bluuebunny/crossref_metadata_2025 huggingface dataset:
Carneiro hidráulico com tubulação de alimentação em aço galvanizado e em PVC
Authors: Abate Caroline , Botrel Tarlei Arriel
Published: April 2005

A recente crise da energia convencional tem ocasionado a exploração de fontes alternativas de energia. O bombeamento de água utilizando carneiro hidráulico é amplamente empregado em propriedades onde a energia elétrica é escassa ou inexistente. Procurando dar subsídios técnicos para a utilização do PVC nos sistemas de alimentação de um carneiro hidráulico, foi desenvolvido um experimento com objetivo de avaliar o desempenho de um carneiro hidráulico quando alimentado por uma tubulação de PVC e outra de aço galvanizado, sob três alturas de queda (2,1, 3,8 e 4,7 m). Foi utilizada a equação de D'Aubussion's para a avaliação do rendimento, calculado a partir de leituras de altura de recalque, vazão de escape, vazão de recalque e altura de alimentação. Pode-se conseguir o máximo rendimento com o carneiro hidráulico utilizando-se de tubulação de PVC com até 4,2 m de desnível; além desse valor a tubulação de aço galvanizado é mais eficiente.
Sulfur utilization by rice and Crotalaria juncea from sulfate - 34S applied to the soil
Authors: Trivelin Paulo Cesar Ocheuze , Bendassolli José Albertino , Muraoka Takashi , Carneiro Jr. Francisco
Published: April 2005

In tropical soils with intensive agriculture an increasing sulfur deficiency has been verified in several crops. The low available S in these soils is caused by the continuous use of concentrated NPK fertilizers. The objective of this work was to evaluate the utilization by rice (Oriza sativa L.) and crotalaria juncea (Crotalaria juncea L.) of sulfur applied to the soil, under greenhouse conditions. Pots with 3 kg of an Argisol (Paleudalf) were used to test the isotopic technique with the stable isotope 34S, adding a solution of sodium sulfate labeled with 34S (14.30 ± 0.05 atom % of 34S) to the soil (70 mg SO4-S per kg-1 of soil) 18 days after sowing both species. The shoots of the crotalaria and rice were harvested, respectively on the 72nd and 122nd days after S fertilization. The concentration and the amount of sulfur in the crotalaria were higher than in rice, due to the higher legume requirement for this nutrient. The sulfur requirement and the short time interval between fertilization and harvest of the crotalaria resulted in a small amount of native SO4-S mineralized in the soil and a small quantity of 34SO4 immobilized by soil microorganisms. Thus, the percentage of sulfur in the crotalaria derived from the fertilizer (Sdff) was higher than in the rice (%Sdff crotalaria = 91.3 ± 3.5%; %Sdff rice = 66.3 ± 0.8%). The expressive values of %Sdff indicate a low rate of mineralization of SO4-S probably as a consequence of the low available sulfur content in the soil.
Descartes de origem animal e o crescimento e ganho de peso do jacaré-de-papo-amarelo, Caiman latirostris (Daudin, 1802), em cativeiro
Authors: Sarkis-Gonçalves Fabianna , Castro Ana Maria Vicente , Verdade Luciano Martins
Published: April 2005

O custo da alimentação é o principal fator limitante para a criação de jacarés em cativeiro. O uso de descartes e subprodutos como fontes de alimento em fazendas de criação de jacarés poderá auxiliar a resolver este problema. No presente estudo, quatro diferentes tipos de descartes provenientes da produção animal foram avaliados como alimento para o jacaré-de-papo-amarelo (Caiman latirostris) durante o primeiro ano de vida. Um total de 120 filhotes provenientes de seis ninhadas foram mantidos em quatro diferentes tanques dentro de uma estufa plástica. As seguintes dietas foram usadas: peixe, suino, frango e mista (peixe + suino + frango em iguais proporções). O delineamento experimental foi de ANOVA por blocos. Ganho de peso e taxas de crescimento do comprimento rostro-anal e da cintura comercial foram medidos e modelos de crescimento foram estabelecidos. A dieta mista resultou em melhores taxas de crescimento e ganho de peso, mas não foram detectadas diferenças consistentes entre as dietas usadas quanto aos modelos de crescimento.
Estabilidade da resistência de genótipos de caupi a Callosobruchus maculatus (Fabr.) em gerações sucessivas
Authors: Lima Marcileyne Pessôa Leite de , Oliveira José Vargas de , Barros Reginaldo , Torres Jorge Braz , Gonçalves Manoel Eneas de Carvalho
Published: April 2005

Callosobruchus maculatus (Fabr.) (Coleoptera: Bruchidae) é a principal praga do caupi (Vigna unguiculata L.) armazenado em condições tropicais e subtropicais. Avaliaram-se a estabilidade da resistência e a capacidade de adaptação de C. maculatus a genótipos de caupi, durante seis gerações. Utilizou-se o teste sem chance de escolha, em delineamento experimental inteiramente casualizado, em esquema fatorial, com dez tratamentos, seis gerações do inseto e cinco repetições. Cada repetição constou de 30 grãos infestados com dois casais da praga. O número de ovos/fêmea diferiu entre os genótipos de caupi apenas na sexta geração, e entre as gerações em BR14-Mulato, Bico de Pato, TE90-180-3E e TE87-98-8G. A viabilidade de ovos diferiu entre as gerações em BR17-Gurguéia, BR14-Mulato, IT89KD-260 e IT89KD-245, e entre os genótipos nas terceira, quinta e sexta gerações. Os genótipos diferiram entre e dentro das gerações, em relação à duração e a viabilidade da fase imatura. Observou-se redução na emergência, especialmente em IT89KD-245, IT89KD-260, CNC 0434, Bico de Pato, TE90-180-10F e BR14-Mulato, provavelmente devido a substâncias químicas presentes nos grãos que afetaram a sobrevivência dos insetos, ao longo das gerações. Os genótipos IT89KD-245 e IT89KD-260 comportaram-se como moderadamente resistentes. Não se observou adaptação de C. maculatus aos genótipos, mantendo-se a resistência estável através das gerações.
Funções estimáveis e hipóteses testáveis nos delineamentos ortogonais e parcialmente ortogonais com três fatores
Authors: Santana Denise Garcia de , Iemma Antonio Francisco
Published: April 2005

