ABSTRACT. Citrus represents one of the main fruit crops grown in the world, highlighting the ‘Tahiti’ acid lime tree. The objective was to compare rootstock varieties combined with this scion to identify those with the best agronomic performance and precocity of production, in addition to Phytophthora gummosis resistance. The experiment was carried out in Capitão Poço, northeast region of Pará, and the following seven rootstock genotypes were evaluated: ‘Sunki Tropical’, ‘BRS O S Passos’, ‘BRS Bravo’, ‘BRS Donadio’, ‘Citrandarin Indio’, ‘BRS Matta’, and ‘LVK x LCR-038’. A randomized block experimental design was used, with three replications and 10 plants per plot. The evaluated characteristics were: plant height (m); crown volume (m3); number of ripe fruit per plant; total yield of ripened fruit per plant (kg plant-1); cumulative fruit yield (fruit kg plant-1); and average productive efficiency (fruit kg m-3 of crown). The average productive efficiency was high. For early selection, the best rootstocks in terms of yield, stability and adaptability were Sunki Tropical, BRS O S Passos, and Cintradarin Indio. The fruit number had the greatest direct effect on fruit yield, and crown pruning was directly harmful. Further studies to understand the complex interaction of G x E for BRS Donadio and Sunki Tropical should be carried out. ABSTRACT world ‘Tahiti Tahiti tree production resistance Poço Pará , Tropical’ Passos Passos’ Bravo, Bravo Bravo’ Donadio, Donadio’ Citrandarin Indio, Indio Indio’ Matta, Matta Matta’ LVK LCR038. LCR038 LCR 038 . LCR-038’ used 1 plot m (m) m3 (m3) plant1 plant-1) 3 m- crown. crown) high selection harmful LCR03 03 LCR-038 (m (m3 plant-1 LCR0 0 LCR-03 plant- LCR-0 LCR-

ABSTRACT This research aimed to evaluate the effect of thinning on the wood volumes per hectare on the tannin content in the bark of Mimosa caesalpiniifolia. The planting was subdivided into two plots, one thinned at 12 and 55 months of age (T1), while the other plot was kept intact (T2). The dendrometric variables were measured, and ten trees were felled, five in each plot. Subsequently, wood and bark’s volume, mass, and moisture content were determined. Then, the total solids content (TST), the Stiasny index (I), and the condensed tannin content (TTC) were quantified. Dry wood productivity was statistically different between the two treatments, with values of 26.7 and 22.8 t ha-1 for T1 and T2, respectively. The percentage of dry bark corresponded to 16% of the total biomass for both treatments. The only variable that showed a significant difference was I, with values with and without thinning, 59.83 and 79.31%, respectively. Therefore, it was verified that the way the thinning was used changed the I and how they were conducted, favoring the emission of boles and increasing the frequency in the lower diametric classes instead of favoring the increase in DBH. It is concluded that thinning interferes with the biomass volumes and the Stiasny index of M. caesalpiniifolia. However, it does not alter the concentration of tannins present in the species’ bark. caesalpiniifolia plots 1 5 T1, T , (T1) T2. T2 . (T2) measured felled Subsequently barks s volume mass determined Then TST, TST (TST) (I) TTC (TTC quantified treatments 267 26 7 26. 228 22 8 22. ha1 ha ha- respectively 16 5983 59 83 59.8 7931 79 31 79.31% Therefore conducted DBH M However species (T1 (T2 (TST (I 2 598 59. 793 3 79.31 (T 79.3 79.

