oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Introdu o e avalia o de gladíolos em ambiente de cerrado no Estado de Roraima. = The introduction and evaluation of gladiolus under Savannah (Cerrado) conditions in The State of Roraima.
Rejane Lanius Boyle,Sandra Cátia Preira Uch?a,Célida Socorro Vieira dos Santos,José Maria Arcanjo Alves
Agro@mbiente On-line , 2009,
Abstract: As plantas ornamentais de corte comercializadas no Estado de Roraima s o importadas de outros Estados do Brasil ou do exterior, como por exemplo: rosas, gladíolos, crisantemos, antúrios, violetas e gérberas. Considerando a potencialidade do Estado de Roraima para o cultivo de plantas ornamentais, objetivou com este trabalho introduzir e avaliar o comportamento de três acessos de gladíolos em condi es de casa de vegeta o no ambiente de cerrado do Estado deRoraima. O experimento foi instalado entre os meses de setembro a novembro de 2007. O delineamento experimental foi o de blocos inteiramente casualizados, com três tratamentos e nove repeti es. Os tratamentos foram três acessos de gladíolos, sendo: 1- Trader Horn; 2- White Friendship e 3- Peter Pears. As variáveis avaliadas foram: índice de germina o, altura da planta, número de dias entre a germina o e a emiss o da inflorescência, número de flores por espiga e número de flores abertas por espiga para fins de corte. Os acessos Trader Horn, White Friendship e Peter Pears desenvolveram-se até a flora o, tendo apresentado um ciclo comercial médio de 73 dias e oito flores por inflorescência, apresentando características de padr o comercial. = The ornamental plants of cutting marketed in the state of Roraima are imported from other states in Brazil orcountries, for example: roses, gladiolus, chrysanthemums, anthuriums, gerberas and violets. Considering the potential of thestate of Roraima to the cultivation of ornamental plants, this work objectived to introduce and evaluate the performance of threeacesses of gladiolus overhead covered in Savannah the State of Roraima. The experiment was conducted between September and November 2007. The experimental design was of randomized blocks with three treatments and nine replications. The treatments were three species of gladioli, which: 1- Trader Horn; 2 - White Friendship and 3 - Peter Pears. The variables were: germination index, plant height, number of days between germination and the issue of inflorescence, number of flowers per spike and number of open flowers per head for cattle. Accesses Trader Horn, White Friendship and Peter Pearswere developed to bloom, and submitted a business cycle average of 73 days and eight flowers per inflorescence, with characteristics of commercial value.
Erodibilidade e suscetibilidade à eros o dos solos de cerrado com plantio de Acacia mangium em Roraima.= Erodibility and susceptibility to erosion of the savannah (cerrado) soils planted with Acacia mangium in the State of Roraima.
José Frutuoso do Vale Júnior,Luciana da Silva Barros,Maria Ivonilde Leit?o de Sousa,Sandra Catia Pereira Uch?a
Agro@mbiente On-line , 2009,
Abstract: Com o objetivo de avaliar erodibilidade e suscetibilidade à eros o de solos sob cerrados e plantios de Acácia mangium no estado de Roraima, foram realizadas visitas nas áreas objeto de estudo para identifi ca o geomorfopedológica e feito coleta de solo representativo de 121 perfi s distribuídos nas áreas de plantio de Acacia mangium pertencentes ao projeto Ouro Verde Agrosilvopastoril Ltda. Os perfi s descritos e coletados foram georreferenciados através de GPS e plotados sobre mapas de declividades no software ARCMAPE 8.0 permitindo cruzar os valores de R com a declividade. Foi avaliada as rela es do tipo de solo, sua posi o na paisagem e suscetibilidade a eros o. Os resultados revelaram que as áreas de estudo est o inseridas em duas unidades geomorfopedológicas distintas: Jacitara/Mucajaí/Santa Cecília (JMSta) e Serra da Lua (SL), apresentando suscetibilidade à eros o bem contrastantes; As unidades JMSta apresentam maiores valores de R, inseridas em relevo plano, com declividade entre 1% a 3%, os solos da unidade SL, apresentam menores valores de R e est o posicionados em relevo com declividade entre 3 a 13%, o que a torna mais vulneráveis a eros o; as classes de solos em ordem decrescente em valores de R s o: Neossolos (RQo), Argissolos (PAd), Gleissolos (GXbd), Latossolos (LAd, LVd, LVAd, LVA Plintico), Plintossolos (FFCd), concluindo-se ent o, a necessidade da ado o de práticas simples de conserva o de solos, tais como plantio em curva de nível e até terraceamento. = With the objective to evaluate the erodibility and susceptibility to erosion of the cerrado and plantations with Acacia mangium in the State of Roraima, visits to the areas were done for geomorfopedologic identifi cation and collection of soils representative of 121 profi les distributed in the areas pertaining to the plantation of Acacia