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Search Results: 1 - 10 of 436457 matches for " Mércia Virginia Ferreira dos;Freitas "
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Decomposi??o de serrapilheira em bosque de sabiá na Zona da Mata de Pernambuco
Freire, Joelma de Lira;Dubeux Júnior, José Carlos Batista;Lira, Mario de Andrade;Ferreira, Rinaldo Luiz Caraciolo;Santos, Mércia Virginia Ferreira dos;Freitas, Erinaldo Viana de;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000800006
Abstract: the research aimed to evaluate the decomposition of sabiá (mimosa caesalpiniifolia benth) litter fractions by using the nylon bag technique. the following litter fractions were incubated: senescent leaves, leaves at the beginning of mineralization, and branches with diameter up to 20 mm. incubation was performed during periods of 0, 4, 8, 16, 64, 100, and 256 days in 2006 and 2007. the fractions were distributed in a random block design with five replications. it was evaluated the disappearance of biomass, nitrogen (n), and phosphorus (p), concentrations of nitrogen and phosphorus and the carbon/ nitrogen ratio of litter during the periods of incubation. in general, the negative exponential model explained the disappearance of biomass, nitrogen, and phosphorus, however, there was a variation among years and, in some cases, despite of being significant, the models showed a low correlation between predicted and observed data. biomass disappearance rate was slow because only 30% of leaf biomass was mineralized after 256 days of incubation. net nitrogen mineralization showed large variation among years, and it differed among the studied fractions. nitrogen content of the litter increased, on average, until 32 days (leaves) and until 64 days (branches) of incubation followed by stabilization. the linear plateau model was used to explain that process. in the course of the incubation periods, the carbon/nitrogen ration decreased. despite of the high content of nitrogen, the decomposition of sabiá litter is slow, what might reduce the loss of nutrients in the forest, increasing its sustainability and reducing the possible deleterious effects to the environment.
Uso de descritores morfológicos e herdabilidade de caracteres em clones de capim-elefante de porte baixo
Silva, Sharlyton Harysson Barbosa da;Santos, Mércia Virginia Ferreira dos;Lira, Mario de Andrade;Dubeux Junior, José Carlos Batista;Freitas, Erinaldo Viana de;Ferreira, Rinaldo Luiz Caraciolo;
Revista Brasileira de Zootecnia , 2009, DOI: 10.1590/S1516-35982009000800008
Abstract: the experiment was carried out with the objectives to evaluate the use of morphologic descriptor in the characterization and selection of dwarf elephant grass genotypes, and to evaluate the heritability of the evaluated traits. nine dwarf elephant grass clones were used (taiwan a.146 - 2.14, taiwan a.146 - 2.27, taiwan a.146 - 2.37, taiwan a.146 - 2.114, merker méxico - 6.2, merker méxico - 6.5, merker méxico - 6.31, cv. mott, and cnpgl92f198.7) was allotted to a randomized complete block design was used with three replications. the morphologic descriptors were applied every 60 days after the staging cut. a total of five cuts were performed at 60-day intervals using a height of 10 cm from ground level. among the evaluated dwarf elephant grass clones the tallest ones were more desirable, and this trait should be considered at the moment of selection. heritability estimate was high for all evaluated traits of dwarf elephant grass, varying from 66% for sheath wax to 100% for mid-rib color. the taiwan a.146 - 2.37 clone was similar to the mott cultivar. heritability values showed genetic variability among clones, detected at 60 days regrowth. some of the used morphologic descriptors allowed characterization of the evaluated genotypes. the clones taiwan a. 146-2.27, taiwan a. 146-2.37, taiwan a. 146-2.114, and merker méxico 6.31 were the tallest and showed greater total tillering intensity, and were more desirable, presenting greater potential for use under cutting.
