7 research outputs found

    Soybean response (Glycine max L.) under the use of biostimulants: A literature review

    Get PDF
    Soybean (Glycine max L.) is a crop with prominence in Brazil and worldwide. The increase in soybean production and production capacity is associated with scientific and technological advances in the productive sector. One of these advances is the use of biostimulants. In this sense, this work aimed to review current knowledge about the effects of biostimulants on soybeans, highlighting the direct or indirect response of the plant when using such substances. This review was carried out through a research with a qualitative approach, being considered a literature review of the narrative type, using other studies and research at the same theme, in high impact magazines from the last five years or more that were relevant to the study, with subsequent critical reading about the subject. Based on found results, it is clear the use of biostimulants in soybeans is a potential alternative input for increasing the growth and development of the crop, as they are able to provide increments in its productive variables. However, further research is needed in order to provide better information on agronomic interests

    Flutuação populacional de moscas-das-frutas (Diptera: Tephritidae) associadas a variedades de manga no município de José de Freitas-Piauí

    No full text
    O Piauí possui uma área considerável de manga, sendo um grande produtor dessa fruta no Brasil. Contudo, a presença de pragas, como as moscas-das-frutas, tem provocado grandes impactos na cadeia produtiva, pois estes insetos fazem parte de um grupo responsável por grandes prejuízos econômicos na cultura da mangueira. O conhecimento da flutuação populacional e a época de maior ocorrência de uma determinada espécie de inseto de importância econômica são requisitos indispensáveis para o estabelecimento de um controle eficiente e racional. O presente trabalho visou registrar a flutuação populacional das espécies de moscas-das-frutas associadas a variedades de manga, bem como correlacionar a ocorrência das moscas com as médias mensais de temperatura, precipitação e umidade relativa, e também avaliar os atrativos alimentares utilizados na captura dos insetos. A pesquisa foi conduzida de junho de 2004 a maio de 2005, em pomar comercial de manga (Mangifera indica L.-Anacardiaceae), das variedades Tommy Atkins, Keitt, Kent e Palmer, localizado no município de José de Freitas-Piauí-Brasil, na latitude 04º50'S e longitude 42º41'W. Anastrepha obliqua e Anastrepha serpentina são as espécies de tephritídeos predominantes na cultura da manga

    A theoretical study of hydrogen complexes of the X H- type between propyne and HF, HCL or HCN.

    No full text
    The present manuscript reports a systematic investigation of the basis set dependence of some properties of hydrogen-bonded (_ type) complexes formed by propyne and a HX molecule, where X= F, Cl and CN. The calculations have been performed at Hartree–Fock, MP2 and B3LYP levels. Geometries, H-bond energies and vibrational have been considered. The more pronounced effects on the structural parameters of the isolated molecules, as a result of complexation, are verified on RC C and HX bond lengths. As compared to double-_ (6-31G**), triple-_ (6-311G**) basis set leads to an increase of RC C bond distance, at all three computational levels. In the case where diffuse functions are added to both hydrogen and ‘heavy’ atoms, the effect is more pronounced. The propyne–HX structural parameters are quite similar to the corresponding parameters of acetylene–HX complexes, at all levels. The largest difference is obtained for hydrogen bond distance, RH, with a smaller value for propyne–HX complex, indicating a stronger bond. Concerning the electronic properties, the results yield the following ordering for H-bond energies, _E: propyne• • •HF > propyne• • •HCl > propyne• • •HCN. It is also important to point out that the inclusion of BSSE and zero-point energies (ZPE) corrections cause significant changes on_E. The smaller effect of ZPE is obtained for propyne• • •HCN at HF/6-311++G** level, while the greatest difference is obtained at MP2/6-31G** level for propyne• • •HF system. Concerning the IR vibrational it was obtained that larger shift can be associated with stronger hydrogen bonds. The more pronounced effect on the normal modes of the isolated molecule after the complexation is obtained for H X stretching frequency, which is shifted downward
    corecore