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Search Results: 1 - 10 of 84347 matches for " Veloso Carlos Alberto Costa "
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ABSOR??O E EXTRA??O DE ALGUNS NUTRIENTES PELA CULTIVAR 'GUAJARINA' DE PIMENTA-DO-REINO
Veloso, Carlos Alberto Costa;Carvalho, Eduardo Jorge Maklouf;
Scientia Agricola , 1999, DOI: 10.1590/S0103-90161999000200026
Abstract: the economic importance of black pepper and the need for information of production sustainability justified this work, to determine the concentration and the distribution of nutrients n, p, k, ca and mg, in several parts of the plant. the experiment was carried out in belém, pará, in a soil classified as yellow latosol (alic haplustox), medium texture, with the following chemical characteristics: ph in h2o = 4.5; om = 17.5 g kg-1; p = 2.0 mg .dm-3 and the exchangeable cations, in mmolc.dm-3, k = 0.48; ca2+ = 4.0; mg2+ =2,0; al3+ = 13.0. the samples were composed of six plants of the cultivar 'guajarina', collected at 28 months after planting, at the production period. the nutrients were extracted in the decreasing order: n> ca> k> mg> p. the amounts of macronutrients exported by the fruits, in kg.ha-1, are: n=11.22; k=6.15; ca=3.84; mg=1.18 and p=1.07.
ABSOR O E EXTRA O DE ALGUNS NUTRIENTES PELA CULTIVAR 'GUAJARINA' DE PIMENTA-DO-REINO
Veloso Carlos Alberto Costa,Carvalho Eduardo Jorge Maklouf
Scientia Agricola , 1999,
Abstract: O potencial econ mico da cultura da pimenta do reino e a necessidade real de pesquisas que sustentem a sua explora o levaram a elabora o deste trabalho que teve por objetivo determinar a concentra o e a distribui o dos nutrientes N, P, K, Ca e Mg, nas diversas partes da planta. O experimento foi conduzido em Belém, PA, em solo classificado como Latossolo Amarelo, textura média, com as seguintes características químicas: pH em H2O = 4,5; M.O = 17,5 g kg-1; P= 2,0 mg dm-3 e os cátions trocáveis, em mmolc.dm-3, K = 0,48; Ca2+= 4,0; Mg2+ =2,0; Al3+ = 13,0. As amostras foram constituídas de um grupo de seis plantas da cultivar Guajarina, coletadas aos 28 meses de idade, na época da produ o. Os resultados obtidos mostraram que os nutrientes extraídos pela pimenta-do-reino obedecem à seguinte ordem: N > Ca > K > Mg > P. As quantidades de macronutrientes exportadas pelos frutos, na colheita em kg.ha-1 foram: N=11,22; K=6,15; Ca=3,84; Mg=1,18 e P=1,07.
Alumínio e a absor??o de cálcio por mudas de pimenta do reino
Veloso, Carlos Alberto Costa;Malavolta, Eurípedes;Muraoka, Takashi;Carvalho, Eduardo Jorge Maklouf;
Scientia Agricola , 2000, DOI: 10.1590/S0103-90162000000100023
Abstract: a nutrient solution experiment with was carried out in a greenhouse with the objective of verifying the specific effects of calcium and aluminum toxicity on black pepper seedlings. the treatments were set up in three concentrations of calcium (10; 40 and 160 mg l-1) added as cacl2 in combination with three concentrations of aluminum (0; 10 and 20 mg l-1) added as alcl3. 6 h2o. the nutrient solution contained the following ion concentrations in mg l-1: n-no3 (80,5); n-nh4 (10,5); p(1,5); k(39,0); mg(24,0); s-so4(32,0); b(0,5); cu(0,06); fe(5,0); mn(1,0); mo(0,03) and zn(0,10). the treatments with aluminum reduced black pepper growth and the diameter of roots increased. calcium absorption increased with the increase of calcium concentration in the solution, in the absence of aluminum. calcium absorption by roots decreased with the increase of the concentration of aluminum in the solution. aluminum absorption decreased with the increase of the concentration of calcium in the solution.
Propriedades químicas de um Latossolo Amarelo cultivado com pastagens na Amaz?nia Oriental
Pereira, Walcilene Lacerda Matos;Veloso, Carlos Alberto Costa;Gama, José Raimundo Natividade Ferreira;
Scientia Agricola , 2000, DOI: 10.1590/S0103-90162000000300025
Abstract: in order to evaluate changes in chemical properties of a xanthic hapludox managed under pasture, using two rotational systems, this research was performed during the rainy and dry seasons, one with brachiaria brizantha (system i) and other with panicum maximum (system ii), in 1996 and 1997. the experimental design was completely randomized, with treatments arranged in subdivided plots, considering periods as subplots within each year, and years as subplots within each forage. twelve replicates were utilized, and data were collected during the rainy and dry seasons. the organic material, incorporated into the soil through vegetable and animal residues, influenced positivelly the chemical characteristics. except for al, levels of ca, mg, k, p, n, c, om and ph increased during 1997. comparing both the brachiaria brizantha and panicum maximum system, the levels of nutrients increased in the rainy season, with the exception for p and ca.