mangium of the Ouro Verde Agrosilvopastoril Ltda project. The described and collected profiles were geo-referenced through GPS and located on maps of declivities by the software ARCMAPE 8,0 allowing to cross the values of R with the declivity. There were evaluate the relations of the type of soils, its position in the landscape and susceptibility the erosion. The results obtained indicated that the areas studiedy are inserted in two distinct geomorphopedologic units: Jacitara/Mucajai/Santa Cecilia (JMSta) and Serra da Lua (SL), and demonstrated distinct susceptibility to erosion; The JMSta units presented the most elevated values of R, inserted in plain relief, with declivity between 1% and 3%. The ground of unit SL, presented small values of R a
Levantamento de plantas daninhas em área rotacionada com as culturas da soja, milho e arroz irrigado no cerrado de Roraima. = Weeds survey of rotational crops of soybean, corn, and irrigated rice in the savannah (cerrado) of Roraima.
Diego Lima de Souza Cruz,Guilherme Silva Rodrigues,Flávio de Oliveira Dias,José Maria Arcanjo Alves
Agro@mbiente On-line , 2009,
Abstract: Objetivou-se com esse trabalho identificar e quantificar os níveis de densidade populacional das espécies de plantas daninhas em lavouras de cultivo rotacionado de soja, milho e arroz irrigado no cerrado de Roraima. Por meio da metodologia do quadrado inventário, foi realizada a identifica o e contagem das espécies das plantas daninhas, totalizando 30 amostragens de 1m2 cada, dentro de uma área de 120 ha. Apesar de também terem sido observadas em outros levantamentos no Brasil, algumas espécies apresentaram-se em níveis de densidade populacional insignifi cante neste levantamento, mesmo assim, n o deixam de ser relevantes, uma vez que os prejuízos causados pelas plantas daninhas s o influenciados tanto pela densidade quanto pela capacidade de sobrevivência de cada espécie. O conhecimento da diversidade e quantidade de plantas daninhasna lavoura é o primeiro passo para a efetua o do controle eficaz. Desta forma, evitam-se os gastos desnecessários com produtos inapropriados e diminuem-se os riscos de polui o ambiental advinda do uso incorreto e abusivo dos herbicidas. Foram identificadas 23 espécies de plantas daninhas distribuídas em 23 gêneros e 15 famílias botanicas. As espécies com maiores popula es foram: Lindernia crustacea (288.667 plantas ha-1), Cyperus iria (171.000 plantas ha-1), Arenaria lanuginosa (153.667 plantas ha-1), Euphorbia heterophylla (144.000 plantas ha-1) e Physalis angulata (125.000 plantas ha-1). As famílias com maior ocorrência foram as Amaranthaceae, Euphorbiaceae e Poaceae. Dentre as espécies, 82,60% pertencem à classe botanica das dicotiled neas. = This study had as its objective to identify and to quantify the levels of population density of the weeds species in crops rotated with soybean, rice, and corn in the savannah of The State of Roraima. Through the inventory square method, the identification and count of the species was realized, with 30 sampling of 1m2 in an area of 120 ha. Although some weeds have also been observed in other surveys in Brazil, some species were in insignificant levels of population in this survey, but were not considered as relevant, because the damage caused by weeds were infl uenced by both the density and the survivability of each species. The knowledge of the diversity and number of weeds in the crop is the fi rst step towards the realization of effectivecontrol. Therefore, it avoids unnecessary spending with inappropriate products and decreases the risks of environmentalpollution arising from the misuse and abuse of herbicides. Twenty three species were identified from 15 botanical families
Resposta do feij?o-caupi as laminas de irriga??o e as doses de fósforo no cerrado de Roraima
Oliveira, Gabriela Almeida;Araújo, Wellington Farias;Cruz, Pablo Lima Souza;Silva, Washington Luis Manduca da;Ferreira, Gilvan Barbosa;
Revista Ciência Agron?mica , 2011, DOI: 10.1590/S1806-66902011000400008
Abstract: this work was carried out to evaluate the effect of irrigation depth and phosphate fertilizer (0; 70; 140; 210 kg ha-1 de p2o5) on yield and production components of cowpea (vigna unguiculata l. walp) cv. novaera at the savanna of roraima, brazil. the experimental design was arranged in a completely randomized block in split-plot and four replications. irrigation depths were applied through a sprinkler line source system. the principal treatments constituted on the depths of irrigation and the secondary treatments by the phosphate fertilizer. significant effects (p < 0.05) of the depth of irrigation and phosphate fertilizer interaction with aerial mass production and mass of 100 grains were observed. the number of grains per pods and size of pod were affected by the phosphate fertilizer only. the highest economical yield (1,306 kg ha-1) was obtained by 89.45 kg of p2o5.
