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Search Results: 1 - 10 of 305595 matches for " Sueyde F de;Vargas "
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Accumulation of nutrients in sweet peppers cultivated in coconut fiber
Charlo, Hamilton César de O;Oliveira, Sueyde F de;Vargas, Pablo F;Castoldi, Renata;Barbosa, José Carlos;Braz, Leila T;
Horticultura Brasileira , 2012, DOI: 10.1590/S0102-05362012000100021
Abstract: the production of sweet peppers in greenhouse has been severely affected by soil pathogens. with this, producers are adopting new cultivation techniques, such as cultivation in substrates, but information about this type of cultivation are still scarce. the aim of the present work was to evaluate nutrient accumulation in sweet peppers cultivated in coconut fiber with fertirrigation in greenhouse. initially, 160 plants (eppo cultivar) were divided into four blocks, where two plants per block were analyzed every 21 days after transplanting. the sweet peppers were cultivated in plastic pots of 13 l, containing coconut fiber, and placed in double rows with spacing of 0.5 x 0.8 m between single rows and 1.10 m between double rows. the commercial production of the mature fruits was estimated to be 97.3 t ha -1, where all the production was classified as extra (maximum quality). the accumulation of the various determined nutrients were: 8.22 g plant -1 of n, 1.14 g plant -1 of p, 7.84 g plant -1 of k, 3.25 g plant -1 of ca, 1.34 g plant -1 of mg, 2.24 g plant -1 of s, 16.65 mg plant -1 of b, 3.36 mg plant -1 of cu, 45.98 mg plant -1 of fe, 34.78 mg plant -1 of mn and 22.28 mg plant -1 of zn.
Growth analysis of sweet pepper cultivated in coconut fiber in a greenhouse
Charlo, Hamilton César de O;Oliveira, Sueyde F de;Castoldi, Renata;Vargas, Pablo F;Braz, Leila T;Barbosa, José Carlos;
Horticultura Brasileira , 2011, DOI: 10.1590/S0102-05362011000300010
Abstract: knowledge about the growth of crops allows the planning of rational cultivation methods which contribute to achieve greater potential of plant species, besides supplying information for the construction of descriptive mathematical models of growth. the growth curve of sweet pepper (eppo hybrid), cultivated in coconut fiber in a greenhouse with fertirrigation, was determined. the experiment consisted initially of 160 plants divided into four blocks. two plants were analyzed per block every 21 days after transplanting, ending at 189 days after transplant. the cultivation was carried out in plastics pots of 13 l containing coconut fiber, which were arranged in double rows, spaced 0.5 x 0.8 m between simple rows and 1.1 m between double rows. in each harvest the plant growth, production and quality of mature fruits were evaluated. the dry mass of the shoot increased with time, following the experimental model exponential of first order, reaching a maximum of 451.5 g/plant, 189 days after transplanting (dat). the production of dry mass of leaves, stem, root and fruit also increased over time reaching maximum values of 68.7, 65.8, 11.5 and 302.9 g/plant, respectively, at 189 dat. the same occurred with the leaf area per plant, plant height and the absolute rate of growth, whose maximum values were 6.183,5 cm2, 136.9 cm and 4.4 g/plant/day, respectively. the growth of the plant was continuous throughout the cycle, and the highest amount of dry mass was accumulated in fruits, reaching a marketable production of 97.3 t ha-1. all fruits were classified as extra.
Determinación de la susceptibilidad en tres poblaciones de Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) a metomilo y buprofezin
Vargas M.,Robinson; Alvear de la F.,Andrés;
Agricultura Técnica , 2000, DOI: 10.4067/S0365-28072000000400003
Abstract: the susceptibility level of trialeurodes vaporariorum to methomyl was determined for three field populations collected from lycopersicum esculentum mill. in quillota, chile. mean lethal time (lt50) was estimated by probit analysis, managing to detect minimum losses of susceptibility in field populations of 1.1, 1.2 and 1.6 times more than the susceptible population. additionally, analysis of variance (anova) permitted the rapid differentiation between a susceptible population and population with less susceptibility. field experiments confirmed the loss of susceptibility to methomyl and in addition the efficacy of buprofezin control. the control failures may be caused by both loss of susceptibility to methomyl and inefficient spraying techniques. a strategy of resistance management is discussed, that includes the use of insecticides with different modes of action, cultural practices, and utilization of biological control via encarsia formosa and eretmocerus corni
Determinación de la susceptibilidad en tres poblaciones de Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) a metomilo y buprofezin Determination of the susceptibility to methomyl and buprofezin in three populations of Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae)
Robinson Vargas M.,Andrés Alvear de la F.
