Water stress and temperature on germination and vigor of Handroanthus impetiginosus (Mart. ex DC)

ABSTRACT Water availability and temperature are among the main abiotic factors that influence seed germination and vigor, since they act directly on biochemical and physiological processes, which result in the production of the primary root. The objective of this study was to verify the effects of stress on germination and vigor of H. impetiginosus (‘ipê-roxo’) seeds under different temperatures and osmotic agents. The experimental design was completely randomized, in a 6 x 2 factorial scheme (osmotic potentials x temperatures) with four replicates of 25 seeds for each osmotic agent. In order to simulate water stress, polyethylene glycol (PEG 6000) and mannitol solutions were used and distilled water was used as control. Osmotic potentials of 0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa were evaluated at temperatures of 25 and 30 °C, under 8 h photoperiod. The variables analyzed were: germination, germination speed index, shoot length, root length, and total dry matter of seedlings. Simulated water stress affected seed germination and seed vigor of H. impetiginosus at both temperatures and osmotic agents from -0.6 MPa

Custos logísticos agroindustriais: avaliação do escoamento da soja em grão do Mato Grosso para o mercado externo Agribusiness logistics costs: evaluation of Mato Grosso state's soybean export

O objetivo deste trabalho é propor e aplicar um modelo de cálculo de custo logístico total para produtos agroindustriais brasileiros voltados para a exportação. O modelo é aplicado para a soja em grão produzida no Mato Grosso e exportada pelo porto de Santos. As avaliações contemplam fluxos de escoamento com rotas unimodais e intermodais. Do ponto de vista teórico, o modelo proposto contempla algumas variáveis comumente negligenciadas em análises deste tipo. Este é, por exemplo, o caso das variáveis ligadas à tributação. Do ponto de vista dos resultados empíricos resultantes da aplicação do modelo, o trabalho mostra que, devido a uma série de fatores e contrariando grande parte da bibliografia disponível sobre o assunto, nem sempre é vantajoso para o produtor brasileiro de soja do Mato Grosso escoar sua produção por alternativas intermodais. Algumas sugestões para trabalhos futuros nesta área são apresentadas ao final do artigo.<br>The objective of this study is to propose and implement a theoretical framework to calculate the total logistics costs of Brazilian agribusiness products meant for export. The framework was applied to soybeans that are produced in Mato Grosso and exported from the port of Santos. The analyses include unimodal and intermodal routes. From a theoretical viewpoint, the proposed framework includes some variables that are often underestimated in this kind of analysis, such as tax variables. With regard to the empirical results from implementing the framework, the study shows that due to a number of factors and contrary to much of the literature available on the subject, it is not always advantageous for the Mato Grosso soybeans producers to transport their production using intermodal alternatives. Future research suggestions are included at the end of the paper