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Search Results: 1 - 10 of 277773 matches for " Souza Paulo Estev?o de "
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Efeito de fungicidas no controle in vitro de Colletotrichum gloeosporioides, agente etiológico da antracnose do mamoeiro (Carica papaya l.)
Tavares, Giltembergue Macedo;Souza, Paulo Estevo de;
Ciência e Agrotecnologia , 2005, DOI: 10.1590/S1413-70542005000100006
Abstract: the efficiency of fungicides on colletotrichum gloeosporioides was evaluated in vitro in the laboratory of epidemiology and diseases management of the department of phytopathology /ufla. the fungicides were applied either in bda medium or in glass slide chambers, the latter to assess the effects on conidial germination. the fungicides tested were: azoxystrobin, chlorothalonil, sodium hypochloride, imazalil, copper oxychloride, prochloraz, propiconazol, tebuconazol, thiabendazol and thiophanate-methyl in the concentrations of 0, 1, 10, 100, 500 and 1.000 ppm to evaluate the inhibition of the mycelial growth and in the concentrations of 0, 1, 10, 50 and 100 ppm to test inhibition of the conidial germination. the fungicides azoxystrobin, chlorotalonil, imazalil, prochloraz, propiconazol and tebuconazol presented high efficiency in the inhibition of the mycelial growth. the fungicides of the benzimidazol group (thiabendazol and thiophanate-methyl) showed low efficiency in the control of c. gloeosporioides. sodium hypochloride showed low efficiency in the control of the mycelial growth of the fungus. for inhibition of the conidial germination, the fungicides oxychloride, chlorothalonil and sodium hypochloride showed high efficiency, even at low concentrations. c. gloeosporioides showed to be tolerant to the fungicides thiabendazole and thiophanate-methyl, as conidial germination and mycelial growth were not affected in the presence of these products.
Progresso da ferrugem do cafeeiro irrigado em diferentes densidades de plantio pós-poda
Paiva, Bernardo Reis Teixeira Lacerda;Souza, Paulo Estevo de;Scalco, Myriane Stella;Santos, Leandro Alvarenga;
Ciência e Agrotecnologia , 2011, DOI: 10.1590/S1413-70542011000100017
Abstract: the objective of this study was to evaluate the effect of different irrigation controls implemented in four planting densities on a system of drip on the incidence and severity of rust and to assess the influence of leaf growth on the progress curve of this disease. the experiment was conducted in the experimental area of the federal university of lavras - mg, using the cultivar rubi mg-1192 with 6 years. the experimental design was randomized blocks with four replicates. the treatments consisted of four tranches represented by planting densities (conventional and non-conventional): 2500 (4.0 x1.0 m), 3333 (3.0 x 1.0 m), 5000 (2.0 x 1.0 m), 10,000 (2.0 x 0.5 m) plants / ha, with four subplots: the tension when irrigation water in the soil reaches values of 20 and 60kpa; using water balance management of irrigation (calculated by the software irriplus) with rounds of irrigation fixed three days per week and a control without irrigation, making a total of 16 treatments. each subplot line consisted of 10 plants with the six central plants considered as useful. the incidence and severity of rust and the percentage of grown of coffee plants were evaluated. after statistical analyses the data were converted to area under the curve of disease and growth progress. it was verified that the management of irrigation influenced the progress curve of growth, but it did not interfere in the progress curve of the incidence and severity of coffee rust. the dense system of plantation favored the incidence of rust. however, the planting densities did not affect growth.