Agricultura Técnica , 2000,
Abstract: Se evaluó el nivel de susceptibilidad a metomilo en tres poblaciones de Trialeurodes vaporariorum (Westwood), colectadas de Lycopersicum esculentum Mill. en Quillota, Chile. Se estimaron los tiempos letales medios (TL50) mediante el análisis probit, logrando detectar mínimas pérdidas de susceptibilidad en las poblaciones de campo de 1,1; 1,2 y 1,6 veces más que la población susceptible. Complementariamente, el análisis de varianza (ANDEVA) permitió diferenciar en forma rápida entre una población susceptible y una población con menor susceptibilidad. El ensayo de campo validó la pérdida de susceptibilidad a metomilo y además mostró la eficacia del control con buprofezin. Las fallas de control pueden ser causadas por la pérdida de susceptibilidad a metomilo y a técnicas deficientes de aplicación. Se discute una estrategia de manejo de resistencia, que sugiere la utilización de insecticidas con diferentes modos de acción, manejos culturales e incorporación del control biológico mediante el uso de Encarsia formosa y Eretmocerus corni The susceptibility level of Trialeurodes vaporariorum to methomyl was determined for three field populations collected from Lycopersicum esculentum Mill. in Quillota, Chile. Mean Lethal time (LT50) was estimated by probit analysis, managing to detect minimum losses of susceptibility in field populations of 1.1, 1.2 and 1.6 times more than the susceptible population. Additionally, analysis of variance (ANOVA) permitted the rapid differentiation between a susceptible population and population with less susceptibility. Field experiments confirmed the loss of susceptibility to methomyl and in addition the efficacy of buprofezin control. The control failures may be caused by both loss of susceptibility to methomyl and inefficient spraying techniques. A strategy of resistance management is discussed, that includes the use of insecticides with different modes of action, cultural practices, and utilization of biological control via Encarsia formosa and Eretmocerus corni
Environmental Exposure Associated with Oxidative Stress Biomarkers in Children and Adolescents Residents in Brazilian Western Amazon  [PDF]
Beatriz Fátima Alves de Oliveira, Leandro Vargas Barreto de Carvalho, Dennys de Souza Mour?o, Rita de Cássia Oliveira da Costa Mattos, Hermano Albuquerque de Castro, Paulo Artaxo, Washington Leite Junger, Sandra Hacon
Journal of Environmental Protection (JEP) , 2018, DOI: 10.4236/jep.2018.94023
Abstract: Oxidative stress is a biological process that occurs in response to an imbalance between prooxidant and antioxidant substances and has been described in the pathophysiology of more than 200 clinical disorders. In this study, we evaluate the relationship between genetic, demographic, social, environmental, and health factors and redox imbalance biomarkers in a group of children and adolescents environmentally exposed to atmospheric pollutants and mercury in the Brazilian Western Amazon. This is a cross-sectional study of the relationship between demographic, genetic, and socioenvironmental factors and serum concentrations of redox imbalance biomarkers (thiol groups, malondialdehyde, and glutathione S-transferase [GST]) in children and adolescents living in the municipality of Porto Velho, Rond?nia. The investigated factors were hierarchically organized into groups of variables and their relationship with redox imbalance biomarkers was estimated by a multiple linear regression model. Children and adolescents with asthma, with C-reactive protein values, with the polymorphic variant GSTP1, and exposed to indoor air pollution presented lower thiol serum concentrations when compared to those categorized in their respective reference groups. GST activity and malondialdehyde serum concentrations were positively related to weekly fish consumption and exposure to PM2.5. This study showed that enzymatic GST activity and malondialdehyde serum concentrations are positively associated with environmental factors, especially air pollution (β = 8.64 U/L for GST and β = 0.244 μmol/L for MDA in high exposure group; p-value < 0.01); while serum thiol concentrations presented an inversely proportional relationship with markers of general health status, such asthma (median: 0.45 mmol/L vs. 0.48 mmol/L; p-value < 0.05), acute inflammation (β = -0.25 mmol/L; p-value < 0.01), and positively with genetic factor (β = 0.12 mmol/L for Val/Val; p-value < 0.05).
Detection of Helicobacter pylori in dental plaque of mexican children by real-time PCR  [PDF]
J. A. Valdez-Gonzalez, P. C. Mares-Moreno, M. J. Kowolik, J. Vargas-Villlarreal, F. Gonzalez-Salazar, M. A. De la Garza-Ramos
Health (Health) , 2014, DOI: 10.4236/health.2014.64034
Abstract:

Dental plaque in adult patients is well identified as a reservoir for Helicobacter pylori. This question still remains unclear in children. The aim of this study is to identify the presence of this bacterium in dental plaque of Mexican pediatric patients, using Real Time Polymerase Chain Reaction (qPCR). Forty patients from 2 to 11 years without dyspeptic symptoms were enrolled. Samples were collected from the subgingival space of the lingual side of the lower molars and cultured in selective medium. Therefore, qPCR analysis was conducted. According to the results obtained in this study, it was found that 35% of the pediatric population who participated tested qPCR positive for the presence of H. pylori in dental plaque samples. No significant associations were detected among isolation rate by gender or age. We found that dental plaque may be a reservoir for H. pylori. However, more research is needed to establish the way of the infection of pediatric population.

