Showing papers in "Pesquisa Agropecuaria Brasileira in 2002"
TL;DR: In the direct bean planting carried out on the straw produced by cover crops, it was verified that the culture yield is more influenced by producer species of straw than by the kind of their cultivation.
Abstract: O objetivo deste trabalho foi estimar o rendimento de materia fresca, materia seca e o acumulo de nutrientes da fitomassa produzida por milheto (Pennisetum americanum (L.) Leek), sorgo (Sorghum bicolor (L.) Moench), milho (Zea mays L.), mucuna-preta (Stizolobium aterrimum) e feijao-de-porco (Canavalia ensiformis (L.) DC.), em cultivo exclusivo e consorciado, e seus efeitos sobre o feijoeiro (Phaseolus vulgaris L. cv. Carioca) em plantio direto. Os tratamentos consistiram no cultivo exclusivo das especies e nos consorcios das gramineas com as leguminosas. Utilizou-se o delineamento experimental em blocos casualizados, com quatro repeticoes. O sorgo em cultivo exclusivo apresenta maior produtividade de materia fresca e, juntamente com o milheto exclusivo e o consorcio milheto e mucuna-preta, maior produtividade de materia seca. Ocorre maior acumulo de nutrientes no milheto exclusivo e consorciado com mucuna-preta. Posteriormente, realizou-se o plantio direto do feijoeiro, cujo rendimento de graos e influenciado pelas diferentes palhadas das plantas de cobertura no sistema plantio direto, sendo mais afetado pela especie produtora de palha do que pela sua forma de cultivo.
182 citations
TL;DR: In this article, the spatial variability of pH, Ca, Mg, P and K under three soil preparation systems (moldboard plough, harrow disc and no-tillage) was studied using geostatistical concepts in clayy Oxisol, in Santo Antonio de Goias, GO, Brazil, at Embrapa-Centro Nacional de Pesquisa de Arroz e Feijao, for five consecutive years (1992-1996).
Abstract: Spatial variability of pH, Ca, Mg, P and K under three soil preparation systems (moldboard plough, harrow disc and no-tillage) was studied using geostatistical concepts in clayey Oxisol, in Santo Antonio de Goias, GO, Brazil, at Embrapa-Centro Nacional de Pesquisa de Arroz e Feijao, for five consecutive years (1992-1996). Within a total of 30 combinations among soil chemical properties, soil depth and preparation system, 14 presented pure nugget effect, indicating absence of spatial dependence. Directional semivariograms revealed strong and moderate spatial dependence in the direction of Y. Experiments conducted for a long time and cultural practice conducted in a single direction tend to change the spatial structure of the soil properties. The anisotropy direction was more associated with harrow disc as a system of soil preparation and the strongest spatial dependence was verified for pH at 5-20 cm soil depth. These results suggest that sample location to estimate the values of the soil chemical properties should take field operations into account and should be carefully selected. Samples should be taken in other directions, so that a more realistic representation of the sampled area could be obtained.
137 citations
TL;DR: In this article, the effect of initial seed water content on the electrical conductivity results and an equation to correct this influence was determined. But the equation was based on regression, including the two years data.
Abstract: The initial seed water content can influence significantly the electrical conductivity results, and can make difficult the test standardization. The present work was carried out in order to study the effect of initial seed water content on the electrical conductivity results and to determine an equation to correct this influence. Six soybean cultivars were used, for two years, each cultivar having lots with high, medium and low seed vigor. Seed water content of each lot was adjusted to 7, 9, 11, 13, 15 and 17% before electrical conductivity test was run. The equation to correct the electrical conductivity values was calculated based on regression, including the two years data. The initial seed water content proved to be of high influence on the electrical conductivity interpretation and the equation is efficient to eliminate the effect of initial seed water content on the electrical conductivity data.
116 citations
TL;DR: Ochroma lagopus and Jacaranda copaia seedlings increased their growth under shade, but seedlings quality was poor, and in choosing shade levels to grow seedlings, shoot/root ratio and development of root system should be considered.
Abstract: The objective of this paper was to assess the development of Jacaranda copaia (Aubl.) D. Don., Hymenaea courbaril L. and Ochroma lagopus (Cav. ex. Lam.) Urban seedlings under different shade levels in the nursery. The experiment was carried out at Experimental Station of Tropical Silviculture (EEST) of Inpa, in Manaus, AM, Brazil. The experiment design was fully randomised blocks with five treatments: two treatments with 50% of shading during 15 and 30 days, respectively and the remaining period under full sun light (0%) and three treatments under 30, 50 and 70% shade, respectively by using black polypropylene screen. Stem diameter, seedling height, root length, leaf area, dry mass of leaves, root and stem, shoot/root ratio and height/diameter ratio were assessed. Hymenaea courbaril had its growth affected under 70% of shade. Ochroma lagopus and Jacaranda copaia seedlings increased their growth under shade, but seedlings quality was poor. In choosing shade levels to grow seedlings, shoot/root ratio and development of root system should be considered.
116 citations
TL;DR: An experiment was carried out at the Crop Production Department, Escola Superior de Agricultura Luiz de Queiroz, of the Universidade de Sao Paulo, Piracicaba, SP, Brazil, to obtain the functional relationship between the LAI and different growth variables.
