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Search Results: 1 - 10 of 10612 matches for " Dirceu Maximino Fernandes "
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Organic compost in physiological potential of broccoli seeds after storage Composto organico no potencial fisiológico de sementes de brócolis após o armazenamento
Felipe Oliveira Magro,Antonio Ismael Inácio Cardoso,Dirceu Maximino Fernandes
Semina : Ciências Agrárias , 2012,
Abstract: The study was carried out with the objective to evaluate the broccoli seeds (cultivar Ramoso Santana) germination and vigor from plants cultivated with different organic compost levels and after storage in dry chamber. At seed production stage, the experiment was conducted in randomized complete blocks design, with five treatments (0; 30; 60; 90 and 120 t ha-1 of Biomix organic compost) and four replications. Soon after harvesting and after 12 and 24 months of conservation in dry chamber room (20oC and 40% relative humidity) it was evaluated germination, following seed analisys rules, and vigor (first count of germination and germination speed index – IVG). There were no differences in germination and vigor in seeds as soon as they were harvested and after 12 month of storage. After 24 months of storage, the lesser the organic compost rates, the lesser seed germination and IVG, with respective values, without compost, of 69% and 12,3. For another hand, the highest values for germination and IVG, 82% and 16,1, respectively, were obtained with the highest rate of organic compost (120 t ha-1). O trabalho foi conduzido com o objetivo de avaliar a germina o e o vigor de sementes de brócolis (cultivar Ramoso Santana) obtidas de plantas cultivadas com diferentes doses de composto organico e armazenadas em camara seca. O delineamento experimental utilizado na produ o de sementes foi o de blocos casualizados, com cinco tratamentos (0; 30; 60; 90 e 120 t ha-1 de composto organico marca comercial Biomix ) e quatro repeti es. Logo após a colheita e durante a armazenagem aos 12 e 24 meses em camara seca (20oC e 40% UR) foi avaliada a germina o e o vigor (primeira contagem da germina o e índice de velocidade de germina o – IVG). N o houve diferen as na germina o e vigor nas sementes recém colhidas e aos 12 meses de armazenamento. Aos 24 meses de armazenamento das sementes, quanto menores as doses de composto organico, menores foram o percentual de germina o e o IVG, com valores respectivos, na ausência de composto, de 69% e 12,3. Já os maiores valores de germina o e IVG, 82% e 16,1, respectivamente, foram obtidos na maior dose de composto organico (120 t ha-1).
Intera??o de doses de calcário e zinco nas características morfológicas e nos componentes de produ??o da mamoneira
Léles, érica Pontes;Fernandes, Dirceu Maximino;Silva, José Iran Cardoso da;Fumes, Leandro Augusto Andrade;
Acta Scientiarum. Agronomy , 2010, DOI: 10.4025/actasciagron.v32i3.5820
Abstract: the objective in this work was to evaluate the effects of lime and zinc levels, as well as their interaction on development in castor bean plants. the hypothesis of this work is that the lime levels reduce the zinc availability in soil for the plant. the experiment was carried out under greenhouse conditions without temperature control, in pots with 17 dm3 of 'dystrophic red latosol', medium texture. the statistical design was of randomized blocks, in a 3 x 5 factorial scheme, with four replicates. the treatments consisted of liming to reach three basis saturations: 40, 60 and 80%, combined with five zinc levels: 0.5, 1.0, 2.0, 4.0 and 8.0 mg dm-3. only one plant per pot was grown up to 174 days after emergence (first mature raceme), at which point the morphologic and production components of plants were evaluated. higher lime levels resulted in greater number of seeds per plant and dry matter of seeds per plant. there was interaction of basis saturation and zinc in plant height, in dry matter of root and in length of raceme (masculine part and total). however, none of these increases reflected a significant difference in weight of 100 castor bean seeds.