Phytoplankton Biogeography and Community Stability in the Ocean
Pedro Cerme?o,Colomban de Vargas,Fátima Abrantes,Paul G. Falkowski
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010037
Abstract: Despite enormous environmental variability linked to glacial/interglacial climates of the Pleistocene, we have recently shown that marine diatom communities evolved slowly through gradual changes over the past 1.5 million years. Identifying the causes of this ecological stability is key for understanding the mechanisms that control the tempo and mode of community evolution.
Desempenho de cultivares de mel?o rendilhado em fun??o do sistema de cultivo
Vargas, Pablo F;Castoldi, Renata;Charlo, Hamilton César de O;Braz, Leila T;
Horticultura Brasileira , 2008, DOI: 10.1590/S0102-05362008000200014
Abstract: in this study the productive characteristics of five net melon cultivars, using two different cultivation systems were evaluated. the study was conducted in a greenhouse from november/05 to february/06. the experiments were carried out using randomized complete block design with a 5 x 2 factorial scheme and four repetitions. the evaluated factors were five net melon hybrids (maxim, b?nus 2, shinju 200, fantasy and louis) and two cultivation systems (in the soil and in substrate of coconut husk fiber). after harvest we evaluated the production per plant (kg planta-1); transverse (dtf) and longitudinal diameters (dlf) of fruit, in mm; format index of fruit (iff); transverse (dtl) and longitudinal diameters (dll) of locule, in mm; format index of locule (ifl); insertion diameters of the grain stalk (dip), in mm; and mesocarp thickness (em), in mm. no interactions were observed among the studied factors. the cultivation in substrate provided better performance when compared to cultivation in soil (2.51 and 1.52 kg planta-1, respectively), where the cultivar fantasy (2.44 kg plant-1) presented the best performance among cultivars, but not differing from louis and maxim. for the characteristics dip, dtl and em, a better performance was observed in plants cultivated in substratum. for the characteristics dtf, dlf, iff and dll no interactions were observed among the cultivation systems. therefore, the cultivation in substrate stood out in relation to cultivation in the soil, the cv. fantasy showing better performance than shinju 200 and bonus 2.
Crescimento, acúmulo de nutrientes e produtividade da cultura da couve-flor
Castoldi, Renata;Charlo, Hamilton César de O;Vargas, Pablo F;T Braz, Leila;
Horticultura Brasileira , 2009, DOI: 10.1590/S0102-05362009000400007
Abstract: the cauliflower is one of the main vegetables grown in brazil. the study of growth and nutrients accumulation by cauliflower could be useful for its fertilization. therefore, a research was conducted in the field to determine the nutrients accumulation by 'verona' cauliflower, from february 23 to june 5, 2006. the experiment consisted initially of 480 plants divided into three blocks. for each period two plants per block were collected. five samples of the vegetative part were collected each 14 days after transplantation and three samples of inflorescences were collected every four days after the beginning of the cauliflower formation. also, plant growth and nutrient accumulation in the inflorescences, stem, leaves and petioles were evaluated. plants showed linear increase of growth and accumulation of dry matter. the greatest accumulation period occurred from the beginning of the inflorescence formation up to the harvest. the decreasing order of accumulated nutrients was: n>k>ca>s>mg>p>fe>mn>zn>b>cu. the export of nutrients (g per plant of macronutrients and mg per plant of micronutrients) by inflorescences was 3.50 of n; 0.296 of k; 0.06 of ca; 0.290 of s; 0.032 of mg; 0.249 of p; 2.08 of fe; 0.375 of mn; 1.01 of zn; 1.45 of b and 0.07 of cu.
Cultivo de mel?o rendilhado com dois e três frutos por planta
Charlo, Hamilton César de O;Castoldi, Renata;Vargas, Pablo F;Braz, Leila T;
Horticultura Brasileira , 2009, DOI: 10.1590/S0102-05362009000200023
Abstract: the pruning of fruits of net melon cultivars was evaluated in this study. the cultivars maxim, louis, fantasy, shinju 200 and b?nus no2 were evaluated in plants bearing two and three fruits. the experimental design was of randomized blocks in factorial scheme 5 x 2, with four replications and the plants arranged in the spacing of 1.0 m between lines and 0.5 m between plants. the experiment was conducted in greenhouse, using fertirrigation and plastic pots of 13 l, filled with coconut fiber golden mix? misto 98. the seedlings were grown in expanded polystyrene trays of 128 cells and transplanted to pots when the first definitive leaf was completely developed. we evaluated the roughness of the rind, the longitudinal and transversal diameters of fruits, the fruit shape index, the longitudinal and transversal diameters of the locule, the locule shape index, the thickness of the mesocarp, the average weight of fruits and the production per plant. no interaction between the studied factors was detected. for the conditions of this experiment, the conduction of two fruits per plant generated greater transverse diameter of fruit, greater longitudinal diameter of the locule, greater roundness of the rind and greater average weight of fruits. however, the greatest productions per plant was observed in plants bearing three fruits. the hybrids fantasy and shinju 200 presented the best fruit characteristics and greater production.
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