Em situações experimentais, não raro, o pesquisador depara-se com a impossibilidade de planejar experimentos balanceados. Um grave problema surge imediatamente, no tocante à interpretação das hipóteses testadas através dos sistemas estatísticos, principalmente quando há vários fatores envolvidos e se faz presente um alto grau de desbalanceamento. Diante disso, o objetivo deste trabalho foi o estudo das funções estimáveis e das hipóteses testáveis em delineamentos ortogonais e parcialmente ortogonais com três fatores, à luz do procedimento GLM do sistema estatístico SAS. Os efeitos principais para os quais o subespaço gerado é ortogonal a cada outro subespaço inerente aos demais fatores são estimáveis e, portanto, as hipóteses correspondentes são testáveis nos modelos sem interações. Na presença de interações, as funções estimáveis apresentam, além de parâmetros do próprio fator, parâmetros das interações nas quais o fator está presente. Para esses casos, independentemente do modelo conter ou não interações, as hipóteses sobre médias ponderadas (tipo I) são equivalentes às hipóteses sobre médias ponderadas ajustadas (tipo II) e, como conjunto completo é condição necessária para a ortogonalidade parcial ou plena, ocorre também a equivalência entre as hipóteses sobre médias não ponderadas ajustadas (tipos III e IV). A igualdade entre as hipóteses dos tipos I e II ocorre para todas as interações, nos delineamentos ortogonais, mas nos delineamentos parcialmente ortogonais, ocorre para as interações formadas pelos fatores que não forem ortogonais entre si. Nessas interações as funções estimáveis apresentam parâmetros da própria interação e parâmetros da interação tripla.
Organic residue, limestone, gypsum, and phosphorus adsorption by lowland soils
Authors: Andrade Alex Teixeira , Fernandes Luiz Arnaldo , Faquin Valdemar
Published: April 2005

Organic residue application is a low cost alternative to reduce the use of inorganic fertilizers and correctives. In order to study the effect of organic residues, limestone and gypsum application on phosphorus adsorption by lowland soils, four experiments were carried out. A Mesic Organosol (OY), a Melanic Gleysol (MG), a Haplic Gleysol (GX), and a Fluvic Neosol (RU) were used in a completely randomized design and factorial scheme (3 x 2), with five replicates: three soil amendment practices (limestone, gypsum and no corrective) and two levels of organic residue (with and without corral manure). Soil samples were incubated for 60 days, with and without organic residue incorporation. After this period, we applied the corrective and incubated the soil for 30 days, then P and basic fertilization (macro and micronutrients) were applied and the soil was incubated for additional 60 days. Equilibrium phosphorus, maximum phosphate adsorption capacity, pH, exchangeable Al and phosphorus-buffering index were measured. Organic residue and limestone application increased soil pH and reduced exchangeable Al, decreasing P adsorption. Gypsum application did not increase the pH but reduced exchangeable Al and P adsorption.
Análise química do pecíolo e limbo foliar como indicadora do estado nutricional dos mamoeiros 'solo' e 'formosa'
Authors: Marinho Cláudia Sales , Monnerat Pedro Henrique , Carvalho Almy Jr. Cordeiro de , Marins Sérgio Lúcio David , Vieira Alcílio
Published: April 2005

A ausência de um consenso na literatura sobre qual parte da folha, limbo ou pecíolo, seria a mais indicada para avaliação do estado nutricional do mamoeiro, dificulta o uso da análise foliar como ferramenta de diagnose para a cultura. Assim, foi conduzido um experimento para comparar a diagnose do estado nutricional efetuada pela análise do limbo e do pecíolo foliar de mamoeiros pertencentes aos grupos 'Solo' e 'Formosa'. Foi adotado o delineamento em blocos casualizados para avaliar seis variedades de mamoeiros, três de cada grupo. Foram retiradas amostras foliares em cinco épocas, a cada três meses. A folha recém-madura foi dividida em limbo e pecíolo, onde foram determinados os teores de N, NO3-, P, K, Ca, Mg, S, B, Cl, Fe, Mn e Zn. Estes teores foram comparados com os citados na literatura como adequados para a cultura. A diagnose do estado nutricional do mamoeiro quando efetuada por meio da análise do limbo ou do pecíolo foliar levou a diferentes diagnósticos mostrando a necessidade de definição de um único padrão. A análise do limbo foliar mostrou-se mais efetiva que a do pecíolo para diagnosticar o estado nutricional, diferenciando melhor as variedades de mamoeiro, em relação a N, P, K e Cl, não diferindo em relação aos demais nutrientes. Sendo assim, o limbo foliar deve ser utilizado como indicador do estado nutricional do mamoeiro.
Número de ínstares larvais de Tuta absoluta (Meyrick) em genótipos de tomateiro
Authors: Giustolin Teresinha Augusta , Vendramim José Djair , Postali Parra José Roberto
Published: April 2005