RESUMO Este trabalho teve por objetivo avaliar o efeito do desbaste sobre os volumes de madeira por hectare e no teor de taninos na casca de Mimosa caesalpiniifolia. O plantio foi subdividido em duas parcelas, uma que sofreu desbaste aos 12 e aos 55 meses de idade (T1), enquanto a outra foi mantida intacta (T2). Foram realizadas medições das variáveis dendrométricas e, em seguida, abatidas dez árvores, sendo cinco em cada uma das parcelas. Posteriormente, determinou-se o volume, a massa e o teor de umidade, da madeira e da casca. Em seguida, foi quantificado o teor de sólidos totais (TST), o índice de Stiasny (I) e o teor de taninos condensados (TTC) na casca. A produtividade de madeira seca foi estatisticamente diferente entre os dois tratamentos com valores de 26,7 e 22,8 t ha-1 para T1 e T2, respectivamente. A porcentagem de casca seca correspondeu a 16% da biomassa total para ambos os tratamentos. A única variável que apresentou diferença significativa foi o I, sendo os valores com e sem desbaste de 59,83 e 79,31%, respectivamente. Portanto, verificou-se que a forma em que o desbaste foi empregado altera o I e a massa de madeira seca, porém não alterou a concentração de taninos presentes na casca da espécie. caesalpiniifolia parcelas 1 5 T1, T , (T1) T2. T2 . (T2) seguida árvores Posteriormente determinouse determinou se volume umidade TST, TST (TST) (I TTC (TTC 267 26 7 26, 228 22 8 22, ha1 ha ha- respectivamente 16 5983 59 83 59,8 7931 79 31 79,31% Portanto verificouse verificou espécie (T1 (T2 (TST 2 598 59, 793 3 79,31 (T 79,3 79,

ABSTRACT In recent years the immunomodulatory actions of vitamin D, a steroid hormone, have been extensively studied. In 2020, due to the COVID-19 pandemic, the question arose as to 25(OH)D status would be related to susceptibility to SARS-CoV-2 infection, since several studies pointed out a higher prevalence and severity of the disease in populations with low levels of 25(OH)D. Thus, we investigated the 25(OH)D levels in adults “Detected” positive for SARS CoV-2 by RT-PCR (reverse transcriptase polymerase chain reaction) test, and in negative controls, “not Detected”, using the Fleury Group's examination database, in Sao Paulo, Brazil. Of a total of 14.692 people with recent assessments of 25(OH)D and RT-PCR tests for COVID-19, 2.345 were positive and 11.585 were negative for the infection. The groups did not differ in the percentage of men and women, or in the age distribution. There were no differences in the distribution of 25(OH)D between the two groups (p = 0.08); mean 25(OH)D of 28.8 ± 21.4 ng/mL and 29.6 ± 18.1 ng/mL, respectively. In the specific population studied, clinical, environmental, socioeconomic and cultural factors should have greater relevance than 25(OH)D in determining the susceptibility to COVID-19.

Abstract Cordia trichotoma is a Brazilian species that has been studied for different forest systems. However, genetic breeding programs could highly improve species use. To obtain a better yield, it is essential to identify the species genotypes with superior performance. Thus, the work objective of this work was to estimate genetic divergence in two C. trichotoma progenies tests based on phenotypic traits. The experimental design adopted was the randomized blocks, one plant per plot, using 40 (area one) and 34 (area two) repetitions, using 3.0 m × 3.0 m spacing. The evaluated traits were diameter at 1.30 m above the soil (DBH-cm), total height (HT-m), collar diameter at 30 cm above the ground (DC-cm), and height of the first whorl (HFW-cm). The estimate of genetic divergence and the Tocher clustering method was performed using the REML / BLUP method. The genetic distances between the progenies in area 1 were 2.13 and 47.74 (17 and 15). In area two the genetic distances between the progenies were 3.64 (9 and 15) and 48.28 (12 and 7). The progenies formed 10 and 4 distinct groups, respectively, in area 1 and area 2). The traits that most contributed to genetic divergence were DBH-2016 (14.65%) in area one, and HT-2014 (14.32%) in area two. In sumary, the C. trichotoma progenies show high genetic divergence. Regarding breeding programs, it is recommended to cross progenies from the most divergent groups to heighten the genetic gain through the selection of more productive genotypes.