Deposi??o e composi??o química de serrapilheira em um bosque de sabiá
Freire, Joelma de Lira;Dubeux Júnior, José Carlos Batista;Lira, Mario de Andrade;Ferreira, Rinaldo Luiz Caraciolo;Santos, Mércia Virginia Ferreira dos;Freitas, Erinaldo Viana de;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000800005
Abstract: this research aimed to evaluate the deposition and chemical composition of the components of the existing and deposited litter in a sabiá (mimosa caesalpiniifolia benth) canopy. the experiment was carried out from august 2006 to july 2007. the evaluation of the existing and deposited litter was performed every 28 days using 20 squares with 1m2 randomly allocated and new areas were chosen for each evaluation. the canopy showed plants with an average diameter of 26.8 cm at breast height. monthly deposition of organic matter of leaves and branches during the experimental period was 15,167 kg and 3,373 kg/ha, respectively, and it increased during the highest precipitation period, in a 0.30 relationship with the accumulation, indicating higher accumulation than deposition. leaf proportion was 87% of the total litter, with means of 2.9% of nitrogen and 0.17% of phosphorus. the carbon/nitrogen ratio of leaves was below 30, while carbon/nitrogen ratio of the branches ranged from 30 to 40, proving a better quality for leaves. during the experimental period, deposition of nitrogen through litter was approximately 462 kg/ha and 30 kg/ha for phosphorus. litter deposition is essential for maintenance of soil fertility in a sabiá canopy and it contributes for conservation and sustainability of the canopy.
Produtividade e composi??o química de gramíneas tropicais na Zona da Mata de Pernambuco
Santos, Mércia Virginia Ferreira dos;Dubeux Júnior, José Carlos Batista;Silva, Maria da Concei??o;Santos, Stuart Francisco dos;Ferreira, Rinaldo Luiz Caraciolo;Mello, Alexandre Carneiro Le?o de;Farias, Iderval;Freitas, Erinaldo Viana de;
Revista Brasileira de Zootecnia , 2003, DOI: 10.1590/S1516-35982003000400006
Abstract: this work was carried out to evaluate the productive potencial and chemical composition of five grasses (pennisetum purpureum schum. cv. pioneiro, p. purpureum schum cv. mott; panicum maximum jacq. cv. momba?a, p. maximum jacq cv. tanzania, e brachiaria brizantha (hochst) stapf. cv. marandu). the cuts were performed at 35 days of intervals and 40 cm above ground. pioneiro showed higher dm yield (7.35 t dm/ha/35 days) when compared to the dwarf elephantgrass (5.28 t dm/ha/35 days) and tanzania grass (5.23 t dm/ha/35 days), being similar to the others. brachiaria brizantha presented the highest total tillering (538.72/m2) however the aerial tiller weight was the lowest for this species. the cultivars of p. purpureum showed higher aerial tillering and lower basal tillering, when compared to the cultivars of p. maximum. the cp concentration ranged from 6.96 to 10.20% and the cultivar pioneiro presented the highest value. no difference was found among the forages for ndf and adf, and the mean values were 73.83 and 39.20%, respectively. at the evaluated cut interval, the forages presented a high proportion of leaves (> 80%), showing potential to be used on livestock pasture-based operations in the forest zone of pernambuco.
Características estruturais e morfológicas de genótipos de Pennisetum sp. sob pastejo no período de seca
Cunha, Márcio Vieira da;Santos, Mércia Virginia Ferreira dos;Lira, Mário de Andrade;Mello, Alexandre Carneiro Le?o de;Ferreira, Rinaldo Luiz Caraciolo;Freitas, Erinaldo Viana de;Nunes, José Carlos;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000300004
Abstract: the experiment was carried out to study structural and morphologic characteristics of five pennisetum sp. genotypes (ce 08 a.d., venezuela, hv-241, elephant b and hexaplóide) under grazing during the dry period in pernambuco forest zone. genotypes were managed under rotational stocking (44 days of resting and four days of grazing period). the experimental design was randomized blocks in a split plot arrangement, and four replications. the genotypes represented the plots, and grazing cycles, the subplots. there was variation in the structural and morphologic characteristics of the pennisetum sp. genotypes. the ce 08 a.d. and elephant b presented high density of green leaf blade, low percentage of dead material and high density of remaining basal tillers and new aerial tillers, with averages of 5.0±0.4 kg dm/ha/cm; 33±0.2%; 22±0.2 and 146±0.4 tillers/m2, respectively. the hv-241 presented high participation of dead material in its aerial biomass (55.6±0.3%) due to high tiller mortality (19±0.3 and 114±0.4 basal and aerial dead tillers/m2, respectively). the genotypes ce 08 a.d. and elephant b had been distinguished as promising to be used under grazing in the dry period. the genotype hv-241, elephantgrass hybrid with pearl millet, was more affected by water stress during the dry period of the year.
