Storage; analysis and communication of information from diverse wheat field trials

Tese de doutoramento em Gestão de Empresas apresentada à Faculdade de Economia da Universidade de CoimbraNas últimas décadas, grandes transformações ocorreram no ambiente competitivo internacional, provocando mudanças significativas no mercado externo e acelerando o processo de internacionalização das empresas, para que possam se manter competitivas. Portanto, esta tese investiga como se articulam os vários antecedentes da internacionalização de empresas brasileiras e avalia a intensidade das relações existentes entre a orientação para o mercado externo, a orientação empreendedora internacional, os recursos e a inovação e o seu impacto na performance exportadora. Este estudo visa a aprofundar o conhecimento sobre a capacidade destes construtos influenciarem o resultado das empresas brasileiras que operam no mercado internacional e avaliarem as relações agregadas entre eles. Para isso, alguns passos foram fundamentais no desenvolvimento da pesquisa: a proposição de um modelo teórico hipotetizando as relações entre os temas; a validação de escalas confiáveis; o teste empírico das hipóteses. As empresas brasileiras exportadoras foram definidas como população-alvo, conforme cadastro oficial da Secretaria de Comércio Exterior (Secex) do Ministério do Desenvolvimento, Indústria e Comércio Exterior (MDIC). A amostra foi composta de 406 empresas pesquisadas. Na análise dos dados aplicou-se a técnica multivariada dos dados, por meio da modelagem de equações estruturais (MEE) e a técnica de redes neurais artificiais (RNA). Testou-se o modelo hipotético através da análise fatorial confirmatória (AFC) e os resultados confirmaram 8 entre as 10 hipóteses estabelecidas a partir do modelo adotado nesta tese. Os resultados apontaram um efeito positivo e integrado entre os construtos antecedentes e a performance exportadora, conforme proposto no modelo estrutural. Os impactos mais fortes do modelo estabeleceram-se nas relações entre a orientação para o mercado externo e os recursos, e na relação entre a orientação empreendedora internacional e a orientação para o mercado externo. Os resultados obtidos através da técnica de redes neurais apresentaram 10 construtos de 1ª ordem com pesos positivos na relação com a performance exportadora e somente 4 com pesos negativos (inibidores). No comparativo entre as duas técnicas de análise, os resultados foram semelhantes, o que pode mostrar que a linearidade das relações é a realidade dominante. No cômputo geral os resultados confirmaram que os construtos de orientação para o mercado externo, a orientação empreendedora internacional, os recursos e a inovação influenciam positivamente na performance exportadora das empresas

Characterization of Mexican wheat landraces using agronomically useful attributes

In 1992, 465 individual spikes of bread wheat were collected from 24 sites in three states of Mexico. They were examined for 15 morphological, agronomic and grain quality attributes as part of the routine regeneration process conducted by the CIMMYT Wheat Genetic Resources Program in unreplicated hill plots in a screen house. A pattern analysis (combined use of classification and ordination methods) of the data provided a good description of the accessions and the collection sites. Since economically useful attributes were used the analysis provided relevant information for both potential users and the germplasm curators. Potential users have a description of the accessions from which to choose relevant breeding material and curators can assess how well the accessions represent the diversity in the collection sites. The analysis would not have been possible if the individual spikes from collection sites were bulked as is the common practice

3-Way Methods for Multiattribute Genotype X Environment Data - An Illustrated Partial Survey

Several ordination and clustering techniques are discussed with respect to their usefulness in analysing multiattribute genotype X environment data. The methods are briefly described and illustrated by application to data from the Australian Cotton Cultivar Trials (ACCT), a series of regional variety trials designed to investigate various cotton (Gossypium hirsutum (L.)) lines in several locations each year. Multivariate techniques applicable to three-way data are necessary to assess these lines using yield and lint-quality data

Analysis of the Environmental Component of Genotype X Environment Interaction in Crop Adaptation Evaluation

Cluster analysis has been useful in summarizing patterns of genotypic performance and environmental productivity when there is a significant amount of genotype x environment (G x E) interaction confounding the plant breeder. There has, however, been little emphasis on analysing the environmental component of G x E interaction or identifying environments which elicit similar patterns of yield response across genotypes. Grouping environments on the basis of genotype mean has been relatively uninformative, because it has largely ignored the G x E interaction. The method discussed here groups environments in such a way that the relative, not the actual, genotype performance is similar within environment groups. The use of genotype yield deviations from environment mean yield as a measure of the G x E effect in pattern analysis (the combined use of numerical classification and ordination), and their representation in bar graphs as a relative genotype ranking index (RGRI), is shown to be very effective in separating differential soybean line responses in different environments in Thailand. Recommendations of cultivars can then be made to farmers in particular regions

Multiattribute Evaluation of Regional Cotton Variety Trials

The Australian Cotton Cultivar Trials (ACCT) are designed to investigate various cotton [Gossypium hirsutum (L.)] lines in several locations in New South Wales and Queensland each year. If these lines are to be assessed by the simultaneous use of yield and lint quality data, then a multivariate technique applicable to three-way data is desirable. Two such techniques, the mixture maximum likelihood method of clustering and three-mode principal component analysis, are described and used to analyze these data. Applied together, the methods enhance each other's usefulness in interpreting the information on the line response patterns across the locations. The methods provide a good integration of the responses across environments of the entries for the different attributes in the trials. For instance, using yield as the sole criterion, the excellence of the namcala and coker group for quality is overlooked. The analyses point to a decision in favor of either high yields of moderate to good quality lint or moderate yield but superior lint quality. The decisions indicated by the methods confirmed the selections made by the plant breeders. The procedures provide a less subjective, relatively easy to apply and interpret analytical method of describing the patterns of performance and associations in complex multiattribute and multilocation trials. This should lead to more efficient selection among lines in such trials