A traça Tuta absoluta (Meyrick) é uma das principais pragas do tomateiro no Brasil e tem sido controlada quase que exclusivamente com inseticidas, o que é indesejável tanto por motivos econômicos quanto ambientais. Esses problemas podem ser minimizados com métodos alternativos de controle, tal como a resistência varietal que é uma alternativa interessante, mas que ainda precisa ser mais estudada. Visando obter mais informações sobre a relação inseto-planta, estudou-se o número de instares da traça em dois genótipos de tomateiro Lycopersicon hirsutum f. glabratum (PI 134417 -- resistente) e L. esculentum (`Santa Clara' - suscetível). O experimento foi desenvolvido em câmara climatizada em duas temperaturas (26 ± 0,5 e 30 ± 0,5ºC). As lagartas recém-eclodidas foram alimentadas com folhas dos dois genótipos. Diariamente foram retiradas 15 lagartas de cada tratamento para medições da largura da cápsula cefálica. O desenvolvimento do inseto seguiu a regra de Dyar e, em qualquer das situações testadas, apresentou quatro ínstares larvais.
Fenólicos e carotenóides totais em pitanga
Authors: Lima Vera Lúcia Arroxelas Galvão de , Mélo Enayde de Almeida , Lima Daisyvângela E. da Silva
Published: April 2005

Em decorrência de uma ampla diversidade genética, a pitanga (Eugenia uniflora L.) apresenta cor que varia do alaranjado até o vermelho escuro quase negro. Em Pernambuco, no entanto, é comum encontrá-la com coloração laranja-avermelhada. Como muitos fitoquímicos presentes em frutos exibem propriedades antioxidantes, com destaque para carotenóides e compostos fenólicos, e frente a escassez de informações sobre seus teores em pitanga, objetivou-se quantificá-los nas seleções cujos frutos apresentam coloração vermelha e roxa. Assim, foram determinados espectrofotometricamente os teores de carotenóides e fenólicos totais nos frutos destas seleções nos estádios maduro e semi-maduro. Na pitanga roxa madura e em sua película também foram determinados os teores de antocianinas, flavonóis e carotenóides totais. Os compostos fenólicos e os carotenóides totais na pitanga roxa madura encontram-se em maiores teores do que na pitanga vermelha no mesmo estádio de maturação. A seleção roxa exibiu quantidade significante de antocianinas, cujo teor foi mais elevado no fruto maduro do que no semi-maduro. Os carotenóides, antocianinas e flavonóis encontram-se mais concentrados na película do que na polpa deste fruto maduro. A presença de antocianinas, flavonóis e carotenóides totais na pitanga roxa fazem deste fruto uma fonte promissora de compostos antioxidantes cujo cultivo deveria ser estimulado.
Flutuação populacional e intensidade de infestação da broca-dos-frutos em cupuaçu
Authors: Thomazini Marcílio José
Published: April 2005

Dentre as pragas do cupuaçueiro Theobroma grandiflorum (Wild. ex Spreng.) Schum., a broca-dos-frutos, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae), é a mais importante, devido aos danos causados e por estar disseminada em alguns Estados da região Norte do Brasil. Os objetivos deste trabalho foram avaliar a flutuação populacional de adultos de C. humeropictus, determinar a intensidade de infestação e caracterizar o ataque de larvas desta praga em frutos de cupuaçueiros, em sistemas agroflorestais no Estado de Rondônia. Para obter a flutuação populacional de adultos da broca, foram amostradas semanalmente, durante o período de março/98 a julho/00, 20 plantas de cupuaçu, pelo método do sacolejo, em duas áreas de agrossilvicultores. A avaliação da população de larvas foi realizada durante duas safras, onde foram coletados e abertos frutos atacados pela broca. A determinação da infestação da praga foi obtida através da porcentagem de frutos broqueados. Adultos de C. humeropictus ocorrem durante todo ano nas plantas de cupuaçu, na área estudada, mas predominam na floração, início da frutificação e durante o período de safra. Tanto os frutos verdes como os maduros são atacados, sendo que larvas de idades diferentes podem ocorrem em um mesmo fruto. Perdas superiores a 50% na produção de frutos, devido ao ataque da broca, ressaltam a importância desta praga na região.
Ruminal parameters analyzed in remaining digestion residue of roughages in the in vitro/gas system
Authors: Campos Fábio Prudêncio de , Sampaio Alexandre Amstalden Moraes , Vieira Paulo de Figueiredo , Bose Max Lázaro Vieira , Sarmento Patrícia
Published: April 2005

