Refinar búsqueda
Resultados 21-30 de 166
USE OF REJECT BRINE FROM DESALINATION ON DIFFERENT DEVELOPMENT STAGES OF HYDROPONIC LETTUCE Texto completo
2011
NILDO DA SILVA DIAS | FRANCISCO AÉCIO DE LIMA | CLÁUDIO RICARDO DA SILVA | OSVALDO NOGUEIRA DE SOUSA NETO | HANS RAJ GHEYI
In order to evaluated the impact of the high salinity reject brine from reverse osmosis desalination on hydroponics lettuce cultivated in greenhouse an investigation was carried out in Mossoro, Northeast of Brazil (5º11'S, 37º20'O and 18m above sea). Two lettuce cultivars ('Verônica' and 'Babá de verão') were cultivated with a basic nutrient solution with 1.1 dS m-1 (control) during the crop cycle (1-28 days after transplanting - DAT) - T0 and with basic nutrient solution containing 50% of the reject water from desalinization with 4.8 dS m-1 exposed during 1-7, 21-28, 7-14 e 1-28 DAT (T1, T2, T3 and T4, respectively). The addition of 50% of brine reject from desalination into the hydroponic nutrient solution allows grow only 'Verônica' lettuce with no reduction in fresh biomass. This lettuce cultivar shows to be more tolerant to salinity for all exposure time with reject brine in the nutrition solution, despite the fact that 'Babá de Verão' cultivar is more productive.
Mostrar más [+] Menos [-]BALANÇO DE RADIAÇÃO NO PERÍMETRO IRRIGADO SÃO GONÇALO - PB MEDIANTE IMAGENS ORBITAIS Texto completo
2011
BERNARDO BARBOSA DA SILVA | ALEXANDRA CHAVES BRAGA | CÉLIA CAMPOS BRAGA
The net radiation is of great importance in studies related to energy and mass exchanges between the land surface and atmosphere, although it is not measured routinely in a meteorological network. In this sense, the use of satellite images over the last decade has been increasingly used for its determination. The present study aimed at determining the radiation balance in the Irrigated São Gonçalo Project - PISG and surrounding areas based on satellite images and a few meteorological data measured within the PISG. Landsat 5 Thematic Mapper images available in 2008 and procedures of SEBAL - Surface Energy Balance Algorithm for Land were used for mapping albedo and net radiation. Three selected areas into the study scene were used to discuss the behavior of different components of the radiation balance under different soil cover types. It was observed that the waters of São Gonçalo dam presented albedo in the range of 3.3 to 7,5%, while in the soil with low vegetation cover the albedo ranged between 32 and 38,7% over the studied period. In the irrigated coconut orchard the albedo ranged between 15.0 to 18.7%, while the net radiation values over the dam and the coconut orchard were consistently higher than those in other areas. It was concluded that the irrigated areas have lower albedo and surface temperature and thus increased net radiation, contributing to reduce the air temperature locally.
Mostrar más [+] Menos [-]EFEITO DAS CARACTERÍSTICAS DO ESGOTO DOMÉSTICO NA UNIFORMIDADE DE APLICAÇÃO DE SISTEMAS DE IRRIGAÇÃO POR GOTEJAMENTO Texto completo
2011
RAFAEL OLIVEIRA BATISTA | FABRÍCIA GRATYELLI BEZERRA COSTA | HUMBELINA SILVA SIQUEIRA LOPES | DANIELA DA COSTA LEITE COELHO | MARIA REGILENE DE FREITAS COSTA PAIVA
O objetivo deste trabalho foi analisar a uniformidade de aplicação de efluente de três sistemas de irrigação abastecidos com diferentes características de esgoto doméstico do condomínio residencial Bosque Acamari, em Viçosa-MG. O experimento foi realizado em área de pesquisa da Universidade Federal de Viçosa (UFV), em Viçosa-MG. Montaram-se três sistemas de irrigação por gotejamento, abastecidos com esgoto doméstico preliminar (EDP), esgoto de tratamento secundário (EDS) e esgoto de tratamento terciário (EDT). Cada sistema de irrigação foi composto por filtro de discos e gotejadores não autocompensantes com vazão nominal de 1,7 L h-1. A uniformidade de aplicação de efluente foi obtida a cada 100 h, totalizando 500 h de operação, com os Coeficientes de Uniformidade de Distribuição (CUD) e de Uniformidade Estatística (Us). Foram realizadas determinações físico-químicas e microbiológicas nos esgotos domésticos. Conclui-se que as características ferro total e coliformes totais representam risco severo de obstrução para gotejadores abastecidos com EDP, EDS e EDT, enquanto para as características manganês total, magnésio e cálcio tal risco é baixo. A formação de biofilme de sólidos suspensos e bactérias foi a principal causa de obstrução de gotejadores. Os valores de CUD e Us apresentaram, após 500 h de operação, redução de 61 e 54%; 27 e 24%; e 57 e 59%, respectivamente, para os sistemas de irrigação abastecidos com EDP, EDS e EDT.
