This study has aimed to diagnose and compare the predominant weed species in cowpea crop in the Amazon region and to evaluate the effectiveness of herbicides applied in pre-emergence. The weed sampling was obtained before planting, the cowpea cultivar was BRS Aracê, by collecting all the plants present within a 0.25 m² hollow frame, randomly thrown 40 times in experimental area to calculate the phytosociological indices. The herbicide efficiency experiment was conducted in a randomized block design with four replications, in time subdivided plot model. Treatments were applied one day after crop planting, their doses (g/ha ai) were: metribuzin (360), sulfentrazone (600), S-metolachlor (1200), pendimethalin (750), oxadiazon (1000), alachlor (2400), metribuzin + pendimethalin (360 + 750), metribuzin + alachlor (360 + 2400), manual weeding and weedy check. The evaluations of weed control were done at 21, 28 and 35 DAP. The most important weed in phytosociology was Tridax procumbens. Cultivation of the crop with weeds caused a reduction of more than 66% in crop productivity. The application of the metribuzin herbicide prevented the emergence of all cowpea seedlings while oxadiazon satisfactorily controlled the weeds without affecting the crop yield.

The goal of this study was to determine the essential fatty acids of the total lipids of the fillet, head and orbital cavity tissue from farmed tambaqui (Colossoma macropomum) fish from a Brazilian Amazon area. The tambaqui were acquired from different fish farms in the Roraima state, located at Western Brazilian Amazon. The meat, the head and the fatty tissue from orbital cavity were dissected for lipid extraction and analysis of fatty acids by gas chromatography. The fatty acids were quantified in mg g-1 of total lipids using C23:0 as an internal standard. The nutritional quality of the lipids was determined by using the atherogenicity and thrombogenicity indices, and also by the ratio between hypocholesterolemic / hypercholesterolemic fatty acids. The orbital cavity tissue had the higher concentration amount of linoleic and α-linolenic acid, whereas the fillet had higher docosahexaenoic acid (DHA). The eicosapentaenoic acid (EPA) concentration was: 1.28, 0.97, 1.71 mg g-1 of total lipids, in the filet, in head, and in orbital cavity tissue, respectively. All essential fatty acids were detected in the three parts analyzed. The nutritional quality of the total lipids from the head and from the orbital cavity tissue was similar to the fillet.

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O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.