Revista Ciência Agronômica

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10361

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Resultados da Pesquisa

Agora exibindo 1 - 10 de 24
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    Lógica fuzzy na avaliação da fertilidade do solo e produtividade do café conilon
    (Universidade Federal do Ceará, 2010) Silva, Samuel de Assis; Lima, Julião Soares de Souza; Souza, Gustavo Soares de; Oliveira, Rone Batista de; Xavier, Alexandre Cândido
    O objetivo deste estudo foi analisar, utilizando a geoestatística e o sistema de classificação fuzzy, a fertilidade de uma área experimental com base em atributos químicos do solo e sua relação com a produtividade do café conilon. O estudo foi realizado na fazenda experimental do INCAPER-ES. As amostras de solo foram coletadas na profundidade de 0 - 0,2 m, sendo analisados os atributos: fósforo, potássio, cálcio e magnésio, alumínio, soma de bases, capacidade de troca catiônica a pH 7 e saturação por bases. Os dados foram submetidos a uma análise descritiva, exploratória e à analise geoestatística. Utilizou-se um sistema de classificação fuzzy utilizando os atributos descritos para inferir sobre a fertilidade do solo e sua relação com a produtividade da cultura. A possibilidade de fertilidade apresentou relação espacial positiva com a produtividade da cultura, com valores mais elevados desta onde a possibilidade de solo fértil é superior.
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    A mixed model applied to joint analysis in experiments with coffee blends using the least squares method
    (Universidade Federal do Ceará, 2019) Paulino, Allana Lívia Beserra; Cirillo, Marcelo Angelo; Ribeiro, Diego Egídio; Borém, Flávio Meira; Matias, Gabriel Carvalho
    The aim of the present study was to propose a mixed model for a sensory analysis of four experiments with blends of different standards of quality, including the species Coffea Arabica L. and Coffea Canephora. Each experiment differed in the proportions used to formulate the blends and the concentrations used in preparing the beverages, these being 7% and 10% coffee powder for each 100 ml of water. The response variables under analysis were the sensory characteristics of the beverage found in an assessment made by a group of trained tasters, considering taste, bitterness and a final score. Each description followed a numerical rating scale of intensity that ranged from 0 to 10. The model was implemented using the least squares method; this led to the conclusion that including random parameters in the model, represented by the experiments, made it possible to compare the effect of each component simultaneously for each of the experiments.
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    Water-retaining polymer and seedling type when planting irrigated coffee
    (Universidade Federal do Ceará, 2016-04) Souza, Antonio Jackson Jesus; Guimarães, Rubens José; Dominghetti, Anderson William; Scalco, Myriane Stella; Rezende, Tiago Teruel
    The aim of this work was to evaluate the use of a water-retaining polymer on the initial growth of coffee plants for different levels of irrigation and types of seedling. The experiment was set up in pots with a clayey soil, in a greenhouse of the Sector for Coffee Production of the Federal University of Lavras, Brazil. The experiment was arranged in a randomised block design into sub-lots with three replications, giving a total of 48 experimental units. Four levels of irrigation (25%, 50%, 75% and 100% of the available water) were randomly assigned to the lots; the type of seedling (grown in bags or tubes) were randomly assigned to the sub-lots, and the use or not of the water-retaining polymer randomly assigned to the sub-sub-lots. In the treatments with water-retaining polymer, a dilution of 1.5 Kg of polymer to 400 litres of water was used at a dose of 1.5 litres of solution per plant. The following were evaluated at intervals of 60 days during the experiment (360 days from planting): stem diameter, plant height, leaf area, number of leaves and number of plagiotropic branches on the coffee plants. Hydrated water-retaining polymer favoured the growth of coffee plants under an irrigated system. Irrigation resulted in greater plant growth, with the seedlings grown in bags showing more growth than those grown in tubes.
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    Alternative for the evaluation of coffee seedlings using Fisher’s discriminant analysis
    (Universidade Federal do Ceará, 2016-04) Campos, Katia Alves; Morais, Augusto Ramalho de; Paixão, Crysttian Arantes
    One of the applications of Fisher’s linear discriminant function (FDF) is its use in transforming multivariate data into a new univariate variable. This then makes possible a new option for the variance analysis of multivariate data, in addition to the multivariate analysis of variance (MANOVA). The aim of this work was to select groups of seven characteristics of quality in coffee seedlings using six criteria for selection, to use the FDF to transform such groupings of characteristics into a new variable, and then to compare interpretation of the results obtained from the univariate and multivariate analyses of variance of the characteristics and this new variable, with a view to its use in evaluating coffee seedlings. A randomised block design was used to assess the effect of organic fertiliser on the formation of seedlings in coffee cv. Catuaí Vermelho IAC- 44, evaluating the following characteristics: seedling height, diameter, root length, dry weight of shoots and roots, leaf area, number of leaves and total dry weight. According to the selection criteria used, different subsets of the selected characteristics are possible. The use of the FDF is shown to be viable in discriminating between treatments. Univariate analysis of the new variable obtained with the FDF and multivariate analysis (MANOVA) was able to detect differences between the treatments, however, it is simpler to apply FDF methodology.