Abstract: Com o objetivo de estudar a variacao temporal do indice de area foliar (IAF) da cultura de cafe, utilizando um metodo simples e nao-destrutivo, foi instalado um experimento no Departamento de Producao Vegetal, da Escola Superior de Agricultura Luiz de Queiroz, da Universidade de Sao Paulo Utilizou-se a cultivar Mundo Novo IAC 388-17, enxertada sobre a cultivar Apoata IAC 2258 (de 15 ate 35 meses de idade), no espacamento de 2,5 x 1,0 m Foram coletadas todas as folhas de duas plantas de cafe, em intervalos de 60 a 150 dias, para a mensuracao da area foliar com o equipamento LI-COR (modelo 3100) Para obter a relacao funcional entre IAF e diferentes variaveis de crescimento (altura da planta, numero e massa total de folhas e area foliar) e arquitetura da copa (area da secao inferior, media e superior do dossel, area lateral do dossel, diâmetro inferior, medio e superior do dossel, volume do dossel da planta e altura do primeiro par de ramos), assumiu-se que a parte aerea do cafeeiro tem a forma conica O diâmetro da secao inferior do dossel (primeiro par de ramos) e a altura da planta podem ser utilizadas para estimar o indice de area foliar do cafeeiro
109 citations
TL;DR: In this paper, a trabalho on quantificar as perdas de N do sistema solo-cana-de-acœcar, nosciclos de cana-planta and of cana soca, was conducted on vasos of 220 L, conten-do solo de classe textural arenosa.
Abstract: Resumo€Œ€O objetivo deste trabalho foi quantificar as perdas de N do sistema solo-cana-de-acœcar, nosciclos de cana-planta e de cana-soca. Desenvolveram-se dois experimentos em vasos de 220 L, conten-do solo de classe textural arenosa. Os€fatores de estudo do experimento com cana-planta foram doistipos de restos culturais incorporados ao solo e quatro doses de N no plantio. No€experimento comcana-soca, estudaram-se duas formas de aplicacao da urOia em superficie: sobre a palha ou sobre o solodescoberto, ou na profundidade de 15€cm, e duas fontes de K: KCl ou vinhaca. Utilizou-se urOia marcadacom
93 citations
TL;DR: Varieties Tres meses and Caiabana were the best for human consumption as fresh roots and all varieties tested behaved as susceptible to post-harvest deterioration when stored under environmental conditions.
Abstract: Resumo – Com o objetivo de identificar novas variedades para consumo humano, na forma de raizesfrescas, 26 variedades de mandioca ( Manihot esculenta , Crantz) foram avaliadas aos 8, 10 e 12 mesesapos o plantio, quanto a produtividade de raizes, teores de amido, de materia seca e de cianeto, o tempode coccao e a deterioracao pos-colheita. A produtividade, os teores de amido e de materia seca das raizesvariaram entre as variedades, e entre as epocas de colheita. Aproximadamente, 81% das variedadescontinham teores de cianeto dentro dos limites aceitaveis (inferior a 100 mg/kg de polpa crua) paraconsumo na forma de raizes frescas (metodo enzimatico). Apenas oito variedades cozinharam ate30 minutos em todas as epocas de colheita, nos dois anos de avaliacao. A deterioracao pos-colheitaocorreu em todas as variedades quando armazenadas sob condicoes ambiente. Houve correlacao positi-va entre a materia seca e o amido (r = 0,9826) e entre a epoca de colheita e o tempo de coccao(r = 0,7304). Entre amido e o tempo de coccao a correlacao foi negativa (r = -0,0570). As variedadesTres meses e Caiabana sao promissoras para consumo humano na forma de raizes frescas.Termos para indexacao: Manihot esculenta , materia seca, amido, coccao, deterioracao pos-colheita.Evaluation of cassava varieties for human consumptionAbstract – This work aimed to select new cassava (Manihot esculenta Crantz) varieties for humanconsumption as fresh roots. A total of twenty six varieties were evaluated after eight, ten and twelvemonths after planting. Parameters were assessed as follow: root productivity, starch, dry matter andcyanide contents, cooking and post-harvest deterioration. Root productivity, starch and dry mattercontents varied among varieties and among harvest period. Nearly 81% of the varieties presentedcyanide content within the acceptable limits for consumption as fresh roots (less than 100 mg/kg of rawpulp), by the enzymatic method. Only eight varieties presented cooking up to 30 minutes during theexperimental evaluation in all harvest period. All varieties tested behaved as susceptible to post-harvestdeterioration when stored under environmental conditions. Correlations between starch and dry mattercontents (r = 0.9826) and between harvest periods and cooking (r = 0.7304) were positive. Correlationbetween starch content and cooking was negative (r = -0.0570). Varieties Tres meses and Caiabana werethe best for human consumption as fresh roots.Index terms: Manihot esculenta, dry matter, starch, cooking, post-harvest deterioration.
83 citations
TL;DR: In this article, the authors evaluate a contribuicao relativa dos componentes do rendimento for a producao final de graos for six genotipos of soja.
Abstract: Seis genotipos de soja foram estudados com o objetivo de identificar a contribuicao relativa dos componentes do rendimento para a producao final de graos. O experimento foi conduzido no ano agricola 1996/97 na EEA/UFRGS, Eldorado do Sul, RS. As avaliacoes foram realizadas em plantas individuais e se estenderam desde o estadio de floracao ate o de maturacao. Os resultados obtidos demonstram que a importância relativa de cada componente do rendimento variou conforme a cultivar. As cultivares FT-2003 e RS 9-Itauba foram significativamente superiores as demais com relacao a producao de graos por planta, com excecao da RS 7-Jacui. Elas se caracterizaram por elevado numero de nos ferteis nos ramos e elevada producao nos mesmos, enquanto a RS 7-Jacui apresentou elevado peso de 100 graos e alto numero de legumes com tres graos. A cultivar CEP 20-Guajuvira apresentou alta porcentagem de fixacao de legumes. O peso de 100 graos e um componente importante na producao de graos da cultivar BR 16. Na cultivar OCEPAR 14, a producao de graos decorre da alta producao de ramos e do numero de nos ferteis nos ramos.
