ResumoA adaptação da cultura da soja a um novo ambiente bem como a necessidade da relação simbiótica entre bactéria do gênero Bradyrhizobium e cultivares comerciais de soja, impõe barreiras no processo produtivo de grãos. Como forma de quantificar tais efeitos, este trabalho objetivou avaliar a interação da nodulação e dos componentes morfofisiológicos sobre o rendimento final de grãos de soja nas condições edafoclimáticas do Recôncavo Baiano. O experimento foi conduzido no Campo Experimental da Universidade Federal da Bahia, Cruz das Almas (BA) em delineamento de blocos casualizados, com nove cultivares de soja e quatro repetições. As avaliações foram realizadas no estádio de florescimento pleno com quantificação do número e a massa de nódulos, área foliar, massa da matéria seca das folhas; e outra no estádio de maturação plena, quantificando o rendimento de grãos. Mais de 40% do rendimento de grão se correlacionaram com os componentes da nodulação dos cultivares de soja, e as cultivares Curió, Conquista e Liderança apresentaram os melhores desempenhos no rendimento de grãos. Palavras-chaves: Glycine Max, área foliar, correlação, Bradyrhizobium AbstractThe adaptations of the soybean crop to a new environment as well as the need of a symbiotic relation among Bradyrhizobium bacteria and the commercial cultivars of soybean impose barriers to the grain productive process. The objective of this work was to evaluate the interaction of nodulation and the morphophysiological components over the final yield of soybean grains in the edaphoclimatical conditions of Recôncavo Baiano Region. The experiment was performed at the Experimental Field of the Federal University of Bahia, Cruz das Almas (BA), with an experimental design of randomized blocks, with nine soybean cultivars and four replications. The evaluations were performed in the stage of full flowering with the quantification of the number and mass of nodules, leaf area, total dry mass; and another evaluation in the full maturation stage, quantifying the grain yield. More than 40% of the grain yield was correlated to the components of nodulation of the soybean cultivars Curió, Conquista and Liderança cultivars presented the best performances in the yield of grain.

Biodegradable packaging may replace non-biodegradable materials when the shelf life of the packaged product is relatively short, as in minimally processed foods. The objective of this work was to evaluate the efficiency of biodegradable films comprising starch/polyvinyl alcohol (PVOH)/alginate with the addition of 0 or 0.5% of essential oil of copaiba (EOCP) or lemongrass (EOLM) compared to poly-vinyl chloride (PVC) films in the storage of minimally processed lettuce. Lettuce samples cut into 1-cm strips were placed in polypropylene trays wrapped with biodegradable films and stored at 6 ± 2 °C for 8 days. PVC films were used as controls. The biofilms presented 11.43-8.11 MPa resistance and 11.3-13.22% elongation, with water vapor permeability (WVP) of 0.5-4.04 x 10 -12 g. s ; thus, the films' properties were considered suitable for the application. The lettuce stored in PVC presented minor total soluble solids (TSS), less luminosity (L), higher intensity of yellow color (b), and eight times less mass loss than that stored in biodegradable films. Multivariate analysis showed that the lettuce lost quality after 2 days of storage in PVC films, representing a different result from the other treatments. Lettuce stored in biodegradable films for 2 and 4 days showed a greater similarity with newly harvested lettuce (time zero). The films with or without the addition of essential oil showed similar characteristics. Biodegradable films were considered viable for the storage of minimally processed lettuce.Index terms: Active packaging; biopolymer; copaiba oil; lemongrass oil. RESUMOAs embalagens biodegradáveis podem substituir as não biodegradáveis quando a vida de prateleira do produto embalado é relativamente curta, como no caso dos alimentos minimamente processados. Neste trabalho o objetivo foi avaliar a eficiência de filmes biodegradáveis de amido/PVOH/alginato adicionados de 0 ou 0,5% de óleo essencial de copaíba (EOCP) ou de capim limão (EOLM) em comparação aos filmes de PVC ao longo do armazenamento de alfaces minimamente processadas. As alfaces cortadas em tiras de 1 cm foram dispostas em bandejas de polipropileno armazenadas a 6 ± 2 °C por 8 dias. Filmes de PVC foram utilizados como controle. Os biofilmes apresentaram 11,43 -8,11MPa de resistência, 11,3 -13,22% de elongação e permeabilidade ao vapor de água (PVA) entre 0,5 -4,04 x 10 -12 g.s -1 .Pa -1 .m -1 , sendo os filmes biodegradáveis considerados adequados á aplicação devido as propriedades apresentadas. As alfaces armazenadas em PVC apresentaram queda brusca dos sólidos solúveis totais (SST), menor luminosidade (L), maior intensidade da cor amarela (b) e perda de massa (2%) oito vezes menor que as armazenadas em filmes biodegradáveis (12-16%) aos 8 dias de armazenamento. A análise multivariada evidenciou que as alfaces em filmes de PVC perderam qualidade aos 2 dias de armazenamento diferindo dos demais tratamentos. Já alfaces armazenadas em biofilmes por 2 e 4 dias apresentaram maior similaridade com as alfaces recém colhidas (tempo zero). Os film...