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    Mathematical models applied to the optimisation of mixtures in the production of silage from coffee by-products
    (Universidade Federal do Ceará, 2017-04) Malta, Marcelo Ribeiro; Cirillo, Marcelo Ângelo; Fassio, Larissa de Oliveira; Barcelos, Adauto Ferreira; Lima, Priscilla Magalhães de
    The aim of this work was to propose a mathematical model to determine the best combination of the by- products of coffee processing in the production of silage. To this end, 13 treatments were evaluated, resulting from the combination of wet coffee husks (WCH) and dried coffee husks (DCH), both with and without the use of molasses (M) and with or without the use of the inoculant Lactobacillus plantarum (I). From these components, various mixtures were proposed and evaluated, using the technique of simultaneous optimisation of multiple response variables. Silages with the best characteristics were obtained from the use of 76.40% WCH, 18.77% DCH, 4.83% of M and 0.0001% I.
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    Influência da aplicação de dois resíduos industriais nas propriedades químicas de dois solos cultivados com café arábica
    (Universidade Federal do Ceará, 2012-01) Nogueira, Natiélia Oliveira; Tomaz, Marcelo Antonio; Andrade, Felipe Vaz; Reis, Edvaldo Fialho dos; Brinate, Sebastião Vinícius Batista
    A grande quantidade de resíduos industriais que constituiu atualmente sérios problemas ambientais tem alertado para a utilização adequada desses materiais que, além de reduzir os impactos ambientais, tem demonstrado potencial para utilização na agricultura. O objetivo deste estudo foi avaliar os efeitos químicos da aplicação de diferentes doses de escória de siderurgia e óxido de magnésio em dois solos sob o cultivo de café arábica. O estudo foi desenvolvido em casa de vegetação do Centro de Ciências Agrárias da Universidade Federal do Espírito Santo, em vasos de 10 dm 3 . O delineamento experimental foi instalado em blocos casualizados, com distribuição fatorial de 2 x 3 x 6, com três repetições, sendo os fatores: dois solos (Latossolo Vermelho-Amarelo distrófico de textura argilosa e Latossolo Vermelho-Amarelo distrófico de textura média); três insumos (calcário como controle e escória de siderurgia e óxido de magnésio como resíduos); seis doses dos materiais corretivos (0; 25; 50; 75; 100 e 125% da necessidade de calagem). Após 180 dias de cultivo, procedeu-se as análises de pH, H + + Al 3+ , Al 3+ , Ca 2+ e Mg 2+ . Os resultados mostraram que as aplicações de doses crescentes de escória e óxido de magnésio até o limite estudado neste trabalho favorecem um decréscimo da acidez do solo. O óxido de magnésio demonstrou maior potencial como corretivo de acidez de solo e como fonte de magnésio para o solo.
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    Yield and nutritional status of the conilon coffee tree in organic fertilizer systems
    (Universidade Federal do Ceará, 2013-10) Silva, Victor Maurício da; Teixeira, Alex Fabian Rabelo; Reis, Edvaldo Fialho dos; Mendonça, Eduardo de Sá
    The conilon coffee tree presents high yield potential, the replacement of soil nutrients usually being by the use of mineral fertilizers. To reduce these fertilizers, the use of organic waste may be an alternative. The objective of this study was to evaluate the effect of organic fertilizer systems on the nutritional status and yield of the conilon coffee tree. On a farm, located in the town of Linhares, Espirito Santo, during the agricultural year of 2009/2010, a trial was set up using a completely randomized block design with a factorial distribution of 2 x 2 x 5 and three replications, the factors being: organic compost (compost 1 and compost 2 ); legumes (the presence and absence of jack beans, sown between the rows of coffee trees); and the proportions of each compost (0; 25; 50; 75 and 100%) as a substitute for the recommended mineral fertilizer. The increase in the proportion of compost 2 was reflected as increases in the P content of the leaves due to the higher concentration of this nutrient in the compost. The increase in compost input increased the S content of the leaves as a response to the increase in soil pH. Maximum values of 61 and 66 sacks ha-1 were obtained with substitutions (mineral source by organic) in the proportion of 40 and 37% for compost 1 and compost 2 respectively. The use of organic-waste composts is an alternative as a partial replacement of mineral fertilizers in the conilon coffee tree, resulting in increases in yield.
