RESUMO Os ditiocarbamatos são os fungicidas mais utilizados e mais detectados em alimentos no Brasil. Este estudo teve como objetivos analisar os níveis de resíduos de ditiocarbamatos em hortaliças produzidas na região de Vargem Bonita, Distrito Federal, e comparar os níveis encontrados com os limites máximos de resíduos (LMR) estabelecidos para esses alimentos. Foram coletadas 84 amostras de diferentes tipos de hortaliças diretamente de 23 produtores no período de junho a novembro de 2018. As análises foram realizadas utilizando o método espectrofotométrico, que determina o nível de CS2 produzido pela degradação em meio ácido do ditiocarbamato presente na amostra. No total, 21 amostras (25%) continham resíduos de ditiocarbamatos acima do Limite de Quantificação do método (LOQ, 0,05 mg/kg CS2). Cinco das 27 amostras de alface analisadas (18,5%) continham resíduos, com níveis de 0,06 a 0,50 mg/kg de CS2, abaixo do LMR para essa cultura. Resíduos também foram encontrados em amostras de salsa, coentro e chicória, em níveis de 0,09 ou 0,10 mg/kg CS2, culturas para as quais não existe registro de uso de ditiocarbamatos no Brasil. Amostras de rúcula, cebolinha, alho poró e agrião, que também não possuem registro para ditiocarbamatos, deram resultado positivo, porém essas culturas são conhecidas por fornecerem resultados falso positivos para CS2, e a ilegalidade dos resíduos não pode ser confirmada. Esse estudo mostrou o uso adequado de ditiocarbamatos em hortaliças por agricultores da Vargem Bonita, com exceção de salsa, coentro e chicória, culturas com número limitado de pesticidas registrados, o que, provavelmente, tenha sido a razão do uso ilegal dos ditiocarbamatos.

ABSTRACT Dithiocarbamates are the most used fungicide and one of the most detected in food in Brazil. This study aims to analyze the levels of dithiocarbamate residues in vegetables produced in the region of Vargem Bonita, Federal District, and to compare the levels found with the maximum residue limits (MRLs) established by the Brazilian legislation. Eighty-four vegetable samples were obtained directly from 23 Vargem Bonita producers from June to November 2018. The analyzes were carried out using a spectrophotometric method, which determines the level of CS2 produced by degrading the dithiocarbamate present in the sample. In total, 21 samples (25%) contained dithiocarbamate residues above the method’s limit of quantification (LOQ, 0.05 mg/kg CS2). Five of the 27 lettuce samples analyzed (18.5%) contained dithiocarbamates, at levels ranging from 0.06 to 0.50 mg/kg CS2, below the MRL for this crop. Residues were also found in parsley, coriander and chicory samples (0.09 or 0.10 mg/kg CS2), cultures for which there is no registered the use of dithiocarbamate in Brazil. Samples of arugula, chive, leek, and watercress, which also do not have registered use, tested positive; however, these crops are known to provide false positive results for CS2, and the illegality of the residues cannot be confirmed. This study shows proper dithiocarbamate use in vegetables by Vargem Bonita farmers, except for parsley, coriander, and chicory, crops with a limited number of registered pesticides, which was probably the reason for the illegal dithiocarbamate use.

Abstract The use of tropical species in forest plantations is an alternative to supply the demand of good quality wood. However, information regarding the performance of planted tropical species is scarce. The aim of this study was to provide an assessment of the lumber potential of Cariniana legalis (“jequitibá-rosa”), Zeyheria tuberculosa (“ipê-felpudo”) and Cordia trichotoma (“louro-pardo”) in a forest plantation. Three trees per species were sampled at age of 50 months, planted in a mixed stand with 2 x 4 m spacing in Porto Seguro, Bahia, Brazil. We assessed characteristics of the trees, the logs, lumber yield, and partial volumetric shrinkage of wood. Total volumetric shrinkage of ipê-felpudo, jequitibá-rosa and louro-pardo would be around 12.80%, 13.40% and 11.58%, respectively. Among the three species analyzed, louro-pardo had the best performance, followed by ipê-felpudo, while jequitibá-rosa had the worst performance. All species had good performance regarding log quality and dimensional stability of wood.

