Desempenho agronômico do sorgo em função de doses e épocas de aplicação do herbicida 2,4-d.

A cultura do sorgo está inserida no plano atual de manejo dos sistemas agrícolas nos cerrados, todavia são escassos os estudos em campo quanto à seletividade e comportamento da cultura ao herbicida 2,4-D. Objetivou-se neste trabalho avaliar os efeitos do 2,4-D sobre o crescimento das plantas, a produção de fitomassa seca e fitomassa verde e a produtividade de grãos na cultura do sorgo. O experimento foi realizado entre janeiro e maio de 2008, em Nova Xavantina-MT, em Latossolo Vermelho-Amarelo distrófico. O sorgo (cultivar Buster) foi semeado em área cultivada sob sistema de plantio direto, em espaçamento de 0,50 m entre linhas, distribuindo-se 10 sementes por metro. Os tratamentos foram dispostos em esquema fatorial 4 x 4, envolvendo quatro doses de 2,4-D (0, 335, 670 e 1.005 g ha-1) e quatro épocas de aplicação (pré-semeadura, três folhas expandidas, seis folhas expandidas e pré-florescimento). Utilizou-se o delineamento de blocos casualizados com quatro repetições. O controle de plantas daninhas na cultura foi realizado manualmente, com utilização de enxada. Verificou-se efeito fitotóxico à cultura do sorgo pelo 2,4-D aos 15 dias após a aplicação (DAA), independentemente da dose ou época de aplicação. O incremento das doses de 2,4-D provocou redução linear da altura de plantas, acúmulo de fitomassa verde e acúmulo de fitomassa seca, tanto aos 30 DAA quanto no ponto de rolagem. A aplicação do 2,4-D prejudica a produtividade do sorgo, especialmente em doses acima de 1.005 g ha-1 e.a. e em aplicações tardias. De maneira geral, a utilização do 2,4-D em pré-semeadura mostrou-se uma boa alternativa no manejo das plantas daninhas na cultura do sorgo. Agronomic Performance of Sorghum as a Response to 2,4-D Application Dosage and Times. Sorghum is part of the current plan of agricultural system management for the cerrado. However, few field studies have been carried out on this culture?s behavior and selectivity towards herbicide 2,4 D. The objective of this study was to evaluate the effects of 2,4-D on plant growth, dry matter production and green biomass and grain yield in sorghum. The experiment was conducted between January and May 2008 in Nova Xavantina-MT in dystrophic Oxisol. Sorghum (cv. Buster) was sown in a cultivated area under no-tillage, with 0.50 m spacing between rows, and ten seeds distributed per meter. Treatments were arranged in a 4 x 4, involving four levels of 2,4-D (0, 335, 670, and 1.005 g ha-1) and four application times (pre-sowing, three fully-expanded leaves, six leaves, and pre-flowering).A randomized block design was used, with four replications. Weed control in the culture was performed manually, using a hoe. Toxic effects caused to sorghum by 2,4-D were observed at 15 days after application (DAA), regardless of dose or time of application. The increasing levels of 2,4-D caused a linear reduction in plant height, biomass and green dry matter accumulation, both at 30 DAA as the point of rollover. The application of 2,4-D affected sorghum yield, especially at doses above 1.005 g ha-1 and late applications. In general, the use of 2,4-D in pre-sowing proved to be a good alternative for the management of weeds in sorghum crop

Ciclagem de nutrientes por plantas de cobertura no cerrado.

O objetivo deste trabalho foi avaliar o desempenho de plantas cultivadas quanto ao acúmulo e a liberação de nutrientes, durante o período de entressafra, em um Latossolo Vermelho distroférrico de Santo Antônio de Goiás, GO e Rio Verde, GO. O delineamento experimental foi o de blocos casualizados, em esquema de parcelas subdivididas no tempo, com as plantas de cobertura avaliadas nas parcelas, e nas subparcelas, as épocas de coleta de fitomassa, com quatro repetições

Effect of crotamine, a cell-penetrating peptide, on blastocyst production and gene expression of in vitro fertilized bovine embryos.

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Produção de fitomassa por plantas de cobertura no cerrado.

