535 research outputs found
Quality Of Soy Bean Seeds Under Tillage With Differe Nt Amounts Of Waste Of Black Oats, Common Vetch And For Age Turnip
Adjusting the cover crop to the agricultural system is essential to reach success during a crop introduction, since this management can influence development, productivity and produced seeds quality. For the soybean cultivar CD 202, traditional, half, and double amounts of crop waste produced by black oats, and a consortium of black oat, common vetch and forage turnip, were evaluated. Tests comprised emergence (emergency speed index (ESI) and emergence rate (ER)), development, field productivity and quality of seeds (germination percentage, accelerated aging, purity, 100-seed weight, and water content). The experimental design was of split plots and the mean values were compared through the Scott-Knott test at a 5% significance level, totaling seven treatments with five replications each. No differences were found in germination percentage, water content, and final height of plants. Some treatments differed in germination and waste use increased ESI; ER was superior for black oats and the best productivity was found under double amount of straw, on both cover crops. The seed strength decreased the under consortium, as shown by accelerated aging under the consortium. The purity of seeds was lower for black oats, decreasing with the least amount of crop waste. The 100-seed weight was lower with the double amount in oats; however, under the consortium the use of cover crop increased their weight. Thus, these species can be a good alternatives for soybean rotation on winter.384292297Bortolini, M.F., Fortes, M.T., Efeitos alelopáticos sobre a germinação de sementes de soja (Glycine max L. Merrill) (2005) Semina: Ciênc. Agr., 26, pp. 5-10(2009) Indicadores da Agropecuária. Ano XVIII, No 1. Compan Hia Nacional de Abastecimento, 64p. , CONAB, Brasília, Brazil(2009) Soja CD 202. Cooperativa Central de Pesquisa Agrícola, , www.coodetec.com.br/php/detalhes_cultivar.php?id=20, CIDADE?, Brazil, (Cons. 02/25/2009)Correia, N.M., Centurion, M.A.P.C., Alves, P.L.C.A., Inf luência de extratos aquosos de sorgo sobre a germinação e o desenvolvimento de plântulas de soja (2005) Ciênc. Rural, 35, pp. 498-503Edmond, J.B., Drapalla, W.J., The effects of temperature, sana and soil, and acetone on ger mination oj ok ra seed (1958) Proc. Am. Soc. Hort. Sci., 71, pp. 428-443(2000) A Cultura da Soja No Brasil, , EMBRAPA SOJA, Londrina, Brazil. CD-ROM(2005) Tecnologia da Produção da Soja. Empresa de Pesquisa Agropecuária, 208p. , EMBRAPA SOJA, Londrina, Brazil(2008) Tecnologia de Produção de Soja. Região Central Do Brasil, 280p. , EMBRAPA SOJA, Empresa de Pesquisa Agropecuária. Embrapa Cerrados: Embrapa Agropecuária Oeste. Londrina, BrazilFerreira, D.F., (1999) Sisvar: Sistema de Análise de Variância Para Dados Balanceados, , DEX / UFLA: Lavras, Brazil(2009) Prognóstico da Produção Agrícola Nacional, , www.ibge.gov.br/home/estatistica/indicadores/agropecuaria/lspa/ lspa_200812-11.shtm, Instituto Brasileiro de Geografia e Estatística, (Cons. 01/16/2009)Kubo, C.T., Produtividade de soja em plantio direto em sucessão ao trigo, aveia branca, aveia preta com e sem adubação nit rogenada (2007) Acta Sci. Agron., 29, pp. 235-240Lopes, R.A.P., Pin Heiro Neto, R., Braccini, A.L., Souza, E.G., Efeito de diferentes coberturas vegetais e sistemas de preparo do solo na produção da cultura da soja (2007) Acta Sci. Agron., 29, pp. 507-515Maguire, J.D., Seeds of germination- aid selection and evaluation seedling emergence and vigor (1962) Crop Sci., 2, pp. 176-177Marcos Filho, J., Teste de envelhecimento acelerado. Cap. 3. (1999) Seed Vigor: Concepts and Tests, pp. 1-24. , Krzyzanowski EFC, Vieira RD, Neto JBF (Eds.), Associação Brasileira de Tecnologia de Sementes. Londrina, Brazil. 