Wheat Landrace Cultivation in Turkey: Household Land-use Determinants and Implications for On-Farm Conservation of Crop Genetic Resources

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 conservation? To address these questions, we incorporate socioeconom ic/household characteristics, as well as information on agroecological heterogeneity, market access, and perceptions of variety attributes into a household land-use decision model to examine plot-level decisions to cultivate wheat landraces. The results of this research have policy implications at several levels. If policy makers support in situ conservation, information on the househo lds most likely to continue to cultivate landraces, as well as the landraces cultivated by those households, can provide an idea of the likelihood of maintaining the current in situ conservation of crop genetic resources without intervention. Information on these households and on the significant determinants of their landrace cultivation can also provide guidance on the types and levels of intervention necessary, as well as the potential costs.Crop Production/Industries, Land Economics/Use,

Maize in China: Production Systems, Constraints, and Research Priorities

Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Using Economics to Explain Spatial Diversity in a Wheat Crop: Examples from Australia and China

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 profitability, other variety characteristics are important in explaining variation in the spatial distribution of modern wheat varieties. Environmental factors and policy variables related to the supply of varieties, international research spillins, and market liberalization are also determinants of the diversity in these systems. Explanatory factors affect richness, abundance and evenness in the distribution of modern wheat varieties in different ways. Comparing results between a small, commercial wheat-producing shire in Australia and a large, heterogeneous area in seven provinces of China illustrates the importance of scale and the nature of the farming system. Further research might include: (1) refinement of methods used to construct spatial diversity indices by incorporating geographically-referenced information; (2) more explicit treatment of the relationship between scale of measurement and diversity indices; (3) refinements in the specification of policy variables, and (4) application of similar methods in zones where traditional varieties are grown.Crop Production/Industries,

Wheat Landrace Cultivation in Turkey: Household Land-use Determinants and Implications for On-Farm Conservation of Crop Genetic Resources

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 conservation? To address these questions, we incorporate socioeconom ic/household characteristics, as well as information on agroecological heterogeneity, market access, and perceptions of variety attributes into a household land-use decision model to examine plot-level decisions to cultivate wheat landraces. The results of this research have policy implications at several levels. If policy makers support in situ conservation, information on the househo lds most likely to continue to cultivate landraces, as well as the landraces cultivated by those households, can provide an idea of the likelihood of maintaining the current in situ conservation of crop genetic resources without intervention. Information on these households and on the significant determinants of their landrace cultivation can also provide guidance on the types and levels of intervention necessary, as well as the potential costs

Using Economics to Explain Spatial Diversity in a Wheat Crop: Examples from Australia and China

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 profitability, other variety characteristics are important in explaining variation in the spatial distribution of modern wheat varieties. Environmental factors and policy variables related to the supply of varieties, international research spillins, and market liberalization are also determinants of the diversity in these systems. Explanatory factors affect richness, abundance and evenness in the distribution of modern wheat varieties in different ways. Comparing results between a small, commercial wheat-producing shire in Australia and a large, heterogeneous area in seven provinces of China illustrates the importance of scale and the nature of the farming system. Further research might include: (1) refinement of methods used to construct spatial diversity indices by incorporating geographically-referenced information; (2) more explicit treatment of the relationship between scale of measurement and diversity indices; (3) refinements in the specification of policy variables, and (4) application of similar methods in zones where traditional varieties are grown

Using Ecological Indices and Economics to Explain Diversity in a Wheat Crop: Examples from Australia and China

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

THE COST OF WHEAT DIVERSITY IN CHINA

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 measures based on named varieties or pedigree information. In this paper, we employ recently developed methods to classify the wheat cultivars grown in China into morphology groups, constructing an index of spatial diversity adapted from the ecology literature using these groups and variety area shares. Since crop area allocations are choice variables, we specify crop genetic diversity as endogenous in a simultaneous system with a cost function and input shares. This approach provides a stronger conceptual linkage between crop genetic diversity, policy variables, and the economic decisions of farmers. The unique data source combines information on variety characteristics and variety area shares with policy, economic and environmental variables for the seven major wheat-producing provinces in China during the time period from 1982 to 1997. Results suggest that the crop genetic diversity, measured as the "equitability" of the spatial distribution of wheat morphology groups, has an economic cost. Future work will further investigate the relationship of crop genetic diversity to economic efficiency and policies

Variety Choice by Australian Wheat Growers and Implications for Genetic Diversity

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

Breeder Demand for and Utilisation of Wheat Genetic Resources in Australia

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 to which they can enhance diversity. The impact of funding constraints, in particular, is shown to influence the extent to which breeders can utilise genetic diversity. The paper raises some important issues for the future genetic diversity of Australia’s wheat industry, and the extent to which economic problems related to genetic diversity may arise in the future