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Search Results: 1 - 10 of 621345 matches for " Sandra Cátia Pereira Uch?a "
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Phosphorus Adsorption of Some Brazilian Soils in Relations to Selected Soil Properties  [PDF]
Valdinar Ferreira Melo, Sandra Cátia Pereira Ucha, Zachary N. Senwo, Ronilson José Pedroso Amorim
Open Journal of Soil Science (OJSS) , 2015, DOI: 10.4236/ojss.2015.55010
Abstract:

A major nutritional problem to crops grown in highly weathered Brazilian soils is phosphorus (P) deficiencies linked to their low availability and the capacity of the soils to fix P in insoluble forms. Our studies examined factors that might influence P behavior in soils of the Amazon region. This study was conducted to evaluate the maximum phosphate adsorption capacity (MPAC) of the soils developed from mafic rocks (diabase), their parent materials and other factors resulting in the formation of eutrophic soils having A chernozemic horizon associated with Red Nitosols (Alfisol) and Red Latosols (Oxisol) of the Amazonian environment. The MPAC was determined in triplicates as a function of the remnant P values. The different concentrations used to determine the MPAC allowed maximum adsorption values to be reached for all soils. The Latosol (Oxisol) and Nitosol (Alfisol) soils presented higher phosphate adsorption values that were attributed to the oxidic mineralogy and high clay texture while the Chernosol (Mollisol) soils presented the lowest phosphate adsorption values.

Seeds germination of tart yellow passion fruit as influenced by heat treatment. = Germina o de sementes de maracujá amarelo azedo em fun o de tratamentos térmicos.
Marina Keiko Welter,Oscar José Smiderle,Sandra Cátia Pereira Ucha,Miguel Torres Chang
Agro@mbiente On-line , 2011,
Abstract: The study aimed to determine the effects of heat treatments applied to seeds of bitter yellow passionfruit (/Passiflora edulis/ Sims f. flavicarpa DEG) in the uniformity of seed germination. The experimental design was completely randomized blocks under a factorial scheme (3 x 2) +1, the factors being temperature (40, 50 and 60°C) and time of water immersion (10 and 15 minutes) plus a control (ambient temperature), with four replicates. The characteristics evaluated were: percentage of germination and speed of germination, being obtained both accumulated germination within 13 days and average germination velocity index. Concerning to cumulative germination percentage, treatments can be grouped into three groups as follows: first group, treatment T1D2 with 74.5%; second group with treatments T0, T1D1 and T2D2 with 55%, 53% and 52.5% respectively; third group with treatments T2D1, T3D1 and T3D2 with 35.5%, 17% and 13.5% respectively. Treatment with bitter passion fruit seed immersion in water heated to 40 oC for 15 minutes showed 75% germination and a better uniformity of seedlings.
Avalia o da fixa o biológica de nitrogênio em feij o-caupi submetido a diferentes manejos da vegeta o natural na savana de Roraima = Evaluation of the biological nitrogen fixation in cowpea subjected to different managements of the natural vegetation of the savanna in Roraima, Brazil.
Victorio Jacob Bastos,Djair Alves Melo,José Maria Arcanjo Alves,Sandra Cátia Pereira Ucha
Agro@mbiente On-line , 2012,
Abstract: Objetivou-se com este trabalho avaliar a fixa o biológica de nitrogênio em feij o-caupi submetido a diferentes manejos da vegeta o natural, com e sem aduba o organica com esterco bovino, da savana de Roraima. O experimento foi instalado na área experimental do CCA/UFRR, em Boa Vista, Roraima. O plantio das sementes de feij o-caupi, cultivar BRS Aracê, inoculadas com Bradyrhizobium BR 3262, foi realizado em julho de 2011 e os tratamentos foram dispostos em umdelineamento experimental de blocos ao acaso em esquema fatorial (3 x 2) com quatro repeti es. O primeiro fator correspondeu ao manejo da vegeta o natural: com aplica o de glifosato, com corte da vegeta o natural e sem corte da vegeta o natural. O segundo fator correspondeu à aplica o de esterco bovino: com e sem aplica o. Aos 35 dias após o plantio foi efetuada a coleta das plantas de feij o-caupi para mensurar o número de nódulos; massa fresca e seca dos nódulos; altura da planta; número de folhas, massa fresca e seca