Resumen Cordia trichotoma es una especie nativa que está siendo evaluada para diferentes sistemas forestales. El hecho de que los individuos empleados en las plantaciones posean algún grado de mejoramiento genético tiene muchas ventajas; para lograr este mejoramiento es fundamental la obtención de genotipos superiores, a fin de obtener un mejor rendimiento del producto final. El objetivo del presente estudio fue estimar la divergencia genética de progenies de C. trichotoma en dos diferentes condiciones de textura de suelo, por medio de caracteres fenotípicos. El diseño experimental fue bloques completos al azar, un árbol por parcela con 40 (área 1) y 34 (área 2) repeticiones, con espaciamiento de 3,0 m × 3,0 m. Los caracteres evaluados fueron: diámetro a altura del pecho, altura total de plantas, diámetro de cuello y altura del primer verticilo. Para estimar la divergencia genética y el agrupamiento de Tocher fue utilizado el método REML/BLUP. Las distancias entre las progenies en el área 1 fueron de 2,13 y 47,74 (17 y 15), en el área 2 las distancias entre las progenies fueron de 3,64 (9 y 15) y 48,28 (12 y 7). Las progenies formaron diez y cuatro grupos distintos (área 1 y área 2). Los caracteres que más contribuyeron para divergencia genética fueron diámetro a la altura del pecho-2016 (14,65%) área 1, y altura total de plantas-2014 (14,32%) área 2. Las progenies de C. trichotoma presentaron alta divergencia genética. En programas de mejoramiento, se recomienda el cruzamiento entre progenies de los grupos más divergentes para priorizar la ganancia con selección de los genotipos más productivos.

Resumen La diversidad de macro-invertebrados está relacionada con el estado de conservación del suelo, no obstante, la remoción de la cubierta vegetal natural para el establecimiento de sistemas ganaderos extensivos afecta su integridad. Una estrategia para la conservación de estos organismos es la implementación de sistemas silvopastoriles; no obstante, en el sureste de México la información aún es limitada. El propósito del presente estudio fue evaluar y comparar la riqueza y la abundancia de macro-invertebrados en cuatro agro-ecosistemas contrastantes: dos sistemas silvopastoriles conformados por Leucaena leucocephala y pastos asociados (i.e. Panicum máximum cv mombaza y Cynodon plectostachyus), un pastizal convencional de Brachiaria brizantha con árboles dispersos en baja densidad y una selva mediana subperennifolia. En cada sistema se delimitó una superficie de una hectárea y se estableció un transecto de 50 m de longitud en los que se colocaron cinco trampas de caída tipo pit-fall cada 10 m. El muestreo se realizó en febrero y mayo 2018 y en cada mes se realizaron cinco recolectas con intervalos de cinco días. Se recolectaron un total de 1 737 organismos pertenecientes a 10 órdenes de la clase Insecta y uno a la clase Gastropoda. Los sistemas con mayor abundancia de macro-invertebrados fueron el sistema de selva media subperennifolia (923 individuos) y el sistema silvopastoril de L. leucocephala con C. plectostachyus (354 individuos). Los órdenes más abundantes fueron: Hymenoptera, Coleoptera, Araneae y Orthoptera. La mayor diversidad de macro-invertebrados se presentó en los sistemas silvopastoriles de L. leucocephala con P. maximum (H’=1.58) y L. leucocephala con C. plectostachyus (H´=1.44). Los resultados encontrados muestran que los sistemas pecuarios manejados con componentes leñosos (árboles/arbustos) albergan una riqueza y abundancia importante de órdenes de macro-invertebrados en comparación con sistemas como selva mediana subperennifolia. Esta diversidad de macro-invertebrates podría contribuir a la integridad y funcionalidad de los agro-ecosistemas.