Animal performance is the most direct measure in the evaluation of feed quality. However, performance data are often insufficient to determine possible interactions that may take place in the ruminal environment. The purpose of the present trial was to evaluate the possible associative effects on the concentrations of volatile fatty acids (VFAs), ammoniacal nitrogen (N-NH3) and pH in the remaining liquid fraction from the dry matter (DM) digestion for exclusive roughages: sugarcane (SC), 60- (EG60) and 180-day elephantgrass (EG180), and corn silage (SIL), as well as for combined roughages: sugarcane+corn silage (SCSIL), sugarcane+60-day elephantgrass (SCEG60), sugarcane+180-day elephantgrass (SCEG180), corn silage+60-day elephantgrass (SILEG60), corn silage+180-day elephantgrass (SILEG180) associated at equal DM proportions (50%). These associative effects present positive or negative effects on bovine performance. Concentrations of VFAs and N-NH3, as well as pH for the treatments were, respectively: SC= 56.9 mmol L-1, 50.1 mg dL-1, 5.7; SCSIL= 61.4 mmol L-1, 50.7 mg dL-1, 5.8; SCEG60= 54.7 mmol L-1, 47.6 mg dL-1, 5.8; SCEG180= 45.4 mmol L-1, 49.4 mg dL-1, 6.0; SIL= 57.2 mmol L-1, 54.0 mg dL-1, 5.8; SILEG60= 57.1 mmol L-1, 53.1 mg dL-1, 5.9; SILEG180= 55.9 mmol L-1, 52.3 mg dL-1, 6.0; EG60= 58.1 mmol L-1, 49.4 mg dL-1, 5.9; and EG180= 44.0 mmol L-1, 46.4 mg dL-1, 6.1. Nonstructural carbohydrates and starch, associated with fiber and protein, contributed to positive associative effect on the 50:50 sugarcane/corn silage mixtures. The high fermentative aspect of such mixture may have promoted the best results in bovine performance.
Biological aspects of the immature stages of Ceraeochrysa everes (Banks) (Neuroptera: Chrysopidae)
Authors: Barbosa Leonardo Rodrigues , Freitas Sérgio de , Auad Alexander Machado
Published: April 2005

A knowledge of the behavior and biological aspects of natural enemies is extremely important for the establishment of biological control programs. Biological aspects of the larvae, pre-pupae and pupae of the predator Ceraeochrysa everes (Banks) were studied. Larvae of the adult F1 generation were reared in the laboratory (25 ± 2°C, 65 ± 10 % RH and 14h photophase) on eggs of the Angoumois grain moth Sitotroga cerealella (Olivier). The duration and viability of the embryonic period, development of the immature stages and egg-adult period were evaluated. The mean embryonic period was 5.0 days, while the mean durations of the first, second and third instars were: 5.1 ± 0.03; 4.3 ± 0.05 and 4.5 ± 0.05 days, respectively, with viability exceeding 90%. Duration of the larval, pre-pupal and pupal stages averaged 13.9 ± 0.07; 5.7 ± 0.07 and 9.6 ± 0.12 days, respectively. Duration of the biological cycle was 34 ± 0.11 days on average. S. cerealella eggs were not suitable for rearing C. everes under laboratory conditions because they affected predator development.
The baltic environmental information dissemination system: using environmental informatics as a tool for sustainable development in the Baltic Sea region
Authors: Leal Filho Walter
Published: April 2005

The on-going economic development of EU-countries as well of the countries in the C&E European region has been leading to a significant use of a great deal of natural resources as well as to noticeable environmental problems. The lack of a wide-spread environmental awareness from the side of those acting in various sectors (industry, public administration, users) sometimes inhibit the implementation of legislation already available as well as the introduction of new technologies deriving, from example, from marine research. An example of this state of affairs is seen in respect of the implementation of the recommendations deriving from Baltic 21 and VASAB 2010, which illustrate the advantages from a cross-sectorial, open mechanism for the dissemination of environmental information in the region. There are various organisations today which act as suppliers of environmental information in the Baltic Sea Region. However, few, if any, are providers concerned with the various ways in which information on matters related to sustainable development is being used by various groups and audiences. This state of affairs makes it necessary to enhance the current mechanisms and approaches in place, so as to enable the wide-range of environmental information available today from areas such as marine research, to be more widely used. It is equally important that the didactic or educational potential of such information be exploited, so as to not only inform, but also to educate various groups and the general public on matters concerned with the environment in European closed seas and give information to planners and politicians to prepare decisions. In order to address such needs, the project "Baltic Environmental Information Dissemination System (BEIDS)" was set in motion. BEIDS has been taking advantage of the most modern information technologies and has been acting as a focal point for the circulation of intelligent information on aspects of the marine environment, but also emphasising related areas such as transport and sustainable development issues, among a sample of six BSR countries: Denmark, Finland, Germany, Sweden (EU) and Lithuania and Poland (non-EU), contributing to networking and know-how exchange, complementing efforts towards transregional cooperation in sustainable spatial planning on the basis of Baltic 21. The results reached to date include: increased awareness of matters related to sustainable development in the six participant countries; enhanced communication exchange and networking among the sample nations; improved information flow and increased participation in events, activities and programmes across the Baltic Sea Region. BEIDS is a prime example of the feasibility of using environmental informatics as a tool for sustainable development.
Simulação do processo de secagem de sementes de milho em camada fixa
Authors: Souza Cristiano Márcio Alves de , Queiroz Daniel Marçal de , Lacerda Filho Adílio Flauzino de
Published: April 2005

