Briquettes and pellets can be an option to produce biofuels made by agricultural residues compression. Therefore, this study aims at provide the characterization of the briquettes made by different residual concentrations of sugar bagasse and straw. Concerning this, we determined rapid analysis and mechanical resistance. Our mechanical test determined the briquettes resistance and friability. The results showed better characteristics of bagasse for briquettes formation, such as lower ash and higher fixed carbon content. Considering the compression resistance, the sugar cane bagasse briquettes in a high concentration had better results. Besides, these briquettes were more resistance to break on the tumbling test. However, briquettes produced with both residues showed feasible results. Thus, the use of blends can be a viable alternative for the use of sugarcane residues.Keywords: Biomass; bioenergy; compression; technological property; wastes. ResumoA produção de briquetes e pellets pode ser uma forma de obtenção de biocombustíveis a partir da compactação de resíduos vegetais. O objetivo deste trabalho foi caracterizar a qualidade de briquetes produzidos a partir de blendas de bagaço e palha da cana-de-açúcar. Determinou-se a análise imediata e a resistência mecânica. Os resultados mostraram que o bagaço e a palha apresentaram diferente comportamento no processo de briquetagem, tendo o bagaço melhores características primordiais para formação de briquetes (como menor teor de cinzas e maior teor de carbono fixo). Nos testes mecânicos, os briquetes produzidos com maiores proporções de bagaço (75 % e 100 %) apresentaram melhores resultados de resistência à compressão além de demonstrarem maior resistência à quebra no teste de tamboramento. Concluiu-se que o uso de palha da cana para a produção de briquetes só se torna viável na composição mista. O uso de blendas pode ser uma alternativa viável para o aproveitamento dos resíduos de cana-de-açúcar.

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-The tetrazolium (TZ) test is an alternative to conventional germination tests, which usually require longer periods for seed quality evaluation. However, it is necessary to develop specific methodologies for each species, determining the concentration and time of exposure to salt. Thus, the objectives of this study were (i) to optimize the application of tetrazolium in forest seeds of Platymiscium floribundum Vog., Lonchocarpus muehlbergianus Hassl. and Acacia polyphylla DC., with the proposal of an evaluation protocol for tetrazolium test in order to reduce the subjectivity of interpretation and (ii) to adapt standardized methodologies to evaluate the seed quality of forest species using TZ. To perform the tests, the seeds were submitted to immersion times and concentrations (0.1, 0.5 and 1.0%) in solution of 2,3,5-triphenyl tetrazolium chloride. The ideal concentrations and immersion time for each species were: P. floribundum -0.5 and 1.0% for 60 minutes; L. muehlbergianus -0,1% for 6 hours and A. polyphylla -0,5% for 4 hours. Each seed was evaluated by color, size and localization of colored spots in three zones of low, medium and significant impact on germinability and after classified in three vigor classes. The protocol and the proposed methodology presented high efficiency according to the established parameters.Index terms: viability, seed analysis, vigor.Otimização do teste de tetrazólio para avaliação da qualidade de sementes de Platymiscium floribundum, Lonchocarpus muehlbergianus e Acacia polyphylla DC.RESUMO -O teste de tetrazólio (TZ) é uma alternativa aos testes de germinação que, geralmente, demandam de maior tempo de execução. Para sua utilização é necessário o desenvolvimento de metodologias especificas de aplicação, determinando a concentração e o tempo de exposição das sementes ao sal. Assim, com este trabalho busca-se (i) otimizar a aplicação do TZ em sementes florestais de Platymiscium floribundum Vog., Lonchocarpus muehlbergianus Hassl. e Acacia polyphylla DC., reduzindo a subjetividade da interpretação dos resultados e (ii) adequar metodologias para avaliar a qualidade de sementes por meio do TZ. Para a realização dos testes, as sementes foram submetidas a tempos de imersão e concentrações (0,1; 0,5 e 1,0%) em solução de 2, 3, 5 trifenil cloreto de tetrazólio. Cada semente foi avaliada por cor, tamanho e localização das manchas em três zonas de baixo, médio e alto impacto para a capacidade de germinação e, classificada em três classes de vigor. As concentrações e tempo de imersão ideais para cada espécie foram: P. floribundum -0,5 e 1,0% por 60 minutos; L. muehlbergianus -0,1% por 6 horas e A. polyphylla -0,5% por 4 horas. O protocolo e a metodologia apresentaram alta eficiência de acordo com os parâmetros estabelecidos.Termos para indexação: viabilidade, análise de sementes, vigor.

The growing demand for forest products and the increasing interest worldwide in this market requires studying the behavior and defining Brazil’s role in relation to other competitive countries in the sector. This study analyzed the international trade in forest products from 2000 to 2014 emphasizing Brazil’s role. The Revealed Comparative Advantage index (RCA) and Revealed Comparative Disadvantage index (RCD) were analyzed based on the matrix of the symmetric Aquino index, also through the intra-industry and interindustry analysis using the Grubel-Lloyd index. Brazil shows RCA in fuel wood, wood panels, wood floors and wood articles as well as wood pulp. Brazil imports relatively small amounts of wood; nevertheless, it still has relatively high dependence on paper importations.

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Growth, nutrition and phytosanity of eucalyptus stands fertilized with boron, copper and zinc in the presence and absence of forest residues The increasing demand for forest products has promoted the growth of planted areas worldwide, from 167 million hectares in 1990 to 280 million in 2015. In the Brazilian planted forest sector, Eucalyptus species supply 90 % of the produced wood in the country. In general, eucalyptus stands are established in areas with unfavorable climatic conditions and low soil fertility. Mineral nutrition has an important influence on productivity and prevention against biotic and abiotic stresses. Micronutrient deficiency is an emerging reality, and B, Cu and Zn are the most problematic nutrients for eucalypt cultivation in soils of the Brazilian Cerrado. These nutrients are related to lignin, phenol and phytoalexin production pathways as cofactors and enzymatic activators. These molecules present relations with the resistance and the susceptibility of the plants to the pathogens attack, besides participating in the functional and structural integrity of membranes and other cellular constituents of plants. Thus, the omission effects were studied and application of B, Cu and Zn associated with the forest residues management. Trees nutrition and their relation with volume and susceptibility to eucalyptus rust (Puccinia psidii) were evaluated. The removal of forest residues from the harvest had little influence on the available levels of B, Cu and Zn in the soil. The omission of B and Zn influenced the availability of these nutrients in the soil; however, only low levels of B were reflected in trees nutrition. The diameter at breast height had a growth reduction at 12 and 15 months after planting. This difference was found between treatments with complete application of nutrients and with Zn omission. The treatment with Zn omission had the highest growth and, in general, the highest leaf concentration of macronutrients and micronutrients. The treatment with Zn omission also showed the lowest infestation and severity of eucalyptus rust. Thus, balanced mineral nutrition of trees favored growth and health of the forest stand.

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