78 citations
TL;DR: In this paper, a monitoramento do Ribeirao do Jardim that abastece a cidade de Guaira, bem como de um de seus afluentes and da agua subterrânea proveniente do Aquifero Guarani, a procura de pesticidas.
Abstract: O objetivo deste trabalho foi determinar os niveis de ocorrencia de pesticidas em agua, tendo em vista preservar a agua de contaminacao por esses produtos na regiao de Guaira, SP. A hipotese foi que o uso intensivo de pesticidas nessa regiao propiciaria a contaminacao das aguas superficiais e subterrâneas por seus residuos. Para a caracterizacao das propriedades, das caracteristicas e da dinâmica da agua do solo, foi selecionada a Fazenda Macauba por possuir relevo e solos caracteristicos da regiao. Aproximadamente 80% da area da fazenda e constituida por Latossolo Vermelho distroferrico tipico (LVdf), profundo. As areas cultivadas apresentam um horizonte superficial (Ap) completamente desprovido de sua estrutura natural e, abaixo deste, um horizonte compactado, ambos frutos das praticas agricolas. Durante dois anos e meio realizou-se o monitoramento do Ribeirao do Jardim que abastece a cidade de Guaira, bem como de um de seus afluentes e da agua subterrânea proveniente do Aquifero Guarani, a procura de pesticidas. A agua superficial foi coletada de 21em 21 dias e a subterrânea, no inicio e no final do periodo monitorado (dois anos e meio). Os produtos monitorados, trifluralina, endosulfan, lambda cialotrina, dicofol (4,4 diclorobenzofenona), captan, metil paration, clorotalonil e clorpirifos, foram selecionados a partir de um levantamento dos pesticidas utilizados em quatro areas agricolas localizadas na bacia do Ribeirao do Jardim e em razao da efetividade de um metodo de analise de residuos multiplos para sua quantificacao. Os resultados analiticos indicaram que nao houve contaminacao da agua subterrânea, mas que ocasionalmente houve contaminacao direta das aguas de superficie. A nao-contaminacao da agua subterrânea deve-se principalmente as caracteristicas dos Latossolos, como sua grande espessura, sua textura argilosa e sua grande capacidade de armazenamento de agua.
78 citations
TL;DR: It was concluded that age at first calving may be used as a selection criterion for sexual precocity and that the selection of bulls for SC can result in daughters with decreased age atfirst calving.
Abstract: The objective of this paper was to estimate heritability coefficients for age at first calving, days to calving (DC), gestation length (GL) and scrotal circumference (SC) as well as genetic correlations between scrotal circumference and these reproductive traits measured in the females, in Nelore cattle. The age at first calving was evaluated in females mated for the first time around 14 months of age (AFC14) and in females mated for the first time around 26 months of age (AFC26). Datasets varying from 6,030 to 94,637 observations were analyzed. Analyses were processed using twotrait animal models. Heritability coefficients obtained for reproductive traits were: 0.19 (AFC14), 0.02 (AFC26), 0.07 (DC), 0.26 (GL), and 0.47 (SC). The genetic correlations were: -0.39 (SC and AFC14), -0.19 (SC and AFC26), 0.02 (SC and DC); and 0.02 (SC and GL). It was concluded that age at first calving may be used as a selection criterion for sexual precocity and that the selection of bulls for SC can result in daughters with decreased age at first calving. The low heritability obtained for DC, associated to its low genetic correlation with SC, suggest the need of studies on other traits to evaluate female fertility.
78 citations
TL;DR: Avaliou-se o efeito de diferentes sistemas de cultivo na estabilidade de agregados em agua de um Latossolo Vermelho-Amarelo de textura media, no Municipio de Querencia, Mato Grosso, Brazil as discussed by the authors.
Abstract: Avaliou-se o efeito de diferentes sistemas de cultivo na estabilidade de agregados em agua de um Latossolo Vermelho-Amarelo de textura media, no Municipio de Querencia, Mato Grosso. Foram selecionadas nove areas contiguas: uma coberta com vegetacao de mata natural de transicao de cerrado para mata amazonica e as outras com sistemas de cultivos anuais. Coletaram-se amostras indeformadas de solo, para a determinacao de estabilidade dos agregados em agua, da granulometria, e da materia orgânica. Ocorreram modificacoes na estrutura e materia orgânica do solo, causadas pelos diferentes sistemas de cultivo, a partir do preparo da area para o primeiro plantio. Os maiores fracionamentos de agregados ocorreram nas areas preparadas com grade aradora e grade niveladora para o monocultivo da soja durante quatro e seis anos. O plantio direto da soja sobre a palhada do milheto, por dois anos consecutivos, proporcionou maior estabilidade de agregados do solo. A porcentagem de materia orgânica correlacionou-se positivamente com a porcentagem de agregados estaveis em agua maiores que 2 mm, com o diâmetro medio ponderado dos agregados e com o grau de floculacao.
TL;DR: In this paper, the potential of organic N contained in sewage sludge is quantified in an Oxisol treated with two anaerobically-digested sewage sludges, one derived from strictly urban sewage and the other from a mixture of urban and industrial sewages.
