304 research outputs found
Impactos potenciais das mudanças climáticas sobre a distribuição geográfica do número de gerações do bicho-mineiro-do-cafeeiro (Leucoptera coffeella) no Brasil.
O presente trabalho teve como objetivo avaliar o impacto potencial das mudanças climáticas na distribuição geográfica do número de gerações do bicho-mineiro-do-cafeeiro (Leucoptera coffella) para o Brasil, baseando-se nas condições climáticas futuras projetadas por dois cenários de emissões do Quarto Relatório do IPCC. Os mapas das projeções mensais do número de gerações da praga para os períodos de 2071-2100, cenários A2 e B1, e de 1961-1990 foram obtidos empregando-se o modelo matemático de desenvolvimento de Parra (1985), em função da temperatura média mensal. Os resultados obtidos prevêem tendência de aumento do número de gerações para ambos os cenários de emissão, com um número maior de número de gerações previsto para o cenário A2
Переводчик не может не быть текстологом. По поводу переводов рассказов юного Чехова
The article deals with the textual decisions made by editors and translators of Chekhov's works in the editing process of his early short stories. The aim is to show to what extent the choices made by editors' and translators' depend on the configuration of the academic Polnoe sobranie sochineniĭ (Complete works). Here, in the volumes devoted to the work of the young Chekhov, the first versions of his short stories are placed in the critical appendix, whereas the main text provides later versions of the same stories. As a consequence, works of the "mature Chekhov" are presented as works of the "young Chekhov", which leads to a misunderstanding scholars, editors and translators, especially the ones not familiar with a textological approach
Atividade microbiana do solo e plantas invasoras em alta concentração de CO2 atmosférica.
Resumo: O objetivo desse trabalho foi avaliar o impacto do aumento de dióxido de carbono (CO2) atmosférica sobre a produção de material seco de plantas invasoras e atividade microbiana do solo. O ensaio foi realizado em campo em estufas de topo aberto ("open-top chambers",OTC), adotando delineamento experimental em blocos inteiramente casualizados, com duas repetições. Cada bloco foi composto por três tratamentos, a testemunha (T) com a concentração de 390 micromol mol-1 de CO2, o tratamento em estufa sem injeção de CO2 com a concentração de 400 miocromol mol-1 de CO2 e o tratamento com injeção de dióxido de carbono e estufa com a concentração de 550 micromol mol-1 de CO2. As plantas invasoras apresentaram maior produção de material seco quando submetidas ao elevado CO2. A atividade microbiana do solo que foi determinada pela quantidade de dióxido de carbono do solo foi maior nas parcelas com o ambiente enriquecido com CO2. Possivelmente as plantas invasoras terão um maior crescimento com acréscimo de dióxido de carbono na atmosfera. A atividade microbiana do solo terá modificações devido ao aumento da concentração de CO2. Abstract: The aim of this study was to evaluate the impact of increased atmospheric CO 2 concentration on dry matter production of weeds and soil microbial activity. The test was conducted in the field in open-top greenhouses (OTC), adopting experimental design in a completely randomized block design with two repetitions. Each block consisted of three treatments, the witness (T) with a concentration of 390 micromol mol -1 CO 2 emissions without treatment with CO 2 injection with a concentration of 400 micromol mol -1 CO 2 and treatment by injecting gases and carbon dioxide with a concentration of 550 micromol mol -1 CO 2 . Invasive plants had higher dry matter production when subjected to elevated CO 2 . The microbial activity of the soil was determined by the amount of soil carbon dioxide was higher in the plots with the environment enriched with CO 2 . Potentially invasive plants have higher growth with the increase of carbon dioxide in the atmosphere. The soil microbial activity may have changes due to increased CO 2 concentration
Organic and conventional tomato cropping systems.