da parte aérea; massa fresca e seca da raiz. A aplica o a lan o de esterco bovino na quantidade de 2,0 L m-2 sobre a vegeta o natural da savana de Roraima favorece o aumento do número de nódulos por planta de feij o-caupi.O manejo da vegeta o natural com o uso do glifosato, independentemente do uso do esterco, favorece a nodula o das raízese contribui com o maior crescimento e desenvolvimento da planta de feij o-caupi.This study evaluated the biological fixation of nitrogen in cowpea beans subjected to different managements of the natural vegetation of the savannah in Roraima. The experiment was done in the experimental area of the CCA/UFRR, Boa Vista, Roraima, Brazil. The planting of the BRS Aracê cowpea seeds, inoculated with Bradyrhizobium BR 3262, wasdone in July, 2011 and the treatments were arranged in factorial schemes (3 x 2) of experimental randomized blocks with fourrepetitions. The first factor was the management of natural vegetation: with the application of glyphosate, cutting the naturalvegetation and without cutting it. The second factor was the application of manure: with and without the manure. 35 days afterthe planting the cowpea plants were collected to measure the number of nodes; fresh and dry mass of the nodes; plant height; number of leaves; fresh and dry mass of the upper segment of the plant; fresh and dry mass of the root and root length. The application of manure, at the amount of 2,0 L m-2, over the natural vegetation of the savanna, favored the increase of the number of nodes per cowpea plant. The management of natural vegetation with the use
Solos da área indígena Yanomami no médio Rio Catrimani, Roraima
Melo, Valdinar Ferreira;Francelino, Marcio Rocha;Ucha, Sandra Cátia Pereira;Salamene, Samara;Santos, Célida Socorro Vieira dos;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000200022
Abstract: in roraima, the spatial distribution of indigenous peoples indicates a background of constant search for soils capable of sustaining shift cultivation. this study aimed to establish a relationship between the understanding of soil by the yanomami tribe from the mid-catrimani river region and the brazilian system of soil classification and evaluate the type of agricultural land use according to soil fertility tests, in two steps. the first consisted of visiting eight indian communities to collect soil samples at 21 sites with different types of agriculture and forests, both from profile soil (depth 0-1.50 m) and pits (depth 0-0.1 m and 0.1-0.3 m) for laboratory analysis. the second step was a workshop addressing the shift cultivation systems (duration 20 h). the discussion focused on the understanding of the environment (urihi) and agricultural production systems, and on the importance of the correct use of knowledge of the soil and its fertility. soils are named according to their morphology and position in the landscape by the yanomami. the choice of agricultural areas is based on these features, aside from the organic matter content and the presence of earthworms. agricultural practices comprise clearing and burning of the native forest immediately before planting a set of separate crops. the soils described in the area were classified according to the brazilian taxonomic system as follows: red yellow argisol (maxita a uuxi wake axi), yellow argisol (maxita a axi) yellow latosol (maxita a axi) and plintosol (maxita a axi a maaxipé). slashing and burning initially increases exchangeable ca, k and available p due to the contribution of the ashes, which allows an agricultural exploitation of these areas for a maximum period of three years.
Avalia o de dois clones de mandioca em duas épocas de colheita. = Evaluation of two cassava clones during two distinct harvest seasons.
José Maria Arcanjo Alves,Fernanda Aguiar da Costa,Sandra Cátia Pereira Ucha,Célida Socorro Vieira dos Santos
Agro@mbiente On-line , 2008,
