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Search Results: 1 - 10 of 31017 matches for " Alexandre Bryan;Ferreira "
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Caracteriza??o dos padr?es de estresse hídrico para a cultura do arroz (ciclo curto e médio) no estado de Goiás e suas conseqüências para o melhoramento genético
Heinemann, Alexandre Bryan;
Ciência e Agrotecnologia , 2010, DOI: 10.1590/S1413-70542010000100003
Abstract: drought stress is a major constraint to crop production and yield stability in many regions of the world. in the state of goiás, most of the rice crop system is rainfed. in a plant breeding program, new genotypes are selected as a result of their adaptability for a determined environment. therefore, a plant breeding program needs information about drought frequency as well as its characteristics, intensity, and time during crop development. a crop simulation model was used to determine patterns of drought stress for 12 locations and six different planting dates for short and medium cycle rice. for upland rice, short and medium cycle, in favourable conditions (no soil impediment), drought stress is not a main constraint for the rice development in the state of goiás.
Avalia??o da eficiência de herbicidas no controle de plantas daninhas em alfafa
Silva, Wilson da;Vilela, Duarte;Cobucci, Tarcísio;Heinemann, Alexandre Bryan;Reis, Fernando Alvarenga;Pereira, Ant?nio Vander;Ferreira, Reinaldo de Paula;
Ciência e Agrotecnologia , 2004, DOI: 10.1590/S1413-70542004000400001
Abstract: the objectives of this study were to evaluate the efficiency and selectivity of herbicides on the weed plants control at the alfalfa crop. two experiments were carried out at the experimental station of agenciarural, located in anápolis, go. in the first experiment it was evaluated eight herbicides (imazethapyr, msma, fomesafen, bentazon, chlorimuron-ethyl and imazamox) post emergency and in the second experiment six different mixed of herbicides [(diuron + msma), (diuron + msma), (diuron + paraquat), (diuron + paraquat)] applied one day after the alfalfa harvesting date. for both experiments were included two checks (weedy check and no weedy check) and it was used a randomized block design, with four replications. the herbicides imazethapyr, msma, fomesafen, bentazon, chlorimuron-ethyl and imazamox were selective to the alfalfa crop and efficient for the weed plants control. the mixed of herbicides (diuron + msma) and (diuron + paraquat) applied after the harvesting date were responsible for damage on leaves and stem remaining. although the new alfalfa budding did not show any signal of toxic and the development and growth was normal. these mix of herbicides showed an efficient weed plants control and did not affect the harvest dry matter and plant height comparing to the weedy check. the no weedy check reduced the plant dry matter and height in 74,5% and 42,8%, respectively.
Avalia??o de cultivares de alfafa na Zona da Mata de Minas Gerais
Lédo, Francisco José da Silva;Pereira, Ant?nio Vander;Botrel, Milton de Andrade;Souza Sobrinho, Fausto de;Oliveira, Jackson Silva e;Xavier, Deise Ferreira;Heinemann, Alexandre Bryan;Ferreira, Reinaldo de Paula;
Ciência e Agrotecnologia , 2004, DOI: 10.1590/S1413-70542004000500025
Abstract: the objective of this experiment was to evaluate and select the alfalfa cultivars (medicago sativa l.) best adapted to the climate and soil of zona da mata, in minas gerais, brazil. the trial was carried out at embrapa gado de leite, in the experiment station located in coronel pacheco, mg, using a randomized complete block design with two replications. fifty-nine cultivars studied between sept. 9, 1999 and dec. 10, 2001 were submitted to 16 evaluating cuts. dry matter production (dmp), plant height (ph), vigor (vg), flowering percent (flo), leaf/stem ratio (rfc) and disease (d) and pests (p) occurrence were observed. there were significant differences among cultivars regarding to dmp, ph, vg, flo and d. cultivars p-30, crioula c-3 and crioula c-2 showed the highest dmp (13,17; 13,13; 13,00 e 12,48 t/ha/year, respectively). taller flo (18,98%) and ph (54,13 cm) were observed during the cuts done during the summer compared to those done during the winter (6,11% and 46,60 cm, respectively). based on the results of the trial, the cultivars p-30, crioula c-1, crioula c-3 and crioula c-2 were selected.