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    Variabilidade espacial dos atributos da planta de uma lavoura cafeeira
    (Universidade Federal do Ceará, 2017-01) Ferraz, Gabriel Araújo e Silva; Silva, Fábio Moreira da; Oliveira, Marcelo Silva de; Custódio, Adriano Augusto Paiva; Ferraz, Patrícia Ferreira Ponciano
    Objetivou-se com esse trabalho caracterizar a estrutura e a magnitude da distribuição espacial de atributos da planta em lavoura cafeeira e realizar o mapeamento desses atributos de forma a visualizar a distribuição espacial, considerando a dependência espacial destes atributos, demostrando a importância deste mapeamento. Este trabalho foi conduzido na fazenda Brejão no município de Três Pontas, Minas Gerais, utilizando-se os seguintes atributos da planta: Produtividade, Índice de Maturação, Enfolhamento, Força de Desprendimento de Frutos Verde, Força de Desprendimento de Frutos Maduros, Diferença entre a Força de Desprendimento de Frutos Verde e Maduros, Altura de Planta e Diâmetro de Copa amostrados em uma malha amostral de 100 pontos georreferenciados (64 pontos da malha base e 36 pontos de zoom). A análise destes dados por meio das técnicas estatísticas e da geoestatística possibilitaram caracterizar a variabilidade espacial dos atributos da planta em estudo, permitindo o mapeamento destas variáveis. Foi possível observar a importância da cafeicultura de precisão no manejo de uma lavoura cafeeira tanto no gerenciamento da colheita quanto no acompanhamento do desenvolvimento da planta.
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    Characterization and delimitation of the terroir coffee in plantations in the municipal district of Araponga, Minas Gerais, Brazil
    (Universidade Federal do Ceará, 2014-01) Silva, Samuel de Assis; Queiroz, Daniel Marçal de; Pinto, Francisco de Assis de Carvalho; Santos, Nerilson Terra
    Differentiating coffees through the notion of terroirs allows us to determine potential areas for specialty coffee production and to characterize the type of coffee in these areas, exploring their potential. The objective of this work was to study spatial variability quality and to characterize and delimit terroirs in coffee crop production in Araponga municipality, Minas Gerais State, Brazil, using sensorial evaluation. The data were collected from four crops, from altitudes ranging from 770 to 1270 m, with the extract increasing from low to high. In each plot of crops, samples of cherry fruits were collected, dried, benefited, subjected to sensorial analysis and given grades ranging from 0 to 100 points for the global drink quality and relative characteristics of honey, body, acidity, flavor and equilibrium. The spatial variability of the quality was analyzed using the Moran Index. To define coffee production terroirs, average quality grades were compared through separation tests and the individual values of the plots were subjected to an analysis of groupings. The study was efficient in identifying terroirs for mountain coffee culture, therefore allowing coffees to be differentiated as a function of their production locations. Araponga has more than one coffee production terroir characterized by two distinct altitude extracts.
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    Allometric model for estimating leaf area in clonal varieties of coffee (Coffea canephora)
    (Universidade Federal do Ceará, 2015-10) Schmildt, Edilson Romais; Amaral, José Augusto Teixeira do; Santos, Jeangelis Silva; Schmildt, Omar
    The evaluation of leaf area is required in several agronomic studies given their importance to assess the plant growth. The objective of this study was to use statistical models to estimate leaf area of five clonal varieties of coffee (Coffea canephora) from linear dimensions (length and width maximum). Were used in the studies five varieties of Coffea canephora Pierre ex Froehner: Emcapa 8111, Emcapa 8121 Emcapa 8131, Emcapa 8141 and at Incaper 8142. The results obtained in this study allow us to conclude that the linear model expresses the best estimate of leaf area. Among the different independent variables adopted, the product of length and greatest width (L.W) was found to be the greatest significance and higher coefficients of determination (R 2 ). The regression equation that best expresses the estimated leaf area for the five clonal varieties is i = 0.6723 + 0.6779 x i , where x i represents the product of the greatest length and the greatest width of the leaves.