Abstract The diversity of macro-invertebrates is related to the state of disturbance of the soil, caused mainly by the land-use change for agricultural activities. A strategy for the conservation of these organisms is the implementation of diversified production systems such as silvopastoral systems. However, in the Southeast of Mexico, information is still limited. The aim of the present study was to evaluate and compare the richness, abundance and composition of macro-invertebrates in four contrasting agro-ecosystems: two silvopastoral systems made of Leucaena leucocephala and associated pastures (i.e. Panicum maximum cv mombaza and Cynodon plectostachyus), a pasture of Brachiaria brizantha with scattered trees in low density and, a medium-statured tropical dry forest. In each system, an area of one hectare was delimited and a transect of 50 m in length was established in which five pit-fall traps were placed every 10 m. The sampling was carried out in February and May of 2018 and in each month five collections were made with five-day intervals. A total of 1 737 organisms belonging to 10 orders of the class Insecta and one of the class Gastropoda were collected. The medium-statured tropical dry forest (923 individuals) and the silvopastoral systems of L. leucocephala with C. Plectostachyus (354 individuals) show the highest abundance of macro-invertebrates. The most abundant genera were: Hymenoptera, Coleoptera, Aracninae and Orthoptera. The higher macro-invertebrate diversity was found in the silvopastoral systems of L. leucocephala with P. maximum (H '= 1.58) and L. leucocephala with C. plectostachyus (H' = 1.44). The results show that livestock systems managed with woody components (trees or shrubs) are home of an important abundance and richness of macro-invertebrates, compared to tropical forests. This diversity of macro-invertebrates may contribute to the integrity and functionality of the agro-ecosystems.

OBJETIVO: O presente trabalho teve por objetivo elucidar se as variáveis físicas e químicas da água, de um riacho de primeira ordem da Reserva Biológica de Saltinho do sul de Pernambuco atuam na distribuição e abundância dos macroinvertebrados bentônicos. MÉTODOS: Sabe-se que tanto as variáveis limnológicas (pH, condutividade, temperatura, turbidez, salinidade e oxigênio dissolvido) quanto as variáveis estruturais do habitat aquático (substrato, disponibilidade de alimento e velocidade do fluxo) influenciam na estrutura da comunidade de macroinvertebrados. O riacho é muito pequeno com largura aproximada de 1-3 m e profundidade de 0,5 m. Foi utilizado um amostrador tipo Surber (100 mm) em três trechos do riacho, cada um com duas unidades amostrais (u.a.) totalizando seis u.a. distantes 50 m, com um esforço amostral de cinco minutos por u.a.; as variáveis da água foram coletadas com o auxílio do medidor multiparâmetro de qualidade da água. RESULTADOS: Dos 11 táxons encontrados nenhum exibiu correlação significativa (p<0,05) com pH, temperatura e salinidade, mas alguns táxons apresentaram com as outras variáveis. Hemiptera aumenta a abundância com o decréscimo de oxigênio dissolvido (OD); Ostracoda aumenta com o acréscimo da condutividade elétrica (CE), turbidez (TB) e o decréscimo do OD; e Trichoptera aumenta com a diminuição da CE e TB e com o aumento do OD. Cada trecho exibiu similaridade em relação à riqueza e abundância dos táxons e às variáveis limnológicas. A distribuição dos táxons no riacho não apresentou o mesmo padrão, agrupando as u.a de trechos distintos, devido às variáveis estruturais do habitat. CONCLUSÕES: Assim, a comunidade de macroinvertebrados variou de acordo com as variáveis abióticas nos diferentes parâmetros estruturais e limnológicos. Este estudo é o primeiro registro de um trabalho associando fauna bentônica e variáveis abióticas na mata atlântica em Pernambuco.