Adaptabilidade e estabilidade de cultivares de alfafa avaliadas em minas gerais
Botrel, Milton de Andrade;Evangelista, Ant?nio Ricardo;Viana, Maria Celuta Machado;Pereira, Ant?nio Vander;Souza Sobrinho, Fausto de;Oliveira, Jackson Silva e;Xavier, Deise Ferreira;Heinemann, Alexandre Bryan;
Ciência e Agrotecnologia , 2005, DOI: 10.1590/S1413-70542005000200019
Abstract: the objective of this experiment was to evaluate the adaptability and stability of forage dry matter production of alfalfa cultivars in three different regions in the state of minas gerais (mata, metalurgica and south). twenty-seven cultivars of alfalfa were evaluated between 1995 and 1998 using randomized block design with three replications. adaptability and stability were evaluated using eberhart & russel (1966) and lin & binns (1988) methodologies. significant differences (p < .01) among cultivars, environments and the cultivar x environment interactions were observed, showing that cultivars performance is affected by environment. cultivars with highest dry matter production showed the best adaptability and stability. cultivars crioula and p-30 should be recommended to be used in the state of minas gerais.
Estimativa da varia??o da produtividade do arroz em diferentes escalas temporais do índice SPI
Fernandes, Diego Sim?es;Heinemann, Alexandre Bryan;
Pesquisa Agropecuária Brasileira , 2011, DOI: 10.1590/S0100-204X2011000400001
Abstract: the objective of this work was to evaluate the accuracy of the drought index spi (standardized precipitation index), at different time scales, for determining the drought occurrences and for estimate their effects on upland rice adjusted yield in six different microregions in goiás state, brazil. precipitation daily data were used from rain gauge stations located at urua?u, aruan?, alexania, mineiros, catal?o and itumbiara, in goiás state, as well as upland rice yield data set for the microregions porangatu, rio vermelho, entorno de brasília, southwest goiás, catal?o and meia-ponte, also located in goiás state. the temporal time scales used in this study were monthly, quarterly, semiannual and annual. the differences among the spi temporal scales were evaluated for the number and frequency of drought occurrences, the percentage accuracy of the variation estimate related to the upland rice adjusted yield data, and the deviations between these estimates and the observed yield. increasing spi temporal scale makes it possible the identification of persistent drought, and the annual scale (spi-12) showed the best performance for estimating the variability of upland rice adjusted yield.
Environmental group identification for upland rice production in central Brazil
Heinemann, Alexandre Bryan;Sentelhas, Paulo Cesar;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000500005
Abstract: upland rice (oryza sativa l.) production is basically concentrated in four central brazilian states, mato grosso, goiás, rond?nia and tocantins. to reduce the genotype and environment (g × e) interactions, the classification of environment groups was proposed. the goal of this study explores possibilities to adjust the upland rice regional breeding systems to optimally fit to the range of environments they are targeting, based on a historical yield data set of the brazilian geographic and statistics institute (ibge, www.ibge.gov.br/home/) from 54 microregions. the specific objectives of this study were: (i) to identify and classify environmental groups in the brazilian upland rice production area; (ii) to validate these environmental groups using yield data set from the upland rice multi-trial experiments (mtes); (iii) and to identify the most representative site for each environmental group. for this the historical upland rice yield data from 54 microregions were detrented from the effects of technological advances and adjusted to the reference year, 2006. the adjusted yield data were used to build a matrix, which was submitted to a cluster analysis allowing the identification of three different environmental groups. these groups were classified as: highly favorable environment (hfe); favorable environment (fe); and less favorable environment (lfe). the hfe is less affected by inter-annual rainfall variability than the other two groups. the upland rice breeding programs must take into account the differences among the environmental groups to conduct their trials and suggest genotypes for the upland production area.