Desempenho de soja-hortali a cultivada em área de cerrado em fun o de tipos de aduba o. = Soybean pod agronomic performance as a function types of fertilization cultivated in the Savannah area of Roraima, Brazil.
Oscar José Smiderle,Jane Maria Franco de Oliveira,Dalton Roberto Schwengber
Agro@mbiente On-line , 2009,
Abstract: Objetivou-se com este trabalho avaliar o desempenho de dois genótipos de soja-hortali a em fun o de três tipos de aduba o em dois anos de cultivo (2007-2008). O delineamento experimental foi de blocos casualizados em esquema de parcelas subdivididas, com cinco repeti es. Nas parcelas foram aleatorizados os três tipos de aduba o: (1) Convencional - aduba o mineral com 100 kg ha-1 de P2O5 (superfosfato simples) e 90 kg ha-1 de K2O (cloreto de potássio); (2) Intermediário - aduba o de base com 1.000 kg ha-1 de termofosfato magnesiano aplicado no sulco de semeadura + 50% do tratamento convencional (1); (3) Alternativo - aplica o de 1.000 kg ha-1 de termofosfato magnesiano aplicado no sulco de semeadura. Os genótipos BR9452273 e BRS 258 foram aleatorizados nas subparcelas. A subparcela experimental apresentava as dimens es de 2,0 x 2,0 m, com espa amento de 0,40 m entre fileiras e dez plantas por metro, perfazendo uma popula o de 250.000 plantas ha-1. Avaliou-se a altura das plantas, produtividade de vagens verdes, número de vagens em 500 gramas, rendimento relativo de gr os verdes, umidade dos gr os, massa de 100 gr os verdes e secos, e estimativa da produtividade de gr os secos. Os resultados indicam o tratamento convencional com maior produ o média de vagens verdes (11.184 kg ha-1), massa de 100 gr os (44,4 g), assim como a estimativa do rendimento de gr os secos (3.235 kg ha-1), no primeiro plantio, e no segundo plantio, os genótipos e as aduba es n o influenciam no rendimento de vagens verdes e a maior massa de 100 gr os é obtida com a BR9452273. = The objective of this study was to evaluated green pod productivity of two vegetable soybean cultivars under three types of fertilization, cultivated for two years (2007/2008). The experimental design was completely randomized blocks under a split plot scheme with five replications. Within plots three fertilization types were randomized: (1) Conventional - fertilization with 100 kg ha-1 of P2O5 and 90 kg ha-1 de K2O; (2) Intermediate - 1.000 kg ha-1 of magnesium thermophosphate at soybean sowing + 50% of conventional treatment; (3) Alternative - 1.000 kg ha-1 of magnesium thermophosphate at soybean sowing. The Genotypes BR9452273 and BRS 258 were randomized within subplot. The experimental subplot presented dimensions of 2 x 2 m, with 0,40 m between soybean rows and 10 plants per meter, resulting a population of 250.000 plants ha-1. The following parameters were evaluated: plant height, plant population, green pod productivity, number of pods in 500 g, greenpod relative yield, grain humidity and gre
Resposta do feij?o-caupi à doses e formas de aplica??o de fósforo em Latossolo Amarelo do Estado de Roraima
Silva, Armando José da;Uch?a, Sandra Cátia Pereira;Alves, José Maria Arcanjo;Lima, Ant?nio César Silva;Santos, Célida Socorro Vieira dos;Oliveira, Jane Maria Franco de;Melo, Valdinar Ferreira;
Acta Amazonica , 2010, DOI: 10.1590/S0044-59672010000100004
Abstract: phosphorus fertilization and ways of phosphate fertilizers application are important factors considering crop management. this study aimed at assessing the effect of phosphorus rates and phosphate fertilizers application forms on growth and phosphorus uptake of cowpea plants cropped on cerrado soil in the state of roraima, brazil. an experiment took place under field conditions, on a yellow latosol, at cauamé campus of roraima's federal university, located in the municipality of boa vista/rr. the experimental design was split-plot, in a completely randomized blocks, with three replicates. the plots consisted of the following phosphoric fertilizers application forms: a) broadcasting; b) single furrow and c) double furrow. sub-plots corresponded to phosphorus doses: 0, 0,5; 1,0; 1,5, and 2,0 times the recommended dose for cowpea maintenance fertilization (60 kg ha-1 of p2o5). there was a significant effect of p rates over plant growth and plant uptake. application of fertilizer in double furrows promoted higher plant growth, grain yield, and plant phosphorous uptake.
