oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 4 )

2019 ( 220 )

2018 ( 322 )

2017 ( 300 )

Custom range...

Search Results: 1 - 10 of 299905 matches for " Rubens J. Campo "
All listed articles are free for downloading (OA Articles)
Page 1 /299905
Display every page Item
Residual effects of successive exposure of soybean Bradyrhizobium strains to aluminium on solid defined medium
Campo, Rubens José;Wood, Martin;
Pesquisa Agropecuária Brasileira , 2001, DOI: 10.1590/S0100-204X2001001100011
Abstract: the aim of these studies was to investigate whether residual toxic effects of exposing soybean root nodule bacteria to al in a solid defined media (sdm) alter tolerance to al, survival, sensitivity to antibiotics, n2 fixation effectiveness and genetic diversity of bradyrhizobium strains. after being exposed four times to al, strains showed variation in al tolerance but there was no evidence of change in their original al tolerance, sensitivity to the antibiotics or genetic diversity. exposure of bradyrhizobium strains to sdm plus al did not alter biological n2 fixation effectiveness of five strains. strain semia 587 showed a reduction in its n2 fixation effectiveness but it seems that it was just a superficial toxic effect because one single passage through the plant eliminated this effect. residual al did not cause increases in al tolerance and reductions in the survival and n2 fixation effectiveness of bradyrhizobium strains usda 143, semia 586, semia 5019, semia 5039 and semia 5073. it also did not alter the resistance to antibiotics of strains usda 143, semia 5039 and semia 5073, and the genetic diversity of the strains semia 587 and semia 5019.
Residual effects of successive exposure of soybean Bradyrhizobium strains to aluminium on solid defined medium
Campo Rubens José,Wood Martin
Pesquisa Agropecuária Brasileira , 2001,
Abstract: The aim of these studies was to investigate whether residual toxic effects of exposing soybean root nodule bacteria to Al in a solid defined media (SDM) alter tolerance to Al, survival, sensitivity to antibiotics, N2 fixation effectiveness and genetic diversity of Bradyrhizobium strains. After being exposed four times to Al, strains showed variation in Al tolerance but there was no evidence of change in their original Al tolerance, sensitivity to the antibiotics or genetic diversity. Exposure of Bradyrhizobium strains to SDM plus Al did not alter biological N2 fixation effectiveness of five strains. Strain SEMIA 587 showed a reduction in its N2 fixation effectiveness but it seems that it was just a superficial toxic effect because one single passage through the plant eliminated this effect. Residual Al did not cause increases in Al tolerance and reductions in the survival and N2 fixation effectiveness of Bradyrhizobium strains USDA 143, SEMIA 586, SEMIA 5019, SEMIA 5039 and SEMIA 5073. It also did not alter the resistance to antibiotics of strains USDA 143, SEMIA 5039 and SEMIA 5073, and the genetic diversity of the strains SEMIA 587 and SEMIA 5019.
Efeito de fontes e doses de molibdênio na sobrevivência do Bradyrhizobium e na fixa??o biológica de nitrogênio em soja
Albino, Ulisses Brigatto;Campo, Rubens José;
Pesquisa Agropecuária Brasileira , 2001, DOI: 10.1590/S0100-204X2001000300018
Abstract: molybdenum (mo) is an essential nutrient for soybean because it is a component of enzyme nitrogenase, responsible for the biological nitrogen fixation (bnf). it has been recommended for application on soybean seeds along with soybean inoculants. however, several works have showed that mo applied together with inoculant reduce bradyrhizobium survival, nodulation and bnf efficiency. the aim of this study was to know if there are alternative ways to supply mo to soybean without affecting bradyrhizobium strains survival, nodulation and bnf efficiency. the alternative ways studied in vitro were to know the growth of strains in liquid medium with different sources and levels of mo, and in glasshouse these sources of mo were compared with the commercial ones on their effects on bacteria survival on the seeds, nodulation and bnf efficiency. the strains of bradyrhizobium showed different growth rate for the mo concentration and sources tested, being the strain semia 5080 the best of them. mo application on the seeds must be avoided, because mo reduces bacteria survival, nodulation and, bnf efficiency. the best mo sources to bnf were ammonium molybdate, mo trioxide and the commercial sources grap and comol.
Efeito de fontes e doses de molibdênio na sobrevivência do Bradyrhizobium e na fixa o biológica de nitrogênio em soja
Albino Ulisses Brigatto,Campo Rubens José
Pesquisa Agropecuária Brasileira , 2001,