Variabilidade e herdabilidade de caracteres morfológicos em clones de capim-elefante na Zona da Mata de Pernambuco
Silva, Ant?nio Luiz Cordeiro da;Santos, Mércia Virginia Ferreira dos;Dubeux Júnior, José Carlos Batista;Lira, Mario de Andrade;Ferreira, Rinaldo Luiz Caraciolo;Freitas, Erinaldo Viana de;Cunha, Márcio Vieira da;Silva, Maria da Concei??o;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010001000005
Abstract: this research was carried out at to evaluate the variability and heritability of morphologic traits in 54 elephant grass clones (three local controls and 51 from the renace/cnpgl) in the forest zone in pernambuco. it was used a complete randomized block design with additional controls. three cuts were performed on the 60th day of regrowth. there were significant differences for stem diameter, basal and aerial tillers density, width of leaf 3, length of leaf 5, leaf blade percentage, stem percentage, and leaf/stem ratio. clones of renace are similar to the ones traditionally cultivated in the conditions of forest zone in pernambuco regarded to morphological characters. cultivar pioneiro showed early flourishing in the environmental conditions of this study. number of basal and aerial/metter tillers showed good heritability, evidencing little influence of the environment on variability among the clones. considering the variability among renace clones for basal and aerial tillers/m and leaf/stem ratio and the high heritability of these characters, it is possible to obtain genetic gains for these traits in the elephant grass breeding program in the forest zone in pernambuco.
Ensaios preliminares sobre autofecunda??o e cruzamentos no melhoramento do capim-elefante
Silva, Maria da Concei??o;Santos, Mércia Virginia Ferreira dos;Lira, Mário de Andrade;Mello, Alexandre Carneiro Le?o de;Freitas, Erinaldo Viana de;Santos, Ramilton Jader Menezes;Ferreira, Rinaldo Luiz Caraciolo;
Revista Brasileira de Zootecnia , 2008, DOI: 10.1590/S1516-35982008000300004
Abstract: the objectives of this work were to evaluate the self-pollination as a tool in the elephantgrass (pennisetum purpureum) breeding and to compare progenies of pennisetum purpureum origined from different breeding strategies: self-pollination, intraspecific crossbreeds, and interspecific crossbreeds with pennisetum glaucum. the experimental treatments were represented by the three fecundation forms: intraspecific crossbreed, interspecific crossbreed and self-pollination. a total of ten families originated from intraspecific crossbreed resulting in 160 progenies; two families originated from interspecific crossbreed resulting in 38 progenies, and two families originated from self-pollination resulting in 40 progenies, was evaluated. the evaluated traits were dry matter production (kg/tussock), dry matter concentration (%), plant height (m), number of basal tillers (n./tussock) and survival index (%), in two evaluations and non-replicated plots. the intraspecific crossbreed, interspecific crossbreed and self-pollination presented average dry matter production of 0.47, 0.78, and 0.46 kg of dm/tussock, at first evaluation and 0.14, 0.23, and 0.22 kg of dm/ tussock, at second evaluation, respectively. this indicates the necessity of plot replication to separate the environmental effect from the genetic effect. the interspecific crossbreed showed potential to generate progenies with satisfactory dry matter concentration which is more appropriated for ensiling. the treatments showed potential to release variability of traits evaluated through vegetative propagation, however, the low survival index of self-pollinated progenies reduces the probability of obtaining pure lines of elephantgrass.
Genótipos de capim-elefante sob pastejo no período de seca na Zona da Mata de Pernambuco: fatores relacionados à eficiência de pastejo
Cunha, Márcio Vieira da;Santos, Mércia Virginia Ferreira dos;Lira, Mário de Andrade;Mello, Alexandre Carneiro Le?o de;Freitas, Erinaldo Viana de;Apolinário, Valéria Xavier de Oliveira;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000200004
Abstract: the experiment was carried out to evaluate factors related to the grazing efficiency of five pennisetum sp. genotypes (ce 08 a.d., venezuela, hv-241, elephant b and hexaplóide) during the dry period in the forest zone of pernambuco. genotypes were managed under rotational stocking (44 days of resting and four days of grazing period). it was used a split-plot arrangement in a complete randomized block design (genotypes represented the plots; grazing cycles, the subplots). six replications were used to determine pre-grazing total leaf blade mass and green and senescent leaf blade mass. four replications were used for leaf blade accumulation and grazing efficiency and, for these variables, it was used a complete randomized blocks design. the ce 08 a.d. and elephant b presented greater pre-graze total leaf blade mass, green leaf blade, green leaf blade accumulation, and grazing efficiency, with averages of 1,374 kg dm/ha, 737 kg dm/ha, 654 kg dm/ha/44 days and 80% of the green leaf blade accumulation, respectively. the highest grazing efficiency (100% of the green leaf blade accumulation) occurred at the hv-241 pastures. this high grazing efficiency was associated to the low green leaf blade accumulation (155 kg of ms/ha/44 days). the lowest grazing efficiency was observed for the hexaplóide (59% of the green leaf blade accumulation), possibly due to high losses under grazing (30% of the pre-grazing total leaf blade mass). the green leaf blade mass decreased mostly until the second grazing day, while the losses of total leaf blade were higher in the second and third grazing days. the genotypes ce 08 a.d. and elephant b presented potential to be used under rotational stocking, in the pernambuco forest zone.