RESUMO Entre as estratégias de Manejo Integrado de Pragas (MIP) estão os fatores que induzem a resistência da planta hospedeira. A adubação mineral com silício pode aumentar a resistência de plantas ao ataque de pragas. Este trabalho teve como objetivo avaliar o potencial da aplicação de silício no controle da traça-das-crucíferas (TDC), Plutella xylostella (Lepidoptera, Plutellidae), na cultura do repolho. O experimento foi conduzido na área de produção de hortaliças da Fazenda Água Limpa, Universidade de Brasília, Brasília-DF. O delineamento experimental foi em blocos ao acaso, com nove tratamentos e quatro repetições, totalizando 36 parcelas. Os tratamentos foram T1= aplicação foliar de Agrosilício® (10,5 % Si); T2= aplicação foliar de Sifol® (12% Si); T3= aplicação do inseticida deltametrina 25 g/L (Decis® 25 EC); T4= aplicação do bioinseticida Bacillus thuringiensis 33,60 g/L (Dipel®SC); T5= Agrosilício® (10,5% Si) + deltametrina 25 g/L (Decis® 25 EC); T6= Agrosilício® (10,5% Si) + Bacillus thuringiensis 33,60 g/L (Dipel®SC); T7= Sifol® (12% Si) + deltametrina 25 g/L (Decis® 25 EC); T8= Sifol® (12% Si) + Bacillus thuringiensis 33,60 g/L (Dipel®SC) e T9= tratamento controle. As aplicações de Agrosilicio® e Sifol® foram realizadas semanalmente via foliar. As aplicações dos produtos deltametrina e Bacillus thuringiensis foram realizadas quando se atingiu o nível de controle definido para a TDC na cultura do repolho. A aplicação de silício via foliar, isolada ou associada aos inseticidas químicos e biológicos, T2, T7 e T8, resultou na melhor estratégia de controle da TDC na cultura do repolho, com menor número de lagartas por planta, menor número de perfurações nas folhas e melhor avaliação estética das plantas de repolho. O uso do silício via foliar apresenta potencial como método auxiliar de manejo da TDC em repolho, seguindo-se as doses recomendadas pelos fabricantes.

ABSTRACT Integrated pest management (IPM) strategies are among the factors promoting plant resistance to pests, and silicon application may increase this resistance. Thus, the aim of this research was to evaluate the control of diamondback moth (DBM), Plutella xylostella (Lepidoptera, Plutellidae) through foliar application of silicon in cabbage crops. The experiment was conducted in the vegetable producing area of Água Limpa Farm, Universidade de Brasília, Distrito Federal, Brasil. The experimental design was of randomized blocks with nine treatments and four replicates, totaling 36 plots. The applied treatments consisted of Agrosilicon® (10.5% Si) (T1), Sifol® (12% Si) (T2), deltamethrin 25 g L-1 (Decis® 25 EC) (T3), Bacillus thuringiensis, 33.60 g L-1 (Dipel® SC) (T4), Agrosilicon® + deltamethrin 25 g L-1(Decis® 25 EC) (T5), Agrosilicon® + Bacillus thuringiensis, 33.60 g L-1 (Dipel® SC) (T6), Sifol® + deltamethrin 25 g L-1 (Decis® 25 EC) (T7), Sifol® + Bacillus thuringiensis, 33.60 g L-1 (Dipel® SC) (T8) and control (T9). Agrosilicon® and Sifol® were applied weekly and the products deltamethrin and Bacillus thuringiensis were applied according to the damage level established for DBM in cabbage crops. Foliar application of silicon, alone or in combination with chemical and biological insecticides - T2, T7 and T8, were the best strategy to control DBM in cabbage crops, resulting in the lowest number of caterpillars per plant, lowest leaf damages and best aesthetic value of plants. Silicon foliar application can be considered as an auxiliary method of DBM management in cabbage crops, followed by the doses recommended by the manufacturers.