Influência das variáveis ambientais no progresso da antracnose do feijoeiro e eficiência de tiofanato metílico + clorotalonil no controle da doen?a
Garcia, Alvanir;Souza, Paulo Estevo de;Pozza, Edson Ampélio;Santos, Florisvalda da Silva;
Ciência e Agrotecnologia , 2007, DOI: 10.1590/S1413-70542007000600016
Abstract: in minas gerais the anthracnose is one of the most important leaf diseases of the common bean due to occur at various planting time and to reduce the production. the present experiment was performed aiming to evaluate occurrence, progress of the disease and the efficiency of fungicide on the control of bean anthracnose. plots with and without fungicide treatment (thiophanate methyl + chlorothalonil, 240 + 600g a. i./ha) were evaluated in five times of evaluation during 24 sowing times of bean cultivar carioca, between april/96 and march/97. the occurrence of the anthracnose was not verified during february and march of 1997. treatment with fungicide resulted in the lower disease severity and higher yield, mainly in the months of higher severity of the disease. there was significant correlation between the severity and the maximum and minimum temperature and relative humidity 43, 57 and 71 days after emergency. there was a negative correlation between severity of the disease and yelds.
Progresso da ferrugem e da cercosporiose em cafeeiro (coffea arabica l.) Com diferentes épocas de início e parcelamentos da fertirriga??o
Talamini, Viviane;Pozza, Edson Ampélio;Souza, Paulo Estevo de;Silva, Antonio Marciano da;
Ciência e Agrotecnologia , 2003, DOI: 10.1590/S1413-70542003000100017
Abstract: evaluations of incidence of rust (hemileia vastatrix berk. & br.) and brown eye spot (cercospora coffeicola berk. & cooke) took place at intervals of 14 days, observing 6 leaves per plant during the period from march 21, 1998 to february 6, 1999 in a 'catuai' culture. the objective was to evaluate the effect of irrigation and fertirrigation on the incidence of rust and in 12 year coffee plants and analyze the progress curve of these diseases and their correlation to climatic variables. the experimental design was the one of randomized blocks with four treatments of different fertilizer splitting (1: 12 hand applications, 2:12 applications via fertirrigation, 3: 24 fertirrigated applications, 4: 36 fertirrigated applications). the plots were divided in 3 subplots that received treatments in different periods at initial irrigation (subplots a: june 1, b: july 15, c: september 1), and 2 checks (additional treats 1: fertilized 4 times and not irrigated, additional treats 2: conventional fertilizer and not irrigated). the area under disease progress curve (audpc) was calculated and submitted to variance analysis and tukey's test at 5% probability. for the coffee rust, no treatment was significant. curve progress showed maximum incidences in the months of july and september. there was a significant correlation at 1% probability among all the treatments and climatic variables, with the exception of the maximum temperature. for brown eye spot, the treatments attributed to the plots and to the subplots were significant at 1% of probability. however, the interaction between the two was non-significant. greater audpc in splitting fertilizer 2 and 4 was observed. in the subplots, greater audpc in check e following for d was observed. curve progress showed maximum incidences from may to july. there was a significant correlation of brown eye spot incidence in the majority of the treatments in relation to climatic variables.
Doen as foliares da alfafa (Medicago sativa L.), em Lavras, Minas Gerais
Pereira Rosana Cristina,Evangelista Ant?nio Ricardo,Souza Paulo Estevo de,Silva Alexandre Christófaro
Revista Brasileira de Zootecnia , 2003,
Abstract: Objetivou-se verificar as doen as foliares que ocorrem na alfafa em Lavras-MG, no período de setembro de 1997 a outubro de 1998. Um ensaio foi conduzido em blocos ao acaso em esquema de parcelas subdivididas. Nas parcelas foram alocadas foram 35 cultivares e nas subparcelas 11 épocas de avalia o. Avalia es foram realizadas aos 28 dias após corte, quando foram coletadas dez hastes de alfafa por parcela para avalia o da desfolha e determina o da severidade das doen as. Os dados foram submetidos à análise de variancia e os contrastes entre médias comparados pelo teste de Scott-Knott a 5%. A mancha-de-Leptosphaerulina ocorreu durante o ano todo, porém com maior severidade nos períodos mais frios do ano. A mancha-negra-das-folhas-e-caule apresentou maior severidade no final do ver o e início do outono e a ferrugem revelou maior severidade apenas nas avalia es de novembro. As maiores porcentagens de desfolha foram obtidas nos meses mais frios do ano. As cultivares mais resistentes à mancha-de-Leptosphaerulina, cercosporiose e à desfolha foram a Crioula, P30 e Costera SP INTA. As cultivares MH 15 e MH 4 destacaram-se pela maior resistência à ferrugem.