Macronutrientes em cultivares de gérbera sob dois níveis de fertirriga??o
Ludwig, Fernanda;Fernandes, Dirceu Maximino;Mota, Poliana RD;B?as, Roberto L Villas;
Horticultura Brasileira , 2008, DOI: 10.1590/S0102-05362008000100013
Abstract: potted gerbera is known world-wide as an ornamental plant; althought there is a reduced volume of information on its cultivation, specially nutrition and fertilization, essential factors for profits in the productive quality. in the present work the content and accumulation of macronutrients was evaluated in four gerbera cultivars under two levels of fertigation. the experiment was carried out in a greenhouse, from may to july, 2006. the experiment was installed in randomized blocks and constituted of a 4x2 factorial scheme, being 4 gerbera cultivars (cherry, golden yellow, salmon rose and orange) and 2 concentrations of nutritive solution (50% and 100%), corresponding to the electrical conductivity of 0,92 and 1,76 ds m-1, during the vegetative period and 1,07 and 2,04 ds m-1, during the reproductive one. the nutrients were applied through manual fertigation, once a day. by the end of the vegetative and reproductive periods, the contents and accumulation of macronutrients were quantified. the nutrients demand differed among the cultivars and the solution concentration presented an important factor in the content and accumulation of n, p, ca, mg and s in the plant. the greatest accumulations was registered at the last third of the production cycle, presenting the following order of absortion: k>n>ca>mg>p>s (415, 327, 33, 32, 20 mg plant-1).
Produ??o de bulbos e incidência de pseudoperfilhamento na cultura do alho vernalizado em fun??o de aduba??es potássicas e nitrogenadas
Büll, Leonardo Theodoro;Bertani, Rosemary Marques de Almeida;Villas B?as, Roberto Lyra;Fernandes, Dirceu Maximino;
Bragantia , 2002, DOI: 10.1590/S0006-87052002000300006
Abstract: two experiments were carried out under greenhouse conditions, with the objective of studying the influence of n x k interaction on vernalizated garlic (allium sativum l.) grown in 50 kg pots. both experiments were in factorial 4 x 4: (a) one in 1993 with four potassium levels in the sowing (original, 4%, 8% and 16% of cec) and four levels of nitrogen in covering (40, 80, 160 and 320 kg.ha-1) applied half at 30 and the remaining at 50 days after seed emergency (dae); (b) the other in 1994, with four potassium levels and four nitrogen levels, both splitted and applied in covering. at 70 dae two plants per pot were collected for nutritional diagnosis. the results indicated that the leaf concentration of nitrogen was slightly reduced by k fertilization applied in the sowing or in covering. however, there were increases in the potassium concentration with the nitrogen concentration in the leaves; the chlorophyll concentration increased with the potassium levels in the leaves, because of variations in k fertilizer rates applied in the sowing, and with the nitrogen rates in covering; increases in n fertilizer rates in covering enhanced the pseudogrowing incidence in the culture, that was not affected by k fertilization in the sowing or in covering; the bulb yield was slightly increased by nitrogen fertilization in covering.
Recupera??o do nitrogênio da mistura de uréia e sulfato de am?nio por plantas do milho
Villas B?as, Roberto Lyra;Boaretto, Antonio Enedi;Godoy, Leandro José Grava de;Fernandes, Dirceu Maximino;
Bragantia , 2005, DOI: 10.1590/S0006-87052005000200014
Abstract: the mixture of urea with fertilizers with acid characteristics applied to the soil can increase the ions h+ concentration close of the granule and promote the reduction of n volatilization losses. the experiment was carried out in pots with 15 kg of a medium textured red latossol, under plastic tunnel, in botucatu, state of s?o paulo, in which corn plants were grown (two plants per pot) until tasseling (66 days after emergency - dae). the treatments comprised application of n-fertilizer (100 mg n dm-3), at the five-leaves stage (30 dae), using the following fertilizers or mixtures: (1) urea (ur) enriched with 15n; (2) ammonium sulphate (as) enriched with 15n; (3) "sulfnitro" (80% of n-ur and 20% of n-as in the same granule); (4) mixture of ur (80% n) and as (20% n and enriched with 15n); (5) mixture of ur (50% n) and as (50% n) both enriched with 15n; (6) mixture of ur (50% n) and as (50% n and enriched with 15n) and (7) mixture of ur (50% n); as (50% n), both enriched with 15n, diluted in water (solution containing 3% of n), plus a treatment did not receive n. the mixture ur and as did not affect n recovery by corn plant. of the total 15n applied, about 67% were recovered by the corn plant (29% in the leaves, 25% in the stem and 13% in the roots) and 6% in the soil, with an estimated loss of 27%. the 15n of urea was recovered in smaller amount in the stem in relation to that from ammonium sulphate.