RESUMEN Objetivo. Se realizaron dos experimentos en un beneficiadero en Brasil, dirigido a la evaluación de las lesiones en la piel de cerdo y la canal en la área de espera del beneficiadero y destinado a evaluar los efectos de glucosa (G), bicarbonato de sodio (SB) y vitamina E (VE) añadida al agua durante el ayuno antes de la masacre en el rendimiento de la canal, de órganos y la calidad de la carne. Materiales y métodos. En primer ensayo incluyó a 1.000 cerdos, observados en la zona de descanso del beneficiadero hasta la entrada en el área del aturdimiento. En el segundo ensayo se utilizaron 500 animales en el último día antes del beneficio, en un diseño experimental incluyendo diez repeticiones. Los tratamientos fueron: agua; 50 g/L G; 50 g/L G + 200 mg/L VE; 75 g/L G; 75 g/L G + 200 mg VE; 0.45% SB; 0.45% SB + 200 mg/L VE; 0.55% SB; 0.55% SB + 200 mg/L VE; 200 mg/L of VE. Resultados. Los rendimiento de la canal y de órganos no se vieron afectados por los tratamientos. La adición de 0.55 % SB + 200 mg VE redujo el pH final de la carne, y de 0.45 % SB reduce el valor de pigmento rojo. Conclusiones. Los principales casos de lesiones en la piel y la canal de cerdos se deben a peleas. La adición de los nutrientes en el agua de bebida no afectó a la carcasa, el rendimiento vísceras y calidad de la carne.

ABSTRACT Objective. Two experiments were conducted on a slaughterhouse located in Brazil, which the first aimed at evaluating the injuries on pig skin and carcass resulting from slaughterhouse waiting area management and the second aimed at assessing how glucose (G), sodium bicarbonate (SB) and vitamin E (VE) added to water during pre-slaughter fasting may affect carcass yield, organ relative weight and pork meat quality characteristics. Materials and methods. First trial included 1000 pigs, which were observed in the slaughterhouse resting area until the moment they entered the stunning process area. In the second trial were used 500 animals distributed on the last pre-slaughter day in a completely randomized design, including ten treatments and ten replicates. The treatments were: water; 50 g/L G; 50 g/L G + 200 mg/L of VE; 75 g/L of G; 75 g/L of G + 200 mg VE; 0.45% SB; 0.45% SB + 200 mg/L of VE; 0.55% SB; 0.55% SB + 200 mg/L of VE; 200 mg/L of VE. Results. Carcass yield and relative organ weight were not affected by treatments. The addition of 0.55% SB + 200 mg VE reduced the final pH of meat, and of 0.45% SB reduced the red pigment intensity. Conclusions. The main occurrences of injuries to the skin and carcass of pigs are due to fights. Also, adding glucose, sodium bicarbonate, and vitamin E to diet did not affect the carcass and viscera yield and meat quality.

RESUMO A oxidação da superfície da pirita é um problema sério na indústria de mineração, uma vez que diminui a sua hidrofobicidade dificultando a flotação desse mineral ou levando a um consumo elevado de coletor. Neste estudo, os produtos da reação entre os íons Fe2+ e HS-, formados na superfície da pirita oxidada e da hematita, foram estudados. As condições para a formação de uma camada hidrofóbica na superfície desses minerais também foram investigadas. Avaliou-se a influência do pH das soluções de hidrossulfeto de sódio (NaHS) para atingir uma condição de Eh-pH adequada para a formação de compostos de enxofre hidrofóbicos nas superfícies minerais. Medidas de ângulo de contato, difração de raios-X (DRX), microscopia eletrônica de varredura/espectroscopia de energia dispersiva (MEV/EDS) e espectroscopia Raman foram as técnicas analíticas empregadas para se verificar a natureza dos produtos formados na superfície desses minerais. Essas análises permitiram a identificação de cristais de enxofre elementar sobre a superfície da hematita e da pirita oxidada, após o condicionamento das amostras em meio redutor, e o melhor resultado foi obtido com condicionamento em pH 8,0 durante 96 horas com solução de NaHS 0,3 M para as duas amostras analisadas.