Abstract: A mandioca é uma cultura de fácil adapta o às diferentes condi es edafoclimáticas e desempenha uma elevada importancia social por se constituir na principal fonte de carboidratos nos países em desenvolvimento. Um dos maiores obstáculos para a utiliza o da mandioca é a alta perecibilidade de sua raiz, quando armazenada em condi es ambientais, pois possuem uma vida útil muito restrita. Neste trabalho procurou-se avaliar as características das raízes tuberosas de dois clones de mandioca para mesa cultivadas nas condi es edafoclimáticas do cerrado de Roraima, colhidas aos 7 e 13 meses, visando o processamento mínimo. Os experimentos foram conduzidos no Campus Cauamé do Centro de Ciências Agrárias daUniversidade Federal de Roraima em Boa Vista, Roraima. Os dados das variáveis quantitativas foram submetidas à análise de variancia (p<0,05). As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Conclui-se que os clones de mandioca para mesa P o e Aciolina podem ser colhidos aos sete meses após o plantio, tanto para o consumo in natura quanto para a indústria, nas condi es edafoclimáticas do cerrado de Roraima. As raízes da Aciolina, colhidas aos 13 meses de idade, apresentam melhor qualidade visual quando armazenadas em ambiente refrigerado (5 ± 2,0 oC) durante 14 dias em rela o às raízes do clone P o e o tempo de coc o das raízes refrigeradas por 30 dias do clone Aciolina é superior a 30 minutos, sendo imprestável para o consumo humano. = The cassava is an easy adaptation culture to the different weather and soil conditions and plays an important social role as being the prime carbohydrates source in the countries under development. One of the biggest obstacles in the use of the cassava is its highly perishable roots, when stored in the environmental climate conditions, since it has a very restricted useful life. In this study, it was sought to evaluate the features of two cassava varieties roots cultivated in the weather and soil conditions of the savannah (cerrado) area, harvested at 7 and 13 months, looking forward the reduced processing. The experiments were conducted in the Campus Cauamé of the Centro de Ciências Agrárias of the Universidade Federal de Roraima (CCA/UFRR) in Boa Vista, Roraima. The data of quantitative variables were submitted to analysis of variance (p<0.05). Means were compared by Tukey test at 5% probability. Concluding: the P o and Aciolina clone can be harvested 7 months after the planting, for the in natura consumption as well as for the industry, in the weather and soil conditions of the savannah (cerrado) ar
Formas de aplica??o de nitrogênio em três cultivares de girassol na savana de Roraima
Ivanoff, Maria Elena Almeida;Ucha, Sandra Cátia Pereira;Alves, José Maria Arcanjo;Smiderle, Oscar José;Sediyama, Tocio;
Revista Ciência Agron?mica , 2010, DOI: 10.1590/S1806-66902010000300001
Abstract: nitrogen is the nutrient that limits most the production in the culture of sunflower (helianthus annuus l). the nutritional requirements among cultivars of the same species is distinct, under the same conditions of culture and for the same agricultural year. with the objective of evaluating four different ways of nitrogen application in the production components of different genotypes of sunflower, an experiment was carried out in a randomized block design in a 3 x 4 factorial scheme (genotypes x ways of nitrogen applying) with four replicates . the treatments consisted on the combination of three varieties: agrobel 960, agrobel 962 and v - 2000 and four different ways of nitrogen application: 100% at 20 days after sowing (das) - (0-100-0-0); 30% at sowing and 70% at 20 das - (30-70-0-0); 30% at sowing, 30% at 20 das e 40% at 40 das (30-30-40-0); 20% at sowing, 30% at 20 das, 30% at 40 das e 20% at 60 das (20-30-30-20). measured variables were: height of the plant, height of the capitulum, diameter of the stem, diameter of the capitulum and achene yield. the ways of nitrogen application affected all components of yield. the n formulation (30-70-0-0) has determined the best results for the variables studied, but the form (30-30-40-0) provided results comparable to treatment (30-70-0-0); treatments where n was applied as (20-30-30-20) caused decrease in the performance of sunflower for all variables. the varietal effect was observed only for plant height and height of the capitulum. the highest yield of achene achieved was 1.639 kg ha-1, with no superiority for the hybrids agrobel 960 and 962 in relation to the variety 122/v2000 embrapa.
Identifica o de Genótipos de Feij o-caupi Tolerantes a Acidez em um Latossolo Vermelho-Amarelo do Estado de Roraima = Identification of cowpea genotypes sensitivity to acidicy conditions in an Oxisol of Roraima State (Brazil).
