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Search Results: 1 - 10 of 10544 matches for " Edson Ampélio;Manerba "
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Metodologias de inocula??o de Rhizoctonia solani na cultura da cenoura
Oliveira, Amanda Cabral Corrêa de;Souza, Paulo Estev?o de;Pozza, Edson Ampélio;Manerba, Felipe de Carvalho;Lopes, Maurício Ferreira;
Ciência e Agrotecnologia , 2008, DOI: 10.1590/S1413-70542008000300044
Abstract: rhizoctonia solani may cause different diseases in carrot (daucus carota l.). to test control methods, artificial inoculation is generally employed. this work aimed to adjust a methodology to inoculate r. solani (ag-4) in carrot. a randomized block outline with five replicates was used, with an experimental unit of a 3l-pot with 40 seeds and a substact composed by a mixture of soil/sand (3:1 v/v). treatments were those in a factorial experiment 4 x 3, with 4 inoculum densities (9; 18; 36; 72 mg of inoculum.kg-1 of soil) and three forms of artificial infestation (incorporated to the substract as a whole; incorporated on the surface; with direct contact with seeds) and an additional control. the experiment was carried out in a growth chamber at 200c and a 12h photoperiod. the evaluations were daily performed from the 8th to the 30th day after sowing, recording plant stand and number of seedlings with damping-off. the emergence index, averge percentage of pre and post emergence. were analyzed the density of 72 mg of inoculum·kg-1 of soil, incorporated on the surface of the susbtract was the most efficient inoculation method.
Efeito do tempo, substrato e temperatura na penetra??o de juvenis do segundo estádio de Meloidogyne javanica e Heterodera glycines em soja
Campos, Hercules Diniz;Campos, Vicente Paulo;Pozza, Edson Ampélio;
Summa Phytopathologica , 2006, DOI: 10.1590/S0100-54052006000200010
Abstract: at 2 days after inoculation, independent of the substrate used, lower penetration of j2 of meloidogyne javanica was observed compared to the other time points tested. when fine sand was used, greater penetration of j2 of m. javanica in soybean roots occurred at 4,4 days after inoculation. by using a mixture of soil and ground sand, the penetration increase was linear between at 2 and 8 days after inoculation. when the fine sand was used number of j2 of heterodera glycines, in the roots was highest at 2 days after inoculation. in the mixture of soil and ground sand, the soybean roots had lowest number of j2 of h. glycines at 2 days after inoculation, decreasing evenly toward day 8. at 24oc the penetration of j2 of m. javanica was higher (p< 0,05) regardless of cultivar resistance. however, in the resistant cultivar the penetration was not affected (p< 0,05) at temperatures between 24 and 28oc. at 32oc occurred significant decrease in penetration which reached 17,97% of the penetration observed at 28oc and with similar values at 16 and 20oc. in the susceptible cultivar the penetration decrease was significant at 28oc and 32oc, amounting to 34,74% of that at 24oc, and even greater than that at 16 and 20oc. at 12oc penetration was not observed in any of the cultivars used. considering h. glycines, the temperatures of 21,3oc provided great penetration of j2 in the susceptible cultivar and at 22,4oc in the resistant one. the penetration of j2 of h. glycines at 12 and 32oc was similar in both susceptible and resistant cultivars, but corresponded approximately to half of that at the temperatures that were better for penetration.
Efeito da temperatura na multiplica??o celular, no desenvolvimento embrionário e na eclos?o de juvenis do segundo estádio de Meloidogyne javanica
Campos, Hercules Diniz;Campos, Vicente Paulo;Pozza, Edson Ampélio;
Summa Phytopathologica , 2008, DOI: 10.1590/S0100-54052008000100006
Abstract: abiotic factors affect the embryonic development, survival and hatching of second-stage juvenile (j2) of meloidogyne spp. the effect of constant temperature has been studied with various species and populations of meloidogyne spp. however, the temperature fluctuation which predominates in the field between day and night or during periods of predominance of polar cold front, has not been well studied. thus, this work aimed to study the effect of temperature fluctuation on egg of m. javanica with standardized embryo development. when eggs with formed juveniles inside were used, highest percentage of hatching occurred at fixed temperature of 28 oc. the reduction of the exposure time at 28 oc reduced hatching. the eggs exposed for 10 hours at 10 oc and complemented by 14 hours at 28 oc resulted in greater j2 hatching as compared to 10 hours at 5 oc complemented by 14 hours at 28 oc. the incubation at fixed temperature of 10 oc rendered lowest hatching. when eggs at the two-cell stage were used and incubated at 28 oc the cell multiplication and embryonic development were speeded up. at constant temperature of 10 oc for egg incubation during 12 days only cell multiplication occurred. however, when the incubation temperatures varied with period of 10 hours at 10 oc and complemented by 14 hours at 28 oc, juveniles were formed inside the eggs and hatched but significantly lower than those at constant temperature of 28 oc. at alternated temperatures of 10 hours at 5 oc, complemented by 14 hours at 28 oc, with the same incubation time, juveniles were not formed. in the eggs occurred only the pluricelular, gastrula and tadpole stages occurred. therefore, the constant temperature of 10 oc allows only the cellular multiplication, and the temperature interval of 5 oc and 10 oc affect drastically several processes involved in embryo development of m. javanica.