AIM: The present study aimed to elucidate if the water physical and chemical parameters from a first order stream of Biological Reserve of Saltinho from south Pernambuco induces in the distribution and abundance of benthic macroinvertebrates. METHODS: Both limnological parameters (pH-value, electrical conductivity, water temperature, turbidity, salinity and dissolved oxygen) and structural variables of aquatic habitat (substrate, food availability and flow velocity) influence the macroinvertebrates community structure. The creek is very small, with an approximate width of 1-3 m and a depth of 0.5 m. It was used a Surber sampler (100 mm) in three stretch of the creek, each one with two sampling units (s.u.) totaling six s.u. distant 50 m, with a sampling effort of five minutes per s.u.. The measurer multiparameter was used in order to obtain the water analysis (limnological parameters). RESULTS: From 11 taxa of macroinvertebrates found no significant correlation (p<0.05) was presented with pH-value, water temperature and salinity, but some taxa showed with electrical conductivity (EC), turbidity (TD) and dissolved oxygen (DO). Hemiptera abundance increases with decreasing DO; Ostracoda abundance increases with increasing EC and TD and the decrease in DO; and Trichoptera abundance increases with the decrease in EC and TD and the increase in DO. The stretches exhibited similarity in relation to the richness and abundance of macroinvertebrates and limnological parameters. The macroinvertebrates distribution in the stream not showed the same pattern, grouping s.u. of different stretch, because the habitat structural variables influenced the distribution. CONCLUSIONS: Therefore, the macroinvertebrates community varies according to abiotic factors in different limnological and structural parameters. This study is the first record of a work that associates benthic fauna and abiotic parameters at the Atlantic forest of Pernambuco.

O pisoteio de bovinos em áreas de lavouras pode agravar a compactação do solo, entretanto as informações sobre esse problema são limitadas. Este trabalho teve por objetivo avaliar algumas características físicas de solo em LVd típico, em Coxilha (RS), após dez anos de estabelecimento de seis sistemas de produção integração lavoura-pecuária. Os tratamentos foram distribuídos em blocos ao acaso com quatro repetições. Foram avaliados também os atributos físicos do solo de um fragmento de floresta subtropical adjacente ao experimento. As culturas, tanto as de inverno como as de verão foram manejadas com sistema plantio direto. Foram comparados os sistemas e os valores dos atributos físicos do solo em cada sistema nas camadas de 0,0-0,05 m ou de 0,0-0,02 m e de 0,10-0,15 m. A densidade de solo e resistência à penetração aumentaram da camada de 0,0-0,05 m ou 0,0-0,02 m para a camada de 0,10-0,15 m. A floresta subtropical, nas camadas de 0,0-0,05 m ou de 0,0-0,02 m e de 0,10-0,15 m, teve menor densidade de solo e resistência à penetração e maior porosidade total e macroporosidade do que a maior parte dos sistemas de produção estudados. Nos solos sob diferentes sistemas de produção integrando lavoura-pecuária, apesar de haver indícios de compactação, esta não atingiu níveis considerados críticos ao desenvolvimento dos cultivos, embora o sistema trigo/soja e pastagem de aveia preta + ervilhaca + azevém/pastagem de milheto tenha mostrado os valores de atributos físicos menos favoráveis às plantas.

Even though raising cattle at crop fields can increase soil compaction, there is scarce information on this problem. This study aimed to evaluate some physical characteristics of soil in a typical Dystrophic Red Latosol (typical dystrophic Hapludox) in the county of Coxilha, State of Rio Grande do Sul, Brazil, after ten years of establishment of six ley farm production systems. The treatments were arranged in blocks with four replications. We also evaluated the fertility of the soil of a subtropical forest fragment adjacent to the experiment. Both winter and summer crops were established under no-tillage. Cropping systems and soil of different sampling depths were compared using the orthogonal contrast procedure. We compared the systems and values of the physical characteristics of soil in each system in the layers of 0.0-0.05 m or 0-0.02 m and also 0.10-0.15 m. Soil bulk density and penetration resistance were lower in the layer of 0-0.05 m or 0-0.02 m. The subtropical forest showed highest soil bulk density and soil penetration resistance and lowest total porosity and macroporosity than most systems studied. The soils under different ley farm production systems, despite showing signs of degradation, did not reach levels considered critical to the development of crops. The system wheat/soybean and black oat + vetch + rye grass/pearl millet pasture (IV) presented the worst physical attributes to plant development.