O processo de secagem realizado de maneira artificial é apontado por vários pesquisadores como um dos principais problemas de produção de sementes. Além disso, esse processo afeta também a qualidade dos grãos, diminuindo consideravelmente o seu valor de mercado para o consumo. O objetivo deste trabalho foi desenvolver um modelo de simulação do processo de secagem de sementes de milho (Zea mays L.), validando-o por meio da comparação de resultados simulados com os de testes experimentais. O método de secagem utilizado consistiu em promover a pré-secagem das sementes nas espigas, posteriormente o produto permanecia em repouso durante 12 horas, sendo então as espigas debulhadas e complementada a secagem a granel, em silos com distribuição radial de ar. A temperatura média do ar de secagem foi de 42°C e a vazão específica de ar no secador de espigas foi de 44,8 m³ min-1 m-2 e, nos silos secadores de 5,9 m³ min-1 m-2. O modelo implementado apresentou respostas satisfatórias para a simulação de secagem de sementes de milho em espigas e a granel, considerando-se que o erro relativo médio foi de 10,88%.
Biological aspects and predatory capacity of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) fed on Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) reared on cotton genotypes
Authors: Santos Terezinha Monteiro dos , Boiça Jr. Arlindo Leal
Published: April 2005

Host plants may influence indirectly biological characteristics of predators, on a positive or negative way, poiting out the importance of studies evaluating the effect of cultivars on the third trophic level. This study evaluates the biological aspects and predatory capacity of Podisus nigrispinus adults fed Alabama argillacea larvae reared on cotton genotypes. The predator was fed daily with fourth instar larvae reared on leaves of the following genotypes CNPA Precoce 1 (hirsute), CNPA 9211-31 (high gossypol level), CNPA 9211-41 (medium gossypol level) and GL2 GL3 (gossypol glandless). The pre-oviposition, oviposition and post-oviposition periods and the oviposition capacity of P. nigripinus were not affected when preyed on cotton leafworms reared on the listed cotton genotypes. Mean weight of predator females was higher (126.2 mg) when they fed on A. argillacea reared on GL2 GL3 cotton leaves, in comparison to the observed weight (96.2mg) of P. nigripinus females fed on larvae reared on CNPA 9211-41. Longevity of P. nigrispinus ranged 30.7 to 31.5 days for females and 38.0 to 66.3 days for males. P. nigrispinus females preyed 125.2 to 184.0 A. argillacea larvae during its adult stage, while adult males preyed 135.7 to 205.0 leafworms. Using plant resistance in association with P. nigrispinus is viable to control A. argillacea, because resistant genotypes do not influence negatively the biological characteristics of the predator.
Nonpreference of whitefly for oviposition in tomato genotypes
Authors: Toscano Luciana Cláudia , Boiça Jr. Arlindo Leal , Maruyama Wilson Itamar
Published: April 2005

The silverleaf whitefly is one of most important pests of tomato (Lycopersicon spp.). The use of host plant resistance to control this insect is an interesting, potentially useful technique, but in demand of more research. The objectives of this work were to evaluate the oviposition non-preference of Bemisia tabaci (Gennadius, 1889) biotype B for different tomato plant genotypes, evaluating the correlation between oviposition preference and pubescence in the genotypes, and analyzing the abaxial and adaxial surfaces of Lycopersicon pennellii leaflets under the scanning electron microscope. Four wild tomato genotypes, LA 716 (L. pennellii); PI 127826 and PI 127827 (L. hirsutum); PI 134417 (L. hirsutum f. glabratum), and two commercial genotypes, Santa Clara and Bruna VFN hybrid (L. esculentum) were evaluated for number of eggs cm-2 in free and no-choice oviposition tests, using randomized block design and completely randomized design, respectively. The number of trichome was measured in 4 mm² and coefficients of correlation between number of trichomes and number of eggs were calculated. The wild genotypes LA 716 and PI 134417 were less preferred showing oviposition nonpreference resistance type in both tests. The Bruna VFN and Santa Clara were more preferred in free-choice test, while wild genotypes PI 127826 and PI 127827 were more preferred in no-choice test. L. pennellii leaflets presented glandular trichomes type IV in both surfaces. Santa Clara genotype presented higher density of trichomes, and B. tabaci biotype B presented higher preference to oviposition.
Calcium, potassium and magnesium treatment of Chrysanthemum morifolium cv. "Bi Time" and callogenesis in vitro
Authors: Borgatto Fábio , Dias Carlos Tadeu dos Santos , Amaral Antônio Francisco Campos , Melo Murilo
Published: April 2005

The chemical composition and vegetative vigor of the donor plant are essential for the satisfactory performance of explants in vitro. In order to test the effect of potassium, calcium and magnesium nutritional status of Chrysanthemum morifolium plants on callogenesis in vitro, pot plants growing in sand were irrigated with nutrient solution containing different levels of potassium (0; 58.5; 117 and 234 mg L-1), calcium (0; 50; 100 e 200 mg L-1) and magnesium (0;12; 48 e 96 mg L-1). After 30 and 45 days, explants (shoot segments and leaf discs) were collected, desinfected and inoculated on MS solid medium supplemented with 0.1 mg L-1 of kinetin and 5.0 mg L-1 of nafthalene acetic acid for callogenesis induction. Callogenesis evaluated as callus fresh weight was affected by nutrients treatment. Callus growth on leaf explants was inversely proporcional to potassium concentration and directly proportional to magnesium concentration in shoot explants. The calcium effect on callogensis of leaf explants was dependent on treatment duration. For 30 days treatment callogenseis was inversely related to calcium concentration and after 45 days was directly related to calcium concentration.
Use of AFLPS to distinguish landraces of pejibaye (Bactris gasipaes) in brazilian Amazonia
Authors: Clement Charles R. , Sousa Nelcimar Reis , Rodrigues Doriane Picanço , Astolfi-Filho Spártaco , Moreno Yolanda Núñez , Pascual Vicente Torres , Rodríguez Francisco Javier Gallego
Published: April 2005