Among several alternative agricultural systems have been developed, organic agriculture has deserved increasing interest from. The objective of this paper was comparing both organic (OS) and conventional (CS) tomato cropping systems for varieties Débora and Santa Clara, through an interdisciplinary study. The experiment was set up in a randomized blocks design with six replicates, in a dystrophic Ultisol plots measuring 25 ´ 17 m. Cropping procedures followed by either local conventional or organic growers practices recommendations. Fertilization in the OS was done with organic compost, single superphosphate, dolomitic limes (5L, 60 g, and 60 g per pit), and sprayed twice a week with biofertilizer. Fertilization in the CS was done with 200 g 4-14-8 (NPK) per pit and, after planting, 30 g N, 33 g K and 10.5 g P per pit; from 52 days after planting forth, plants were sprayed once a week with foliar fertilizer. In the CS, a blend of insecticides, fungicides and miticides was sprayed twice a week, after planting. In the OS, extracts of black pepper, garlic, and Eucalyptus; Bordeaux mixture, and biofertilizer, were applied twice a week to control diseases and pests. Tomato spotted wilt was the most important disease in the OS, resulting in smaller plant development, number of flower clusters and yield. In the CS, the disease was kept under control, and the population of thrips, the virus vector, occurred at lower levels than in the OS. Variety Santa Clara presented greater incidence of the viral disease, and for this reason had a poorer performance than 'Débora', especially in the OS. Occurrence of Liriomyza spp. was significantly smaller in the OS, possibly because of the greater frequency of Chrysoperla. The CS had smaller incidence of leaf spots caused by Septoria lycopersici and Xanthomonas vesicatoria. However, early blight and fruit rot caused by Alternaria solani occurred in larger numbers. No differences were observed with regard to the communities of fungi and bacteria in the phylloplane, and to the occurrence of weeds
Control of Ralstonia solanacearum in tomato potting medium by the use of a solar collector.
A solar collector was used to disinfest potting medium inoculated with Ralstonia solanacearum. Tomato plantlets grown in the potting medium treated in the solar collector for one full day had no symptoms of bacterial wilt
Eradication of Ralstonia solanacearum from tomato growth substrate using a solar collector.
Bacterial wilt caused by Ralstonia solanacearum constitutes one of the most difficult diseases to control. The use of disinfested substrates is important for the production of disease-free seedlings and prevents the dissemination of this pathogen. An equipment was developed at Embrapa Environment, in Brazil, aiming to disinfest substrates with solar radiation. The solar collector is efficient to control several fungal plant pathogens, including species of Fusarium, Pythium, Rhizoctonia, Sclerotium, Sclerotinia, Phytophthora, as well as nematodes such as Meloydogyne (1, 2), after the treatment of the substrate during only one sunny day. The purpose of this work was to determine the efficacy of the solar collector for the control of the bacterial wilt caused by R. solanacearum
Humic Substances from sediments of Lobos Pond (Argentina). Isolation, Characterization and Limnological Implications
Humic substances (HS) were isolated from the sediments of Lobos Pond (Argentina) using mild conditions to preserve their native structure. The HS (humic and fulvic acids) were characterized by means of elemental analysis and FTIR spectroscopy. Also a by-product obtained during fulvic acids (FA) fractionation (an amorphous white solid residue) was analyzed. Results revealed possible interactions between FA and inorganic-organic substances that may have implications referring to bioavailability. Other limnological implications, such as autochtonous origin of HS linked with the hydrology, and change of pH during stormy weather that affects HS interactions, are discussed.Laboratorio de Investigación de Sistemas Ecológicos y Ambientale
Humic Substances from sediments of Lobos Pond (Argentina). Isolation, Characterization and Limnological Implications
Humic substances (HS) were isolated from the sediments of Lobos Pond (Argentina) using mild conditions to preserve their native structure. The HS (humic and fulvic acids) were characterized by means of elemental analysis and FTIR spectroscopy. Also a by-product obtained during fulvic acids (FA) fractionation (an amorphous white solid residue) was analyzed. Results revealed possible interactions between FA and inorganic-organic substances that may have implications referring to bioavailability. Other limnological implications, such as autochtonous origin of HS linked with the hydrology, and change of pH during stormy weather that affects HS interactions, are discussed.Laboratorio de Investigación de Sistemas Ecológicos y Ambientale
Impacto do aumento da concentração de dióxido de carbono sobre o oídio da videira.
Segundo o Painel Intergovernamental de Mudanças Climáticas (IPCC), a concentração do dióxido de carbono (CO2) até o final do século chegará aos 550 ppm. Este aumento poderá causar impactos positivos ou negativos sobre a interação planta-patógeno. Na região Nordeste, o oídio da videira causa danos consideráveis à produção por apresentar condições climáticas favoráveis ao desenvolvimento do patógeno durante todo o ano. O trabalho teve como objetivo avaliar o impacto do aumento da concentração de CO2 sobre o oídio da videira. O experimento foi realizado em câmaras de crescimento com controle da concentração de CO2 e temperatura. No experimento mudas de videira da cultivar Crimson foram inoculadas com uma suspensão de 105 esporos/ml por meio de pulverização até o ponto de escorrimento. Para cv. Crimson, o aumento da concentração de CO2 proporcionou um aumento na severidade da doença
Severidade da ferrugem em videira cv. Sugraone sob o aumento da concentração de CO2 atmosférico.
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