49 research outputs found

    Production of cuttings and nutrient export by Coffea canephora in different periods in the Southwestern Amazon.

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    Cutting is the main vegetative propagation method used for the production of Coffea canephora plantlets. In this method, parent plants are conducted in a specific field, called clonal garden, which must be managed to produce clonal cuttings. The objective of this study was to evaluate the production of cuttings and the export of nutrients by Coffea canephora in different periods in the Southwestern Amazon. The experiment was carried out in a 6 × 3 split-plot scheme (repeated measures in time), consisting of the combination of six clonal Coffea canephora genotypes (plot) and three cutting collection periods (subplots). The genotypes were: C-057, C-088, C-089, C-125, C-130 and C-160; and the evaluation sampling times were January/2017, May/2017 and September/2017. The applied design was a completely randomized design with four repetitions. The dry season, from May to September, promotes lower orthotropic stem dry mass accumulation by Coffea canephora, but allows obtaining a larger number of viable cuttings for the production of clonal plantlets. Nutrient accumulation by orthotropic stems for cutting production follows the following order: N > K > Ca > Mg > S > P > Mn > Fe > Zn > Cu. Nutrient export by the cuttings follows a descending order: K > N > Ca > Mg > P > S > Mn > Fe > Zn > Cu. A estaquia é o principal método de propagação vegetativa utilizado na produção de mudas de Coffea canephora. Neste método, são utilizadas matrizes conduzidas em um campo específico, denominado de jardim clonal, que deve ser manejado para produção de estacas clonais. Assim, objetivou-se avaliar a produção de estacas e a exportação de nutrientes por cafeeiros Coffea canephora em diferentes épocas na Amazônia Sul Ocidental. O experimento foi conduzido em esquema de parcelas subdivididas no tempo, 6 × 3, formado pela combinação de seis genótipos clonais de Coffea canephora (parcela) e três épocas de coleta de estacas (sub parcelas). Os genótipos foram: C-057, C-088, C-089, C-125, C-130 e C-160; e as épocas de coleta de avaliação foram: janeiro/2017, maio/2017 e setembro/2017. O delineamento foi o inteiramente casualizado com quatro repetições. O período de estiagem, que foi de maio a setembro, proporciona menor acúmulo de massa seca de hastes ortotrópicas por plantas matrizes de Coffea canephora, porém, possibilita a obtenção de maior número de estacas viáveis para produção de mudas clonais. O acúmulo de nutrientes pelas hastes ortotrópicas destinadas a produção de estacas segue a seguinte ordem: N > K > Ca > Mg > S > P > Mn > Fe > Zn > Cu. A exportação de nutrientes pelas estacas segue ordem decrescente: K > N > Ca > Mg > P > S > Mn > Fe > Zn > Cu

    Teores de nutrientes em mudas clonais de Coffea canephora BRS Ouro Preto em diferentes volumes de tubetes.

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    Objetivou-se com este trabalho avaliar o desenvolvimento de mudas de cafeeiros C. canephora ?Conilon ? BRS Ouro Preto? em diferentes volumes de tubetes. o experimento foi instalado no Campo Experimental da Embrapa Rondônia, no município de Ouro Preto do Oeste. o experimento foi conduzido com cinco tratamentos e uma testemunha adicional. os tratamentos foram constituídos por cinco volumes de tubetes (50, 100, 170, 280 e 400 cm³).Organizado por: Henrique Nery Cipriani; Alaerto Luiz Marcolan; Fernando Machado Pfeifer: Alexandre Martins Abdão dos Passos; Marcelo Curitiba Espíndula; Angelo Mansur Mendes

    Characterization of new exopolysaccharide production by Rhizobium tropici during growth on hidrocarbon substrate.

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    Made available in DSpace on 2017-11-08T23:29:06Z (GMT). No. of bitstreams: 1 PCharacterizationofnewexopolysaccharide....pdf: 1212598 bytes, checksum: 41efcdb7f61e0fa725e08b591933202d (MD5) Previous issue date: 2017-11-08bitstream/item/166445/1/P-Characterization-of-new-exopolysaccharide....pd

    Application of Optimal Control of Infectious Diseases in a Model-Free Scenario

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    Optimal control for infectious diseases has received increasing attention over the past few decades. In general, a combination of cost state variables and control effort have been applied as cost indices. Many important results have been reported. Nevertheless, it seems that the interpretation of the optimal control law for an epidemic system has received less attention. In this paper, we have applied Pontryagin’s maximum principle to develop an optimal control law to minimize the number of infected individuals and the vaccination rate. We have adopted the compartmental model SIR to test our technique. We have shown that the proposed control law can give some insights to develop a control strategy in a model-free scenario. Numerical examples show a reduction of 50% in the number of infected individuals when compared with constant vaccination. There is not always a prior knowledge of the number of susceptible, infected, and recovered individuals required to formulate and solve the optimal control problem. In a model-free scenario, a strategy based on the analytic function is proposed, where prior knowledge of the scenario is not necessary. This insight can also be useful after the development of a vaccine to COVID-19, since it shows that a fast and general cover of vaccine worldwide can minimize the number of infected, and consequently the number of deaths. The considered approach is capable of eradicating the disease faster than a constant vaccination control method

    Influence of nitrogen fertilization in mother plants on the growth and quality of clonal seedlings of Coffea canephora ?Robusta? plants.