Doen?as foliares da alfafa (Medicago sativa L.), em Lavras, Minas Gerais
Pereira, Rosana Cristina;Evangelista, Ant?nio Ricardo;Souza, Paulo Estevo de;Silva, Alexandre Christófaro;Muniz, Joel Augusto;
Revista Brasileira de Zootecnia , 2003, DOI: 10.1590/S1516-35982003000600002
Abstract: it was aimed to verify the chief leaf diseases that occurs in alfalfa, in lavras-mg, state of minas gerais, of 1997 september to 1998 october. a randomized block trial subplots in time, whose factors were 35 alfalfa cultivars in the plots and 11 evaluation times, which corresponded to the months, in subplots. evaluations were performed at 28 days after the cut, when ten stems here collected by plots for evaluation of defoliation and determination of severity of the diseases. the data here submitted to the variance analysis and the contrasts among averages compared by scott-knott test at 5%. the leaf spot happened during the whole year, with a greatest severity in the periods more colds of the year. the summer black stem and leaf spot, it presented greater severity at the end of summer and beginning of the autumn and the rust reveled a greatest severity in the evaluations of november. the most resistant cultivars to leaf spot, summer black stem and leaf spot and defoliation were crioula, p 30 and costera sp inta. the cultivars mh 15 and mh 4 stood out by larger resistance to the rust.
AVALIA O DO POTENCIAL FUNGITóXICO DO óLEO ESSENCIAL DE Syzygium aromaticum(L.) MERR & PERRY (CRAVO-DA-íNDIA)
Luís Gustavo Martinez dos Santos,Maria das Gra?as Cardoso,Rafaela Karin de Lima,Paulo Estevo Souza
Tecno-Lógica , 2007,
Abstract: As plantas produzem uma variedade de compostos organicos. Muitos destes s o conhecidos como metabólitos secundários, eest o relacionados com a intera o da planta e o meio ambiente, como por exemplo, a defesa da planta contra insetos, bactérias efungos. Os óleos essenciais constituem um tipo de metabólito secundário de grande importancia econ mica, pois muitos podem serutilizados como medicamentos, inseticidas e antimicrobianos. O objetivo do presente trabalho foi verificar o potencial fungitóxico doóleo essencial de Syzygium aromaticum sobre fungos fitopatogênicos. O óleo essencial foi extraído dos bot es florais secos,empregando a técnica de arraste a vapor de água, utilizando o aparelho de Clevenger modificado. A fungitoxicidade do óleo foiavaliada sobre Fusarium oxysporum e Rhizoctonia solani. Os testes foram realizados “in vitro”, observando-se o crescimento destesfitopatógenos, na presen a de diferentes concentra es de óleo 100, 200, 500, 1000 e 2000mg/Kg, usando o meio de cultura BDA(Batata-Dextrose-ágar). Os fungos foram incubados em camara de germina o com controle de temperatura e luz, realizando-se 3repeti es. Observou-se que o óleo essencial de Syzygium aromaticum reduziu o crescimento micelial de Fusarium oxysporum eRhizoctonia solani. A inibi o do crescimento micelial (ICM) ocorreu em todas as concentra es citadas acima, sendo que a partir de500mg/Kg ocorreu a inibi o total dos fungos.