218 ppMarcos Filho, J., Cicero, S.M., Silva, W.R., (1987) Avaliação da Qualidade de Sementes, 230p. , FEALQ. Piracicaba, BrazilMartins, G.I., (2006) Potencial Alelopático de Plantas de Cobertura Na Germinação de Sementes e Crescimento de Plântulas de Soja. Trabalho de Conclusão de Curso, 42p. , Universidade Estadual do Oeste do Paraná. Brazil(2009) Regras Para Análise de Sementes. 388 Mapa/ACS, 399p. , MAPA, Ministério da Agricultura, Pecuária e Abastecimento. Brasília, BrazilNedel, J.L., Fundamentos da qualidade de sementes (2003) Sementes: Fundamentos Científicos e Tecnológicos, pp. 95-138. , Peske ST, Rosenthal MD, Rota GR (Eds.), Universidade Federal de Pelotas. BrazilNóbrega, L.H.P., Germinação de sementes e crescimento de plântulas de soja (Glycine max L. Merrill) sob cobertura vegetal (2009) Acta Sci. Agron., 31, pp. 461-465Nunes, U.R., Qualidade fisiológica de sementes de feijão em plantio direto sobre diferentes coberturas de plantas em Diamantina MG (2007) Ciênc. Agrotécn., 31, pp. 1737-1743Piccolo, G., (2008) Manejo de Coberturas Vegetais Na Cultura da Soja, 63p. , Thesis. Universidade Estadual do Oeste do Paraná, Unioeste. BrazilRice, E.L., (1974) Allelopathy, 333p. , Academic Press. New York, USA(2008) Área e Produção: Principais Culturas Do Paraná, , www.seab.pr.gov.br/, SEAB, Secretaria da Agricultura e do Abastecimento do Paraná. (Cons. 12/22/2008)Souza, C.M., Pires, F.R., (2002) Adubação Verde e Rotação de Culturas, 72p. , Universidade Federal de Viçosa. BrasilSouza Filho, A.P., Alves, S.M., Mecanismos de ação dos agentes alelopáticos (2002) Alelopatia. Princípios Básicos e Aspectos Gerais. Embrapa Amazônia Oriental, pp. 132-154. , Souza Filho AP, Alves SM (Eds.), Belém, BrasilTokura, L.K., Nóbrega, L.H.P., Alelopatia de cultivos de cobertura vegetal sobre plantas infestantes (2006) Acta Sci. Agron., 28, pp. 379-38
Xylella fastidiosa comparative genomic database is an information resource to explore the annotation, genomic features, and biology of different strains
The Xylella fastidiosa comparative genomic database is a scientific resource with the aim to provide a user-friendly interface for accessing high-quality manually curated genomic annotation and comparative sequence analysis, as well as for identifying and mapping prophage-like elements, a marked feature of Xylella genomes. Here we describe a database and tools for exploring the biology of this important plant pathogen. The hallmarks of this database are the high quality genomic annotation, the functional and comparative genomic analysis and the identification and mapping of prophage-like elements. It is available from web site http://www.xylella.lncc.br
Delocalization in harmonic chains with long-range correlated random masses
We study the nature of collective excitations in harmonic chains with masses
exhibiting long-range correlated disorder with power spectrum proportional to
, where is the wave-vector of the modulations on the random
masses landscape. Using a transfer matrix method and exact diagonalization, we
compute the localization length and participation ratio of eigenmodes within
the band of allowed energies. We find extended vibrational modes in the
low-energy region for . In order to study the time evolution of an
initially localized energy input, we calculate the second moment of
the energy spatial distribution. We show that , besides being dependent
of the specific initial excitation and exhibiting an anomalous diffusion for
weakly correlated disorder, assumes a ballistic spread in the regime
due to the presence of extended vibrational modes.Comment: 6 pages, 9 figure
A Weyl-Dirac Cosmological Model with DM and DE
In the Weyl-Dirac (W-D) framework a spatially closed cosmological model is
considered. It is assumed that the space-time of the universe has a chaotic
