Uso da alelopatia como alternativa de controle de plantas infestantes em pomar de laranjeira Pera.

O controle de plantas infestantes no sistema de produção de citros é um fator preponderante para a manutenção da boa produtividade dos pomares. No manejo convencional, esse controle é feito quase que exclusivamente a partir do uso de herbicidas

Uso da alelopatia como alternativa de controle de plantas infestantes em citros.

A citricultura brasileira apresenta números expressivos que traduzem a grande importância econômica e social que a atividade tem para a economia do país. Nessa direção, este trabalho estuda alternativas de manejo e controle de plantas infestantes para a cultura dos citros, visando sua sustentabilidade e redução dos custos com insumos, sobretudo herbicidas, em pomares localizados nos solos dos Tabuleiros Costeiros, a partir da supressão da interferência da matovegetação pela ação alelopática de palhadas de coberturas vegetais (roçadas), tanto nativas como implantadas, avaliando sua eficiência e comportamento como auxiliares no controle do mato.PDF. 193_11

Edge phonons in black phosphorus

Exfoliated black phosphorus has recently emerged as a new two-dimensional crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have potentially important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and the behavior of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.Comment: 15 pages, 4 figure

Manejo de colônias de abelhas-sem-ferrão.

Introdução; Ninho; Escolha de espécie; Localização do meliponário; Caixa racional; Instalação das colmeias; Revisão das colônias; Fortalecimeto das colônias; Alimentação; Divisão de colônias; Inimigos naturais; Produção de mel; Referências.bitstream/item/95760/1/CT219.pd

Competição de cultivares de sorgo forrageiro para plantio na safrinha no nordeste maranhense.

A base da alimentação dos bovinos na região de Cerrado do nordeste do Maranhão são as pastagens nativas, que, além de estarem sujeitas aos efeitos da sazonalidade quanto a oferta de alimentos, vêm sofrendo expressivas reduções de espaço, por causa da intensa incorporacão de áreas ao sistema de produção da soja. Uma alternativa para auxiliar na solução do problema da escassez de alimento, principalmente na época da seca, é a utilização de sorgo forrageiro, de pastejo ou corte verde, tendo em vista que a cultura apresenta grande tolerância ao estresse hidrico e possibilita alta producão de biomassa.bitstream/item/36211/1/Doc96.pd

Green Purchases and Sustainability in Amazon’s Coffee Management

This study was conceived in the cradle of the Brazilian Amazon region, on managerial and cognitive knowledge of the perspectives of sustainable management in coffee cultivation. The objective is to study the green purchasing process and sustainability in coffee management; (1), to map the factors that interfere in the green purchasing processes and sustainability in the researched scenario (2), propose the innovation required with participative management in the face of sustainability with green purchasing (3). With a base on Contingency theories of adaptive nature and emerging demands, Ecodevelopment interprets and performs compatible actions for sustainable local development, the U Theory confronts the problems and transforms them with innovative solutions. The Method of Study adopted is the Case study, of a qualitative nature, such as bibliographic survey procedures, data collection by semi-structured interviews with social actors of the coffee system, data analysis through triangulation and criticism with the theoretical framework and construction of the innovation sustainable development proposal. The result shows the lack of knowledge about green purchasing and the sustainability aspect of the practices used in the Global Coffee Platform. The quality work of the coffee farmers was evidenced in an individual form, but in order to meet the quantitative demands of the market, it is required the structural and leadership development for the construction of APL or agricultural cooperative. The mental design configured at the base of the productive chain needs to break paradigms that interfere in the sustainable posture, to understand the needs of the consumers and to emphasize their participation on the responsibility with the Amazon and the beneficiary society as a whole. We presented suggestions of innovation discussed from the gaps detected by the mapping of factors

Avaliação da decomposição do resíduo de coberturas melhoradoras de solo em pomar de laranja ?Pera?.

O solo é uma importante parcela do ecossistema, interferindo diretamente na qualidade do ar e da água. A cobertura vegetal protege o solo dos raios solares, diminui a evaporação de água, diminui o impacto das gotas de chuva e aumenta a eficiência da ciclagem dos nutrientes, além de amenizar significativamente a infestação de plantas infestantes no ambiente.PDF. 192_11

On the chromospheric activity of stars with planets

Context. Signatures of chromospheric activity enhancement have been found for a dozen stars, pointing to a possible star-planet interaction. Nevertheless in the coronal activity regime, there is no conclusive observational evidence for such an interaction. Does star-planet interaction manifest itself only for a few particular cases, without having a major effect on stars with planets in general? Aims. We aim to add additional observational constraints to support or reject the major effects of star-planet interactions in stellar activity, based on CaII chromospheric emission flux. Methods. We performed a statistical analysis of CaII emission flux of stars with planets, as well as a comparison between CaII and X-ray emission fluxes, searching for dependencies on planetary parameters. Results. In the present sample of stars with planets, there are no significant correlations between chromospheric activity indicator log(R'HK) and planetary parameters. Further, the distribution of the chromospheric activity indicator for stars without planets is not distinguishable from the one with planets.Comment: 6 pages, 5 figures, submitted to A&