Mixtures of starch and other polymers have been used to produce biodegradable materials with low‐cost and enhanced properties. In this study, films containing starch mixed with alginate (ALG) and/or polyvinyl alcohol (PVOH) were characterized. Films produced using binary starch–alginate mixtures (F3, F5, and F9) had the highest tensile strength (19–28 MPa) and elongation capacity (22–17%). However, films produced using ternary starch–alginate–PVOH mixtures (F8 and F9) exhibited the best water‐barrier efficacy, with lower water‐vapor permeability (WVP) values (5 × 10 and 5.56 × 10−13 g/s/Pa/m1, respectively) than that of the starch films (23.60 × 10−13 g/s/Pa) and diffusion coefficient (Dw) values approximately seven times lower than that of films produced solely with starch. The results of the infrared analyses showed a decrease in the band representing OH stretching in films created using ternary starch–alginate–PVOH mixtures, suggesting interaction between the polymers. The films containing starch mixed with ALG and PVOH showed low monolayer. The results indicated that ternary blends created better physical barriers to the passage of water vapor and diminished the availability of active sites for water binding. The optimal proportions were found to be 80% starch, 11.4% ALG and 8.6% PVOH.

RESUMOO ruído das máquinas agrícolas, com o passar do tempo, pode provocar problemas auditivos nos operadores. De acordo com as normas regulamentadoras do Ministério do Trabalho e Emprego (NR 15), a exposição diária máxima permitida, durante uma jornada de trabalho de 8 horas, é de 85 decibels (dB (A)). Baseado neste contexto, este trabalho teve como objetivo avaliar os níveis de ruído emitidos por 12 tratores agrícolas de diferentes modelos e potências, bem como avaliar a existência de itens de ergonomia e segurança destes, comparando os resultados com as normas vigentes no Brasil. Os itens ergonômicos e de segurança dos tratores foram vistoriados e listados quanto sua conformidade ou não. Observou-se que para tratores sem cabina fechada o nível de ruído próximo (10 cm) ao ouvido dos operadores foi superior ao nível permitido pela Norma Regulamentadora (NR15), sendo necessário o uso de protetor auricular por parte dos operadores. Conclui-se ainda que a diminuição dos ruídos junto ao ouvido do operador é proporcionada pela presença de cabinas fechadas originais de fábrica. Ademais, verificou-se que os tratores mais novos atendem melhor aos requisitos de segurança e ergonomia. Palavras-chave: Conforto do operador, medição de ruídos e exposição do operador NOISE LEVEL EVALUATION, ITEMS SECURITY AND ERGONOMIC IN AGRICULTURAL TRACTORS ABSTRACTThe levels of noise emission from agricultural machinery, are not immediately apparent, but the cumulative effects over time include hearing loss According the Brazilian Ministry of Labor and Employment (NR 15), A noise level above the maximum allowed for an 8-hour workday, is 85 decibels (dB (A)). This study aims to evaluate the levels of noise emitted by 12 agricultural tractors of different models powers and to compare the results with existing regulations in Brazil. Ergonomic and safety features of the tractors were surveyed and listed as their compliance or not. It was observed that for tractors without enclosed without cab protection noise level close (10 cm) to the ears of operators were higher than the levels allowed by the Regulatory Standard (NR15), requiring the use of hearing protection for operators. In conclusion although the reduction of noise close to the ear of the operator is provided by the presence of closed factory originating booths. In addition it was found that the newest tractors best meet the safety requirements and ergonomics.

A B S T R A C T Search for greater operating efficiency of seeders via increased speed in sowing operation has caused many problems in soybean plantability which may affect its yield components and final yield. Due to it, this study was carried out with the objective to evaluate a seeder performance under different operating speeds and its relation to soybean cultivars yield components and final yield in a no-till system. Experiment was laid out as a random block design, in a 2×4 factorial scheme, composed of two soybean cultivars and four seeder operating speeds. It was noticed that the seeder operating speed of 9.2 km hG 1 caused a reduction of 1.5 cm in the seed sowing depth resulting in an increase of 14% of exposed seeds. Moreover, soil disturbed area at the center of crop row showed an increase of 23.7% reducing so the seed emergence rate at 9.6% dayG 1 , affecting soybean final plant population what resulted in an yield decrease of 20%. The evaluated parameters showed similar results for the 7.7 and 3.4 km hG 1 seeder operating speeds, although, the best seeder performance was noticed at the lower operating speeds.