A diversidade de espécies de vespas sociais associadas à vegetação de cerrado no Oeste da Bahia foi analisada neste estudo. Dentre as dezenove espécies de vespas sociais encontradas, Chartergus globiventris de Saussure, Chartergellus communis Richards e Metapolybia cingulata (Fabricius) são registradas pela primeira vez para o estado. O cerrado arbóreo, apesar de apresentar maior riqueza (S = 19) e maior diversidade de espécies (H' = 2,33), apresentou níveis de abundância (N = 87 ninhos) inferiores aos sistemas agrícolas (N = 107 ninhos; S = 8 espécies; H' = 1,84). A fisionomia de cerrado campo sujo apresentou a menor abundância de colônias de vespas sociais (N = 61) e valores intermediários de riqueza (S = 13) e diversidade (H' = 2,20).

This study aimed to analyze the social wasps species diversity in a cerrado vegetation at the west region of the State of Bahia. Nineteen species of social wasps were found, with Chartergus globiventris de Saussure, Chartergellus communis Richards and Metapolybia cingulata (Fabricius) being recorded for the first time for the State of Bahia. The arboreous cerrado showed a higher species richness (S = 19) and diversity (H' = 2,33) than the agroecossistems (farms) (S = 8; H' = 1,84). However, nest abundance was higher at the agroecossystems (N = 107 nests) than at the arboreous cerrado (N = 87 nests). The physiognomy of "cerrado campo sujo" showed the lowest abundance of social wasps colonies (N = 61 nests) and intermediate values of species richness (S = 13) and diversity (H' = 2,20).

This paper presents a simulation of electricity production from several small wind turbines in the wind regime of Olinda-PE-Brazil, taking into account a number of records wind speeds and temperature in 1998, with the aim of developing a performance analysis tool that allows its selection. The hourly wind speed data were discretized at appropriate intervals to allow better handling of the information contained in the curves of electricity, supplied by manufacturers. The tool allows a comparative analysis of the performance of wind turbines, both in the aspect of the electrical energy production as its efficiency in function of wind speed. The results show that of the local wind regime influenced the production of electricity and that the data provided by manufacturers must be certified.

Este trabajo se presenta la simulación de la producción de electricidad a partir de varios aerogeneradores de pequeño tamaño, en el régimen de vientos de Olinda-Pernambuco-Brasil, teniendo en cuenta una serie de registros de velocidades del viento y la temperatura en 1998. Los datos de velocidad de viento fueron discretizados a intervalos apropiados para permitir una mejor manipulación de la información contenida en las curvas de energía eléctrica, suministradas por los fabricantes. La herramienta permite realizar un análisis comparativo del rendimiento de aerogeneradores, tanto en el aspecto de la producción de energía generada de cada aerogenerador como de los rendimientos en función de la velocidad del viento. Los resultados muestran que el sistema de los vientos locales influyó en la producción de electricidad y que los datos facilitados por los fabricantes deben ser certificados.

A compreensão e a quantificação do impacto do uso e manejo do solo na qualidade física são fundamentais no desenvolvimento de sistemas agrícolas sustentáveis. Com o objetivo de avaliar o efeito de sistemas de manejo de solo e de rotação de culturas sobre alguns atributos físicos de solo em um experimento instalado em 1985, em Latossolo Vermelho Distrófico típico argiloso, em Passo Fundo (RS), estudou-se a variação desses atributos entre 2001 e 2005. Os tratamentos consistiram de quatro modos de manejo de solo: 1) plantio direto (PD); 2) cultivo mínimo (CM); 3) preparo convencional de solo com arado e grade de discos (PCD) e 4) preparo convencional de solo com arado de aivecas e grade de discos (PCA), e três sistemas de rotação de culturas: I (trigo/soja), II (trigo/soja e ervilhaca/milho ou sorgo) e III (trigo/soja, aveia branca/soja e ervilhaca/milho ou sorgo). O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. A parcela foi constituída pelos sistemas de manejo de solo, e as subparcelas, pelos sistemas de rotação de culturas. Amostras de solo também foram coletadas em um fragmento de floresta subtropical adjacente ao experimento, como testemunha da condição original do solo. Os sistemas de manejo e de rotação de culturas influenciaram os atributos físicos do solo quando comparados entre si e com a condição sob floresta subtropical. Em quatro anos (2001 a 2005) ocorreram alterações significativas nos atributos físicos dos solos entre os distintos tipos de manejo. No sistema PD houve maior densidade de solo e microporosidade em comparação aos demais, principalmente na camada subsuperficial, e os sistemas de rotação de plantas não afetaram positivamente os atributos físicos de solo independentemente do tipo de manejo.