Abstract: Mineralization of organic N contained in sewage sludges is a key factor in determining the rates of these materials to be applied to agricultural soils. This work aimed at quantifying the potential of mineralization of the organic N in an Oxisol treated with two anaerobically-digested sewage sludges (one derived from strictly urban sewage - Franca, Sao Paulo State, Brazil -, and the other from a mixture of urban and industrial sewages - Barueri, Sao Paulo State). The sludges were applied at four rates: 1.5, 3, 6 and 12 g kg-1 (Franca), and 4, 8, 16 and 32 g kg-1 (Barueri), and the incubation period, was 15 weeks. Net inorganic N accumulation in the soil measured at the end of the incubation period was proportional to the rate of organic N applied as sludges. The potential of mineralization estimated by the single exponential model for the soil without sludge was 24 mg kg-1 of N, and ranged from 44 to 265 mg kg-1 of N, for the sludge-treated soil. The fraction of potential mineralization of the organic N contained in the sludges was estimated in 31%. N mineralization was slower in the soil treated with the two higher rates of the Barueri sludge. Sewage sludges caused soil acidification; Franca sludge was more effective in this way than Barueri sludge.
TL;DR: In this paper, the efeito do espacamento entre linhas (45 and 60 cm), densidade das plantas (10, 13, 16, 19, 22, and 22) and uniformidade da semeadura (espacamentos aceitaveis 25, 35, 60%, 60% e 100%), sobre a produtividade da soja, was evaluated.
Abstract: O objetivo do presente estudo foi avaliar o efeito do espacamento entre linhas (45 e 60 cm), da densidade das plantas nas linhas (10, 13, 16, 19 e 22 plantas m-1) e da uniformidade da semeadura (espacamentos aceitaveis 25%, 35%, 60% e 100%), sobre a produtividade da soja. O experimento foi conduzido nos anos 1997/1998 e 1998/1999, com a cultivar CAC-1. O delineamento experimental utilizado foi o de blocos ao acaso, com tres repeticoes, com os tratamentos em esquema de parcelas sub-subdivididas. Houve aumento na produtividade da soja no espacamento de 45 cm com a reducao da densidade para 10 plantas m-1, e com a uniformidade de espacamento entre plantas dentro das linhas acima de 60%. A altura das plantas e o grau de acamamento foram reduzidos significativamente; porem, a porcentagem de sobrevivencia das plantas aumentou a medida que ocorreu reducao da densidade populacional das plantas. Tambem foi detectado que o aumento da uniformidade de espacamento entre as plantas dentro das linhas reduziu-lhes o acamamento.
TL;DR: Seasonal influence on levels of vitamin C, physical (fruit weight and diameter) and physico-chemical (TSS) characteristics were found and UFRPE 7 produced the best quality fruits and presented higher stability in most of the characteristics evaluated.
Abstract: Este trabalho teve por objetivo avaliar caracteristicas fisico-quimicas dos frutos de acerola, em tres estadios de maturacao. Foram usadas acerolas oriundas de duas matrizes (UFRPE 7 e UFRPE 8), durante as estacoes seca e chuvosa, num pomar comercial. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2 x 3 (plantas matrizes x estadios de maturacao dos frutos), e tres repeticoes. Foram avaliados os teores de vitamina C e solidos soluveis totais (SST), alem do pH, do peso e tamanho dos frutos. As aceroleiras UFRPE 7 e UFRPE 8 produziram frutos com teores de vitamina C adequados tanto para o mercado interno como para o externo. Os frutos verdes apresentaram teores de vitamina C significativamente maiores que os maduros e semimaduros, podendo ser utilizados pela industria farmaceutica. Houve influencia sazonal nos teores de vitamina C nas caracteristicas fisicas (peso e diâmetros dos frutos) e fisico-quimicas (SST) das matrizes estudadas. O conteudo de vitamina C foi mais elevado durante a estacao seca, e decresceu com a maturacao do fruto. A UFRPE 7 produziu frutos de melhor qualidade, apresentando tambem maior estabilidade nas caracteristicas avaliadas do que a UFRPE 8.
TL;DR: In this article, the authors evaluated the bioactivity of humic acids isolated from sludge of the station of sewer treatment (HAL) and from vermicompost (HAV) through the action of those substances on primary transport of protons of the plasma membrane of coffee and corn root cells and its relationship with the development of those species.
Abstract: – The bioactivity of humic acids (HA) isolated from sludge of the station of sewer treatment(HAL) and from vermicompost (HAV) was evaluated through the action of those substances onprimary transport of protons of the plasma membrane of coffee and corn root cells and its relationshipwith the development of those species. A stimulation in the superficial area of roots was observed forboth species cultivated with both humic acids, exhibiting an optimum concentration, about 40 mg L -1 ofHA. In this condition the treatment with HAL and HAV stimulated the plasma membrane H + -ATPaseof corn and coffee roots. HAL were more effective to promote those effects than HAV. The modifica-tion of the chromatographic profile of the HA in solution before and after the cultivation of theseedlings revealed that the interaction plant-HA promoted a rearrangement of the average molecularweight of those substances suggesting a dynamic mobilization of bioactive subunits of the HA by plantexudates. The structural analysis of the HA has detected the presence of auxin groups. A comparativeanalysis of the action of those HA on the monocotyledonous (corn) and dicotyledonous (coffee) plantsindicates to the activation of plasmallema H
TL;DR: In this paper, the occurrence of macauba (Acrocomia aculeata (Jacq.) Lodd. ex Martius) in Minas Gerais State, Brazil, was compared to climatic, pedological and vegetation attributes.
