Arthropoda diversity in irrigated rice under different organic fertilization regimes

Os campos de cultivo de arroz constituem agroecossistemas que podem abrigar uma rica diversidade de plantas e animais, dependendo do manejo ao qual são submetidos. O objetivo deste estudo foi avaliar os artrópodes associados ao arroz irrigado com manejo orgânico no período de desenvolvimento vegetativo e reprodutivo da cultura comparando a diversidade em relação à utilização de dois compostos orgânicos em diferentes doses. Os tratamentos foram a Testemunha (sem aplicação de composto); 2, 4 e 6 t ha-1 de dois compostos orgânicos (Ecocitrus® e Folhito®). Em cada tratamento foram definidos três transectos percorridos com rede de varredura para coleta dos artrópodes, quinzenalmente de dezembro de 2013 a fevereiro de 2014. Foram coletados no total 41.236 artrópodes de 11 ordens. As mais abundantes foram Diptera, Hemiptera, Odonata, Orthoptera, Coleoptera e Araneae. Hymenoptera, Lepidoptera, Blattodea, Neuroptera e Phasmatodea foram as menos abundantes. Este é o primeiro registro de Schizaphis graminum em arroz irrigado no Brasil. Não houve diferença no número de capturas por transecto entre os tratamentos durante o ciclo do arroz. A maior abundância de artrópodes foi registrada no início da fase reprodutiva da cultura.Rice fields are agroecosystems that can hold a rich diversity of plants and animals, depending on the management to which they are submitted. This study aimed to evaluate arthropods associated with irrigated rice with organic management during the period of vegetative and reproductive development of the crop comparing the diversity in response to two organic compounds in different doses. The treatments were: Control (without application of compost); 2, 4 e 6 t ha-1 of two organic compost (Ecocitrus® and Folhito®). In each treatment were defined three transects which form covered with sweep net to collect the arthropods, twice a month from December 2013 to February 2014. Were collected 41.236 arthropods of 11 orders. The most abundant orders were Diptera, Hemiptera, Odonata, Orthoptera, Coleoptera and Araneae. Hymenoptera, Lepidoptera, Blattodea, Neouroptera and Phasmatodea were less abundant. This is the first record of Schizaphis graminum in irrigated rice in Brazil. There was no difference in the collection number by transect among the treatments during the rice cycle. The greatest abundance of arthropods was recorded at the beginning of the reproductive stage of the culture

PERSPECTIVAS DA AGROENERGIA NO BRASIL

Este texto tem por objetivo fazer uma revisão do estágio atual da produção mundial de biocombustíveis, das políticas adotadas nos vários países e das perspectivas de inserção do Brasil neste processo como produtor e exportador de biocombustíveis, conciliando isto com o desenvolvimento econômico e social e com o respeito ao meio-ambiente. Os autores destacam a necessidade de conciliação das ações da iniciativa privada com a adoção de políticas publicas, visto que apenas o “mercado” ainda não é capaz de gerar os incentivos necessários para a conciliação entre a busca de negócios lucrativos e sustentabilidade econômica e social. A metodologia de pesquisa usada foi de revisão bibliográfica e pesquisa de dados estatísticos em publicações especializadas, relatórios de pesquisa e artigos acadêmicos. O texto conclui que o Brasil tem vantagens competitivas na produção de etanol e está se consolidando como um grande exportador. Mas as perspectivas de crescimento com base no mercado interno são mais seguras e duradouras. No caso do Biodiesel, a competitividade é comprometida pelo estágio inicial da produção, sendo que outros países já estão mais avançados. Assim, o Brasil deve se preocupar em ocupar a oportunidade de exportar que existe hoje,mas não pode descuidar de assuntos que podem comprometer a nossa situação no futuro, como a evolução tecnológica e as questões ambientais.------------------------------------------------This text has the objective to make a revision of the actual stage of the world-wide production of biofuels, of the politics adopted in some countries and of the perspectives for brazilian insertion as producer and exporter of biofuels, conciliating this with the economic and social development and the respect to the environment. The authors emphasized the necessity of conciliation with private actions and initiatives and the adoption of public policies, because only the “market” is not capable to generate the necessary incentives for the conciliation between the business-oriented lucrative activities and economic and social support. The research methodology used was bibliographical revision and research of statistical data in specialized publications, academic reports of research and articles. The text concludes that Brazil has competitive advantages in the production of etanol and is if consolidating as a great exporter. But the growth perspectives on the basis of the domestic market are safer and lasting. In the case of the Biodiesel, the competitiveness is affected by the initial status of the production, being that other countries already are more advanced. Thus, Brazil must be worried in occupying the chance to export that it exists today, but cannot neglect of subjects that can compromise our situation in the future, as the technological evolution and the ambient questions.ambiente Institucional, biocombustíveis, políticas-públicas, grupos de interesse, desenvolvimento econômico e social, Institutional Environment, Biofuels, Public Policies, organized groups, economic and social development, Resource /Energy Economics and Policy,