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    The nutritional management of the coffee clonal garden influences the production and physiological quality and seedlings production of vegetative propagules. Thus, this study aimed to analyze the seedlings? production from clonal cuttings taken from Coffea canephora mother plants grown with increasing nitrogen mineral doses. The cuttings were taken from C. canephora var. botany Robusta, from the Embrapa Genetic Improvement Program of Rondônia. The mother plants received nitrogen fertilizer at different doses: 0 (Control); 50; 100; 150; 200; 250 and 300 kg of N per hectare divided into 4 applications, during 150 days of orthotropic stems growth (shoots). The following parameters were evaluated: Dry mass of cuttings, nutritional content of cuttings, and seedlings production, with growth analysis at 0, 48, 61, 80, 101, 122, 143, and 164 days after staking (DAS) and analysis of vegetative characteristics at 122 DAS. The nitrogen fertilization in the mother plant resulted in the variation of macronutrient accumulation in cuttings, but the order K> N> Ca> P> Mg> S was maintained, regardless of N dose. In addition, a positive correlation between nitrogen doses and dry matter accumulation, as well as the physiological quality of seedlings was identified

    Genetic divergence based on leaf vegetative and anatomical traits of Coffea canephora clones.

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    O conhecimento da expressão de características associadas a tolerância a seca é importante para mitigar os impactos na produção cafeeira em um cenário de mudanças climáticas. Objetivou-se com o presente trabalho entender a divergência de natureza genética entre genótipos de Coffea canephora cultivados na Amazônia Ocidental, com base em características vegetativas e anatômicas foliares. Para isso, quinze genótipos foram avaliados em delineamento de blocos casualizados com cinco repetições de uma planta por parcela, para análise de três características vegetativas (área foliar, volume de raiz, massa seca total) e cinco características anatômicas foliares (diâmetro polar e equatorial; densidade e número de estômatos e área estomática). Os dados foram interpretados utilizando análise de variância e o teste de Scott-Knott (p ≤ 0,05). Para quantificar a divergência genética foi interpretado o agrupamento estimado pelo método de otimização de Tocher e a dispersão no plano obtida utilizando a técnica de componentes principais. O agrupamento de Tocher separou os 15 clones em cinco grupos, e a dispersão no plano em três grupos. A densidade estomática foi a característica que mais contribuiu para a dissimilaridade entre os genótipos com potencial para ser utilizada em estudos futuros de seleção de genótipos tolerantes ao déficit hídrico. O genótipo BRS 3213 apresentou maior dissimilaridade genética, constituindo um grupo isolado dos demais genótipos quanto as características anatômicas. Os Híbridos 12 e 15 apresentam características anatômicas foliares com maior potencial de tolerância a seca

    Amazonian forest degradation must be incorporated into the COP26 agenda

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    Nations will reaffirm their commitment to reducing greenhouse gas (GHG) emissions during the 26th United Nations Climate Change Conference (COP26; www.ukcop26.org), in Glasgow, Scotland, in November 2021. Revision of the national commitments will play a key role in defining the future of Earth’s climate. In past conferences, the main target of Amazonian nations was to reduce emissions resulting from land-use change and land management by committing to decrease deforestation rates, a well-known and efficient strategy1,2. However, human-induced forest degradation caused by fires, selective logging, and edge effects can also result in large carbon dioxide (CO2) emissions1,2,3,4,5, which are not yet explicitly reported by Amazonian countries. Despite its considerable impact, forest degradation has been largely overlooked in previous policy discussions5. It is vital that forest degradation is considered in the upcoming COP26 discussions and incorporated into future commitments to reduce GHG emissions

    Skin color and severe maternal outcomes: evidence from the brazilian network for surveillance of severe maternal morbidity

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    Taking into account the probable role that race/skin color may have for determining outcomes in maternal health, the objective of this study was to assess whether maternal race/skin color is a predictor of severe maternal morbidity. This is a secondary analysis of the Brazilian Network for Surveillance of Severe Maternal Morbidity, a national multicenter cross-sectional study of 27 Brazilian referral maternity hospitals. A prospective surveillance was performed to identify cases of maternal death (MD), maternal near miss (MNM) events, and potentially life-threatening conditions (PLTC), according to standard WHO definition and criteria. Among 9,555 women with severe maternal morbidity, data on race/skin color was available for 7,139 women, who were further divided into two groups: 4,108 nonwhite women (2,253 black and 1,855 from other races/skin color) and 3,031 white women. Indicators of severe maternal morbidity according to WHO definition are shown by skin color group. Adjusted Prevalence Ratios (PRadj - 95%CI) for Severe Maternal Outcome (SMO=MNM+MD) were estimated according to sociodemographic/obstetric characteristics, pregnancy outcomes, and perinatal results considering race. Results. Among 7,139 women with severe maternal morbidity evaluated, 90.5% were classified as PLTC, 8.5% as MNM, and 1.6% as MD. There was a significantly higher prevalence of MNM and MD among white women. MNMR (maternal near miss ratio) was 9.37 per thousand live births (LB). SMOR (severe maternal outcome ratio) was 11.08 per 1000 LB, and MMR (maternal mortality ratio) was 170.4 per 100,000 LB. Maternal mortality to maternal near miss ratio was 1 to 5.2, irrespective of maternal skin color. Hypertension, the main cause of maternal complications, affected mostly nonwhite women. Hemorrhage, the second more common cause of maternal complication, predominated among white women. Nonwhite skin color was associated with a reduced risk of SMO in multivariate analysis. Nonwhite skin color was associated with a lower risk for severe maternal outcomes. This result could be due to confounding factors linked to a high rate of Brazilian miscegenation.2019CNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológico402702/2008-
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