ABSTRACT The pyrite surface oxidation is a serious problem in the mining industry, since it decreases its hydrophobicity turning it difficult to float or leading to a high collector consumption. In this study, the products of the reaction between the Fe2+ and HS-, formed on the surface of oxidized pyrite and hematite, were studied. The conditions for the formation of a hydrophobic layer on the surface of these minerals were also investigated. The pH influence of sodium hydrosulphide (NaHS) solutions was evaluated in order to achieve a suitable Eh-pH condition for the formation of hydrophobic sulfur compounds on mineral surfaces. Measurements of contact angle, X-ray diffraction (XRD), scanning electron microscopy/dispersive energy spectroscopy (SEM/EDS) and Raman spectroscopy were the analytical techniques used to verify the nature of the products formed on the surface of those minerals. The formation of elemental sulfur crystals on the hematite and oxidized pyrite surfaces was identified after the conditioning in a reducing medium, and the best result was obtained at pH 8.0 during 96 hours with a 0.3 M NaHS solution for the two samples analyzed.

Abstract: INTRODUCTION Toxoplasmosis during pregnancy can be severe; thus, it is essential to diagnose the disease via serological tests. METHODS An enzyme-linked immunosorbent assay (ELISA) was used to investigate anti-Toxoplasma gondii immunoglobulin A (IgA), M (IgM) and G (IgG) antibodies in 62 high-risk pregnant women. RESULTS Forty-three (69.4%) women were positive for IgA, 31 (50%) for IgG, and 57 (91.9%) for IgM; 4 (6,5%) were positive for IgA but negative for IgM; 10 (16.1%) were negative for IgA and IgM but positive for IgG. CONCLUSIONS Testing for these antibodies can help diagnose infection in pregnant women, thereby contributing to clinical management.

RESUMO Com o objetivo de avaliar a produção e distribuição da biomassa da parte aérea de diferentes genótipos de pinhão-manso no semiárido brasileiro, foi implantado um experimento na Fazenda Gabriela, localizada no município de Santa Maria da Boa Vista, Pernambuco. O delineamento experimental adotado foi em blocos casualizados, com dez tratamentos (genótipos de pinhão-manso) e três repetições, em parcelas lineares de seis plantas, com bordadura simples e espaçamento de 3,0 x 2,0 m. Foram aplicadas uma adubação correspondente a 150 g de NPK (06:24:12) por cova no plantio e duas adubações de cobertura com 150 g.planta-1 de NPK (10:10:10) aos seis e aos doze meses de idade. As plantas foram irrigadas semanalmente por gotejamento com uma aplicação média de 20 litros de água por planta durante o período de estiagem da região. Aos 24 meses de idade, foi medida a altura total das plantas, o diâmetro médio das bifurcações a 1,30 m da superfície do solo e o número de bifurcações a 0,5 m de altura. Foram feitas 26 colheitas semanais de frutos/sementes. Os frutos foram colhidos maduros, antes de sua queda ao chão, durante sete meses. Os genótipos apresentaram elevada uniformidade agronômica, exceto para a variável número de bifurcações, onde o genótipo 1701 foi superior aos genótipos 1501, 1602, 1703 e 1601. A produção de biomassa dos genótipos em condições irrigadas no semiárido é elevada e a distribuição da biomassa dos genótipos nos diferentes componentes seguiu a ordem decrescente: raiz>frutos>galhos grossos>folhas>casca>galhos finos.