Evaluation and quantification of soil use impact on its physical quality are important to achieve sustainable cropping systems. Soil physical attributes were assessed after twenty years of implementation (1985 to 2005) on a typical Dystrophic Red Latosol (Rodic Hapludox) located in Passo Fundo, Rio Grande do Sul State, Brazil. Four soil tillage systems were evaluated: 1) no-tillage; 2) minimum tillage; 3) conventional tillage using a disk plow plus disk harrow, and 4) conventional tillage using a moldboard plow plus disk harrow. Three crop rotation systems were evaluated: I (wheat/soybean), II (wheat/soybean and common vetch/corn or sorghum), and III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean). A randomized complete block design, with split-plots and three replicates, was used. The main plots were formed by the soil tillage systems, while split-plots were composed by crop rotation systems. As control, soil samples were collected in a subtropical forest fragment adjacent to the experiment. Soil tillage systems and crop rotation systems influenced soil physical parameters when compared to the samples collected in a fragment of subtropical forest. During four years (2001 to 2005) the physical attributes were altered among different soil tillage management. The no-tillage system (PD) presented higher soil bulk density and microporosity in comparison to the other systems, mainly in 0.10 to 0.15 m layer, characterizing high soil compaction levels. Crop systems did not promote favorable changes in physical attributes independent of the type of soil management.

No Brasil, ainda são escassos os estudos disponíveis com experimentos de longa duração em sistemas de manejo de solo e de rotação de culturas. Após vinte anos (1985 a 2005), a fertilidade de solo foi avaliada, em Latossolo Vermelho distrófico típico, em Passo Fundo (RS), em quatro sistemas de manejo de solo (SMSs) - 1) plantio direto (PD), 2) cultivo mínimo (CM), 3) preparo convencional de solo com arado de discos e com grade de discos (PCD) e 4) preparo convencional de solo com arado de aivecas e com grade de discos (PCA) - e em três sistemas de rotação de culturas (SRCs): I (trigo/soja), II (trigo/soja e ervilhaca/milho) e III (trigo/soja, ervilhaca/milho e aveia branca/soja), incluindo como testemunha um fragmento adjacente de floresta subtropical (FST). O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. As parcelas (4 x 90 m) no total de 12, foram constituídas pelos SMSs, e as subparcelas, pelos SRCs (4 x 10 m), no total de 72. Os valores de pH, carbono, P extraível e K disponível diferiram entre os SMSs. No PD, houve acúmulo de carbono orgânico, P e K, na camada superficial. Não houve diferença do nível de matéria orgânica (MOS) entre PD e FST, em todas as camadas estudadas. O nível de MOS e os teores de P e K foram mais elevados na camada 0-0,05 m, quando comparados com os observados de 0,15-0,20 m de profundidade, sob PD e nas rotações II e III. Observou-se que em FST os valores de pH, Ca, P e de K foram menores do que os dos SMSs e SRCs.