Association between the morphological and productive characteristics in the selection of elephant grass clones
Cunha, Márcio Vieira da;Lira, Mario de Andrade;Santos, Mércia Virginia Ferreira dos;Freitas, Erinaldo Viana de;Dubeux Junior, José Carlos Batista;Mello, Alexandre Carneiro Le?o de;Martins, Kalina Gerciane Rodovalho;
Revista Brasileira de Zootecnia , 2011, DOI: 10.1590/S1516-35982011000300004
Abstract: the objectives in this work were to study the association between the morphological and productive characteristics in pennisetum sp. clones, and to identify the morphological characteristics responsible for the productivity in pennisetum cp. clones. the canonical correlations were evaluated and the path analysis was made from the simple genotypic correlation matrix between the morphological and productive characteristics of eight pennisetum sp. clones (taiwan a-146 2.37, taiwan a-146 2.27, taiwan-146 2.114, merker méxico mx 6.31, mott, hv-241, elefante b and iri-381). the canonical correlations were significant at 1% probability by the chi-square test. the first pair of canonic factors, with correlation of 0.9999, related the plants with the highest dry matter content to plants with lower leaf area indexes, light perception and leaf angle. the second pair of canonic factors, with correlation of 0.9999, related the plants with the highest dry matter production to the plants with higher basal tiller density, height, and low green leaf number per tiller. the results of the path analysis indicated that the light interception is determinant in dry matter content expression of pennisetum sp. clones, while the basal tiller density and plant height are responsible for dry matter production in these clones.
Utiliza o de técnicas multivariadas na avalia o da divergência genética entre clones de palma forrageira (Opuntia ficus-indica Mill.)
Ferreira Carlos Adonai,Ferreira Rinaldo Luiz Caraciolo,Santos Djalma Cordeiro dos,Santos Mércia Virginia Ferreira dos
Revista Brasileira de Zootecnia , 2003,
Abstract: Avaliou-se, por meio de técnicas multivariadas, a divergência genética entre clones de palma forrageira (Opuntia ficus-indica Mill.), em um experimento instalado na Esta o Experimental da Empresa Pernambucana de Pesquisa Agropecuária - IPA, Caruaru - PE. O delineamento foi em blocos casualizados, com três repeti es. Os tratamentos foram 19 clones de palma do Banco de Germoplasma do IPA. Foram mensuradas: a) medidas em artículos, conforme a ordem: comprimento, largura, espessura, número e peso da matéria verde. b) medidas por planta: presen a de espinho, número de artículos por ordem e total, altura total, infesta o por cochonilha e peso da matéria verde. Realizaram-se análises de variancia univariada (ANOVA) e multivariada (MANOVA), das variáveis can nicas (VC) e de agrupamento (AA). Na ANOVA, foi verificada diferen a entre as médias de clones e por meio da MANOVA, diferen a entre vetores de médias de clones. Com a aplica o da VC, foi possível reduzir a dimensionalidade original para duas dimens es, com explica o de 85,03% da varia o total. Foi considerada, como característica passível de descarte, a porcentagem de infesta o por cochonilha. Na AA discriminaram-se nove grupos. A característica porcentagem de infesta o por cochonilha n o deve ser incluída no estudo da diversidade genética nas condi es estudadas. As características de maior discrimina o foram espessuras dos artículos primário, secundário e terciário, número de artículo primário e pesos médios de matéria verde por artículos secundário e terciário. Em um programa de melhoramento de palma forrageira, devem-se considerar o grupo de clones e o desempenho do clone quanto às características de maior relevancia agron mica e zootécnica.
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