Deterrência alimentar e redução no ganho de peso de lagartas provocadas por extrato de Vernonanthura montevidensis (Spreng.).

Este trabalho avaliou em laboratório a ação de extratos de folhas de Vernonanthura montevidensis (Spreng.) H.Rob. (Asteraceae), popularmente chamada de vassoura-rosa, sobre lagartas de Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), conhecida como lagarta-da-soja e considerada um dos principais desfolhadores dessa cultura. Lagartas de A. gemmatalis foram submetidas a testes sem chance de escolha, sendo alimentadas com folhas de soja contendo extrato da planta a 14% em quatro diferentes solventes (hexano, diclorometano, metanol e água), todos comparados com a devida solução testemunha, composta de solvente e água. As lagartas com aproximadamente sete dias de idade foram pesadas, individualizadas em placas de Petri e deixadas em jejum por duas horas antes do início do bioensaio. O extrato foi oferecido às lagartas sobre folhas de soja previamente higienizadas, secas à sombra e submetidas ao medidor de área foliar. As folhas foram mergulhadas nas soluções contendo o extrato por 20 segundos. Após a secagem, cada folha foi oferecida a uma lagarta acondicionada em placa de Petri, havendo 15 repetições por tratamento. O bioensaio foi conduzido em ambiente controlado a 27 ± 1°C, 70% de umidade e fotoperíodo de 12h:12h (Luz:Escuro). Após 24 horas, as folhas foram retiradas e novamente submetidas ao medidor de área, as lagartas foram novamente pesadas e transferidas para os copos contendo dieta própria para o inseto. As lagartas ainda foram pesadas ao terceiro e sétimo dia da montagem do experimento. Foi avaliada a redução no ganho de peso das lagartas e a área foliar consumida (cm2) pelas lagartas, sendo que as médias foram comparadas pelo teste de Tukey. As lagartas consumiram menor área de folhas com o extrato em água e diclorometano, entretanto, foi o extrato em hexano que causou a maior redução da porcentagem do ganho de peso

Defensivos sugeridos para o manejo integrado das pragas do algodoeiro.

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Untargeted metabolomics analysis by UHPLC-MS/MS of soybean plant in a compatible response to Phakopsora pachyrhizi infection.

Abstract: Phakopsora pachyrhizi is a biotrophic fungus, causer of the disease Asian Soybean Rust, a severe crop disease of soybean and one that demands greater investment from producers. Thus, research efforts to control this disease are still needed. We investigated the expression of metabolites in soybean plants presenting a resistant genotype inoculated with P. pachyrhizi through the untargeted metabolomics approach. The analysis was performed in control and inoculated plants with P. pachyrhizi using UHPLC-MS/MS. Principal component analysis (PCA) and the partial least squares discriminant analysis (PLS-DA), was applied to the data analysis. PCA and PLS-DA resulted in a clear separation and classification of groups between control and inoculated plants. The metabolites were putative classified and identified using the Global Natural Products Social Molecular Networking platform in flavonoids, isoflavonoids, lipids, fatty acyls, terpenes, and carboxylic acids. Flavonoids and isoflavonoids were up-regulation, while terpenes were down-regulated in response to the soybean?P. pachyrhizi interaction. Our data provide insights into the potential role of some metabolites as flavonoids and isoflavonoids in the plant resistance to ASR. This information could result in the development of resistant genotypes of soybean to P. pachyrhizi, and effective and specific products against the pathogen

Partial replacement of corn by cassava starch byproduct on performance and carcass characteristics of feedlot heifers

The objective of this work was to study the effects of partial substitution of corn grain (COR) by dry cassava starch byproduct (CAS) on feed intake, weight gain, feed conversion and carcass physical characteristics in crossbred beef heifers finished in feedlot. Fifty-four heifers, of approximately 15 mo of age and 317 kg mean liveweight, were randomly distributed, in blocks according to breed group, between two treatments, with 27 replicates for performance characteristics and 9 for carcass evaluation. The animals were fed ad libitum twice daily, with corn silage and one of two different concentrates, based on soybean meal and either COR or half COR and half CAS as energy source. No differences (P>0.05) were found between treatments in the variables studied, overall mean values being: daily weight gain (1.1 kg), dry matter (DM) intake (9.1 kg), DM intake/100 kg liveweight (2.6 kg), feed conversion ratio (8.4), warm carcass weight (209.3 kg), carcass weight in arrobas (13.9), carcass yield (51.7%) carcass length (121.1 cm), leg length (71.5 cm), rump roast thickness (25.5 cm), subcutaneous fat thickness (6.6 cm), muscle percentage (30.5), bone percentage (15.5), and muscle plus fat:bone proportions (5.4:1). The dry cassava byproduct can replace 50% of corn in the concentrate without effects on performance and carcass characteristics of crossbred heifers finished in feedlot

Dinâmica de uso e cobertura da terra nas bacias hidrográficas de Guapi-Macacu e Caceribu - RJ.

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Dynamics of early establishment of SARS-CoV-2 VOC Omicron lineages in Minas Gerais, Brazil

Brazil is one of the nations most affected by Coronavirus disease 2019 (COVID-19). The introduction and establishment of new virus variants can be related to an increase in cases and fatalities. The emergence of Omicron, the most modified SARS-CoV-2 variant, caused alarm for the public health of Brazil. In this study, we examined the effects of the Omicron introduction in Minas Gerais (MG), the second-most populous state of Brazil. A total of 430 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) samples from November 2021 to June 2022 from Belo Horizonte (BH) city were sequenced. These newly sequenced genomes comprise 72% of all previously available SARS-CoV-2 genomes for the city. Evolutionary analysis of novel viral genomes reveals that a great diversity of Omicron sublineages have circulated in BH, a pattern in-keeping with observations across Brazil more generally. Bayesian phylogeographic reconstructions indicate that this diversity is a product of a large number of international and national importations. As observed previously, São Paulo state is shown as a significant hub for viral spread throughout the country, contributing to around 70% of all viral Omicron introductions detected in MG