Análise de crescimento em Heteranthera reniformis, sob diferentes teores de Ca, Mg e S
Domingos, Vanessa David;Martins, Dagoberto;Fernandes, Dirceu Maximino;Costa, Neumarcio Vilanova da;Paschoa, Paulo Lovo de;
Bragantia , 2006, DOI: 10.1590/S0006-87052006000200015
Abstract: the objective was to study the growth, biomass allocation and concentration of nutrients in heteranthera reniformis ruiz & pav. under the effect of different concentrations of ca, mg and s. the plants were cultivated in plastic pots fulfilled with rolled stone, in nutrient solutions of 80% of the original concentration of sarruge. the experiment was carried out in a complete randomized design, with 4 contents (0, 25, 50 and 75% of the base solution) evaluated in ca, mg and s, plus the control (100% of the solution base), with 4 replicates in the period of 35 days in greenhouse. the increase of contents of ca produced significant reduction in the leaf. the largest areas leaf occurred in solutions of 25% of ca and 50% of mg and s. the largest proportion of dry biomass was found in the stem, except with 25% of ca (40 mg.l-1) in solution that produced larger leaf area and larger specific leaf area. among different mg contents, larger biomasses were observed at 50% of mg (19, 2 mg.l-1) and, for s, there were not significant differences, except at 0% of s in solution. the solution with 160 mg.l-1 of ca produced the largest concentration of ca in leaf (56, 6 g.kg-1). the contents of ca, mg and s in solution corresponded to a proportional increase in the plant. the contents of sulfur in leaves and in stems increased with the concentration of s, whereas the content in roots reduced in the concentrations between 12,8 and 38,4 mg.l-1.
Uso do clorofil?metro no manejo da aduba??o nitrogenada para milho em sucess?o a pastagem de Brachiaria decumbens
Godoy, Leandro José Grava de;Souto, Lauter Silva;Fernandes, Dirceu Maximino;Villas B?as, Roberto Lyra;
Ciência Rural , 2007, DOI: 10.1590/S0103-84782007000100007
Abstract: the corn response to the nitrogen fertilizing cultivated after pasture depends on of the species, straw amount, c: n rate, microbial population, climatic conditions and other factors. the study was aimed at evaluating the use of the green color intensity of the leaf (gci), measured by the chlorophyll meter, as indicative for nitrogen fertilizing management sidedress in the corn crop, after b. decumbens stapf pasture. the experiment was carried out in greenhouse conditions, in pots with 29 liters of a red latosol (oxisol), with three corn plants per pot. the randomized blocks design was used, in 4x4 factorial arrangement, with five replications, constituted by four nitrogen rates (0, 50, 100 and 150mg dm-3 of soil) and four levels of b. decumbens straw (0, 5, 10 and 15mg ha-1), applied in sidedressing. the n doses were splitting in three times: a) 1/3 in the seeding; b) 1/3 in the 4-5 leaves stage and c) 1/3 in the 7-8 leaves stage. the determinations of gci of the leaf were made one day before and one week after the sidedress nitrogen fertilizing. the levels of b. decumbens straw only influenced gci in the seven-eight leaves stage. the maintenance of larger gci of the four-five leaves stage (46.6) to the eight-nine leaves (53.0) made possible the largest accumulation of the corn shoot dry matter. the monitoring of gci can help in the evaluation of the n available for the corn during season.
