Mayze grain yield under different sprinkler irrigation systems

O objetivo do trabalho foi avaliar o desempenho de diferentes sistemas de irrigação por aspersão e seus efeitos sobre o rendimento de grãos de milho, no sul do Brasil. Três experimentos foram conduzidos em Eldorado do Sul, RS. A data de semeadura e os tratamentos testados em cada experimento foram: Experimento 1 – 08 de novembro de 2005; dois sistemas de irrigação, aspersão convencional e autopropelido com canhão sem sobreposição e quatro híbridos de milho (AS 1560, Dow 2A120, P 30F53 e PENTA); Experimento 2 – 12 de setembro de 2006; três sistemas de irrigação, aspersão convencional, autopropelido com canhão sem sobreposição e autopropelido com barras; Experimento 3 – 01 de outubro de 2007; três sistemas de irrigação, autopropelido com barras, autopropelido com canhão sem sobreposição e autopropelido com canhão com sobreposição. Cada experimento contou com um tratamento testemunha sem irrigação. O uso de irrigação complementar por aspersão aumentou o rendimento de grãos de milho em relação aos tratamentos sem irrigação, com incrementos de 6,2, 3,4 e 9,2 t ha-1, respectivamente nos Experimentos 1, 2 e 3, na média de híbridos e sistemas de irrigação avaliados. Além disso, o rendimento de grãos de milho variou conforme o sistema de irrigação e, no primeiro ano, também com o híbrido testado. O uso de irrigação complementar com equipamentos de irrigação por aspersão é uma estratégia eficiente para aumentar o rendimento de grãos de milho no sul do Brasil. Os sistemas de irrigação autopropelido com barras, autopropelido com canhão com sobreposição e aspersão convencional são mais eficientes para atender a demanda hídrica do milho do que o autopropelido com canhão sem sobreposição de lâmina.The objective of this work was to evaluate the performance of different sprinkler irrigation systems and their effects on maize grain yield in southern Brazil. The sowing date and treatments in each experiment were: Experiment 1 – November, 8 2005; two irrigation systems, spraying and self-propelled cannon without overlapping and four hybrids (AS 1560, Dow 2A120, P 30F53 and PENTA). Experiment 2– September, 12 2006; three irrigation systems, spraying, selfpropelled cannon without overlapping and self-propelled with bars; Experiment 3– October, 01 2007; three irrigation systems, self-propelled with bars, self-propelled cannon without overlapping and self-propelled cannon with overlapping. Each experiment had also a control treatment with no irrigation. The use of sprinkler irrigation increased grain yield as compared to the control, regardless the system used. The increase of grain yield was 6.2, 3.4 and 9.2 t ha-1 for experiments 1, 2 and 3, respectively for average of hybrids and irrigation systems tested. Moreover, maize grain yield varied according to the irrigation system, and also with the hybrid tested in the first year. The use of supplementary irrigation with sprinkler irrigation equipment is an effective strategy to increase maize grain yield in southern Brazil. The systems of selfpropelled with bars, self-propelled cannon with overlapping and spraying are more efficient to meet water demand of maize than the the system of self-propelled cannon without overlapping

Inquérito de toxoplasmose e de tripanossomíases realizado no Território do Amapá pela III Bandeira Científica do Centro Acadêmico "Oswaldo Cruz" da Faculdade de Medicina da Universidade de São Paulo

The survey was performed in three localities, in January 1962, and included inhabitants with 10 or more years of age and who had never left the Amazon Region.The Sabin-Feldman dye test was positive in 68.1 percent of 354 persons examined and the intradermal test with toxoplasmin in 46.4 percent of 366. The distribution of positive tests by locality, age, sex and race are presented.Through the complement fixation test for Chagas' disease (Guerreiro and Machado's test) performed in 353 persons and the xenodiagnosis in 116, no evidence of trypanosome infection was found.A severe malária outbreak which was occurring in the region is discussed.Descreve-se uma excursão realizada em janeiro de 1962 por estudantes da Faculdade de Medicina da Universidade de São Paulo ao Território do Amapá, onde realizaram inquéritos de toxoplasmose e tripanossomíase na cidade de Macapá e nas vilas de Paredão e Ferreira Gomes.A reação de Sabin-Feldman foi positiva em 68,1 % das 354 pessoas examinadas e a intradermorreação com toxoplasmina em 46,4% de 366. A distribuição das provas positivas é apresentada por localidade, sexo, idade e côr.A reação de fixação do complemento para doença de Chagas (prova de Guerreiro e Machado, técnica quantitativa), feita em 353 pessoas, não apresentou nenhum resultado seguramente positivo, sendo ainda negativos os 116 xenodiagnósticos efetuados com ninfas de triatomíneos (Rhodnius prolixus).Fazem-se ainda considerações sobre o intenso surto de malária que ocorria então na região

Using remote sensing images for stratification of the cerrado in forest inventories

Remote sensing imagery can be a very useful auxiliary tool for native forests inventory. Thus, the objective of this study was to evaluate the stratification of a cerrado (Brazilian savanna) patch based on visual image interpretation techniques as well as to compare the errors from two sampling designs, the Stratified Random Sampling (SRS) and the Systematic Sampling (SS).The study area corresponds to a cerrado sensu stricto patch located in the municipality of Papagaios, Minas Gerais, Brazil. The cerrado wood volumes were obtained from a forest inventory field campaign where 32 plots were measured systematically. The study area was stratified based on a visual interpretation of a Landsat 5 TM image, and the strata formed were: “Strata I”, “Strata II”, “Strata III”, water and riparian forests. There was a reduction of 43% on the inventory errors using the SS estimators compared to the inventory errors using the SRS estimators. We concluded that the stratification based on image interpretation techniques was efficient since there was a reduction on the cerrado inventory errors

Seasonal dynamics of Aedes aegypti (Diptera: Culicidae) in the northernmost state of Brazil: a likely port-of-entry for dengue virus 4

Roraima is the northernmost state of Brazil, bordering both Venezuela and Guyana. Appropriate climate and vector conditions for dengue transmission together with its proximity to countries where all four dengue serotypes circulate make this state, particularly the capital Boa Vista, strategically important for dengue surveillance in Brazil. Nonetheless, few studies have addressed the population dynamics of Aedes aegypti in Boa Vista. In this study, we report temporal and spatial variations in Ae. aegypti population density using ovitraps in two highly populated neighbourhoods; Centro and Tancredo Neves. In three out of six surveys, Ae. aegypti was present in more than 80% of the sites visited. High presence levels of this mosquito suggest ubiquitous human exposure to the vector, at least during part of the year. The highest infestation rates occurred during the peak of the rainy seasons, but a large presence was also observed during the early dry season (although with more variation among years). Spatial distribution of positive houses changed from a sparse and local pattern to a very dense pattern during the dry-wet season transition. These results suggest that the risk of dengue transmission and the potential for the new serotype invasions are high for most of the year