O objetivo do trabalho foi avaliar a produção de fitomassa por plantas de cobertura semeadas em safrinha no desempenho do arroz de terras altas e soja, semeada em rotação, em sistema de plantio direto e preparo convencional, em Latossolo Vermelho do município de Rio Verde, Goiás. O trabalho foi realizado no período de abril de 2008 a fevereiro de 2009. Utilizou-se o delineamento em faixas, em esquema de parcelas subdivididas no tempo, com quatro repetições. Nas faixas horizontais foram testadas as plantas de cobertura, nas faixas verticais dois sistemas de manejo (plantio direto e convencional, ambos com três anos de implantação), e nas subparcelas seis épocas de coletas de fitomassa após a dessecação das plantas de cobertura, que ocorreu aos 0 , 15, 30, 60, 90 e 120 dias à partir da dessecação de manejo das plantas de cobertura, com quatro repetições

Selection of high-performance black-eyed cowpea (Vigna unguiculata) through GYT biplot analysis: a new methodology based on multiple characteristics.

Cowpea bean is a common crop quite appreciated in Brazil. However, it is known that its low yield depending on soil and climatic conditions. The aim of this research is the selection of high-performance black-eyed cowpea through GYT biplot analysis. Twelve (12) cowpea bean strains were assessed between 2016 and. The study followed a randomized complete block design, with four repetitions; two commercial cultivars were used ascheck. The following variables were assessed: number of days required for flowering, final stand, value for cultivation, pod yield, pod length, mean number of grains per pod and grain weight. The analysis of variance showed genetic variability between strains, differences between the assessed years and different strain-performance in each growing year. Based on the GYT biplot graph, cultivar BRS Itaim, and strains L9 and L7 recorded the best performance for the set of yield characteristics. Variable ?pod length? had positive correlation to bedding, number of days required for flowering and number of grains per pod. Variable ?100-grain weight? had positive correlation to final stand, pod yield and mean grain weight per pod. Strains L9, L7 and cultivar BRS Itaim recorded the best yield regarding the assessed variables

Spatio-Temporal Tracking and Phylodynamics of an Urban Dengue 3 Outbreak in São Paulo, Brazil

The dengue virus has a single-stranded positive-sense RNA genome of ∼10.700 nucleotides with a single open reading frame that encodes three structural (C, prM, and E) and seven nonstructural (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) proteins. It possesses four antigenically distinct serotypes (DENV 1–4). Many phylogenetic studies address particularities of the different serotypes using convenience samples that are not conducive to a spatio-temporal analysis in a single urban setting. We describe the pattern of spread of distinct lineages of DENV-3 circulating in São José do Rio Preto, Brazil, during 2006. Blood samples from patients presenting dengue-like symptoms were collected for DENV testing. We performed M-N-PCR using primers based on NS5 for virus detection and identification. The fragments were purified from PCR mixtures and sequenced. The positive dengue cases were geo-coded. To type the sequenced samples, 52 reference sequences were aligned. The dataset generated was used for iterative phylogenetic reconstruction with the maximum likelihood criterion. The best demographic model, the rate of growth, rate of evolutionary change, and Time to Most Recent Common Ancestor (TMRCA) were estimated. The basic reproductive rate during the epidemics was estimated. We obtained sequences from 82 patients among 174 blood samples. We were able to geo-code 46 sequences. The alignment generated a 399-nucleotide-long dataset with 134 taxa. The phylogenetic analysis indicated that all samples were of DENV-3 and related to strains circulating on the isle of Martinique in 2000–2001. Sixty DENV-3 from São José do Rio Preto formed a monophyletic group (lineage 1), closely related to the remaining 22 isolates (lineage 2). We assumed that these lineages appeared before 2006 in different occasions. By transforming the inferred exponential growth rates into the basic reproductive rate, we obtained values for lineage 1 of R0 = 1.53 and values for lineage 2 of R0 = 1.13. Under the exponential model, TMRCA of lineage 1 dated 1 year and lineage 2 dated 3.4 years before the last sampling. The possibility of inferring the spatio-temporal dynamics from genetic data has been generally little explored, and it may shed light on DENV circulation. The use of both geographic and temporally structured phylogenetic data provided a detailed view on the spread of at least two dengue viral strains in a populated urban area