaptive evolutionary processes to continue in the species that are being conserved. For a cultivated crop species, in situ conservation involves farmers' management of their own genetic resources even as the farmers themselves adapt to a changing environment. Improved seed selection practices and other on-farm breeding strategies have been proposed as a means of providing economic incentives for farmers to continue growing traditional varieties or landraces identified as important for conservation. This paper describes a pilot study among a group of indigenous farmers in the Sierra de Santa Marta, Veracruz, Mexico, who have collaborated in such efforts. The findings raise key issues about... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Crop Production/Industries. |
| Ano: 1997 |
URL: http://purl.umn.edu/7690 |
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| Brennan, John P.; Godden, David P.; Smale, Melinda; Meng, Erika C.H.. |
| Genetic diversity in agricultural systems relies on both the supply of diversity through varieties produced by breeding programs, and the demand for that diversity, through farmers' usage of varieties. Variety choice by farmers is demonstrated through the mix of varieties that is grown in a given region. In this paper, the conceptual issues relating to the supply of and demand for genetic diversity are explored. An empirical analysis of the varietal demand, based on the varieties grown in the Temora Shire in southern NSW over the post-War period, is undertaken. Changes over time in the choice of varieties by farmers are analysed, and some implications for genetic diversity are discussed. |
| Tipo: Presentation |
Palavras-chave: Genetic/diversity/wheat/variety/demand/growers; Crop Production/Industries. |
| Ano: 1999 |
URL: http://purl.umn.edu/123785 |
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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: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries. |
| Ano: 2005 |
URL: http://purl.umn.edu/19445 |
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| Benin, Samuel; Smale, Melinda; Gebremedhin, Berhanu; Pender, John L.; Ehui, Simeon K.. |
| On farm conservation of crop diversity entails policy challenges, especially when the diversity of crops maintained on farms has both inter-specific (among crops) and infra-specific (within a crop) components. Survey data is used to compare the determinants of inter- and infra-specific diversity on household farms in the highlands of northern Ethiopia. Physical features of the farm, and household characteristics such as livestock assets and the proportion of adults that are men, have large and significant effects on both the diversity among and within cereal crops grown, varying among crops. Demographic aspects such as age of household head and adult education levels affect only infra-specific diversity of cereals. Though there are no apparent trade-offs... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries. |
| Ano: 2003 |
URL: http://purl.umn.edu/25833 |
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| Registros recuperados: 71 | |
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