EFEITO DA DEFICIêNCIA HíDRICA NO DESENVOLVIMENTO E RENDIMENTO DE QUATRO CULTIVARES DE ARROZ DE TERRAS ALTAS EFFECT OF WATER DEFICIT ON THE DEVELOPMENT AND GRAIN YIELD OF FOUR UPLAND RICE CULTIVARS
Alexandre Bryan Heinemann,Luís Fernando Stone
Pesquisa Agropecuária Tropical , 2009, DOI: 10.5216/pat.v39i2.3819
Abstract: A cultura de arroz de terras altas está sujeita a múltiplos estresses abióticos. Dentre eles, destaca-se a deficiência hídrica, ocasionada por períodos sem precipita o, ou com precipita es abaixo da demanda da cultura. Este estresse é um dos principais responsáveis pela varia o, ano a ano, no rendimento da cultura do arroz de terras altas. Assim, este estudo teve como objetivo analisar os efeitos da deficiência hídrica no desenvolvimento e componentes do rendimento, de quatro cultivares de arroz de terras altas, sendo duas de ciclo curto, Guarani e Soberana, e duas de ciclo médio, Curinga e Primavera. Dois ensaios, um em condi o de deficiência hídrica e outro sem deficiência hídrica, foram conduzidos, simultaneamente, na esta o experimental da Agenciarural, no município de Porangatu, GO. Concluiu-se que a deficiência hídrica reduziu a produtividade de gr os, pela redu o no número de panículas e de gr os por panícula e pelo aumento da esterilidade de espiguetas. A diferen a em produtividade das cultivares de arroz, em condi es de deficiência hídrica, foi condicionada à proximidade do período de ocorrência da máxima intensidade do estresse, em rela o à data de sua flora o. A menor produtividade das cultivares precoces, sob deficiência hídrica, ocorreu devido à coincidência da sua flora o com o período de máxima intensidade do estresse. As cultivares de arroz n o diferiram na produtividade de gr os, em condi es irrigadas. Entretanto, sob deficiência hídrica, a cultivar Curinga, de ciclo médio, apresentou a maior produtividade. PALAVRAS-CHAVE: Oryza sativa L.; data de flora o; dura o do ciclo. Rainfed upland rice is subject to multiple abiotic stresses. Among them, water deficit is the most common one, due to periods without precipitation or with less precipitation than the water plant requirements. This stress is responsible for grain yield variation among years. This study intends to analyze the effects of water deficit on the development and yield components of four cultivars, two early cycle (Guarani and Soberana), and two medium cycle (Curinga and Primavera). Two independent experiments, one with and another without water stress, were carried out at the Agenciarural Experiment Station, in Porangatu, Goiás State, Brazil. It was concluded that the water deficit reduced grain yield, by reducing the number of panicles and
Livres, escravos e a constru??o de um conceito moderno de criminalidade no Brasil Imperial
Ferreira, Ricardo Alexandre;
História (S?o Paulo) , 2009, DOI: 10.1590/S0101-90742009000200012
Abstract: in the last decades, has become common, building sources based in police and judicial records in historic research. in brazilian historiography the issue most significantly marked by this phenomenon was the enslavement of africans and their descendants. with special attention to the construction of the sources analyzed in such studies, this article aims to understand and interpret the role given by members of the imperial brazilian state to the freeman and slave in the picture of building a modern concept of criminality. to reach this objective, besides the penal codes, we analyzed the reports issued by the ministers of justice. trying to contribute to the debate expert, this study asserts that, despite the perpetuation of slavery after the political independence of the country, many were the circumstances in which distinction between the freeman and the slave went not expressed.
Simula??o de microestruturas de ligas ternarias pelo método do Campo de Fase
Furtado, Alexandre Ferreira;
Matéria (Rio de Janeiro) , 2007, DOI: 10.1590/S1517-70762007000400009
Abstract: a phase field model for solidification of ternary alloys is proposed. in this paper, the relations between material properties and phase-field parameters are presented. in the development of this work, the ternary-alloy solidification model for the analysis of diffusivity is employed. for two-dimensional computations, the dendritic growth is simulated for fe-c-p ternary alloys. the change in phosphorus concentration affects the interface velocity. this change in the interface velocity is due to the small diffusivity of phosphorus during the solidification process.
é tudo verdade: tendências e perspectivas do documentário
Alexandre Figueir?a Ferreira
Galáxia , 2008,
Abstract:
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