Impactos da sojicultura de exporta o sobre a biodiversidade do Cerrado / Impacts of the international trade of soybeans on the biodiversity of Cerrado Savannah
Fábio Albergaria de Queiroz
Revista Sociedade & Natureza , 2009,
Abstract: The complex relationship between free trade and environment is, nowadays, one of the mostimportant issues found at the international affairs agenda. Much has been discussed, but fewconclusive answers on the so-called environmental impact by free trade have been drawn. Anaccurate analysis on the issue will depend on the individual study of each case due to its complexity.In order to verify such assumption this paper has analyzed the impacts of the international trade ofsoybeans on the biodiversity of Cerrado Savannah. From that specific study it has been possible toverify the existence of a direct relationship between the international trade of soybeans and theloss of biodiversity in that biome.
Carbono organico e biomassa microbiana do solo em plantios de Acacia mangium no Cerrado de Roraima
Sim?es, Sara Magda Oliveira;Zilli, Jerri édson;Costa, Mirian Cristina Gomes;Tonini, Hélio;Balieiro, Fabiano de Carvalho;
Acta Amazonica , 2010, DOI: 10.1590/S0044-59672010000100003
Abstract: the aim of this study was to evaluate the effects of acacia mangium plantation in the roraima's savanna, on soil organic carbon and soil microbial biomass. soil samplings were collected on the depths of 0-20 cm and 20-40 cm in two acacia mangium plantation sites, about five years old, and in two sites of native savanna as reference. one of the a. mangium sites (located at fazenda cigolina) was composed by a homogeneous plantation (3.6 m between row and 2.0 m between trees) and, the other one (located at campo experimental agua boa experimental - ceab) was composed by a plantation on which the planting distances had strips of two rows 6 meters apart, 2.5 meters between trees and 30 meters between strips). soil samples were analyzed regarding soil organic carbon, microbial biomass carbon, soil basal respiration and metabolic quotient, besides soil fertility attributes. results showed that a. mangium plantations did not provide significant increases of organic carbon on the soil comparing with sites used as reference. however, generally, a. mangium plantation increased soil microbial biomass carbon and reduced metabolic quotient, indicating a possibility of soil organic carbon accumulation in long-term. it was also observed that, soil biomass microbial carbon was higher, followed by smaller metabolic quotient at ceab a. mangium plantation compared with cigolina and reference sites, showing that planting design exercised influence on soil microbial biomass.