Diferen?as na intensidade e na expans?o da pústula da ferrugem do cafeeiro em dois acessos de Hemileia vastatrix
Salustiano, Maria Eloisa;Pozza, Edson Ampélio;Ferraz Filho, Antonio Carlos;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000700023
Abstract: the aim of this work was to study, under controlled environment, the differences in the disease intensity and pustule expansion of two hemileia vastatrix accesses, sampled in cultivar catuai coffee (coffea arabica l.) plants from coromandel (cor2) and ijaci (iij1), towns located respectively in the west and south of minas gerais state. the inoculated plants were submitted to three temperatures (15, 20 and 25oc) and three leaf wetness durations (24, 48 e and 72 hours) in a factorial scheme with three replicates. both accesses presented a higher disease severity when submitted to 24h leaf wetness duration after inoculation. the higher infection frequency for iij1 was at 15oc, while the temperature did not influence this variable for cor2. there was a higher severity for cor2 inoculated plants when incubated at 25oc. the higher pustule expansion, for leaves inoculated with iij1 was at 15oc with 7.59cm2 and a lower at 25oc, with 5.37cm2, while for cor2 when temperature raised from 15 to 25oc, there was an increase in the pustule expansion from 1.44 to 6.62 cm2, respectively. fungal lines from ijaci and from coromandel presented differences in the intensity and pustule expansion of rust, under controlled environment.
Efeito da temperatura no crescimento micelial, produ??o e germina??o de conídios de Colletotrichum spp. isolados de Coffea arabica L
Dias, Moab Diany;Pozza, Edson Ampélio;Abreu, Mario Sobral de;Miranda, Edin Orosco;
Ciência e Agrotecnologia , 2005, DOI: 10.1590/S1413-70542005000300006
Abstract: the objective of this study was to assess the effect of temperature on micelial growth, production and conidial germination of colletotrichum spp. isolates from branches, leaves and fruits of coffee with symptoms of blister spot and tip blight. the isolates presented differentiated behavior regarding the speed of mycelial growth, sporulation capacity and the formation of reproductive structures, showing high capacity of adaptation to different temperatures.
Bactérias endofíticas como agentes promotores do crescimento de plantas de tomateiro e de inibi??o in vitro de Ralstonia solanacearum
Barretti, Patrícia Baston;Souza, Ricardo Magela de;Pozza, Edson Ampélio;
Ciência e Agrotecnologia , 2008, DOI: 10.1590/S1413-70542008000300005
Abstract: out of one hundred and fifty isolates of endophytic bacteria from leaves, stems and roots of healthy tomatoes (solanum lycopersicum l.), fifty three showed ability to promote tomato plant growth, among these, ten isolates ufv-e17, ufv-e22, ufv-e25, ufv-e26, ufv-e27, bacillus cereus (ufv-e29), ufv-e49, ufla 06-ls, ufla 08-ls and ufla 11-ls, provided the largest plant growth promotion. weekly assessment of plant height and number of leaves and leaflets were carried out during 45 days. after the sixth evaluation, the leaf area and the fresh and dry weight of the aerial part of plants and of the roots were measured. isolate ufv-e49 provided the largest values of height, leaf area, number of leaves and fresh and dry weight of the aerial part of plants as well as the root. from the selected isolates, only two presented antimicrobial activity against ralstonia solanacearum.
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 Estev?o 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 Estev?o 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.
Rela??o entre a temperatura e o molhamento foliar no monocíclo da Sigatoka-negra
Uch?a, Cleilson do Nascimento;Pozza, Edson Ampélio;Albuquerque, Keline Sousa;Moraes, Wilson da Silva;
Summa Phytopathologica , 2012, DOI: 10.1590/S0100-54052012000200006
Abstract: the influence of temperature (21, 24, 27 and 30 °c) and leaf wetness duration (0, 12, 24, 48 and 72 hours) on the penetration of the causal agent of black sigatoka (mycosphaerella fijiensis) was quantified under controlled environment. the area under disease progress curve (audpc) and the incidence were influenced by temperature and leaf wetness duration. there were significant differences (p=0.05) in audpc for the different temperatures, as well as a significant interaction (p=0.05) between temperatures and leaf wetness. symptoms were observed at all temperatures; however, higher audpc was observed for inoculated leaves kept at 24 and 27°c, from 48 hours of leaf wetness. at temperatures of 21°c and 30°c, the incidence of black sigatoka was low. the minimum leaf wetness duration for the disease progress was 24 hours. symptoms of black sigatoka were not observed for inoculated leaves with 0 and 12-hour leaf wetness at all temperatures. after 5 days in humid chamber, all asymptomatic leaves presented symptoms characteristic of black sigatoka, demonstrating that the conidia inoculated in the leaves kept viable for a certain period in the absence of free water on the leaf.
Germina??o de urediniósporos de Phakopsora pachyrhizi em diferentes métodos de armazenamento
Zambenedetti, Elisandra Batista;Alves, Eduardo;Pozza, Edson Ampélio;Araújo, Dejania Vieira de;
Summa Phytopathologica , 2007, DOI: 10.1590/S0100-54052007000100013
Abstract: the objective of this study was to evaluate the effect of different storage methods on the viability of the urediniospores of p. pachyrhizi. urediniospores were collected and stored in five different conditions: detached dry leaves (24°c), desiccator (10°c) + liquid nitrogen (-196°c) after 60 days, refrigerator (4°c), deep-freezer (from -60°c to 80°c) and liquid nitrogen (-196°c). the percentage of germination from stored urediniospores was evaluated every thirty days in water-agar medium. urediniospores stored in liquid nitrogen presented the highest germination percentage after 270 days of storage. in desiccator, the germination was zero at ninety days of evaluation, and when urediniospores were transferred to and kept in liquid nitrogen, the germination was up to 30%. the urediniospores stored under others conditions presented a decline in germination at sixty days and at the ninety days the germination declined to zero. based on these results, the most efficient way of storing urediniospores of p. pachyrhizi was using liquid nitrogen.
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