Abstract: O molibdênio (Mo) é essencial para a soja, por participar da enzima nitrogenase, sintetizada pelas bactérias durante o processo de fixa o biológica do nitrogênio (FBN) por simbiose. A aplica o do Mo nas sementes no momento da semeadura antecede a aplica o do inoculante. O contato do Mo com o inoculante prejudica o Bradyrhizobium e, conseqüentemente, a FBN. O presente trabalho teve como objetivo estudar alternativas de fornecer Mo para a soja e a FBN sem afetar a sobrevivência da bactéria, a nodula o e a eficiência do processo de FBN. Avaliou-se, in vitro, a capacidade das estirpes de Bradyrhizobium de crescerem em meio líquido contendo concentra es crescentes de diversas fontes de Mo, e, em casa de vegeta o, os efeitos de doses crescentes de molibdato de sódio e de outras fontes de Mo na sobrevivência do Bradyrhizobium, na nodula o e na eficiência da FBN. As estirpes apresentaram tolerancia distinta com rela o a fontes e doses de Mo; a estirpe SEMIA 5080 apresentou o melhor crescimento entre elas. A aplica o de Mo nas sementes com o inoculante deve ser evitada, porque ele reduz o número de células de Bradyrhizobium, a nodula o e a FBN. As fontes de Mo mais eficientes para a FBN s o molibdato de am nio, trióxido de Mo e as fontes comerciais Grap e Comol.
Eficácia da inocula??o de Bradyrhizobium em pré-semeadura da soja
Zilli, Jerri édson;Campo, Rubens José;Hungria, Mariangela;
Pesquisa Agropecuária Brasileira , 2010, DOI: 10.1590/S0100-204X2010000300015
Abstract: the objective of this work was to evaluate the effect of bradyrhizobium inoculation on soybean pre-sowing and the effect of the treatments of seeds using fungicides on nodulation. control treatments consisted of two non-inoculated treatments, with or without n-fertilizer supply (200 kg ha-1 of n). inoculation at pre-sowing had a performance similar to the standard inoculation at sowing regarding soybean nodulation, dry matter production, grain yield and n accumulation in tissues and grains. however, when seeds were treated with fungicides, nodulation and grain yield decreased.
Inocula??o de Bradyrhizobium em soja por pulveriza??o em cobertura
Zilli, Jerri édson;Marson, Leandro Carvalho;Marson, Bruno Franco;Gianluppi, Vicente;Campo, Rubens José;Hungria, Mariangela;
Pesquisa Agropecuária Brasileira , 2008, DOI: 10.1590/S0100-204X2008000400014
Abstract: the objective of this work was to evaluate a bradyrhizobium inoculation method on soybean by spraying inoculant over plants. an experiment was conducted in the cerrado of roraima. treatments tested were: control without inoculation; standard inoculation method with two doses of inoculant per hectare applied on seeds; inoculation with threefold standard inoculation dose applied 18 days after plants emergence (dae); fertilization with 200 kg ha-1 of nitrogen, without inoculation. the inoculation by spraying on covering increased nodulation and plant dry matter in the 45 and 60 dae. it also increased significantly grain yield and n content, similarly to n fertilization treatment, and was superior to the control, and inferior to the standard inoculation related to grain yield.
In-furrow inoculation of soybean as alternative to fungicide and micronutrient seed treatment
Campo, Rubens José;Araujo, Ricardo Silva;Mostasso, Fábio Luís;Hungria, Mariangela;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000400010
Abstract: soybean is a major grain crop in brazil, and yields can be considerably improved by inoculation with selected bradyrhizobium strains. however, the incompatibility between inoculation and seed treatments with fungicides and micronutrients represents a major barrier to the achievement of high rates of biological n2 fixation. inoculation practices that can alleviate the negative effects of agrochemicals must therefore be found and in-furrow inoculation seems to be an attractive alternative. this study reports the results of seven field experiments conducted in three growing seasons in brazil; three in soils previously cropped with inoculated soybean (> 104 cells g-1 of soil of bradyrhizobium), and four in areas where the crop was sown for the first time (< 102 cells g-1 of soil of bradyrhizobium). the compatibility with fungicides and micronutrients was compared in seeds inoculated with peat or liquid inoculants, or treated with different doses of liquid inoculant in-furrow. in areas with established bradyrhizobium populations, seed-applied agrochemicals did generally not affect nodulation, but also did not increase yields, while inoculation always increased n grain accumulation or yield, and n fertilizer decreased both nodulation and yield. where soybean was sown for the first time, the seed treatment with agrochemicals affected nodulation when applied together with peat or liquid inoculant. in-furrow inoculation alleviated the effects of seed treatment with agrochemicals; the best performance was achieved with high bradyrhizobium cell concentrations, with up to 2.5 million cells seed-1.