Desenvolvimento inicial de trigo sob doses de nitrogênio em Latossolo Vermelho de Cerrado Initial development of wheat under different nitrogen levels in an Oxisol of the 'Cerrado'  [cached]
William Pietro-Souza,Edna M. Bonfim-Silva,Alessana F. Schlichting,Matheus de C. Silva
Revista Brasileira de Engenharia Agrícola e Ambiental , 2013,
Abstract: As condi es de solo, clima, topografia e variedades adaptadas, têm favorecido o cultivo de trigo no Cerrado; contudo, no que concerne à aduba o nitrogenada, ela é responsável pelo incremento de produ o. Assim, o objetivo deste estudo foi avaliar o desenvolvimento inicial e a produ o de massa seca de plantas de trigo cv. Guamirim adubado com nitrogênio em Latossolo Vermelho do Cerrado. O experimento foi conduzido em casa de vegeta o da Universidade Federal do Mato Grosso - Campus Universitário de Rondonópolis, em vasos com capacidade para 5 dm3. O delineamento experimental foi o inteiramente casualizado com seis doses de nitrogênio (0, 80, 160, 240, 320 e 400 mg dm-3), cinco repeti es e cinco plantas por vaso. Os períodos de avalia es foram: 26, 33, 40 e 47 dias após a emergência, determinou-se: número de folhas e perfilhos, altura de planta, massa seca da parte aérea e raízes. A aduba o nitrogenada influencia o desenvolvimento das plantas de trigo em todos os períodos avaliados. As melhores respostas do trigo à aduba o nitrogenada ocorrem nas doses entre 80 a 195,6 mg dm-3. The soil conditions, climate, topography and adapted varieties have favored the cultivation of wheat in the 'Cerrado'. However, regarding the nitrogen fertilization, it is considered the main factor for increasing production. The objective of this study was to evaluate the initial development and dry mass production of wheat plants cv. Guamirim fertilized with nitrogen in the 'Cerrado' Oxisol. The experiment was carried out in a greenhouse at the University of Mato Grosso - Campus of Rondonópolis, in recipients of 5 dm3. The experimental design was completely randomized with six levels of nitrogen (0, 80, 160, 240, 320 and 400 mg dm-3), five replications with five plants per pot. The evaluation periods were: 26, 33, 40 and 47 days after emergence, where the number of leaves and tillers, plant height, dry mass of shoots and roots were determined. Nitrogen fertilization affected the wheat plant development for all evaluated periods. The best responses of wheat to nitrogen fertilization occurred at doses ranging from 80 to 195.6 mg dm-3.
época de colheita e armazenamento de sementes de arroz produzidas no cerrado de Roraima. = Harvesting time and storage of rice seeds in savanna area of Roraima, Brazil.
Oscar José Smiderle,Carlos Tadeu dos Santos Dias
Agro@mbiente On-line , 2011,
Abstract: A época de colheita é um dos fatores mais importantes que influenciam as características da semente de arroz (Oryza sativa L.). Objetivou-se com o presente trabalho determinar a melhor época de colheita em fun o do período de armazenamento, produtividade, qualidade de sementes e rendimento de sementes inteiras no armazenamento de sementes de arroz BR IRGA 409. Para tanto foram avaliados o teor de água, viabilidade, massa seca de 100 sementes, rendimento desementes inteiras, produtividade e armazenabilidade das sementes produzidas em Boa Vista, RR. O delineamento experimental utilizado foi o inteiramente aleatorizado, em esquema fatorial (6 x 3) com quatro repeti es, sendo o primeiro fator as épocas de colheita (colheita aos 15; 22; 29; 36; 44 e 50 dias após o florescimento) e segundo fator os períodos de avalia o (zero; seis e doze meses). As sementes obtidas aos 15 e 22 dias revelaram-se inferiores em todas as variáveis estudadas. As sementes colhidas aos 29 dias mostraram boa qualidade, e a produtividade foi equivalente à dos períodos subseqüentes. Aquelasprovenientes da colheita realizada aos 50 dias exibiram qualidade física e fisiológica, exceto no rendimento de sementes inteirasno armazenamento. A melhor faixa de colheita foi a de 29 a 43 dias após o florescimento, quando as sementes apresentam maior qualidade fisiológica, maior massa seca de 100 sementes, maiores rendimentos de sementes inteiras e produtividade de sementes. As sementes de arroz colhidas apresentam e mantém a qualidade fisiológica no armazenamento. = Harvesting time is one of most important factors that have influence on rice seed characteristics. With the objective to determine the best harvest time concerning to storage period, productivity, seed quality and undamaged rice yield during storage of BR IRGA 409 rice seeds. In this way, the following parameters were assessed: water content, viability, dry mass of 100 seeds, undamaged seed yield, productivity and storability, being all produced in Boa Vista, RR. The experimental design utilized was completely randomized, in a factorial (6 x 3) scheme with four replicates, the first factor related to harvest times15; 22; 29; 36; 44 and 50 days after flowering and the second factor related to periods of evaluation (zero, six and twelve months). Seeds obtained 15 and 22 days after flowering were inferior in all parameters analyzed. Seeds harvested 29 days after flowering presented good quality, and productivity was equivalent to subsequent periods. Seeds obtained from harvest 50 days after flowering showed physical and physiological
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.