ABSTRACT In order to assess production and distribution of biomass shoots of different genotypes of Jatropha curcas under irrigation in the semiarid region of Pernambuco, Brazil, an experiment was established in Gabriela Farm, in the municipality of Santa Maria da Boa Vista-PE. The experimental design was randomized blocks with ten treatments (genotypes of Jatropha curcas), and three replications in row plots of six plants, with a single border and spacing of 3.0 x 2.0 m. Plants were fertilized with 150 g of NPK (06:24:12) at planting time, and a topdressing with 150 g.planta-1 NPK (10:10:10) applied at six and twelve months of age. The plants were irrigated weekly using a dripping system with an average water application of 20 l.plant-1 during the dry period of the region. At 24 months of age, the overall height of the plants, the average diameter of bifurcations at 1.30m from the soil level and the number of bifurcations at 0.5 m of height were evaluated. Twenty six fruit/ seed harvests were done weekly. Fruits were harvested ripe, before falling on the ground, for seven months. To determine dry biomass, the plants were cut at 0.30 m from soil level. The genotypes showed high agronomic uniformity, except for the variable number of bifurcations, where the genotype 1701 was superior to the genotypes 1501, 1602, 1703 and 1601. Biomass production of genotypes in irrigated conditions in the semiarid region is high and the distribution of biomass followed the decreasing order: root>fruit>thick branches>leaves>bark>thin branches.

RESUMO Objetivou-se, com este trabalho, propor e ajustar modelos matemáticos ao processo de secagem de espuma de graviola em diferentes condições de ar, determinar o coeficiente de difusão efetivo e obter a energia de ativação. Para a formação da espuma foi adicionada, à polpa, albumina, na concentração de 7,43% em massa e submetida à agitação em batedeira doméstica, durante 15 min; em seguida, esta foi espalhada sobre bandejas formando uma camada fina de cerca de 5,0 mm de espessura cujas condições de secagem foram: de 40, 50, 60, 70 e 80 °C, 5,6 m s-1 e 60%. O modelo para determinar o binômio teor de água crítico e tempo crítico e o de Midili se ajustaram bem aos dados experimentais da secagem de espuma de graviola e se obteve acréscimo no coeficiente de difusão efetiva com a elevação da temperatura de secagem e energia de ativação de 33,10 kJ mol-1.

ABSTRACT The aim of this paper was to propose and to adjust mathematical models for drying process of soursop foam in different air conditions, to determine the effective diffusion coefficient and to obtain the activation energy. For foaming, albumin was added to the pulp at concentration of 7.43% and stirred in mixer for 15 min. Then, it was spread onto trays forming a thin layer about 5.0 mm thick, and the drying conditions were: 40, 50, 60, 70 and 80 °C, 5.6 m s-1 and 60%. The model for determining the binomial critical water content and critical time, and the Midili model, adjusted well to the experimental data of soursop foam drying. Furthermore, an increase was obtained in the effective diffusion coefficient with increase in drying temperature and activation energy of 33.10 kJ mol-1.

Objetivou-se avaliar a influência de diferentes arranjos espaciais de árvores ((3×2)×20 m, (2×2)×9 m e 9×2 m) e locais de amostragem (centro e lateral da entrelinha) na quantidade e qualidade de luz no sub-bosque de sistemas silvipastoris e seus efeitos na produção e composição bromatológica da pastagem. O delineamento utilizado foi blocos casualizados em parcelas subdivididas, com três repetições. O local de amostragem influenciou a irradiância absoluta, a radiação fotossinteticamente ativa incidente (RFAi), interceptação luminosa (IL) e relação vermelho/vermelho distante, sendo determinados maiores valores no centro das entrelinhas. Observou-se correlações altas e positivas entre IL/índice de área foliar (IAF), IL/produção de massa seca (PMS) e IAF/PMS no centro e IL/IAF e RFAi/PMS na lateral das entrelinhas. O arranjos espaciais (3×2)×20 m apresentaram maiores valores para altura da planta (AP), PMS e teor de fibra em detergente neutro, enquanto o (2×2)×9 m apresentou maiores valores para relação folha:colmo e teor de proteína bruta. Quanto ao local de amostragem, os maiores valores de AP e PMS foram observados no centro. A composição da forragem não foi influenciada pelos locais de amostragem. A maior PMS foi obtida no arranjo (3×2)×20 m e melhorias na composição da forragem foram observados nos arranjos mais adensados.

