The availability of single assai palm (Euterpe precatoria) seedlings with good quality is a fundamental requirement to expand the cultivation of the species. This study aimed to assess the use of fruit agro-industry residues as substrate for producing single assai seedlings. The experiment was carried out under nursery conditions, in a completely randomized design, with four replications and eight plants per plot. Fifteen treatments were evaluated: a commercial substrate, four dry and crushed agro-industrial residues (Brazil nut shell, acerola pit, assai pit and cupuassu peel) and ten combinations of these materials in the proportion of 1:1. The following variables were also measured: shoot height; stem diameter; number of leaves; shoot, root and total dry mass; and Dickson Quality Index score. The substrate formulated with Brazil nut shell + acerola pit stood out for promoting a higher growth and dry biomass, resulting in seedlings with a better quality. The pure assai pit residue was not efficient for producing seedlings, but it showed a good potential when mixed in equal proportion with other materials (e.g. Brazil nut shell and cupuassu peel).

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The objective of this work was to evaluate the effect of different doses of silicon on the production of lettuce seedlings. The treatments were arranged in a 4x2 factorial scheme, totaling 8 treatments. The first factor corresponded to 4 Si doses (Ca silicate) added to the substrate for seedling production (0; 13.3; 32.3 and 53.2 g.kg-1 of Si on the substrate). The second factor corresponded to two varieties of lettuce, being Mônica SF31 (Crespa) and Rafaela (Americana). The experimental design was the completely randomized, with 4 replicates. The number of leaves (NF), fresh aerial mass (MFPA), dry shoot mass (MSPA), fresh radicular mass (MFRA) and root dry mass (MSRA) were evaluated. Data were submitted to analysis of variance by the F test, and the means of the treatments compared by the Tukey test at 5% probability. The seedlings of the Mônica SF31 and Rafaela lettuce varieties do not present differences regarding the Si requirement for the production of MFPA, MSPA, MFRA and MSRA. The application of Si to the substrate can be a viable alternative for the production of lettuce seedlings with higher NF, MFPA, MSPA, MFRA and MSRA. Doses of 32.0 to 43.7 g.kg-1 of Si in the substrate are suitable for higher production of MFPA, MSPA, MFRA and MSRA of lettuce Mônica SF31. Doses of 31.5 to 39.8 g.kg-1 of Si in the substrate are suitable for higher production of MFPA, MSPA, MFRA and MSRA of Rafaela lettuce seedlings.

RESUMO -O buriti (Mauritia flexuosa L.) é uma palmeira cujo fruto é rico em vitamina A, B, C, cálcio, ferro, proteínas e seu óleo têm quantidades significativas de carotenóides. É bastante promissor para as indústrias de cosméticos e alimentos, no entanto, a produção do óleo é baixa ou insuficiente para atender a demanda do mercado. Devido à falta de incentivo à sua utilização pela indústria em geral, busca-se através desta pesquisa estudar as propriedades de qualidade do óleo de buriti em diferentes ambientes. Na avaliação dos fatores degradativos do óleo, as amostras foram submetidas à câmara escura em temperatura ambiente, câmara com luz fluorescente (15W), congelador e estufa (50°C). Os parâmetros oleoquímicos analisados foram: índice de acidez, índice de saponificação e dienos conjugados. Através das análises experimentais foram verificados vários fatores influentes nas características do óleo de buriti, evidenciando o efeito destes fatores nas propriedades de qualidade deste.

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