Abstract: The objective of this work was to relate the occurrence of macauba (Acrocomia aculeata (Jacq.) Lodd. ex Martius) in Minas Gerais State, Brazil, to climatic, pedological and vegetation attributes. The State has three huge regions where macauba occurs: Alto Paranaiba, Zona Metalurgica, and Montes Claros. The Montes Claros region is relatively warmer and drier than the two others, although these regional macroclimatic differences do not limit the macauba occurrence. Within those regions, nine soil sequences were selected and sampled in the landscape, totalizing 27 soil profiles, being also registered the primitive vegetation in each case. The use of soil chemical and physical attributes allowed to discriminate the sets of landscape segments (sites) with and without macauba through the principal components analysis; the correlations with the chemical attributes were the most relevant. The macauba occurrence followed soil areas where the natural fertility was higher and where the primitive vegetation was forest, showing that the species advances as pioneer, avoiding extreme conditions of deficiencies of nutrients and water. The surveyed data evidence that in all cases the macauba occurrence only happened when the primitive vegetation is semideciduous forest.
TL;DR: In this article, a lysimeter experiment was carried out with sugarcane aiming to evaluate the leaching of nitrogen derived from either urea (15N) or the soil/sugarcane crop residues.
Abstract: A lysimeter experiment was carried out with sugarcane aiming to evaluate the leaching of nitrogen derived from either urea (15N) or the soil/sugarcane crop residues. The leaching of K+, Ca2+, and Mg2+ was also evaluated. The experiment was a factorial 2x4. The influencing factors were: firstly, the differential addition of two kinds of sugarcane remains to the soil, simulating conditions of cane- plantation renewal after the cane crop harvest, with and without previous straw removal by burning; secondly, four doses of N: 0, 30, 60, and 90 kg ha-1. During the experimental period the total volume of water received by the sugarcane-soil system was 2,015 mm, with 1,255 mm as precipitation and 760 mm as irrigation. The loss of N by leaching from the fertilizer (15N) was not detected. In the first three weeks the largest losses of N by leaching occurred, originating from the soil/sugarcane remains-N. The mean of leached N during the experimental period of 11 months was of 4.5 kg ha-1. The mean losses of K+, Ca2+, and Mg2+ were of 13, 320 and 80 kg ha-1, respectively.
Abstract: The soil-geomorphic surface relationships were investigated in an area of the Central Brazilian Plateau, based upon a high intensity reconnaissance pedological survey, aiming at the prevision of the soil attributes and their distribution in adjacent areas which don't have pedological maps. Three geomorphic surfaces, with distinctive soil distribution patterns, were identified. In the highest geomorphic surface, the soil distribution is highly related to the hydric regime variation along the hillsides, occurring Red-Latosol (RL), Red-Yellow Latosol (RYL), Yellow Latosol (YL), Plinthic Yellow Latosol, Petroplinthic Yellow Latosol (PYL) (concretionary soil) and Haplic Plinthosol. These soils show very clayey texture, values of Fe2O3 and TiO2 relatively homogeneous, and Ki and Kr indexes indicatives of oxidic mineralogy. In the second surface, the soils show higher variation with respect to texture and iron and titanium contents. RL, Acricferric RL, RYL and YL are the dominant soils, with occurrence of Acriferric Endopetroplinthic RYL and YL near the borders of the high tablelands. In the third surface, that cuts the first and second ones, predominate less weathered soils, with high variable attributes, such as Haplic Cambisol, Red and Red-Yellow Argisols, Eutroferric Red Nitosol, Litholic Neosol and Fluvic Neosol. This work includes a proposition of a regional landscape evolution model.
TL;DR: In this article, the influence of Zn, Mn and Cu on shoot dry matter yield and uptake of macro and micronutrients in upland rice, common bean and corn was determined.
Abstract: (2) Abstract - The objective of this work was to determine the influence of Zn, Mn and Cu on shoot dry matter yield and uptake of macro and micronutrients in upland rice, common bean and corn. Six greenhouse experiments were conducted using a Dark Red Latosol (Typic Haplusthox). Treatments consisted of application of Zn at 0, 5, 10, 20, 40, 80 and 120 mg kg -1 , of Mn at 0, 10, 20, 40, 80, 160, 320 and 640 mg kg -1 and of Cu application at 0, 2, 4, 8, 32, 64 and 96 mg kg -1 . Zinc increased yield of rice, Mn increased yields of corn and bean and Cu improved yields of rice and bean. Uptake of N, Ca, and Cu in rice was decreased by zinc treatment. In common bean, uptake of N, Mg, and Cu was increased by zinc application, whereas, uptake of P was decreased. Manganese increased uptake of Mg, Zn and Fe and decreased uptake of Ca, in corn. Uptake of K, Zn and Mn was increased and uptake of P and Cu was decreased by Mn application, in bean. Copper had positive and negative interactions in the uptake of macro and micronutrients, depending on crop species and nutrients involved.
TL;DR: It was concluded that 'Thap Maeo' has potential to substitute 'Mysore', and the hybrids evaluated present quality to be recommended to the farmers.