The aim was to evaluate the influence of different spatial arrangements of trees [(3×2)×20 m, (2×2)×9 m and 2×9 m] and sampling sites (center of row spacing and side of tree rows) with regard to the amount and quality of light in the understory of silvopastoral systems and their effects on the production and chemical composition of pasture. The experimental design was a randomized block in a split plot, with three replications. The sampling site affected absolute irradiance, photosynthetic active radiation (PAR), light interception (LI) and red/far red ratio, with higher rates in the center of spacing. There were high and positive correlations between LI/leaf area index (LAI), LI/dry mater (DM) and LAI/DM in the center and LI/LAI and FAR/DM in the side of tree rows. Spatial arrangement (3×2)×20 m had higher rates for plant height (PH), DM and neutral detergent fiber rate, while (2×2)×9 m had high leaf/stem ratio and crude protein rate. In the case of the sampling site, higher rates of PH and DM were reported in the center. Forage composition was not affected by sampling sites. Highest production of DM was obtained in the (3×2)×20 m arrangement and improvements in forage composition were observed in denser arrangements.

An experiment was carried out to evaluate the performance, egg quality and morphometry of the reproductive tract, liver, pancreas and tongue of laying hens submitted to different molting methods. Two hundred and eighty eight 72-week-old Isa brown layers were distributed according to a completely randomized design with six treatments (molting methods) and six replicates of eight birds each. Layers were fed diets containing 3000 ppm zinc oxide, 60 ppm or 120 ppm nicarbazin, 30 ppm or 60 ppm salinomycin, or were submitted to feed fasting. Data were submitted to analysis of variance and means were compared by the test of Tukey at 5% probability level. Molting methods alternative to feed fasting were effective to induce molting in layer and provided good performance results in the second laying cycle.

O objetivo deste trabalho foi determinar o rendimento gravimétrico em taninos condensados nas cascas de Anadenanthera peregrina em diferentes classes diamétricas. Coletaram-se amostras de cinquenta e nove árvores de Anadenanthera peregrina, a 1,30 m do solo (Diâmetro a altura do peito - DAP), distribuídas em sete classes diamétricas. As cascas foram secas ao ar e trituradas em moinho de martelo. Foram realizadas amostragem composta para o preparo do extrato. A extração foi feita em água, na relação 15:1 (v/p), adicionados 3% de sulfito de sódio (v/v) em banho-maria a 70ºC por 4 horas. O material foi filtrado com emprego de coador de pano fino e concentrado em chapa de aquecimento a aproximadamente 150 g. Foi determinada a massa do extrato e retirados 10 g para a obtenção do teor de sólidos e 20g para a para o índice de Stiasny. Os valores médios de teor de sólidos totais, índice de Stiasny, teor de tanino condensado e teor de compostos não tânicos foram de 11,34%; 75,79%; 12,76% e 4,07%, respectivamente. O teor de sólidos, índice de Stiasny, teor de compostos não tânicos tiveram diferenças significativas entre as classes diamétricas. Já para a produção de taninos condensados, o parâmetro classe diamétrica não influenciou.