Mostrar más [+] Menos [-]RESISTÊNCIA NATURAL DA MADEIRA DE SABIÁ (Mimosa caesalpiniifolia Benth.) A CUPINS SUBTERRÂNEOS Texto completo
2011
FRANCISCO HUGO HERMÓGENES DE ALENCAR | JUAREZ BENIGNO PAES | OLAF ANDREAS BAKKE | GIRLAINE SOUZA DA SILVA
The objective of this research was to evaluate the wood natural resistance of Mimosa caesalpiniifolia Benth. of phenotypes (plants) with and without prickles to subterranean termite (Nasutitermes corniger Motsch.) in forced feeding and feeding preference assays, under laboratory conditions. Wood test samples measuring 2.54 x 1.50 x 0.64 cm (forced feeding) and 10.00 x 1.50 x 0.64 cm (feeding preference), with the largest measurement in the fiber direction, were obtained from three positions from pith to bark direction. The samples were exposed for 28 days (forced feeding) and 45 days (feeding preference) to Nasutitermes corniger Motsch. termites. In forced feeding assay the termites caused superficial attack in wood and lived during 8 to 10 days, thus the wood was classified as resistant. In forced feeding assay more mass loss and attack in wood of external positions to both phenotypes was observed. To the waste and survival time of termites were similar to both types. In feeding preference a larger mass loss and waste to inner position in both phenotypes was observed. In general, the plants with prickles lost more mass than the one without prickles. Therefore, the wood of plants without prickles is more suitable to be use in construction of fences, sheepfolds and other similar uses where the wood shall be subject to attack by termites.
Mostrar más [+] Menos [-]LIXIVIAÇÃO DE POTÁSSIO EM UM CULTIVO DE PIMENTÃO SOB LÂMINAS DE IRRIGAÇÃO E DOSES DE POTÁSSIO Texto completo
2011
FRANCIMAR DA SILVA ALBUQUERQUE | ÊNIO FARIAS DE FRANÇA E SILVA | AMANDA EMANUELLA ROCHA DE SOUZA | MÁRIO MONTEIRO ROLIM
With the aim of determining the concentration of potassium (K+) and electrical conductivity (EC) in water drainage in the cultivation of sweet pepper (Maximos F1), and to evaluate the possible risk of contamination of groundwater was conducted a experiment on a battery of 40 drainage lysimeters, whose experimental plot consisted of three plants in each lysimeter, located at campus of the Federal Rural University of Pernambuco (UFRPE), Recife, PE, in a completely randomized factorial scheme 5 x 2, with four replications, being five irrigation depth (80, 90, 100, 110 and 120% of ETc) and two levels of potassium (80 and 120 kg ha-1 of K2O), applied parceled according to phenological phase, through a drip irrigation system, with selfcompensable emitters. Throughout the cycle proceeded to the measurement of volumes generated from natural drainage and the fortnightly water balances in the lysimeters, and collection of samples for tests to determine the K+ and EC. The K+ content and the EC showed significant linear adjustments in all phases of the cycle, whose mean values were 9.79 mg L-1 and 0.35 dS m-1, respectively. The drained volume showed increases in certain events of water balance due to the high rainfall during the period, leaching more potassium ions. It was observed that with the application of higher blade and the higher dose losses were higher K2O, an average 60.10 kg ha-1.
Mostrar más [+] Menos [-]INFLUÊNCIA DE DIFERENTES QUALIDADES DE ESGOTO DOMÉSTICO NA VAZÃO DE GOTEJADORES Texto completo
2011
RAFAEL OLIVEIRA BATISTA | ANTÔNIO ALVES SOARES | DÉBORA ASTONI MOREIRA | ALEX PINHEIRO FEITOSA | JOEL MEDEIROS BEZERRA
This paper aimed to analyze the flow rate drippers of three sets supplied with different qualities of domestic sewage from condominium Bosque Acamari in Viçosa-MG. The experiment was accomplished in experimental area of the Federal University of Viçosa (UFV), Viçosa-MG. Three sets of drip irrigation were mounted and supplied with preliminary sewage (EDP), secondary sewage (EDS) and tertiary sewage (EDT). Each irrigation set consisted of filter discs and non self-compensating emitters with nominal flow of 1.7 L h-1. The flow rate of drippers was obtained in 100 hours, totaling 500 hours of operation. Were accomplished physico- chemical and microbiological analysis in domestic sewage. Conclude that the presence of total coliforms and iron in domestic sewage confer severe risk of clogging the emitters. The chemical characteristics manganese, magnesium and calcium represent low risk of clogging the emitters. The EDP and EDT sewage caused high reductions in the emitter discharge in relation to EDS, due to higher concentration of suspended solids that interacted with the bacterial slimes.