Long term field studies on crop rotation and soil tillage systems under Brazilian conditions are scarce. Soil fertility characteristics were assessed after twenty years (1985 to 2005) on a typical dystrophic Red Latosol located in Passo Fundo, in Rio Grande do Sul, the southernmost state of Brazil. Four soil tillage systems (STS) - 1) no-tillage, 2) minimum tillage, 3) conventional tillage using disk plow followed by disk harrow, and 4) conventional tillage using moldboard plow followed by disk harrow - and three crop rotation systems (CRS): I (wheat/soybean), II (wheat/soybean and common vetch/corn), and III (wheat/soybean, common vetch/corn, and white oat/soybean) were evaluated, including as check a fragment of subtropical forest (FST). A randomized complete block design, with split-plots and three replicates, was used. The main field plots (4 x 90 m) in a total of 12, were the soil tillage systems, whereas the subplots (4 x 10 m), in a total of 72 comprised the crop rotation systems. Values of soil pH, soil organic carbon, extractable P, and exchangeable K were affected by soil tillage systems (STSs). Higher levels of soil organic matter and contents of soil carbon, extractable P, and exchangeable K were observed in the 0-0,05 m layer for the no-tillage system. No statistical differences were found in soil organic matter levels between no-tillage and tropical forest, in any soil layer. Values of soil organic matter, P, and K were higher in the 0-0,05 m layer, when compared to the ones observed in the 0,15-0,20 m layer, in no-tillage and II and III CRSs. Values of pH, Ca, P, and K observed in all STSs and CRSs were higher than in the tropical forest area.

Com o presente trabalho, avalia-se a produção de milho verde e grão em cultivo orgânico e a massa de leguminosa no consórcio milho, feijão-de-porco, em duas épocas de cultivo. Foram realizados dois experimentos de campo, em Viçosa (MG), no período de outono/inverno e de primavera/verão. O milho e o feijão-de-porco foram semeados simultaneamente na mesma linha, espaçadas de 1m. Os tratamentos foram as densidades de feijão-de-porco, 0, 2, 4 e 6 plantas m-1 e as duas épocas de cultivo, no esquema fatorial 4 x 2, utilizando-se o delineamento de blocos casualizados, com quatro repetições. A produção de milho foi influenciada somente pela época do ano, atingindo 7,26 e 9,64 Mg ha-1 de milho verde e 5,01 e 7,46 Mg ha-1 de grãos nos cultivos de outono/inverno e primavera/verão, respectivamente. Houve efeito significativo da densidade de plantas, da época de amostragem e da época de cultivo sobre a produção de massa do adubo verde. A maior produção de biomassa de feijão-de-porco (5,07 Mg ha-1) foi obtida no final do ciclo do milho no cultivo de outono/inverno, com 4,8 plantas m-1. No cultivo de primavera/verão a produção máxima (2,95 Mg ha-1) foi obtida com 6 plantas m-1 também no final do ciclo da cultura do milho. Conclui-se que a produção de milho em cultivo orgânico não é prejudicada pela consorciação com feijão-de-porco.

This work evaluates the yield of fresh and grain corn in organic system and the leguminous mass in the intercropping corn, jack beans, in two cropping seasons. Two field experiments were carried out in Viçosa (MG), on Autumn/Winter and Spring/Summer. Corn and jack beans were sown simultaneously in the same rows 1 m apart. The treatments were the jack beans density (0, 2, 4 or 6 plants m-1) and the two cropping season, arranged in a 4 x 2 factorial design and randomized blocks with four repetitions. The corn yield was influenced only by cropping season, reaching 7.26 and 9.64 Mg ha-1 of fresh and grain corn in Autumn/Winter season and 5.01 and 7.46 Mg ha-1 of fresh and grain corn in the Spring/Summer season. It was verified a significative effect of both plant density, sampling date and cropping season on the green manure mass production. The highest jack beans biomass yield (5.07 Mg ha-1) was obtained at corn grain harvest stage on Autumn/Winter season, at 4.8 plants m-1. On the Spring/Winter season the highest yield (2.95 Mg ha-1) was achieved with 6 plants m-1also at corn grain harvest stage. It is concluded that the organic production of corn was not affected by the intercropping with jack beans.

In the present paper the authors describe and illustrate a new species of proteocephalidean cestode, Monticellia belavistensis, sp.n., parasite of a freshwater siluriform fish (thorny catfish). Pterodoras granulosus (Valenciennes, 1833), from the Itaipu Reservoir and Paraná River, in the region of Porto Rico. This is the first reference of a proteocephalid in this host. The values of prevalence and mean intensity of infection are given and the life cycle is discussed.