Resposta de cultivares de pimenta-do-reino aos nutrientes NPK em um Latossolo Amarelo da Amaz?nia Oriental
Veloso, Carlos Alberto Costa;Carvalho, Eduardo Jorge Maklouf;Malavolta, Eurípedes;Muraoka, Takashi;
Scientia Agricola , 2000, DOI: 10.1590/S0103-90162000000200023
Abstract: the present work was developed with the objective of establishing response curves of black pepper to nitrogen, phosphorus and potassium in an oxisol (yellow latosol, dystrophic) in senador josé porfírio county, km 35 of the transamazonian road, in brazil. the levels of nitrogen, applied manually every year were (0; 40; 80; 120 and 160 kg ha-1 n) in the urea form, five phosphorus levels (0; 30; 60; 90 and 120 kg ha-1 p2o5) in the form of triple superphosphate and five potassium levels (0; 30; 60; 90 and 120 kg ha-1 k2o) in the form of potassium chloride. the experimental design consisted of blocks with three replicates, being the treatments disposed as an incomplete factorial. the spacing was of 3.0 m between lines and 2.5 m between plants with six useful plants per plot. the results evidenced positive response of nitrogen in relation to black pepper grain yield with the application of 72 and 78 kg ha-1 of n, for cultivars cingapura and bragantina, respectively. only cultivar guajarina responded to the phosphorus application. growing levels of k2o, reduced the present potassium content in the foliar tissue of the peppers. the potassium addition favored the increase of the production of grains with the application of 42, 13 and 22 kg ha-1 of k2o, for the cingapura, bragantina and guajarina cultivars, respectively.
Alumínio e a absor o de cálcio por mudas de pimenta do reino
Veloso Carlos Alberto Costa,Malavolta Eurípedes,Muraoka Takashi,Carvalho Eduardo Jorge Maklouf
Scientia Agricola , 2000,
Abstract: Um experimento com solu o nutritiva foi conduzido em casa de vegeta o com o objetivo de verificar os efeitos da nutri o de cálcio na toxicidade de alumínio em mudas de pimenta do reino. Os tratamentos constituíram-se de três concentra es de cálcio (10; 40 e 160 mg L-1) adicionados como CaCl2 em combina o com três concentra es de alumínio (0; 10 e 20 mg L-1) adicionados como AlCl3.6H2O. A solu o nutritiva continha as seguintes concentra es dos íons expressos em mg L-1: N-NO3 (80,5); N-NH4 (10,5); P(1,5); K(39,0); Mg(24,0); S-SO4(32,0); B(0,5); Cu(0,06); Fe(5,0); Mn(1,0); Mo(0,03) e Zn(0,10). Os tratamentos com alumínio retardaram o crescimento das mudas de pimenta do reino, induziram sintomas de toxicidade de alumínio na parte aérea e principalmente aumentaram o diametro das raízes. O acúmulo de cálcio aumentou com o incremento da concentra o de cálcio na solu o na ausência de alumínio, nas raízes o conteúdo de cálcio foi diminuído com o aumento da concentra o de alumínio na solu o. A absor o de alumínio diminuiu com o aumento da concentra o de cálcio na solu o.
Propriedades químicas de um Latossolo Amarelo cultivado com pastagens na Amaz nia Oriental
Pereira Walcilene Lacerda Matos,Veloso Carlos Alberto Costa,Gama José Raimundo Natividade Ferreira
Scientia Agricola , 2000,
Abstract: A pesquisa foi conduzida com o objetivo de avaliar as modifica es das propriedades químicas de um Latossolo Amarelo com cultivo de pastagens, submetidos a dois modelos de sistemas rotacionados, nos períodos chuvoso e seco, um com Brachiaria brizantha e o outro com Panicum maximum, nos anos de 1996 e 1997. O delineamento experimental utilizado foi em blocos casualizados, com os tratamentos dispostos num esquema de parcelas subdivididas, com doze repeti es. As parcelas foram constituídas pelas forrageiras braquiar o e tobiat e as subparcelas foram constituídas pelos períodos chuvoso e seco dentro de cada ano. Para o estudo das propriedades químicas do solo, foram coletadas amostras nos períodos chuvoso e seco. O material organico incorporado ao solo através de restos de vegetais e a presen a de excremento animal alterou as propriedades químicas nos anos estudados. Os teores de Ca, Mg, K, P, MO e o valor de pH foram maiores no ano de 1997. Teores mais elevados de Ca e Mg foram obtidos no sistema de pastejo com tobiat do que no sistema com braquiar o. No período chuvoso os teores de Mg, K, MO e o valor de pH foram maiores, com exce o de P e Ca para o ano de 1997.