This work aimed to determine the gravimetric yield of condensed tannins in the Anadenanthera peregrina bark in different diameter classes. Fifty-nine trees samples were collected of Anadenanthera peregrina, at 1.30m of the ground (diameter at breast height - DBH), distributed in seven diameter classes. The barks were dried and crushed in mill of hammer. Composite sample was made to prepare the extract. The extraction was done using water in the ratio 15:1 (v/w), added 3% sodium sulfite (w/w) in water-bath at 70°C for 4 hours. The material was filtered using fine cloth strainer and concentrated on a heating plate at approximately 150 g. It was determined the extract mass and removed 10 g for obtaining solids content and 20g for the Stiasny's index. The average values of total solids content, Stiasny's index, condensed tannin content and the compound content non-tannin were 11.34%; 75.79%; 12.76% and 4.07%, respectively. The content of solids, Stiasny's index, compound content non-tannin show significant differences between diameter classes. For the condensed tannins production, the diameter class parameter there was no influence.

The objective of the present experiment was to compare the performance, egg quality and organ morphometrics of commercial layers submitted to alternative forced molting methods using dietary fibers. The experimental period included the phases of molting, rest, and second laying cycle (six periods of 28 days each). In the trial, 320 commercial Isa Brown layers with 72 weeks of age were distributed, according to a completely randomized experimental design into five treatments with eight replicates of eight birds each, totaling 40 experimental units. Molting was induced by feeding diets with the inclusion of alfalfa or soybean husks at 80% and 60% or feed fasting. Treatments were applied for 14 days. Performance and egg quality parameters were evaluated for the second laying cycle and organ morphometrics (liver, gizzard, proventriculus, reproductive apparatus) in two different slaughter dates. The obtained data were submitted to analysis of variance using the General Linear Model (GLM) procedure of SAS statistical package (SAS Institute, 2002). Alternative molting methods promoted similar performance and egg quality results after molting were similar to those obtained by the conventional fasting method. Feeding fiber produced the expected effects in terms of organ weight regression and recovery and may be used to induce molting in commercial layers.

An experiment was conducted to evaluate the biometrics of organs (ovary, oviduct, liver, proventriculus and gizzard) of laying hens submitted to different forced-molting methods of molt and maintained at three different temperature. Organs were evaluated after molting and resting period. Six hundred birds were distributed according to a completely randomized experimental design in a 5x3 factorial arrangement (forced-molting methods x environmental temperatures) into 15 treatments with 5 replicates of 8 birds each. The molting methods applied were the dietary inclusion of 90%, 70%, 50% of alfalfa, 2,800 ppm zinc oxide, or total feed restriction. Birds were kept at ±20 ºC, ±27 ºC, or ±35 ºC. Data were submitted to analysis of variance and means were compared by orthogonal and polynomial contrasts. The traditional forced-molting method (feed fasting) resulted in adequate performance. However, as the aim of the present study was to find an alternative method to feed fasting, the highest dietary alfafa inclusion level (90%) was shown to be efficient compared with other methods, particularly when hens were kept at high temperature. Therefore, this alternative forced-molting may be applied, especially when bird welfare is taken into consideration.

O objetivo deste trabalho foi determinar o efeito das relações N:K, aplicadas via fertirrigação, sobre a infestação do ácaro rajado, Tetranychus urticae, e a produtividade de duas cultivares de morangueiro sob cultivo protegido. As plantas receberam, via gotejamento, as seguintes doses referidas em gramas de N e K por planta por semana: 0,27 e 0,13; 0,27 e 0,50; 0,27 e 0,76 e testemunha (água+micronutrientes). Foram feitas 22 colheitas e avaliadas as características de produção, sendo os frutos classificados em comerciais e refugos. O estado nutricional das plantas foi avaliado com quatro análises foliares e as densidades populacionais do ácaro foram determinadas semanalmente. Houve interação significativa entre a cultivar Diamante e a maior dose de K, onde as maiores doses propiciaram redução nas densidades populacionais de ovos e formas ativas de T. urticae. Os elementos K e P apresentaram correlação negativa para ambas as variáveis, enquanto o N apresentou correlação positiva. Não houve efeito das adubações sobre as características de produção do morangueiro, provavelmente, por estarem associadas à elevada infestação do ácaro rajado (> 40 ácaros/folíolo) em todas as parcelas durante a maior parte do ciclo de cultivo. A simples manipulação das relações entre N e K no manejo da adubação, nas condições deste experimento, não garantiu o controle do ácaro rajado e nem a redução das perdas ocasionadas pelo mesmo.