Although the first inhabitants of western Amazonia domesticated pejibaye (Bactris gasipaes Kunth, Palmae) or peach palm for its fruits, today it is widely planted for its heart-of-palm. Like other domesticates, pejibaye presents a complex hierarchy of landraces developed before the conquest of the Americas. The existence of three landraces (Pará, Solimões, Putumayo) was proposed along the Amazonas and Solimões Rivers, Brazil, based on morphological characteristics. There are some questions remaining about the intermediate landrace being an artifact of the morphometric analysis. AFLPs were used to evaluate the relationships among samples of these putative landraces. DNA was extracted from 99 plants representing 13 populations maintained in the Pejibaye Germplasm Bank, Manaus, AM; six primer combinations generated 245 markers via PCR, which were scored in an ABI Prism 310 sequencer and analyzed with GeneScan Software; Jaccard similarities were estimated and a dendrogram was generated with UPGMA. Two groups of plants were observed in the dendrogram instead of three, and were similar at 0.795. Each group contained two subgroups, similar at 0.815. One group (n=41) contained 73% Pará landrace plants, with one subgroup (n=22) containing 91% Pará, and the other (n=19) containing 53% Pará. The other group (n=58) contained 53% Solimões and 40% Putumayo landrace plants, with one subgroup (n=21) containing 52% Solimões and 43% Putumayo, and the other (n=35) containing 57% Solimões and 37% Putumayo. The first group confirmed the Pará landrace. The second group suggested that the Solimões landrace does not exist, but that the Putumayo landrace extends along the Solimões River to Central Amazonia.
Long-life tomato cultivars growing under the hydroponic Nutrient Film Technique
Authors: Gualberto Ronan , Oliveira Paulo Sérgio Rabelo de , Resende Francisco Vilela
Published: April 2005

Farmers are interested in hydroponic tomato cultivation because of the high demand of high quality products by the consumers. Three trials here carried out under greenhouse conditions in Marília, SP, Brazil, using the hydroponic nutrient film technique, in order to evaluate yield and quality of long-life salad tomato (Lycopersicon esculentum) varieties, during 1998 and 1999. Four varieties (Carmen, Diva, Graziela, and Vita) were tested using a randomized block design, with six replications. The variety x crop season interaction effect was significant, meaning that varieties have distinct performances during the different cropping seasons. The Vita variety presented commercial valid yield, with mean fruit weights higher than the other varieties.
Simulating wind effect on microsprinkler water distribution
Authors: Conceição Marco Antônio Fonseca , Coelho Rubens Duarte
Published: April 2005

Wind incidence can affect microsprinkler water distribution. Evaluations of those conditions can be facilitated using simulations by computational models. The present work evaluates the performance of a ballistic model on simulating the wind effect on microsprinkler water distribution. Experimental tests were carried out using self-compensating microsprinklers, nozzle sizes 1.00 mm (gray), 1.10 mm (brown), 1.48 mm (orange), and 1.75 mm (yellow). The gray and brown nozzles used black swivels and the orange and yellow nozzles used blue swivels. The wind effect was artificially caused by fourteen 200 W fans. Computational simulations were realized using SIRIAS software, based on a ballistic model originally developed for sprinkler systems. The correlation coefficients (r) varied from 0.619 to 0.880, while the exactness coefficients (d) varied from 0.842 to 0.944. Swivels internal geometry influenced results. Tested models presented performances classified as very good for the black swivel nozzles and regular for the blue swivel nozzles.
Planning soil tillage using quality function deployment (QFD)
Authors: Milan Marcos , Barros José Wandmark Duarte , Gava José Luiz
Published: April 2005

The Brazilian forest sector represents about 4% of gross domestic product (GDP) which is correspondent to US$ 21.0 billion. The natural forest area is approximately 4.8 million hectares and for the near future there will be a need to increase the planted area. To avoid or minimize the impact of mechanized practices on forest soils, the reduced tillage has been developed. The aim of this work is to define the technical priorities of the reduced tillage for eucalyptus seedlings, using quality function deployment (QDF). The design requirements classified as the most important to attend seedling demands were the furrow width and depth, and clod sizes. QFD has the potential to be applied to agro-forestry systems to translate plant demands into technical requirements.
Invertase and sucrose synthase activities in coffee plants sprayed with sucrose solution
Authors: Silva José Carlos da , Alves José Donizeti , Alvarenga Amauri Alves de , Magalhães Marcelo Murad , Livramento Dárlan Einstein do , Fries Daniela Deitos
Published: April 2005

One management practice of which the efficiency has not yet been scientifically tested is spraying coffee plants with diluted sucrose solutions as a source of carbon for the plant. This paper evaluates the effect of foliar spraying with sugar on the endogenous level of carbohydrates and on the activities of invertase and sucrose synthase in coffee (Coffea arabica L.) seedlings with reduced (low) and high (normal) levels of carbon reserve. The concentrations used were 0.5 and 1.0% sucrose, and water as a control. The use of sucrose at 1.0% caused an increase in the concentration of total soluble sugars in depauperate plants, as well as increased the activity of the following enzymes: cell wall and vacuole acid invertase, neutral cytosol invertase and sucrose synthase. In plants with high level of carbon reserve, no increments in total soluble sugar levels or in enzymatic activity were observed. Regardless of treatments or plants physiological state, no differences in transpiration or stomatal conductance were observed, demonstrating the stomatal control of transpiration. Photosynthesis was stimulated with the use of 0.5 and 1.0 % sucrose only in depauperate plants. Coffee seedling spraying with sucrose is only efficient for depauperate plants, at the concentration of 1.0%.
Leaf area index of ground covers in a subtropical watershed
Authors: Xavier Alexandre Cândido , Vettorazzi Carlos Alberto
Published: April 2005