Incidence of arthoropods and grain yield in organic rice pre-germinated in response to application of compost

A demanda por alimentos livres da contaminação por agrotóxicos vem aumentando e a produção orgânica desponta como uma das alternativas para alcançar este objetivo. Produtores de arroz orgânico utilizam resíduos vegetais e animais na fertilização dos solos. Entretanto, estudos demonstram que uma maior concentração de nutrientes solúveis no tecido vegetal pode favorecer o ataque de insetos fitófagos. Este trabalho teve como objetivo avaliar a incidência de artrópodes e a produtividade em arroz orgânico mediante a aplicação de dois compostos orgânicos em diferentes doses. Os experimentos foram montados em duas formas distintas. Sete quadros de 0,5 ha para avaliação de artrópodes com delineamento experimental em pseudoréplicas e um quadro de 0,25 ha para avaliar produtividade com delineamento experimental em blocos ao acaso. Os tratamentos foram T: Testemunha (sem aplicação de insumo); 2, 4 e 6 t ha- 1 de dois compostos orgânicos (Ecocitrus® e Folhito®). As avaliações compreenderam a bicheira-da-raiz Oryzophagus oryzae (Costa Lima, 1936) (Coleoptera: Curculionidae) e artrópodes presentes na parte aérea da planta de novembro de 2013 a fevereiro de 2014. O acúmulo de biomassa e nutrientes das plantas de arroz foi avaliado na antese (R4) e antecedendo a colheita (R9) foram avaliados o rendimento de grãos e os componentes do rendimento sendo calculada a Eficiência de recuperação do Nitrogênio (ERN) e a Eficiência agronômica do nitrogênio (EAN). As aplicações de compostos orgânicos nas doses testadas neste experimento em arroz irrigado não interferiram na população de O. oryzae. Na avaliação dos artrópodes da parte aérea do arroz foram registrados 41.236 indivíduos distribuídos em 11 ordens e o número médio por ocasião amostral não diferiu entre os tratamentos. No entanto, a abundância de artrópodes variou durante o ciclo do arroz com pico populacional no início da fase reprodutiva predominando insetos importantes para esta cultura, das ordens Hemiptera, Odonata e Coleoptera. Ocorreu aumento no número médio de pragas (Schizaphis graminum Rondani) (Hemiptera: Aphidiidae) e O. oryzae ao mesmo tempo do grupo de predadores (Odonata) entre os estádios V9 e R0. A temperatura máxima apresentou correlação significativa com a abundância de artrópodes. O maior acúmulo de biomassa e nitrogênio na parte aérea do arroz foi constatado nos tratamento E6 e F6. A utilização de composto pode aumentar a produtividade em lavouras de arroz irrigado prégerminado em sistema orgânico. A ERN e a EAN foram afetadas pelos diferentes tratamentos testados.The demand of food free from pesticides contamination has been increasing and the organic production arises as one of the alternatives to reach such goal. Plant and animal residues have been used by rice organic producers to fertilize the soil. However, studies have shown that a higher concentration of soluble nutrients on the plant tissue may favor the attack of phytophagous insects. This paper had as goal to evaluate the incidence of arthopods and the productivity in organic rice by the application of two organic compounds in different doses. The experiments were set in two different ways. Seven squared areas of 0.5 ha to evaluate the arthropods with an experimental design in pseudoreplications in a square of 0.25 ha to evaluate productivity with an experimental in randomized blocks design. The treatments were T: Control (without application of compost); 2, 4 e 6 t ha-1 of two organic compost (Ecocitrus® and Folhito®). Were evaluated rice weevil Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae) and the other arthropods present in the aerial portion of the plant from November 2013 to February 2014. The accumulation of rice plants biomass and nutrients was evaluated in the anthesis (R4) and preceding the harvest (R9) were evaluated the grains yield and the yield components, calculating the Nitrogen Recovery Efficiency (NRE) and Nitrogen agronomic efficiency (NAE). The application of organic compounds in those doses tested in this experiment in irrigated rice does not interfere on O. oryzae population. In the evaluation of the arthropods on the aerial part of the plant were registered 41.236 individuals distributed in 11 orders, and the average number of insects per sampling occasion did not differed among the treatments. However, the abundance of arthropods varied during the rice crop cycle, with a population peak in the beginning of the reproductive stage, predominating important insects to this crop as Hemiptera, Odonata and Coleoptera orders. Occurred a increase in the average number of pests Schizaphis graminum (Rondani) (Hemiptera: Aphidiidae) and O. oryzae at the same time as the predators group (Odonata) increased between the stages V9 and R0. The maximum temperature presented a significative correlation with the abundance of arthropods. The biggest accumulation of biomass and Nitrogen in the shoot the rice was found in treatments E6 and F6. The use of compost can increase productivity in crops of pre-germinated rice in organic system. The NRE and NAE were affected by the different treatments tested