Effectiveness of essential oils in the treatment of Colletotrichum truncatum-infected soybean seeds
André Costa da Silva,Paulo Estevo de Souza,José da Cruz Machado,Bruno Marques da Silva
Tropical Plant Pathology , 2012, DOI: 10.1590/s1982-56762012000500001
Abstract: The aim of the study was to evaluate the antifungal activity of essential oils from "hortel do campo" (Hyptis marrubioides), "alfazema-do-Brasil" (Aloysia gratissima) and "erva-baleeira" (Cordia verbenacea) and their efficacy in the treatment of soybean seeds infected with Colletotrichum truncatum. In vitro assays were performed to evaluate the effects of the oils on spore germination, mycelial growth, and the production and viability of C. truncatum conidia. Soybean seeds inoculated with C. truncatum were treated with essential oils at concentrations ranging from 0.5 to 2% and grown under greenhouse conditions. Seed health and germination percentages were evaluated according to standard protocols. Seedling emergence, stand establishment and the percentages of dead seedlings were determined, together with the emergence speed index, plantlet height and dry weight of aerial biomass. The oils from H. marrubioides, C. verbenacea and A. gratissima inhibited the germination and production of conidia as well as the growth of C. truncatum. At concentrations ≥ 1%, the effectiveness of the oils against soybean anthracnose was superior to, or at least comparable with, that of the fungicide carbendazim. The viability of conidia and the germination of soybean seeds were not affected by any of the treatments with essential oils. It is concluded that essential oils from H. marrubioides, A. gratissima and C. verbenacea have potential as alternatives to synthetic fungicides in the control of anthracnose in soybean seeds.
Avalia??o da atividade fungitóxica de óleos essenciais de folhas de Eucalyptus sobre Fusarium oxysporum, Botrytis cinerea e Bipolaris sorokiniana
Salgado, Ana Paula Soares P.;Cardoso, Maria das Gra?as;Souza, Paulo Estevo de;Souza, Josefina Aparecida de;Abreu, Celeste Maria P.;Pinto, José Eduardo B. P.;
Ciência e Agrotecnologia , 2003, DOI: 10.1590/S1413-70542003000200001
Abstract: most plants are resistant to different pathogens and this resistance may be related to the existence of naturally produced fungistatic components. the present work evaluated the fungitoxic activity of essential oils from three eucalyptus species. the essential oils were obtained from eucalyptus leaves by steam distillation using a modified clevenger apparatus. the phytopatogens fusarium oxysporum, botrytis cinerea and bipolaris sorokiniana were employed in the biological tests. the growth of fungi in the presence of different concentrations of oil (5, 50, and 500 mg/kg), using bda (potato-dextrose-agar) and pca (potato-carrot-agar) culture media were evaluated. significant inhibition of the micelial growth of the fungal species was observed at the concentration of 500 mg/kg of oil after a period of seven days. the essential oil of eucalyptus urophylla showed the greatest fungitoxic activity. this fact was attributed to the presence of the compound globulol, which was absent in the oils obtained from e. camaldulensis and e. citriodora.
Distribui??o e identifica??o de Phakopsora pachyrhizi, agente causal da ferrugem da soja no estado de Minas Gerais
Sousa, Patrícia Ferreira Cunha;Alves, Eduardo;Castro, Hilário Ant?nio de;Souza, Paulo Estevo de;Almeida, álvaro Manuel Rodrigues de;Hochenbach, Silvana Regina;
Ciência e Agrotecnologia , 2007, DOI: 10.1590/S1413-70542007000300011
Abstract: the soybean rust is caused by two species: phakopsora pachyrhizi e p. meibomiae. in brazil this diseases has been responsible for great losses in the production of soybean in the last years. the distribution of the disease and identification of the prevalent species in the producing areas in brazil became necessary to guide the planning control measures. the molecular characterization based on pcr has been showing as useful tool to satisfy that need. in this study 86 samples of leaves infected by phakopsora from the main areas producing soybean in the state of minas gerais (triangulo, alto paranaíba, noroeste, sudoeste and sul) were used. the extraction of dna was made by the method of ctab. for the polimerase chain reaction, specific primers were used for each species, been primer ppm1/ppa2 specific for p. pachyrhizi and ppm1/pme2 specific for p. meibomiae. the results showed that the 86 samples belonged to the species p. pachyrhizi, agent causal of the "asian" rust. in other words, there was the production of bands specific from the group primer ppm1/ppa2 with approximate size of 141 pairs of bases. these results show that the species phakopsora present in 100% of the areas analyzed in the state of minas gerais was p. pachyrhizi. this information is important to guide futures breeding programs for resistance to the agent of soybean rust in the state.
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