Revista Ceres

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9884

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Resultados da Pesquisa

Agora exibindo 1 - 5 de 5
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    Eficiência na produção de frutos e alocação relativa de nutrientes em cultivares de cafeeiro
    (Universidade Federal de Viçosa, 2010-03) Amaral, José Francisco Teixeira do; Martinez, Herminia Emilia Prieto; Laviola, Bruno Galveas; Fernandes Filho, Elpidio Inácio; Cruz, Cosme Damião
    Considerando a baixa produtividade das plantas em solos de menor fertilidade natural e o alto custo dos insumos agrícolas, torna-se necessária a seleção de cultivares mais eficientes na absorção e utilização dos nutrientes minerais. Foram avaliados quatro cultivares de cafeeiro arábica (Acaiá IAC 474 19, Icatu Amarelo IAC 3282, Rubi MG 1192 e Catuaí Vermelho IAC 99) quanto à eficiência na produção de frutos e alocação relativa de nutrientes. O experimento foi conduzido em Viçosa – MG, em condições de campo, no delineamento experimental em blocos ao acaso, envolvendo quatro cultivares, quatro repetições e três níveis de adubação (baixo, normal e alto). As parcelas úteis constituíram-se de nove plantas espaçadas de 2 x 1 m. O cultivar Icatu Amarelo IAC 3282 foi o mais produtivo no ambiente com restrição de nutrientes, enquanto Rubi MG 1192 e Catuaí Vermelho IAC 99 mostraram-se mais produtivos em ambientes com alto suprimento de nutrientes. A eficiência de produção de café em coco por unidade de P, Ca, Mg e B acumulados na planta foi maior no nível alto de adubação. Os cultivares Rubi MG-1192 e Catuaí Vermelho IAC 99 apresentaram maior eficiência de utilização de nutrientes para produção de frutos no nível alto de adubação. Considerando a média de alocação relativa de nutrientes nos frutos para os quatro cultivares, no nível normal de adubação, verificou-se que eles possuem 38,1% do N, 46,34% do P, 40,19% do S, 42,68% do K, 13,19% do Ca, 25,04% do Mg, 40,63% do Cu, 19,49% do Zn e 17,73% do B.
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    Growth and nutrient uptake of coffee seedlings cultivated in nutrient solution with and without silicon addition
    (Universidade Federal de Viçosa, 2012-05) Cunha, Ana Catarina Monteiro Carvalho Mori da; Oliveira, Mila Liparize de; Caballero, Enrique Combatt; Martinez, Hermínia Emília Prieto; Fontes, Paulo Cézar Rezende; Pereira, Paulo Roberto Gomes
    In recent years, the application of silicon (Si) in crops, including coffee, has become a common practice. The objective of this study was to assess the silicon uptake by coffee seedlings and its effects on plant growth, water and macro and micronutrient uptake. The research was conducted using nutrient solution in a greenhouse at the Departa- mento de Fitotecnia da Universidade Federal de Viçosa, in a completely randomized design with two treatments (with and without silicon) and three replications. Each plot consisted of three plants grown in a 800 mL vessel containing the treatment solutions. At every three days, water consumption, the concentration of OH - and the depletion of Si and K were assessed in the nutrient solutions. After 33 days, the plants were assessed with regard to their fresh and dry weight of leaves, roots and stem, shoot height and total length of the plant (shoot and root). Number of leaves and internodes, and the content and accumulation of silicon, macro, and micronutrients were also determined. The consumption of water, the amount of potassium uptake and, biomass accumulation were greater in plants grown in solution without silicon addition. However, the concentration of OH - in the solution and the amount of silicon uptake were greater in plants grown in solution with added silicon. Silicon accumulation was greater in leaves than in stem and roots. Silicon decreased coffee plant accumulation of phosphorus, potassium, calcium, zinc, copper and iron.
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    Efficiency and response of conilon coffee clones to phosphorus fertilization
    (Universidade Federal de Viçosa, 2013-05) Martins, Lima Deleon; Tomaz, Marcelo Antonio; Amaral, José Francisco Teixeira do; Bragança, Scheilla Marina; Martinez, Herminia Emilia Prieto
    Studies on nutritional efficiency of phosphorus in conilon coffee plants are important tools to unravel the high limitation that natural low levels of this nutrient in soil impose to these species cultivars. Therefore, this study aimed at evaluating the nutritional efficiency and the response to phosphorus of conilon coffee clones. Plants were managed during 150 days in pots containing 10 dm 3 of soil, in greenhouse. A factorial scheme 13 x 2 was used, with three replications, being the factors: 13 clones constituting the clonal cultivar “Vitória Incaper 8142” and two levels of phosphate fertilization (0% and 150% of the P2O5 usualy recommended), in a completely randomized design (CRD). The results indicate a differentiated response of dry matter production and of phosphorus content on each level of phosphate fertilization for the conilon coffee clones and that CV-04, CV-05 and CV-08 clones are nutritionally efficient and responsive to the phosphate fertilization.
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    Nutrição mineral do cafeeiro e qualidade da bebida
    (Universidade Federal de Viçosa, 2014-11) Martinez, Herminia Emilia Prieto; Clemente, Júnia Maria; Lacerda, José Soares de; Neves, Yonara Poltronieri; Pedrosa, Adriene Woods
    Os nutrientes minerais interferem na qualidade final do café por duas vias, uma direta, por seu papel no metabo- lismo da planta e acúmulo de compostos químicos desejáveis, do ponto de vista do aroma e sabor do café, e, outra, indireta, por seu papel na produção de compostos que desfavorecem o desenvolvimento microbiano nos grãos. Neste trabalho, procurou-se destacar as características químicas dos grãos associadas à qualidade da bebida e suas possíveis interações com os macro e micronutrientes, bem como relatar os resultados de pesquisa que relacionam nutrição mineral, qualidade da bebida e produção de compostos a ela associados.
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    Calcium and potassium contents in nutrient solution on Phoma leaf spot intensity in coffee seedlings
    (Universidade Federal de Viçosa, 2016-07) Catarino, Aricléia de Moraes; Pozza, Edson Ampélio; Pozza, Adélia Aziz Alexandre; Santos, Leone Stabile dias; Vasco, Gabriel Brandão; Souza, Paulo Estevão de
    Coffee is one of the main export commodities of Brazilian agribusiness. Phoma leaf spot [Phoma tarda (Stewart) Boerema & Bollen] is one of the most important coffee fungal diseases in Brazil. Therefore, this study aimed to evaluate the intensity of Phoma leaf spot in coffee seedlings supplied with different rates of Ca +2 and K + . The study was conducted under controlled conditions in a growth chamber, at the Department of Phytopathology – UFLA, from February 2010 to December 2011. The assay was repeated twice under the same conditions. The nutrient solutions consisted of five concentrations of K + (3, 4, 5, 6, 7 mmol L -1 ) and Ca +2 (2, 4, 6, 8 and 10 mmol L -1 ). The experiment was arranged in a randomized block design, with 25 treatments and three replicates, with two plants per plot. The areas under incidence progress curve (AUIPC) and severity (AUSPC) were calculated. At the lowest rate of Ca 2+ (2 mmol L - 1 ) and highest K + (6 and 7 mmol L -1 ), approximately, the AUIPC was the smallest. For the AUSPC, the lowest rates of Ca +2 and K + resulted in the lowest severities. Supply of Ca +2 and K + in nutrient solution reduced AUIPC and AUSPC of Phoma leaf spot, and these nutrients can be recommended for the management of the disease.