Sandra Cátia Pereira Ucha,Armando José da Silva,José Maria Arcanjo Alves,Valdinar Ferreira Melo
Agro@mbiente On-line , 2007,
Abstract: O presente trabalho foi realizado com o objetivo de identificar genótipos de feij o-caupi (Vigna unguiculata (L) Walp.), tolerantes à acidez. O trabalho foi realizado em casa de vegeta o localizada no Campus do Cauamé, da Universidade Federal de Roraima, utilizando um Latossolo Vermelho-Amarelo de Boa Vista-RR. Foi adotado o delineamento experimental de Blocos Inteiramente Casualizados em esquema fatorial 2 x 5 x 10 com três repeti es. Os tratamentos resultaram de duas formas de localiza o do calcário (localizada e n o-localizada), 5 profundidades (0-5; 5-10; 10-15; 15-20; 20-25 cm) e 10 genótipos de feij o-caupi(IT85D-3428-4-R2,4-HM; Apiaú; Hikari Graúdo; Pretinho Precoce 1; IT85D-3428-4-3-HP; USA; UFRR Gr o Verde; BRS-Mazag o; Canapum e Sempre Verde). A unidade experimental foi constituída por 2dm3 de solo, dispostos em tubo de PVC com 25cm de altura,10cm de diametro e duas plantas de feij o. Os tubos foram confeccionados por meio da jun o de 5 anéis com 5 cm cada, sendo que no anel inferior foi colocada uma placa delgada de isopor para permitir a acomoda o do solo. Aos 40 dias após a emergência, as plantas foram coletadas, sendo determinada à produ o de matéria seca das raízes e parte aérea. Os genótipos IT85D-3428-4-3-HP e UFRRGR O VERDE foram classificados como sendo de baixa tolerancia, os genótipos USA, BRS-Mazag o, IT85D-3428-4-R2,4-HM e Sempre Verde, medianamente tolerantes e os genótipos Apiaú, Hikari Graúdo, Pretinho Precoce 1 e Canapum, tolerantes à acidez.= This research was carried out objecting to identify the sensibility of cowpea (Vigna unguiculata (L) Walp) genotypes to acidity conditions. The experiment was installed in a greenhouse located at Campus of Cauamé (Universidade Federal de Roraima) in an oxisol of Roraima State (Brazil). The experimental design adopted was a completely andomized blocks in a factorial scheme 2 x 5 x 10 with three replicates. The terms of this factorial refers to two forms of lime applying (localized and uniform), five depths of soil (0-5; 5-10; 10-15;15-20; 20-25 cm), and ten genotypes of cowpea (IT85D-3428-4-R2,4-HM, Apiaú, Hikari Graúdo, Pretinho Precoce 1, IT85D-3428-4-3-HP, USA, UFRR Gr o Verde, BRS-Mazag o, Canapum, and Sempre Verde). The experimental unity consisted of 2 dm3 of soil inside PVC tube 25 cm in height and diameter of 10 cm with two cowpea plants. Forty days after the germination, the plants were collected and the dry matter yield was determined. The genotypes IT85D-3428-4-3-HP and UFRR Gr o Verde showed high sensibility to acidity, the genotypes USA, BRS-Mazag o, IT85D-3428-4-R2,4-H
Characterization of cassava clones produced in Roraima for in natura consumption. = Caracteriza o e identifica o de clones de mandioca produzidos em Roraima para o consumo in natura.
Natália Trajano de Oliveira,José Maria Arcanjo Alves,Sandra Cátia Pereira Ucha,Guilherme Silva Rodrigues
Agro@mbiente On-line , 2011,
Abstract: The objective of this study was to characterize and identify cassava clones produced in Roraima State, Brazil, for human consumption. There was the planting of six clones of cassava (Aciolina, P o, P o-do-Chile, água Morna, Enxuta and Amazonas), in double rows, following the spacing of 2.0 m x 0.8 m x 0.8 m, total of 8,928 plants ha-1 . It was used randomized blocks experimental design with four replications. At eight months after planting was carried out to harvest the roots, being evaluated for hydrocyanic acid, starch content by the method of hydrostatic balance and artisanal mining, ability to release the film and bark, bark color and flesh color raw. The cassava clones were classified according to HCN content in: Mansi (Enxuta and P o-do-Chile), intermediate (Aciolina and água Morna) and Brava (P o and Amazonas). The starch obtained by the method of hydrostatic balance overestimates the starch content by the method artisanal mining. The Aciolina clone stood out among the clones for human consumption, it is also recommended for industrial use. The P o and Amazonas clones have restrictions for both human consumption and for industrial used.
Avalia o da Capacidade de Enraizamento, em água, de Brota es, Ponteiros e Estacas Herbáceas de Clones de Mandioca de Mesa. = Evaluation of the rooting capacity, inside water, of shoots, pointers and steam cuttings of table cassava clones.