Intera??o silício e alumínio em plantas de arroz de terras altas cultivadas em solo alumínico
Freitas, Lucas Barbosa de;Fernandes, Dirceu Maximino;Maia, Suelen Cristina Mendon?a;
Revista Brasileira de Ciência do Solo , 2012, DOI: 10.1590/S0100-06832012000200020
Abstract: soils with high levels of toxic al can cause damage to plants and consequently decrease yields; a proper management is therefore essential to increase yields. silicon can be a good alternative to reduce the toxicity of al in the soil. the objective of this study was to evaluate the influence of the interaction between silicon and al in rice plants grown in naturally aluminous soil. the experiment was arranged in a completely randomized, 2 x 5 factorial design with four replications. the treatments consisted of two highland rice cultivars: brs talento - susceptible to al toxicity, modern; guarani - tolerant to al toxicity, traditional, and five si rates (0, 30, 60, 90, and 120 mg dm-3). the si supplied in soil contributes to decrease the al toxicity in both cultivars. however the response in yield was noted only in brs talento cultivar. there was a positive correlation between yield of brs talento cultivar and si content in leaves; al content in leaves correlated negatively to yield; and the same behavior was noted between si and al in leaves. it can concluded that there is an interaction between si and al in plants of rice.
Compara??o entre métodos para determina??o de carbono organico em amostras de solo mensuradas por volume ou massa
Sampaio, Thalita Fernanda;Fernandes, Dirceu Maximino;Guerrini, Iraê Amaral;Bogiani, Julio Cesar;Backes, Clarice;
Revista Brasileira de Ciência do Solo , 2012, DOI: 10.1590/S0100-06832012000200021
Abstract: the use of mass (g) or volume (cm3) as a measure of the amount of soil for determination of soil organic matter (som), as well as methods of quantitative analysis used for the same purpose, can directly affect the interpretation of results. therefore, the methods of titulometric and colorimetric determination of organic matter were compared in three soils with different texture, sampling the soil based on mass and on volume. the organic matter content determined for a same soil differed between the methods. the use of mass or volume directly affected the interpretation of organic matter contents in soils with different texture.
Avalia??o nutricional em folhas de bananeira 'Prata-an?' adubadas com composto organico
Damatto Junior, Erval Rafael;B?as, Roberto Lyra Villas;Leonel, Sarita;Fernandes, Dirceu Maximino;
Revista Brasileira de Fruticultura , 2006, DOI: 10.1590/S0100-29452006000100030
Abstract: the present work was carried out aiming to evaluate nutritional plants conditions with different organic compost rates in the first production cycle of banana 'prata an?' in botucatu-sp. different organic compost rates were used for the treatments: t1 = 0 g of k2o/plant (zero of the compost); t2 = 98,5 g of k2o/plant (43 kg of the compost/plant); t3 = 197,0 g of k2o/plant (86 kg of the compost/plant); t4 = 290,5 g of k2o/plant (129 kg of the compost/plant ); and t5 = 394,0 g of k2o/plant (172 kg of the compost/plant). the compost rates were calculated based on the quantity of potassium contained in the compost. the experiment was arranged in randomized blocks design, with 5 treatments, 5 replications and 2 plants per plot. the obtained data were submitted to variance analyses and to regression analyses. the effects of organic fertilization were evaluated by chemical leaves analyses of macro and micro nutrients during blooming and harvest. the organic fertilization didn't provide differences in leaves nutrients concentration of banana 'prata an?'. therefore it was observed that the potassium contents in the leaves, considered appropriate to 'prata-an?' banana, could be smaller than the ones recommended to the culture.
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