Resposta de cultivares de pimenta-do-reino aos nutrientes NPK em um Latossolo Amarelo da Amaz nia Oriental
Veloso Carlos Alberto Costa,Carvalho Eduardo Jorge Maklouf,Malavolta Eurípedes,Muraoka Takashi
Scientia Agricola , 2000,
Abstract: O presente trabalho foi desenvolvido, com o objetivo de estabelecer curvas de resposta da pimenteira-do-reino a nitrogênio, fósforo e potássio, num Latossolo Amarelo distrófico (Oxisol), no município de Senador José Porfírio, km 35 da rodovia Transamaz nica. As doses de nitrogênio, aplicadas manualmente a cada ano foram: (0; 40; 80; 120 e 160 kg ha-1 de N) na forma de uréia, cinco doses de fósforo (0; 30; 60; 90 e 120 kg ha-1 P2O5) na forma de superfosfato triplo e cinco doses de potássio (0; 30; 60; 90 e 120 kg ha-1 K2O) na forma de KCl. Utilizou-se o delineamento em blocos ao acaso, com três repeti es, sendo os tratamentos dispostos em esquema fatorial incompleto.O espa amento foi de 3,0 m entre linhas e 2,5 m entre plantas, com seis plantas úteis por parcela. Os resultados evidenciaram resposta positiva de nitrogênio com rela o a produ o de gr os de pimenta do reino com a aplica o de 72 e 78 kg ha-1 de N, para as cultivares Cingapura e Bragantina, respectivamente. Somente a cultivar Guajarina, respondeu à aplica o de fósforo. Doses crescentes de K2O, reduziu os teores de potássio presentes no tecido foliar das pimenteiras. A adi o de potássio favoreceu o aumento da produ o de gr os com a aplica o de 42, 13 e 22 kg ha-1 de K2O, para as cultivares Cingapura, Bragantina e Guajarina, respectivamente.
Produtividade e estabilidade fenotípica de cultivares de milho em três municípios do Estado do Pará
Souza, Francisco Ronaldo Sarmanho de;Ribeiro, Pedro Hélio Estevam;Veloso, Carlos Alberto Costa;Corrêa, Luiz André;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000900010
Abstract: the area cultivated with grains in the state of pará, brazil, is around 553 thousand hectares and 57% of this area is cultivated with corn. corn average yield is very low due to the production systems adopted which do not include the use of fertilizers, liming and adapted cultivars. the objective of this work was to evaluate the yielding performance and the phenotypic stability of corn cultivars under four environments. thirty-seven commercial and pre-commercial corn cultivars were used in a simple 6x6 lattice. the plots consisted of two rows of 5 m, spaced 0.90 m apart with 5 plants/m after thinning. there were significant differences by the f test for most sources of variation taken into account. within the group of highest yielding cultivars, yield varied from 5.64 to 6.58 ton/ha and within the second group, between 4.03 and 5.52 ton/ha of grains. the variety br-5102 used as control was classified in the highest-yielding cultivars group, outyielding more than 66% of the cultivars tested. the cultivars which presented the lowest risk of adoption for recommendation were ag 4051, c 333b and 984-n. the results showed that it is possible to identify cultivars bearing good yielding performance and good stability.
Desenvolvimento e produ??o de frutos de bananeira em resposta à aduba??o nitrogenada e potássica
BRASIL, EDILSON CARVALHO;OEIRAS, ANT?NIO HENRIQUE LOPES;MENEZES, ANT?NIO JOSé ELIAS AMORIM DE;VELOSO, CARLOS ALBERTO COSTA;
Pesquisa Agropecuária Brasileira , 2000, DOI: 10.1590/S0100-204X2000001200011
Abstract: the effect of the n and k fertilization on the development and production of the banana plant (musa spp.), cv. pioneira, was evaluated in an experiment carried out in capit?o po?o county, pará state, brazil, in a yellow latosol, using a randomized blocks design, in factorial arrangement of 4x4. the treatments were: 0, 80, 160 and 240 g of n per plant per year; 0, 150, 300 and 450 g of k2o per plant per year. urea and potassium chloride were used as nutrient sources. the results of plant growth showed that there was effect of n on circumference of pseudostem and plant height. the quadratic model was better adjusted to all the variables. the results of production of the second cycle indicated that k increased quadratically the bunch weight, hands weight per bunch and average weight of hands, with production increments of 73, 76 and 39%, respectively, in comparison to the treatment without potassium. the nitrogen application promoted a linear increase of the weight of bunch and hands per bunch, with increments of 32 and 30%, respectively, proportionate by the highest level of n, in relation to the treatment without this nutrient. during the third production cycle only k application influenced the weights of bunch, of hands per bunch and average weight of hands, with increments of 39, 40% and 26%, respectively.
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