Seed longevity of Eragrostis plana Nees buried in natural grassland soil

The objective of this research was to evaluate the seed longevity of Eragrostis plana Nees buried at different soil depths, in a natural-grassland area in the Pampa biome (46 m altitude, 30º05´S and 51º40´W) of Rio Grande do Sul State, Brazil. The experimental design was a split-plot type in complete blocks with two factors: seeds buried at five different depth levels (soil surface and 2.5, 5, 10 and 20 cm) and seven exhumation dates. The blocks were allocated in natural grassland grazed by cattle, allocated in a 12-m-long transection. Fifty-four permeable nylon bags filled with 100 seeds in each division, with five vertical divisions, were buried in each row. Seven exhumation dates were used: the first on October 14, 2003 and the last on January 14, 2006. The percentage of viable seeds of E. plana, collected at seven exhumation times and set at different depths in the soil horizon, were described by simple negative exponential equations. Based on the model, the percentage of viable seeds collected at the five depths, (soil surface and 2.5, 5, 10, and 20 cm), after 2.5 years of burial, were 0.1, 0.5, 1.0, 7.4 and 22.1%, respectively. Increase in depth is directly associated with physical and physiological seed integrity of E. plana. Negative simple exponential equations can be used to predict seed longevity of E. plana buried in nylon bags. This invader species accumulates soil seed-bank of high longevity

Longevidade de sementes de Capim-Annoni-2 em função da sua posição no solo

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Efeito da remoção de dormência sobre a germinação de sementes de capim-branco

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Longevidade de sementes de Capim-Annoni-2 em função da sua posição no solo

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Produtividade e incidência de cancro cítrico em laranjeiras-de-umbigo 'Monte Parnaso' enxertadas sobre sete porta-enxertos

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Seed longevity of Eragrostis plana Nees buried in natural grassland soil

The objective of this research was to evaluate the seed longevity of Eragrostis plana Nees buried at different soil depths, in a natural-grassland area in the Pampa biome (46 m altitude, 30º05´S and 51º40´W) of Rio Grande do Sul State, Brazil. The experimental design was a split-plot type in complete blocks with two factors: seeds buried at five different depth levels (soil surface and 2.5, 5, 10 and 20 cm) and seven exhumation dates. The blocks were allocated in natural grassland grazed by cattle, allocated in a 12-m-long transection. Fifty-four permeable nylon bags filled with 100 seeds in each division, with five vertical divisions, were buried in each row. Seven exhumation dates were used: the first on October 14, 2003 and the last on January 14, 2006. The percentage of viable seeds of E. plana, collected at seven exhumation times and set at different depths in the soil horizon, were described by simple negative exponential equations. Based on the model, the percentage of viable seeds collected at the five depths, (soil surface and 2.5, 5, 10, and 20 cm), after 2.5 years of burial, were 0.1, 0.5, 1.0, 7.4 and 22.1%, respectively. Increase in depth is directly associated with physical and physiological seed integrity of E. plana. Negative simple exponential equations can be used to predict seed longevity of E. plana buried in nylon bags. This invader species accumulates soil seed-bank of high longevity