Showing papers by "Universidade Federal de Viçosa published in 1980"
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TL;DR: There was a significant interaction between herbicide and soil, as affecting population decline of M. phaseolina in soil.
Abstract: The effect of five herbicides, EPTC, dinoseb, alachlor, fluorodifen and fluometuron, on the inoculum density of Macrophomina phaseolina (Tassi) Goid. was tested in two field soils. The herbicides were applied at commercially recommended rates. All herbicides tested incited a significant drop in the population of M. phaseolina. In soils treated with dinoseb, the population of M. phaseolina declined by 96 % in sandy-clay-loam and by 61 % in sandy-loam soil 10 days after treatment. In fluorodifen treated sandy-loam soil, the population dropped gradually by 85 %, whereas in sandy-clay-loam soil, it declined by 50 %, over a fifty day test period. The population of M. phaseolina dropped by 46 % to 63 % in both soils treated either with EPTC, fluometuron or alachlor, over the entire test period. There was a significant interaction between herbicide and soil, as affecting population decline of M. phaseolina in soil.
19 citations
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TL;DR: In this article, the authors describe the susceptibility of various samples of Boophilus microplus from the southern region of Minas Gerais State in Brazil to the four commonest organophosphorus acaricides employed in the area.
Abstract: This paper describes the susceptibility of various samples ofBoophilus microplus from the southern region of Minas Gerais State in Brazil to the 4 commonest organophosphorus acaricides employed in the area. All samples showed some degree of resistance to each of the compounds used. The resistance factor varied from 1.42 to 132.90, being less in the case of dicrotophos and fenthion than with chlorpyrifos and coumaphos.
13 citations
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TL;DR: The population of Macrophomina phaseolina (Tassi) Goid declined more rapidly when soil was amended with nitrogen-enriched wheat straw or glucose and nitrogen than if amended with either corn, bean or alfalfa straw and when soilwas amended with low C:N ratios.
Abstract: Population changes of Macrophomina phaseolina (Tassi) Goid were followed in two soils amended with either wheat, corn, bean or alfalfa straw, or with nitrogen-enriched wheat straw or glucose and sodium nitrate at different C:N ratios The population declined significantly initially in both soils with any amendment but later increased in soils amended with wheat or corn straw and in one soil amended with bean or alfalfa straw Population declined with no subsequent increase when soil was amended with nitrogen-enriched wheat straw or glucose and sodium nitrate at C:N ratios equal to that of the natural plant residues In general the population declined more rapidly when soil was amended with nitrogen-enriched wheat straw or glucose and nitrogen than if amended with either corn, bean or alfalfa straw and when soil was amended with low C:N ratios
13 citations
01 Jan 1980
13 citations
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7 citations
01 Jan 1980
5 citations
01 Jan 1980
4 citations
01 Jan 1980
4 citations
01 Jan 1980
4 citations
01 Jan 1980
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TL;DR: The accelerated aging test was effective to differentiate treatments, showing that seeds from non-weeded plots had less vigor than seeds from plots treated with EPTC + trifluralin.
Abstract: Objetivando avaliar o efeito de herbicidas no controle de plantas daninhas, na producao e na qualidade fisiologica das sementes de feijoeiro (Phaseolus vulgaris L.) cv. Rico 23, foi instalado um experimento no campo, em solo Podzolico Vermelho-Amarelo Câmbico, fase terraco, com 2,8% de materia orgânica e textura argilosa. Usaram-se os tratamentos: testemunha com capina; testemunha sem capina; EPTC a 5,70 kg i.a./ha; trifluralina a 0,75 kg i.a./ha; EPTC a 2,00 kg i.a./ha + trifluralina a 0,60 kg i.a./ha; nitralina a 1,00 kg i.a./ha e pendimethalin a 1,50 kg i.a./ha. Avaliaram-se a populacao inicial e a producao de graos pelo feijoeiro e o numero de plantas daninhas Realizaram-se, tambem, testes de avaliacao da qualidade fisiologica das sementes do feijoeiro. pelo teste-padrao de germinacao, teste de primeira contagem, peso de materia seca das plantulas na primeira contagem e teste de germinacao apos 20, 40 e 60 horas de permanencia das sementes na câmara de envelhecimento precoce. No campo, observou-se predominância de trevo (Oxalis sp), picao-branco (Galinsoga parviflora) e tiririca (Cyperus rotundus). Nao se observaram diferencas significativas entre os tratamentos, quanto ao controle de plantas daninhas e > inicial e producao do feijoeiro. O teste-padrao de germinacao nao foi bom parâmetro para diferenciar niveis de vigor das sementes. O herbicida trifluralina nao prejudicou o acumulo de materia seca pelas plântulas. O tratamento das sementes do feijoeiro na câmara de envelhecimento precoce, a 42 ± 3oC e 95% U.R., pelo periodo de 20 horas, promoveu, nas sementes do tratamento testemunha sem capina, deterioracao precoce, diferenciando-o do EPTC + trifluralina, que permaneceu vigoroso.
01 Jan 1980
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TL;DR: In this paper, a serie of ensaios biologicos for medir a inativacao e a mobilidade do herbicida metribuzin in two different materials, namely, Latossolo and Podzolico, were used to investigate the effect of densidade on the performance of herbicide lixiviado.
Abstract: Numa serie de ensaios em laboratorio e casa-de-vegetacao, estudou-se a mobilidade e a inativacao do herbicida metribuzin em materiais de um Latossolo e de um Podzolico representativos de duas regioes do Estado de Minas Gerais, em funcao de diferentes densidades aparentes. Ensaios biologicos foram utilizados para medir a inativacao e a mobilidade do metribuzin nos diferentes solos e densidades. A densidade aparente alterou de forma pronunciada a quantidade de herbicida lixiviado atraves das colunas dos materiais dos solos estudados. Quanto maior a densidade, menor a quantidade de herbicida lixiviado. A quantidade de herbicida que permaneceu biologicamente ativo ao longo da coluna foi diretamente relacionada com a densidade, em cada solo. A mobilidade do metribuzin no material do Latossolo foi maior que no de Podzolico, em consequencia de maior atividade coloidal deste.