Abstract: New productive banana hybrids, presenting good fruits and disease resistant, have been generated at Embrapa-Centro Nacional de Pesquisa de Mandioca e Fruticultura Tropical The objective of this work was to evaluate some of these genotypes in four production cycles, to recommend them to the farmers The experiment was carried out in the completely randomized design with 18 replications in Cruz das Almas, BA, Brazil The genotypes evaluated were the varieties Grande-Naine, Nanica, Nam, Thap Maeo, Mysore, Caipira, Prata-Comum, Pacovan and Prata-Ana and the hybrids Pioneira, PA03-22, FHIA-18, PV03-76, PV03-44 and JV03-15 The characteristics analyzed were plant height, pseudostem diameter, bunch weight, number of fruits, fruit length and cycle Along the cycles, 'Nanica' presented the smallest plant height, while 'Prata-Ana' stood out in the pseudostem diameter, followed by 'Prata-Comum' and JV03-15 'Thap Maeo' stood out in the bunch weight and in the number of fruits, followed by FHIA-18, in the first character, and by 'Mysore', 'Caipira' and FHIA-18, in the second 'Grande-Naine' and 'Nanica' presented the largest fruit length, while FHIA-18 and PA03-22 stood out in the precocity It was concluded that 'Thap Maeo' has potential to substitute 'Mysore', and the hybrids evaluated present quality to be recommended to the farmers
TL;DR: Evaluated genetic diversity, its organization and the genetic relationships within oil palm and E. guineensis revealed that genetic divergence between the twospecies is of the same magnitude as that among provenances of E. oleifera, in discrepancy with the supposed early tertiary separation of the two species.
Abstract: – The objective of this work was to evaluate the genetic diversity, its organization and thegenetic relationships within oil palm ( Elaeis oleifera (Kunth) Cortes, from America, and E. guineensis(Jacq.), from Africa) germplasm using Restriction Fragment Length Polymorphism (RFLP) and AmplifiedFragment Length Polymorphism (AFLP). In complement to a previous RFLP study on 241 E. oleiferaaccessions, 38 E. guineensis accessions were analyzed using the same 37 cDNA probes. These accessionscovered a large part of the geographical distribution areas of these species in America and Africa. Inaddition, AFLP analysis was performed on a sub-set of 40 accessions of E. oleifera and 22 of E. guineensisusing three pairs of enzyme/primer combinations. Data were subjected to Factorial Analysis ofCorrespondence (FAC) and cluster analysis, with parameters of genetic diversity being also studied.Results appeared congruent between RFLP and AFLP. In the E. oleifera, AFLP confirmed the strongstructure of genetic diversity revealed by RFLP, according to geographical origin of the studied material,with the identification of the same four distinct genetic groups: Brazil, French Guyana/Surinam, Peru,north of Colombia/Central America. Both markers revealed that genetic divergence between the twospecies is of the same magnitude as that among provenances of E. oleifera. This finding is in discrepancywith the supposed early tertiary separation of the two species.Index terms: Elaeis oleifera, Elaeis guineensis, population genetics, palm species, genetic resources,molecular chacterization.Diversidade e relacao genetica entre o dende americano e o africanorevelada por marcadores moleculares do tipo RFLP e AFLPResumo – O objetivo deste trabalho foi avaliar a diversidade genetica, sua organizacao e a relacaogenetica no germoplasma de dende ( Elaeis oleifera (Kunth) Cortes, de origem americana, e E. guineensis(Jacq.), africana), pelas tecnicas de Polimorfismo de Comprimento de Fragmentos de Restricao (RestrictionFragment Length Polymorphism – RFLP) e Polimorfismo de Comprimento de Fragmentos Amplificados(Amplified Fragment Length Polymorphism – AFLP). Em complemento a um estudo previo de RFLPem 241 acessos de E. oleifera, 38 acessos de E. guineensis foram analisados usando as mesmas 37sondas de cDNA. Os acessos estudados cobrem uma grande parte da area de distribuicao geograficadestas duas especies nos continentes Americano e Africano, respectivamente. Alem disso, analises commarcadores AFLP foram realizadas em uma subamostra com 40 acessos de E. oleifera e 22 de E. guineensis,empregando tres combinacoes de pares enzima/primer. Os dados foram submetidos a analise fatorial decorrespondencia (AFC) e analise de cluster, sendo tambem estimados parâmetros de diversidade genetica.Os resultados obtidos apresentaram grande coerencia entre as duas tecnicas utilizadas, RFLP e AFLP.Na especie E. oleifera, a tecnica AFLP confirmou a forte estruturacao da diversidade genetica reveladapela tecnica de RFLP, de acordo com a origem geografica do material estudado e com a identificacao dosmesmos quatro grupos geneticos distintos: Brasil, Guiana Francesa/Suriname, Peru e norte da Colombia/America Central. Entretanto, ambos os marcadores revelaram que a divergencia entre as duas especiese da mesma magnitude da divergencia dentro da especie americana. Este resultado esta em discrepânciacom uma suposta separacao das duas especies durante a era terciaria.Termos para indexacao: Elaeis oleifera , Elaeis guineensis , genetica de populacao, palmeiras, recursosgeneticos, caracterizacao molecular.
TL;DR: In this paper, the ganhos preditos por diferentes criterios of selecao, em seis caracteristicas de crescimento em familias de meios-irmaos de Eucalyptus camaldulensis, were avaliados.
