310 research outputs found

    Déficit hídrico severo afeta as reservas orgânicas do cafeeiro.

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    Os fotoassimilados, produzidos na parte aérea durante o processo de fotossíntese, são translocados para toda a planta a fim de suprir a demanda de energia que irá ser responsável pela formação de novos tecidos. A intensidade da produção, translocação e uso desses carboidratos depende entre outros fatores, da carga pendente de frutos e do status hídrico das plantas. Esse trabalho teve por objetivo verificar ao efeito do déficit hídrico nas reservas orgânicas de cafeeiros com diferentes níveis de produtividade. Os resultados mostram que os efeitos da seca afetaram em maior intensidade os níveis de reservas orgânicas das plantas e o crescimento de radicelas do que a carga pendente da cultura

    Direcionamento das linhas de plantio em diferentes orientações cardeais e seus reflexos sobre a produtividade de cafeeiros.

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    Uma variação ambiental que provoca alterações na morfologia externa da planta de café se refere à localização das fileiras do café em relação a orientações dos pontos cardeais. Objetivou-se neste estudo avaliar a produtividade individual de cada lado de plantas de café implantadas em diferentes orientações cardeais buscando subsídios para otimizar o plantio direcionado e o manejo de lavoura em solo com topografia plana a suave ondulada. Observa-se de maneira geral que, independentemente do direcionamento das ruas de café em relação as orientações cardeais, a produtividade de café, no lado da planta que recebeu sol pela manhã, foi sempre maior que aquela apresentada pelo lado da planta que recebeu sol à tarde. Estas observações levam a concluir que os melhores direcionamentos de rua de café são no sentido leste-oeste e nordeste-sudoeste e que os dois lados da planta, relacionados com o posicionamento solar, comportam-se como se pertencessem a diferentes lavouras, já que os dois lados da planta apresentam diferenças na morfo-anatomia, na partição de carboidratos, na assimilação do CO2 e nas características hídricas a ponto de alterar o crescimento das plantas e sua produção

    Metabolic profiles of Brazilian tropical wines determined by H NMR spectroscopy and chemometrics.

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    Tropical wines are a new concept of vitiviniculture that is being developped principally in Brazil

    Yield, water use efficiency, and yield response factor in carrot crop under different irrigation depths

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    The aim of the present study was to evaluate the effect of different irrigation depths on the yield, water use efficiency (WUE), and yield response factor (Ky) of carrot (cv. 'Brasília') in the edaphoclimatic conditions of Baixada Fluminense, RJ, Brazil. Field trials were conducted in a Red-Yellow Argisol in the 2010-2011period. A randomized block design was used, with 5 treatments (depths) and 4 replicates. Depths were applied by drippers with different flow rates, and the irrigation was managed by time domain reflectometry (TDR) technique. The reference (ETo) and crop (ETc) evapotranspiration depths reached 286.3 and 264.1mm in 2010, and 336.0 and 329.9mm in 2011, respectively. The root yield varied from 30.4 to 68.9t ha-1 as a response to treatments without irrigation and 100% replacement of the soil water depth, respectively. Values for WUE in the carrot crop varied from 15 to 31kg m-3 and the mean Ky value was 0.82. The mean values for Kc were obtained in the initial (0.76), intermediate (1.02), and final (0.96) stages. Carrot crop was influenced by different water depths (treatments) applied, and the highest value for WUE was obtained for 63.4% of soil water replacement.Publicada online Online em 5 de abril de 2016

    Controle de plantas voluntárias de soja com herbicidas utilizados em milho.

