|
|
|
| Registros recuperados: 10 | |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Meng, Erika C.H.; Smale, Melinda; Rozelle, Scott; Ruifa, Hu; Huang, Jikun. |
| Initial efforts to estimate the effects on productivity of diversity among modern varieties in a production function framework have been unsatisfactory in at least two respects. First, the conventional primal approach estimates the marginal effects of diversity on technical efficiency but is unable to examine issues of allocative efficiency since it does not explicitly address producer behavior with respect to prices. Second, measures of genetic diversity used in previous studies may not have fully represented the diversity present in the crop. The development and incorporation of a biologically meaningful index of crop genetic diversity into an economic decision-making model is not straightforward. Previous studies have most often used diversity... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries; Productivity Analysis. |
| Ano: 1999 |
URL: http://purl.umn.edu/21580 |
| |
|
|
| Smale, Melinda; Meng, Erika C.H.; Brennan, John P.; Hu, Ruifa. |
| Spatial diversity indicators may serve an important function for policymakers as they seek to manage crop genetic diversity and potential externalities associated with diffusion of some types of genetically improved crops. This paper adapts spatial diversity indices employed by ecologists in the study of species diversity to area distributions of modern wheat varieties in contrasting production systems of Australia and China. The variation in three interrelated concepts of diversity "richness, abundance, and evenness" is explained by factors related to the demand and supply of varieties, agroecology, and policies using the econometric method of Zellner's seemingly unrelated regression (SUR). Results suggest that in addition to expected yield and... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Crop Production/Industries. |
| Ano: 1999 |
URL: http://purl.umn.edu/7697 |
| |
|
|
| 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 |
| |
|
| |
|
| |
|
|
| Kruzich, Tyler J.; Meng, Erika C.H.. |
| The continued cultivation of landraces by household farms in centers of domestication and diversity is considered to be an in situ means of conservation of crop genetic resources. However, because in situ conservation has continued into the present does not ensure that this de facto strategy for conserving crop genetic resources will continue into the future. Whether or not traditional varieties continue to be cultivated rests primarily on factors influencing the crop decisions of these household farms. This paper focuses on two questions: 1) what are the significant determinants influencing the household cultivation of traditional wheat varieties; and 2) how do those determinants affect on-farm levels of diversity and the stability of on-farm... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries; Land Economics/Use. |
| Ano: 2006 |
URL: http://purl.umn.edu/25617 |
| |
|
| |
| Registros recuperados: 10 | |
|
|
|