Abstract: Foram avaliados os ganhos totais preditos por diferentes criterios de selecao, em seis caracteristicas de crescimento em familias de meios-irmaos de Eucalyptus camaldulensis. A situacao simulada consistiu na selecao de 25% das 44 familias estudadas, e de 17% das plantas dentro dessas familias, proporcionando, assim, uma selecao de 4,25% dos individuos constantes do ensaio. Os criterios de selecao empregados foram: selecao direta e indireta; indice classico de Smith & Hazel, com quatro pesos economicos, e indice de Pesek & Baker, em tres situacoes. Os criterios de selecao utilizados mostraram-se semelhantes entre si, com ligeira superioridade do indice classico quando se estabeleceu como vetor de pesos economicos o coeficiente de variacao genetica associado a cada uma das caracteristicas analisadas.
TL;DR: Populations revealed potential to be used in breeding programs; however, those more intensively sub- mitted to selection could provide larger genetic progress, showing the importance of population growth for the increment of the heterosis in maize.
Abstract: Genetic progress depends on germplasm quality and breeding methods. Twelve maize popu- lations and their crosses were evaluated to estimate combining ability and potential to be included as source populations in breeding programs. Plant height, point of insertion of the first ear, number of ears per plant, number of grains per ear, root and stalk lodging and grain yield were studied in two locations in Brazil, during the 1997/98 season. Genotype sum of squares was divided into general (GCA) and specific (SCA) combining ability. Results indicated the existence of genetic divergence for all traits analyzed, where additive effects were predominant. The high heterosis levels observed, mainly in Xanxere, suggested the environmental influence on the manifestation of this genetic phenomenon. Populations revealed potential to be used in breeding programs; however, those more intensively sub- mitted to selection could provide larger genetic progress, showing the importance of population im- provement for the increment of the heterosis in maize.
TL;DR: In this article, the authors proposed a methodology for CV classification bands definition, independently of their distribution; the new methodology is based on the use of the median and the pseudosigma, and the variation of the values of CV evidences the importance of considering both the variable in study, but also the experimental design.
Abstract: The assessment of coefficients of variation (CV) as a measure of precision in experiments has been done for various crops, and some researchers have proposed a methodology to get classification bands of CV, and others defining the classification bands itself; based on the mean and on the standard deviation of the CV, assuming that they have normal distribution, which is not always true. This study had as objective to propose a methodology for CV classification bands definition, independently of their distribution; the new methodology is based on the use of the median and the pseudosigma. Data from 110 experiments of upland rice, designed in randomized complete blocks, generalized incomplete blocks and square lattices were analyzed, selecting the characters related to diseases, lodging, yield and yield components. CV classification bands were constructed for each character studied, in general, and considering the experimental design utilized for experiments with 30 to 100 treatments. The method proposed is efficient for the definition of CV bands, independently of their distribution, and the variation of the values of CV evidences the importance of considering, not only the variable in study, but also the experimental design. Experiments with smaller CV were those that utilized Incomplete Block Design. The variables related to diseases and lodging were those that presented larger coefficient of variation.
TL;DR: The use of selection indexes allows simultaneous prediction of gains in the two main traits of corn kernels (Zea mays L) using random blocks design at Embrapa-Centro Nacional de Pesquisa de Milho e Sorgo in Sete Lagoas, MG, Brazil.
Abstract: Simultaneous breeding for expansion volume and grain yield in popcorn (Zea mays L.) is difficult because of negative correlation between these traits. The use of selection indexes allows to overcome this difficulty. In 1997/1998, at Embrapa-Centro Nacional de Pesquisa de Milho e Sorgo, in Sete Lagoas, MG, Brazil,166 half-sib families from CMS-43 popcorn were evaluated, using random blocks design. The selection indexes used were Smith and Hazel, Pesek & Baker, Elston and Williams. The selection index of Smith and Hazel allowed larger predicted gains in more traits, and on the contrary, the prediction using the selection index of Williams was insignificant. The use of selection indexes allows simultaneous prediction of gains in the two main traits.
TL;DR: The correlation and path analyses showed that the relationships between yield and the other traits varied according to the cross, sowing date and year, and an index combining days to maturity, height at flowering and number of trifoliolate nodes can contribute to yield selection.
Abstract: A associacao entre a produtividade e outras caracteristicas da planta identifica caracteres para uso na selecao indireta para produtividade. A produtividade da soja e muito influenciada pelo fotoperiodo e pela temperatura, e a semeadura fora de epoca acarreta reducao na produtividade. Os programas de melhoramento procuram desenvolver cultivares adaptadas a um periodo mais amplo de semeadura. No Brasil, entretanto, nao ha estudos sobre as inter-relacoes entre a produtividade e algumas caracteristicas de importância agronomica da soja (dias para maturacao, altura da planta no florescimento e numero de nos da haste principal), em um periodo mais amplo de semeadura (setembro a dezembro). Este trabalho procura quantificar essas relacoes e identificar possiveis criterios de selecao indireta em relacao a produtividade, avaliando linhas puras derivadas dos cruzamentos entre BR85-29009, FT-2, BR-13 e OCEPAR-8. O delineamento experimental usado foi o inteiramente casualizado. Os estudos de correlacoes e analise de trilha revelaram que a influencia das caracteristicas sobre a produtividade dependeu do cruzamento, da epoca de semeadura, e do ano. As correlacoes fenotipicas e genotipicas entre as caracteristicas e a produtividade foram essencialmente positivas. As analises de trilha mostraram que dias para maturacao e altura da planta no florescimento, individualmente, ou a combinacao dias para maturacao, altura da planta no florescimento e numero de nos em um indice, podem auxiliar na selecao quanto a produtividade. A contribuicao dos dois primeiros caracteres para o aumento na produtividade foi maior em semeaduras realizadas em novembro e outubro, respectivamente.