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    O presente trabalho teve por objetivo avaliar a eficiência de diversos herbicidas no controle de plantas voluntárias de soja. O experimento foi conduzido em casa de vegetação, onde as unidades experimentais foram compostas de vasos de 10 dm3 de capacidade, dispostos em delineamento inteiramente casualizado em esquema fatorial 2 x 12, com quatro repetições. As cultivares Conquista e Valiosa RR® foram submetidas à aplicação dos herbicidas: atrazine (1.500 g ha-1), tembotrione (100 g ha-1), mesotrione (120 g ha-1), nicosulfuron (40 g ha-1), 2,4-D (670; 1.050 e 1.340 g ha-1), diquat (300 g ha-1), paraquat (400 g ha-1), [paraquat + diuron] (500 + 250 g ha-1) e glyphosate (1.500 g ha-1), além de uma testemunha sem aplicação. A aplicação foi realizada quando as plantas encontravam-se no estádio fenológico V3. Os herbicidas atrazine, glyphosate, [paraquat + diuron] e diquat apresentaram os maiores níveis de controle das plantas voluntárias de soja da variedade Conquista. Os herbicidas atrazine, [paraquat + diuron] e 2,4-D na dose de 1.340 g ha-1 foram os mais eficientes no controle das plantas voluntárias de soja da variedade Valiosa RR®. A suscetibilidade das plantas voluntárias de soja provenientes da variedade convencional (Conquista) e da variedade resistente ao glyphosate (Valiosa RR®) foi variável de acordo com o herbicida aplicado. Control of volunteer soybean plants with herbicides used in corn. This study aimed at evaluating the effectiveness of several herbicides on the control of volunteer soybean plants. The experiment was carried out in a greenhouse, where the experimental units were composed of vessels with 10 dm3 capacity, arranged in a completely randomized design, in a 2 x 12 factorial scheme, with four replications. The cultivars Conquista and Valiosa RR® underwent an application of the herbicides: atrazine (1.500 g ha-1), tembotrione (100 g ha-1), mesotrione (120 g ha-1), nicosulfuron (40 g ha-1), 2.4 D (670; 1,050 and 1,340 g ha-1), diquat (300 g ha-1), paraquat (400 g ha-1), [paraquat + diuron] (500 + 250 g ha-1), and glyphosate (1,500 g ha-1), besides an untreated control. The application was made when the plants were in the phenological stage V3. The herbicides atrazine, glyphosate, [paraquat + diuron] and diquat showed the highest control levels of the volunteer soybean plants of the variety Conquista. The herbicides atrazine, [paraquat + diuron] and 2.4-D at the dose of 1,340 g ha-1 were the most effective ones in controlling volunteer soybean plants of the cultivar Valiosa RR®. The susceptibility of the volunteer soybean plants from the conventional variety (Conquista) and the glyphosate-resistant variety (Valiosa RR®) was variable depending on the applied herbicide

    Genetic polymorphisms and coronary artery disease in the portuguese population: the GENEMACOR Study

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    PosterMultiple studies have showed an association between genetic polymorphisms and the risk of coronary artery disease (CAD). Initially, studies focused mainly in variants acting in pathophysiological axis of CAD or its risk factors. Genome-Wide Association Studies (GWAS) revealed other genes that, besides having an unknown mechanism, are statistically significant. The importance of these in the development of CAD in the Portuguese population is unknown. Objective: Analyze the genetic polymorphisms associated with the development of CAD in a Portuguese population. Methods: We performed a case-control study with 1321 consecutive coronary patients (mean age 53.4 ± 8.1 years, 78.8% male) and 1148 controls (adjusted for age and sex) selected from GENEMACOR Study, an ongoing study designed to analyze the genetic profile of a Portuguese population. We evaluated, in both groups, 29 genetic variants previously associated with CAD: ACE I/D, AGT235 M/T, ATIR A/C, MTHFR C/T and 1298 A/C, PON192 Q/R and 55 L/M,LPA T/C, APO E, Locus 9p21.3 (rs1333049), CDKN2B (rs4977574), GJA4 C/T, PCSK9 A/G, TAS2R50 A/G, KIF6 C/T, IGF2BP2 G/T, ADAMTS7 A/G, MC4R T/C, PPARG Pro12 Ala, ZNF259 C/G, SMAD3 C/T, MIA3 C/A, MTHFD1L A/G, SLC30A8 C/T, TCF7L2 C/T, HNF4 C/G, FTO A/C and ADIPOQ C/G. Allele and genotypic frequencies of individuals with and without CAD were compared and the strength of association was expressed by the OR as well as by CI 95%. Results: The variants rs4340 (ACE I/D), rs266729 (ADIPOQ C/G), rs458560 (PON55 L/M), rs429358 (APOE2), LPA T/C, rs1333049 (locus 9p21.3) and rs4977574 (CDKN2B A/G) were significantly associated with CAD (p<0.05) (Table). Conclusions: In our population, the genetic polymorphisms significantly related to CAD were: ACE, associated with hypertension; ADIPOQ, associated with obesity; PON55, associated with oxidation; APOE and LPA, associated with dyslipidemia and finally the locus 9p21.3 with a unclear mechanism so far.info:eu-repo/semantics/publishedVersio

    One-Particle Spectral Properties of Mott-Hubbard Insulators

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    We use an exact holon and spinon Landau-liquid functional which describes the holon - spinon interactions at all scattering orders, to study correlation functions of integrable multicomponent many-particle problems showing both linear and non-linear energy bands. We consider specific cases when the dominant non-linear band terms are quadratic and apply our results to the evaluation of the 1D Hubbard model correlation functions beyond conformal-field theory.Comment: 10 Pages, Revte
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