Inocula??o da soja com Bradyrhizobium no sulco de semeadura alternativamente à inocula??o de sementes
Zilli, Jerri édson;Gianluppi, Vicente;Campo, Rubens José;Rouws, Janaina Ribeiro Costa;Hungria, Mariangela;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000600011
Abstract: biological n fixation in soybean is indispensable in brazil, sparing the use of mineral n and reducing crop production costs. the objective of this study was to compare in-furrow inoculation of soybean with bradyrhizobium to the traditional practice of seed inoculation, in an experiment performed in a soil with low organic matter content and without soybean-nodulating rhizobia. a field experiment was carried out in the cerrado of roraima in 2006 and repeated in 2007, with the treatments: (1) control (no inoculation and no mineral nitrogen application), (2) application of 200 kg ha-1 n as urea, (3) in-furrow inoculation, and, (4) seed- inoculation. the two inoculation methods were evaluated in seeds treated or not with fungicides (carboxin + thiram and carbendazim + thiram). soybean performance in the treatment with in-furrow inoculation resulted in nitrogen fixation contribution similar to seed inoculation, with no differences in plant dry matter weight, grain yield, and n accumulated in shoots and grains. on the other hand, when the seeds were treated with fungicides, especially carbendazim + thiram, there was a decrease in nodulation, shoot development, and grain yield in the seed inoculation treatment, while no effects were observed in the in-furrow treatment. consequently, was demonstrated that in-furrow inoculation is useful alternative for soybean inoculation when the seeds are fungicide-treated.
Influence of fungicide seed treatment on soybean nodulation and grain yield
Zilli, Jerri édson;Ribeiro, Karen Gon?alves;Campo, Rubens José;Hungria, Mariangela;
Revista Brasileira de Ciência do Solo , 2009, DOI: 10.1590/S0100-06832009000400016
Abstract: biological n2 fixation is a major factor contributing to the increased competitiveness of brazilian soybeans on the international market. however, the contribution of this process may be limited by adverse conditions to symbiotic bacteria, such as fungicide seed treatments. this study aimed to evaluate the effects of the fungicides carbendazim + thiram and carboxin + thiram on soybean nodulation, plant growth and grain yield. two field experiments were carried out in the cerrado region of the state of roraima, in a soil with a low organic matter content and no soybean bradyrhizobia. in 2005, seeds were treated with fungicide carbendazim + thiram and commercial inoculants containing the bradyrhizobium elkanii strains semia 5019 and semia 587 and b. japonicum strains semia 5079 and semia 5080. in 2006, soybean seeds were treated with the fungicides carbendazim + thiram or carboxin + thiram and inoculated separately with each one of the four strains. the plants were evaluated for number of nodules and dry weight, shoot dry weight and total n accumulated in shoots 35 days after plant emergence, while grain yield and n grain content were determined at harvest. both fungicides reduced soybean nodulation, especially in the presence of b. elkanii strains. the fungicide carbendazim + thiram reduced nodulation by about 50 % and grain yield by more than 20 % (about 700 kg ha-1), in the treatment inoculated with of strain semia 587.
O lugar e as elei es: a express o territorial do voto no Brasil
Rubens de Toledo Júnior
Geotextos : Revista da Pós-Gradua??o em Geografia da Universidade Federal da Bahia , 2008,
Abstract: Tratamos aqui das elei es brasileiras após a redemocratiza o e a conquista do direito a voto a todos os cargos executivos e legislativos e discorremos sobre as contribui es da Geografia para a análise desse comportamento eleitoral. Partidos políticos e candidatos de diferentes perfis possuem lógicas diversas na distribui o de seus votos, que se d o segundo a posi o que possuem no espectro ideológico, repercutindo em sua atua o política e estratégia eleitoral. O estudo geográfico das diferen as socioespaciais dos votos permitiu a compreens o do papel do lugar na forma o de valores e conhecimentos na forma o da preferência dos eleitores, sua rela o com a territorialidade dos candidatos, e uma interpreta o da atual dinamica eleitoral.
Page 1 /299905
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.