Leaf Area Index (LAI), an important structural variable descriptive of vegetation, is directly related to evapotranspiration and productivity. The objective of this work was to measure and analyze monthly LAI of different ground covers in a subtropical watershed. A field campaign to collect monthly LAI data was carried out during the year 2001, with a LAI-2000 (plant canopy analyzer) device, in sugarcane, pasture, corn, eucalypt, and riparian forest patches. Riparian forest presented a maximum LAI of 4.90; LAI values decreased as precipitation decreased, as it is a characteristic of this type of semideciduous vegetation. LAI for sugar cane presented the greatest variability throughout the year, related to plant characteristics and crop management in the study area. Results represent an initial step for the understanding of LAI dynamics in the study area and areas under similar conditions.
Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature
Authors: Nascimento Warley Marcos
Published: April 2005

Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.
Heterosis expression in crosses between maize populations: ear yield
Authors: Silva Ricardo Machado da , Miranda Filho José Branco de
Published: April 2005

The phenomenon of heterosis has been exploited extensively in maize (Zea mays L.) breeding. The objective of this study was to evaluate the genetic potential of ten maize populations for ear yield following the diallel mating scheme. Six parental populations were obtained through phenotypic selection of open-pollinated ears in Rio Verde, GO, Brazil, (GO populations) and four parental populations were synthesized in Piracicaba, SP, Brazil (GN populations): GO-D (DENTADO), GO- F (FLINT), GO-A (AMARELO), GO-B (BRANCO), GO-L (LONGO), GO-G (GROSSO), GN-01, GN-02, GN-03 and GN-04. Experiments were carried out in three environments: Anhembi (SP) and Rio Verde (GO) in 1998/99 (normal season crop) and Piracicaba (SP) in 1999 (off-season crop). All experiments were in completely randomized blocks with six replications. Analysis of variance grouped over environments showed high significance for heterosis and its components, although mid-parent heterosis and average heterosis were of low expression. The interaction treatments x environments was not significant. Total mid-parent heterosis effects ranged from de -4.3% to 17.3% with an average heterosis of 3.37%. Population with the highest yield (7.4 t ha-1) and with the highest effect of population (v i = 0.746) was GN-03, while the highest yielding cross was GO-B x GN-03 with 7,567 t ha-1. The highest specific heterosis effect (s ii' = 0.547) was observed in the cross GO-B x GN-03.
Tillering of Tifton 85 bermudagrass in response to nitrogen rates and time of application after cutting
Authors: Premazzi Linda Monica , Monteiro Francisco Antonio , Corrente José Eduardo
Published: April 2005

Nitrogen fertilization is determinant for pasture productivity, as it results in increasing forage yield and is associated with the growth physiology of forage plants. An experiment was carried out in a greenhouse to evaluate the effects of nitrogen rates and times of application after cutting on Tifton 85 Bermuda grass (Cynodon spp.) tillering. Plants were grown in a Typic Quartzipsamment soil and nitrogen rates were 0, 80, 160 and 240 mg kg-1 of soil; times of application were immediately after and seven days after cutting. A 4 x 2 factorial experiment was set in a completely randomized block design (n= 4). Plants were evaluated in two sequential growth periods - 39 and 41 days. Nitrogen rates affected tiller density, considering the initial number of tillers in the second growth and the emerged and final number of tillers at the end of the growth periods. Tiller weight increased up to the nitrogen rate of 201 and 185 mg kg-1 of soil in the first and second growth periods, and the correlation coefficients between the final number of tillers and dry matter yields in the top part of the plant for these periods were 0.92 and 0.94, respectively. The rate of tiller development, evaluated in each of the seven-day periods, was affected by nitrogen rates and time of application. There was an effect of rates and time of application in the first and a significant interaction between rates and time in the second growth period.
Identification of a non-host plant of Xylella fastidiosa to rear healthy sharpshooter vectors
Authors: Marucci Rosangela Cristina , Giustolin Teresinha Augusta , Miranda Marcelo Pedreira de , Miquelote Helen , Almeida Rodrigo Piacentini Paes de , Lopes João Roberto Spotti
Published: April 2005

Rearing leafhopper (Hemiptera: Cicadellidae) vectors free of Xylella fastidiosa is a requirement for studies of various aspects of vector-pathogen interactions. The selection of a plant that allows vector development but not bacterial multiplication is desirable to produce healthy vectors. In this study, two leafhopper hosts, Vernonia condensata ('boldo') and Aloysia virgata ('lixeira') were needle inoculated with citrus and coffee strains of X. fastidiosa to evaluate if these plants support pathogen colonization. The inoculated plants did not present symptoms and the pathogen was not detected by culture and PCR tests, neither soon after inoculation (7-14 days) nor later, at 1, 4, 6 and 12 months after inoculation. To obtain healthy adults of the leafhopper vectors Acrogonia citrina, Bucephalogonia xanthophis, Dilobopterus costalimai, Homalodisca ignorata and Oncometopia facialis, early-instar nymphs were reared on V. condensata. X. fastidiosa was not detected in any of 175 adults obtained. V. condensata and A. virgata are nonpropagative hosts of X. fastidiosa and enable the production of healthy leafhoppers for vector studies.
Biomass, virus concentration, and symptomatology of cucurbits infected by mild and severe strains of Papaya ringspot virus
Authors: Pacheco Davi Andrade , Rezende Jorge Alberto Marques , Piedade Sônia Maria de Stefano
Published: April 2005