The effect of N:K relationship was evaluated when applied through fertigation, on two-spotted-spider mite, Tetranychus urticae, infestation and on the yield of two strawberry cultivars. Strawberry plants received weekly doses of N and K (g/plant) by drip irrigation: 0.27 and 0.13; 0.27 and 0.50; 0.27 and 0.76 and control (water+micronutrients). Fruits were collected twenty two times during crop cycle. Marketable, non-marketable fruits and other yield parameters were evaluated. Leaf nutrient content analysis was performed to determine the nutritional condition of the plants. Population density of T. urticae was evaluated weekly. A significant interaction between K doses and pest population was observed. Higher doses of the nutrient reduced the number of eggs and active forms of the pest population and the cultivar Diamante showed the smallest pest density. K and P showed negative correlation with both variables, but N showed a positive one. No effects were observed of fertilization on yield parameters due, probably, to the high mite infestation (>40 individuals per leaflet) in all treatments during most of the crop cycle. Solely the use of different N:K ratios on the strawberry fertilization management at this specific experimental condition, was not sufficient to control two-spotted spider mite nor to reduce losses caused by that pest.

A utilização de barragens para diversos fins, tais como abastecimento e armazenamento de água, navegação, controle de cheias, irrigação e geração de energia elétrica, entre outros, resolve vários problemas, mas, infelizmente, cria muitos outros. A gestão da água não é uma tarefa simples, e a presença de barragens gera consequências sociais, físico-químicas, biológicas e ambientais. Entre os vários impactos associadosà implantação e operação de barragens, as questões relacionadas ao transporte e deposição de sedimentos são muito significativas, embora muitas vezes difíceis de avaliar. O objetivo deste trabalho é apresentar os resultados de estudos realizados próximo à barragem de uma pequena usina hidrelétrica localizada no Rio Paraibuna, na parte sudeste do Brasil. A granulometria dos sedimentos e sua caracterização química foram avaliadas antes e após uma descarga de fundo. Dois levantamentos batimétricos em uma seção de 1.6 km a montante da barragem foram também realizados, um logo antes e outro logo após a descarga de fundo, para avaliar a sua influência na batimetria do rio. Os resultados mostraram que, após a descarga pelo fundo, a quantidade de sedimentos finos a montante da barragem tornou-se menor. No que se refere à presença de metais pesados, os sedimentos de fundo coletados a montante e a jusante da barragem apresentaram, em diversas amostras, valores superiores ao limiar acima do qual efeitos adversos na biota são esperados, em particular para o cádmio, chumbo e zinco, em ordem de importância.

The utilization of dams for many purposes, such as water supply, navigation, flood control, irrigation, storage of water and generation of electricity, among others, solves several problems but unfortunately creates many others. Water management is not a simple task, and the presence of dams generates social, physical, chemical, biological and environmental consequences. Among these severe impacts associated to the implantation and operation of dams, the issues related to the transported and deposited sediments are very significant, although many times hard to evaluate. The objective of this paper is to present the results of studies performed close to the dam of a small hydro power plant located in the Paraibuna River, in the southeast part of Brazil. A grain size analysis of the sediments and its chemical characterization were evaluated before and after a bottom discharge. Two bathymetric surveys in a section of 1.6 km upstream the dam were also performed, one just before and other just after the bottom discharge, in order to evaluate its influence in the bathymetry of the river. The results showed that after the bottom discharge, the amount of muddy sediments upstream the dam became smaller. Regarding to the heavy metal content, the bottom sediments collected upstream and downstream the dam presented, in several samples, values higher than the threshold above which a probable adverse effect on the biota is expected, in particular for cadmium, chromium and zinc, in order of importance.