Weylian microstructure but is described on a large scale by Riemannian
geometry. Locally fields of the Weyl connection vector act as creators of
massive bosons having spin 1. It is suggested that these bosons, called
weylons, provide most of the dark matter in the universe. At the beginning the
universe is a spherically symmetric geometric entity without matter. Primary
matter is created by Dirac's gauge function very close to the beginning. In the
early epoch, when the temperature of the universe achieves its maximum,
chaotically oriented Weyl vector fields being localized in micro-cells create
weylons. In the dust dominated period Dirac's gauge function is giving rise to
dark energy, the latter causing the cosmic acceleration at present. This
oscillatory universe has an initial radius identical to the Plank length =
1.616 exp (-33) cm, at present the cosmic scale factor is 3.21 exp (28) cm,
while its maximum value is 8.54 exp (28) cm. All forms of matter are created by
geometrically based functions of the W-D theory.Comment: 25 pages. Submitted to GR
Multi-temporal analysis of radiometric changes in satellite images of forest edges to infer selective-logging areas in the Amazon forest
Transmissão por mãos contaminadas e ausência de transmissão embrionária do vírus do amarelo letal do mamoeiro
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In the last years many populations of anurans have declined and extinctions have been recorded. They were related to environmental pollution, changes of land use and emerging diseases. The main objective of this study was to determine copper sensitivity of the anuran of the Amazon Rhinella granulosa and Scinax ruber tadpoles at stage 25 and Scinax ruber eggs exposed for 96 h to copper concentrations ranging from 15 µg Cu L-1 to 94 µg Cu L-1. LC50 at 96 h of Rhinella granulosa Gosner 25, Scinax ruber Gosner 25 and Scinax ruber eggs in black water of the Amazon were 23.48, 36.37 and 50.02 µg Cu L-1, respectively. The Biotic Ligand Model was used to predict the LC50 values for these species and it can be considered a promising tool for these tropical species and water conditions. Copper toxicity depends on water physical-chemical composition and on the larval stage of the tadpoles. The Gosner stage 19-21 (related to the appearance of external gills) is the most vulnerable and the egg stage is the most resistant. In case of contamination by copper, the natural streams must have special attention, since copper is more bioavailable.Nos últimos anos foram registrados muitas extinções e declínios de populações de anuros. Eles estavam relacionados com a poluição do ambiente, a mudanças no uso da terra e ao surgimento de doenças. O principal objetivo deste estudo foi determinar a sensibilidade dos anuros amazônicos ao cobre. Os girinos de Scinax ruber e Rhinella granulosa no estadio 25 e os ovos de Scinax ruber foram expostos por 96 horas a concentrações de cobre entre 15 µg Cu L-1 a 94 µg Cu L-1. A CL50 -96 h dos girinos de Rhinella granulosa, dos girinos de Scinax ruber e dos ovos de Scinax ruber em águas pretas da Amazônia foram 23,48; 36,37 e 50,02 µg Cu L-1, respectivamente. O modelo do ligante biótico foi usado para prever os valores de CL50 para essas duas espécies e pode ser considerado uma ferramenta promissora para essas espécies tropicais e para essas condições de água. A Toxicidade de cobre depende da composição físico-química da água e do estagio larval dos girinos. O estadio 19-21 de Gosner (relacionados ao aparecimento das brânquias externas) são os mais vulnerável e o estagio de ovo é o mais resistente. Em caso de contaminação por cobre, os igarapés naturais devem ter uma atenção especial, uma vez que o cobre é mais biodisponível nesse ambiente
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