Pre-immunization with mild strains of Papaya ringspot virus - type W (PRWV-W) has allowed the mosaic disease to be controlled in different cucurbit species, with increases in marketable fruit yield. The objective of this study was to compare virus concentration, biomass and symptomatology of 'Caserta' zucchini squash, 'Menina Brasileira' long-neck squash and 'Crimson Sweet' watermelon plants infected by three mild strains and one severe strain of PRSV-W. Plants were inoculated at the cotyledonary stage, under greenhouse conditions, sampled at 7, 14, 21, 28 and 35 days after inoculation (DAI), and analyzed by PTA-ELISA. The severity of the symptoms was scored according to a scale from 1 to 5, and the fresh and dry biomass of the aerial part of the plants were evaluated at 40 DAI. Concentrations of the mild strains, based on absorbance values of the PTA-ELISA, were lower than the concentration of the severe strain for all species. The mild strains did not cause mosaic in infected plants of all species. Plants of zucchini squash and watermelon infected by the severe strain exhibited severe mosaic symptoms, but the same was not noticed for infected long-neck squash plants. Biomass values from zucchini squash and watermelon plants infected by the mild strains were 1.7 % to 12.4 % lower as compared to healthy plants. Biomass values of zucchini squash and watermelon plants infected by the severe strain presented greater reduction, varying from 29 % to 74 %. However, biomass values of long-neck squash plants infected by the mild and severe strains were similar for all treatments.
Cloning and expression of cellulase XF-818 of Xylella fastidiosa in Escherichia Coli
Authors: Wulff Nelson Arno , Carrer Helaine , Pascholati Sérgio Florentino
Published: April 2005

Xylella fastidiosa's genome was the first of a plant pathogen to be completely sequenced. Through comparative sequence analysis many genes were identified and, among them, several potentially involved in plant-pathogen interaction. However, the biological role of each gene should be assigned experimentally. On this regard, heterologous protein expression is a powerful tool to produce proteins from such genes, allowing their characterization. X. fastidiosa lives inside xylem vessels and eventually would degrade pit membranes from xylem cells to move radialy into the host. The identification of several putative plant cell wall degrading enzymes on X. fastidiosa genome prompted the assession of the function of such proteins. The open reading frame (ORF) Xf-818 was cloned into expression vector pET20b and E. coli cells harboring such plasmid exhibited cellulase activity. Using IPTG at 0.4 mmol L-1 with a 12 h incubation at 32°C are the best conditions to produce higher amounts of heterologous protein. The enzyme degrades cellulose confirming the endoglucanase activity of Xf-818.
Planosol soil sample size for computerized tomography measurement of physical parameters
Authors: Pedrotti Alceu , Pauletto Eloy Antonio , Crestana Silvio , Cruvinel Paulo Estevão , Vaz Carlos Manoel Pedro , Naime João de Mendonça , Silva Alvaro Macedo da
Published: April 2005

Computerized tomography (CT) is an important tool in Soil Science for noninvasive measurement of density and water content of soil samples. This work aims to describe the aspects of sample size adequacy for Planosol (Albaqualf) and to evaluate procedures for statistical analysis, using a CT scanner with a 241Am source. Density errors attributed to the equipment are 0.051 and 0.046 Mg m-3 for horizons A and B, respectively. The theoretical value for sample thickness for the Planosol, using this equipment, is 4.0 cm for the horizons A and B. The ideal thickness of samples is approximately 6.0 cm, being smaller for samples of the horizon B in relation to A. Alternatives for the improvement of the efficiency analysis and the reliability of the results obtained by CT are also discussed, and indicate good precision and adaptability of the application of this technology in Planosol (Albaqualf) studies.
Leaf consumption by Diabrotica speciosa (Coleoptera: Chrysomelidade) adults on difFerent host plants
Authors: Ávila Crébio José , Parra José Roberto Postali
Published: April 2005

Studies related to the feeding behavior of pest insects provide information that will aid the development of control tactics. Leaf consumption by Diabrotica speciosa adults fed on bean, corn, potato and soybean was determined in the laboratory under free-choice (multiple or double-choice) and no-choice (confinement) conditions. In the multiple-choice tests leaf circles were randomly arranged in a circular pattern (arena) inside Petri dishes. The degree of preference for the hosts was determined under double-choice conditions, where common bean was considered the standard host and the remaining plants (soybean, potato and corn) as test hosts. In all trials, two Diabrotica speciosa couples were released and maintained within the dish for 24 hours; the leaf area consumed by the insects was determined after this feeding period. Food type (host) influenced leaf area consumption by D. speciosa adults both in free-choice and in no-choice tests (P < 0.05). Under free-choice conditions, the insects preferred to feed on bean rather than on soybean, potato or corn, with no differences among these last three host plants (P > 0.05). As to the no-choice test, the consumption was higher for corn than for potato, probably to compensate the low nutritional quality of the first host.
Weed supression by smother crops and selective herbicides
Authors: Severino Francisco José , Christoffoleti Pedro Jacob
Published: April 2005

Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.