Mostrar más [+] Menos [-]DESEMPENHO E VIABILIDADE ECONÔMICA DE NOVILHOS SUPLEMENTADOS NAS ÁGUAS MANTIDOS EM PASTAGEM DE CAPIM-MARANDU Texto completo
2011
CARLA HELOISA AVELINO CABRAL | MARISTELA OLIVEIRA BAUER | REGINA CÉLIA CARVALHO | CARLOS EDUARDO AVELINO CABRAL | WELTON BATISTA CABRAL
The aim of this paper was to evaluate economical viability and steers performance in grazing receiving supplements with increasing levels of crude protein in the rainy season and its correlation with the pasture's composition. The test animals were 21 not castrated steers supplemented with mineral supplement and multiple supplements with 20% and 40% of crude protein and heavy at the beginning and the end of the experiment, after being submitted to fasting from liquids and solids for 14 hours. For analysis of the economic viability was used the difference between the Total Revenue and Total Cost. The protein supplementation didn't influence of the animals performance in grazing. The average daily gain of animals was 0.849 kg. The content of crude protein in the cell wall was negatively correlated with animal performance, and the structural characteristics of the pasture just the mass of forage showed a strong and positive correlation. This activity in the studied period presented economic viability when considered return on capital of 8% a year.
Mostrar más [+] Menos [-]DESEMPENHO AGRONÔMICO DE CULTIVARES DE FEIJÃO-COMUM CONSORCIADO COM MAMONA Texto completo
2011
ITAMAR ROSA TEIXEIRA | GISELE CARNEIRO DA SILVA | PAULO CÉSAR TIMOSSI | ALESSANDRO GUERRA DA SILVA
In Brazil, especially in the state of Goiás, bean (Phaseolus vulgaris L.) are largely cropped in small and mean farms where the association beans+corn is predominant. The castor beans has draw the attention as a promising crop for biodiesel production, and being suggested by federal authorities as a primary choice in family run small farmer¿s agricultural projects. However, to attain that purpose, a careful selection of high yielding varieties is imperative. The objective was to assess the bean cultivars intercropped with castor bean in "Cerrado". The experimental design was a completely randomized block, in a 6 x 2 + 1 factorial, with four replications. Treatments comprised a combination of six cultivars of beans (Pérola, Pontal, Requinte, Grafite, Diamante Negro and Radiante) grown under two cropping systems (non-intercropped and intercropped castor bean), and the additional treatment of the castor beans non-intercropped. Bean cultivar Pérola yield best when intercropped as well as when single crop. Castor bean cultivar Paraguaçu performed similarly in both cropping systems. Bean yield decreased in the intercropping, but in the range of 38 to 71% was more efficient than in single crop.
Mostrar más [+] Menos [-]PARÂMETROS PRODUTIVOS E NUTRICIONAIS DO CAFEEIRO SUBMETIDO ADUBAÇÃO NITROGENADA NA REGIÃO DE GARANHUNS Texto completo
2011
MATHEUS PIRES QUINTELA | TONNY JOSÉ ARAÚJO SILVA | EDNA MARIA BOMFIM-SILVA | ENIO FARIAS FRANÇA SILVA | FELIZARDA VIANA BEBÉ
Among the factors that affect the production of coffee distinguishes itself by its high nitrogen demand. The aim of the current paper was to evaluate the productivity of coffee plants, the leaf N level critical stages of grain maturation and export of N, depending on the nitrogen, in order to optimize its recommendation. The experiment was performed in Garanhuns - PE, in a plantation crop. The experimental design was completely used with six treatments (0; 100; 200; 300; 400 and 500 kg ha-1 of N) and four replications. The productivity with the maximum economic efficiency was of 54 bags for hectare of benefited coffee for an application of 196.43 kg ha-1 of N, which represented a decrease of 41.85% in nitrogen. The critical nitrogen ranged from the filling phase to maturity, and their values, from 25.72 to 27.19 g kg-1 and 29.24 to 29.6 g kg-1. For a dose of 328.62 kg ha-1 of N, it was the largest export of this element by the fruit that was 204.31 kg ha-1 of N.
Mostrar más [+] Menos [-]MEDIÇÃO DE ÁREA FOLIAR DE ACEROLEIRA Texto completo
2011
RAFAELLA RAYANE MACEDO DE LUCENA | THAÍZA MABELLE DE VASCONCELOS BATISTA | JEFERSON LUIZ DOLLABONA DOMBROSKI | WELDER DE ARAÚJO RANGEL LOPES | GARDÊNIA SILVANA DE OLIVEIRA RODRIGUES
The determination of leaf area is of interest to producers and sectors of research, and techniques should be simple, quick and accurate. This study aimed to compare methods for estimating leaf area of Barbados cherry in orchard. 60 leaves were collected randomly, and after collection, were measurements of leaf area by five methods: squares, linear dimensions, leaf area integrator AM 300, leaf disks and Digital Image Analysis (Scanner). All methods were compared with the reference method (scanner), based on the criterion of determination coefficient of linear regression (R2). The method that is closer to the leaf area of reference was the integrator portable AM 300.
Mostrar más [+] Menos [-]