TL;DR: O objetivo deste trabalho foi avaliar a capacidade e o potencial de solubilizacao de 56 isolados inoculados em meio GES contendo fosfato (Anitapolis, Araxa ou Catalao), usando-se um fatorial 57x3 completamente casualizado com tres repeticoes.
Abstract: A utilizacao de microrganismos solubilizadores tem sido sugerida como alternativa ao uso de fertilizantes fosfaticos. Para serem utilizados num programa de inoculacao controlada, os microrganismos devem apresentar grande capacidade e potencial de solubilizacao. O objetivo deste trabalho foi avaliar a capacidade e o potencial de solubilizacao de 56 isolados inoculados em meio GES contendo fosfato (Anitapolis, Araxa ou Catalao), usando-se um fatorial 57x3 (56 isolados + testemunha e tres fosfatos) conduzido em delineamento completamente casualizado com tres repeticoes. Apos 15 dias de incubacao, determinaram-se as quantidades de P e o pH do meio. Foram verificados efeitos dos fosfatos, dos isolados e da interacao. Baixos valores de pH foram obtidos por isolados que apresentaram medio a alto potencial. O teor medio de P foi superior no fosfato de Anitapolis, seguido do Araxa. Trinta e um isolados solubilizaram quantidades significativas. O 310 apresentou o mais alto potencial (media de 263 m g mL -1 de P). Quatro isolados (177, 262, 251 e 269) apresentaram alto potencial (120 a 150 m g), e doze (201, 309, 199, 195, 249, 202, 198, 305, 253, 196, 203 e 307), mostraram valores medios (80 a 120 m g). O comportamento dos isolados foi diferente entre os fosfatos. Apenas quatro isolados solubilizaram os tres fosfatos (310, 251, 199 e 249). As caracteristicas apresentadas pelos isolados 310, 251, 199 e 249 os qualificam para um programa de selecao visando a inoculacao controlada.
TL;DR: Since the objective of mass rearing facilities of predatory bugs is to produce the maximum possible number of nymphs per day it is recommended to use females of P. rostralis with weight above 60.0 mg.
Abstract: (4) Abstract - Considering the importance of predatory Pentatomidae as biological control agents it is necessary to optimize mass production facilities of these species. The objective of this research was to evaluate the influence of body weight on survival and reproductive parameters of females of Podisus rostralis (Stal) (Hemiptera: Pentatomidae). Treatments were represented by females of this predator with the following mean weight: 39.5 mg, 45.5 mg, 51.5 mg, 57.5 mg and 63.5 mg. Heavier females of P. rostralis showed shorter preoviposition period while the number of eggs and of nymphs per day presented a positive linear relationship with female weight of this predator. Longevity of females of P. rostralis was similar between treatments with no tendency of variations as a function of body weight of these females. Since the objective of mass rearing facilities of predatory bugs is to produce the maximum possible number of nymphs per day it is recommended to use females of P. rostralis with weight above 60.0 mg.
TL;DR: In this article, two experiments were conducted to test the use of three initial compositions of storage atmospheres (3kPa O2+10kPa CO2, 5kPaO2+15kPaCO2 or ambient air) and two storage periods (7 or 14 days) at 0oC on the quality of strawberries (Fragaria x ananassa Duch).
Abstract: Two experiments were conducted to test the use of three initial compositions of storage atmospheres (3 kPa O2 + 10 kPa CO2, 5 kPa O2 + 15 kPa CO2 or ambient air) and two storage periods (7 or 14 days) at 0oC on the quality of strawberries (Fragaria x ananassa Duch.) cv. Oso Grande. The fruits were originated from a grove of Farroupilha, RS, Brazil. In the first experiment, strawberries were stored in glass bottles with 1,700 mL of capacity. In the second experiment, polyethylene bags of 53 cm x 90 cm and 90 mm of thickness were used. The use of atmospheres with 3 kPa O2 + 10 kPa CO2 or 5 kPa O2 + 15 kPa CO2 resulted in a good storage potential of strawberries for up to 7 days. The modification of the atmosphere in polyethylene bags, using initial concentrations of ambient air also resulted in adequate fruit quality up to 7 days. The use of these atmospheres resulted in the maintenance of the pulp firmness, good fruit color and higher contents of total sugars and of ascorbic acid.
TL;DR: Epicotyl segments were adequate explants for transformation, regenerating plants by direct organogenesis, and genetic transformation was confirmed by performing b-glucoronidase (GUS) assays and, subsequently, by PCR amplification for the nptII and GUS genes.
Abstract: The development and optimization of efficient transformation protocols is essential in new citrus breeding programs, not only for rootstock, but also for scion improvement. Transgenic 'Hamlin' sweet orange (Citrus sinensis (L.) Osbeck) plants were obtained by Agrobacterium tumefaciens-mediated transformation of epicotyl segments collected from seedlings germinated in vitro. Factors influencing genetic transformation efficiency were evaluated including seedling incubation conditions, time of inoculation with Agrobacterium and co-culture conditions. Epicotyl segments were adequate explants for transformation, regenerating plants by direct organogenesis. Higher percentage of transformation was obtained with explants collected from seedlings germinated in darkness, transferred to 16 hours photoperiod for 2-3 weeks, and inoculated with Agrobacterium for 15-45 min. The best co-culture condition was the incubation of the explants in darkness, for three days in culture medium supplemented with 100 mM of acetosyringone. Genetic transformation was confirmed by performing b-glucoronidase (GUS) assays and, subsequently, by PCR amplification for the nptII and GUS genes.