Alessandra Ribeiro Rodrigues,José Maria Arcanjo Alves,Sandra Cátia Pereira Ucha,José de Anchieta Alves de Albuquerque
Agro@mbiente On-line , 2008,
Abstract: Este trabalho teve o objetivo de avaliar a capacidade de enraizamento, em água, de brota es, ponteiros e estacas herbáceas de clones de mandioca de mesa por meio da técnica de propaga o rápida. Foram realizados quatro experimentos na área experimental do CCA-UFRR, em Boa Vista, Roraima, em delineamento inteiramente casualizado. Avaliou-se a percentagem de enraizamento das partes da planta (brota es, ponteiros e estacas herbáceas) quando imersas em água de po o artesiano, filtrada e água proveniente da chuva. De acordo com os resultados obtidos pode-se concluir que o clone de mandioca de mesa P o apresenta uma alta capacidade de enraizamento quando se utiliza o método de propaga o rápida por meio de microestacas; a capacidade de enraizamento, em água, de brota es, ponteiros e estacas herbáceas de plantas de mandioca depende do fator genético e da origem da água utilizada; e a água proveniente da chuva pode ser uma excelente op o para ser utilizada para promover o enraizamento das estruturas vegetativas da mandioca no processo de propaga o rápida. = This work heads to evaluate the rooting capacity, in water, of shoots, pointers and steam cuttings of cassava clones of table by the fast propagation technique. Four experiments were carried out in the CCA-UFRR experimental area, in Boa Vista, Roraima state, in a completely randomized design. The rooting percentage was evaluated in plant cuttings (shoots, pointers and cutting steams) when inside well`s water, filtrated water and rain water. The following conclusions are based on the obtained results: the table cassava clones “P o” shows high capacity of rooting by the fast propagation technique by micro steams cuttings; the capacity of rooting, in water, of shoots, pointers and steams cutting of cassava depends on genetic factor and the kind of water used; the rain water may be an excellent option of rooting of vegetative structures of cassava in fast process of propagation.
Métodos de aplica o de potássio na qualidade do milho verde em sucess o ao cultivo de melancia. = Potassium application methods on green corn quality in succession to watermelon crop.
Diego Lima de Souza Cruz,Sandra Cátia Pereira Ucha,José Maria Arcanjo Alves,Valdinar Ferreira Melo
Agro@mbiente On-line , 2009,
Abstract: Este trabalho foi realizado em área de savana (cerrado), recém incorporada ao sistema produtivo, localizada no Centro de Ciências Agrárias da UFRR, no município de Boa Vista, em Roraima. Objetivou-se avaliar o efeito de seis métodos de aplica o de potássio nas características da planta e na qualidade de espigas de milho verde cultivadas em covas novas e em covas remanescente do cultivo de melancia. Os métodos de aplica o do potássio foram: 1 - 100% do potássio aplicado no plantio com a adi o de esterco bovino na cova; 2 - 100% de K no plantio; 3 - 50% de K no plantio e 50% aos 20 dias após a emergência (DAE); 4 - 50% de K no plantio, 25% aos 20 DAE e 25% aos 30 DAE; 5 - 25% de K no plantio, 25% aos 20 DAE, 25% aos 30 DAE e 25% aos 40 DAE; 6 - 25% de K no plantio, 25% aos 50 DAE, 25% aos 60 DAE e 25% aos 70 DAE. O delineamento experimental foi o de blocos casualizados, em parcela subdividida, com quatro repeti es. Nas parcelas foram aleatorizados os métodos de aplica o de potássio e nas subparcelas foram os tipos de covas. Os métodos de aplica o de potássio influenciaram positivamente nas variáveis analisadas, sobretudo nas covas remanescentes da melancia (CM), destacando-se os métodos 1, 3 e 4. Os métodos 2 e 6 determinaram os piores desempenhos. = An experiment took place within the savannah ecosystem, in Boa Vista, Roraima, between May and July, 2007, with the objective of evaluate the influence of the methods of applications of potassium on the plant and the quality of green corns cultivated in two types of burrowing system: a new hole and hole remained from the previous crop with watermelon. Six methods of potassium application were evaluated: 1) total potassium (100%) applied at sowing to which bovine manure was added; 2), total potassium (100%) applied at sowing; 3) 50% of potassium applied at sowing and 50% 20 days after emergency (DAE); 4) 50% of potassium applied at sowing, 25% at 20 DAE, followed by 25% at 30 DAE; 5) 25% of potassium applied at sowing, 25% at 20 DAE, 25% at 30 DAE, and 25% at 40 DAE; and 6) 25% of potassium applied at sowing, 25% at 50 DAE, followed by 25% at 60 DAE and 25% at 70 DAE). Two systems of burrows were evaluated: CM - burrows from a remaining watermelon crop, and CN, new burrows). The experimental design was completely randomized blocks in split plot, with four replicates. The methods of the application of potassium influenced on most of the variables that were analyzed, principally, in remaining burrows from a revious watermelon crop (CM), highlighting the methods 1, 3 and 4. The methods 2 and 6 determine the
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