Showing papers in "Revista Ciencia Agronomica in 2014"

Rendimento quântico e trocas gasosas em maracujazeiro amarelo sob salinidade hídrica, biofertilização e cobertura morta

Abstract: Um experimento foi conduzido a ceu aberto no municipio de Remigio, PB, para se avaliar as respostas do maracujazeiro amarelo relacionadas a eficiencia fotossintetica e trocas gasosas. O delineamento experimental utilizado foi em blocos casualizados, no esquema fatorial 2 x 2 x 2, referente a irrigacao com agua nao salina (0,5 dS m-1) e salina (4,5 dS m-1), sem e com biofertilizante bovino, sem e com cobertura morta, com tres repeticoes e tres plantas por parcela, em recipientes plasticos circulares utilizados como lisimetros de pressao, com 130 dm3 de volume e drenos na parte inferior para a lixiviacao do excesso de sais. A irrigacao com agua de baixa salinidade e aplicacao de biofertilizante bovino comum estimularam a eficiencia fotossintetica das plantas. O uso simultâneo de agua de alta salinidade, biofertilizante e cobertura morta reduziram a condutância estomatica do maracujazeiro amarelo. As plantas sob estresse salino apresentaram atividade fotoquimica do fotossistema II e fotossintese liquida inibida.

Research on Integrated Crop-Livestock Systems in Brazil

Abstract: Integrated crop-livestock systems (ICLS) are designed to exploit synergisms and emergent properties resulting from interactions between different soil-plant-animal-atmosphere compartments that integrate themselves at different spatial-temporal scales. In this review, a panorama of the evolution of studies based on ICLS is presented. Specific keywords were used as search terms to construct a database of 450 articles from 93 national and international journals published up to and including 2013. These articles were classified according to the region of origin within Brazil (subtropical or tropical) and categorized regarding the studied components: soil, plant, animal and 'others'. Within these components, groups of variables that could characterize the different thematic lines were listed. The number of publications worldwide has been increasing, and Brazil is one of the main suppliers of scientific work within this area. Although the number of scientific studies seeking better understanding of ICLS may have increased in Brazil, further studies with a systematic view and with larger temporal and spatial scales are still required to help identify interactions between diverse biotic and abiotic factors that define new properties that emerge from these systems.

Soil fauna and its relation with environmental variables in soil management systems

Abstract: The present study aims to generate knowledge about the soil fauna, its relation to other explanatory environmental variables, and, besides it, to select edaphic indicators that more contribute to separate the land use systems (LUS). Five different LUS were chosen: conventional tillage with crop rotation (CTCR); no-tillage with crop rotation (NTCR); conventional tillage with crop succession (CTCS); no-tillage with crop succession (NTCS) and minimum tillage with crop succession (MTCS). The samples were made in the counties Chapeco, Xanxere and Ouro Verde located in the state of Santa Catarina, Brazil, and were considered the true replicates of the LUS. In each site, nine points were sampled in a sampling grid of 3 x 3. At the same points, soil was sampled for the physical, chemical and biological attributes (environmental variables). Pitfall traps were used to evaluate the soil fauna. Data were analyzed using principal component analysis (PCA) and canonical discriminant analysis (CDA). The soil fauna presented potential to be used as indictors of soil quality, since some groups proved to be sensible to changes of the environmental variables and to soil management and tillage. The soil management using crop rotation (NTCR and CTCR) presented higher diversity, compared to the systems using crop succession (NTCS, MTCS and NTCS), evidencing the importance of the soil tillage, independent of the season (summer or winter). The variable that better contributed to explain these changes were the chemical variables (potassium, pH, calcium, organic matter, available phosphorus, potential acidity), and biological variables (Shannon diversity index, Collembola, Pielou equitability index and microbial biomass carbon), respectively.

Definições e terminologias para Sistema Integrado de Produção Agropecuária

Abstract: RESUMO - A pesquisa sobre Sistema Integrado de Producao Agropecuaria tem experimentado crescente importância no Brasil. Ha incremento no numero de publicacoes neste topico, refletindo seu renovado interesse. No entanto, a literatura brasileira que referencia esse sistema e confusa, por causa de diferentes termos, siglas e conceitos utilizados. Muitas publicacoes refletem caracteristicas regionais, sem aderencia a terminologia internacional. Ha necessidade de avancar no uso de terminologias e definicoes mais precisas, visando garantir clareza na comunicacao nacional e internacional. O objetivo deste artigo e desenvolver consenso para esclarecer definicoes e terminologias a serem adotadas na descricao do Sistema Integrado de Producao Agropecuaria. A regra proposta e usar a terminologia adotada pela Food and Agriculture Organization of the United Nations como referencia. Espera-se que os termos e definicoes discutidos tornem-se padrao para uso em publicacoes referentes a esse sistema, e auxiliem para uniformidade de uso na lingua portuguesa e de palavraschave usadas para indexacao internacional. Por fim, espera-se que essa padronizacao ajude na apropriada comunicacao em areas como ciencia, educacao e industria, a fim de promover essa tecnologia como caminho a seguir visando a intensificacao sustentavel na producao de alimentos. Palavras-chave: Integracao lavoura-pecuaria. Sistema misto de producao. Terminologia.

The influence of land use systems on soil and surface litter fauna in the western region of Santa Catarina

Abstract: The aim of this study was to evaluate the abundance of soil and surface litter fauna in the western region of Santa Catarina state, southern Brazil, in the following land use systems (LUS): no-tillage crops (NT), integrated crop-livestock (ICL), pasture (PA), Eucalyptus plantation (EP) and native forest fragments (NF). Sampling was done in three counties in the western region of Santa Catarina: Xanxere, Chapeco and Sao Miguel do Oeste, in two seasons (winter and summer). The evaluation of soil/litter fauna in each LUS was performed by installing nine "pitfall traps" per sampling grid (3 x 3). The counties are true replicas. The soil for the chemical attributes was collected at the same sampling points for soil fauna. Altogether, 17 taxa were identified in the five LUS. The presence of groups of fauna was influenced by the type of soil management used. The LUS NF and EP provide better soil conditions for the development of a higher diversity of soil fauna groups compared to other LUS, which showed varying degrees of human intervention, regardless of the sampling season (winter or summer). However, annual crop systems NT and ICL groups showed greater richness and total abundance when compared to the perennial systems (EP and PA). Principal component analysis is an important tool in the study of biological indicators of sustainability because it allows use of soil attributes (chemical and physical) as explanatory environmental variables, which helps in the interpretation of ecological

Yield of soybean, pasture and wood in integrated crop-livestock-forest system in Northwestern Paraná state, Brazil.

Abstract: The integrated crop- livestock-forest system can enhance the production of soybeans, meat and wood in regions characterized by sandy soils and warm climate. The aim of this study was to evaluate the yield of soybean, Urochloa ruziziensis grass and eucalyptus in an integrated system during the first four years after the establishment of eucalyptus in the northwestern region of Parana state, Brazil. The experiment was established in October 2009, using soybean (summer) -U. ruziziensis (autumn/winter) succession between single rows of Corymbia maculata (eucalyptus species). The spacing between tree rows and eucalyptus plants in the row were 14 and 4.2 m, respectively. Adjacent plots had the same soybean-U. ruziziensis succession, but without eucalyptus. The spatial variability of soybean grain yields and grass shoot dry matter production was evaluated with and without trees, and the data was analyzed using geostatistics, with the results expressed as spatial variability maps. The tree component did not significantly affect soybean yield in the first two growing seasons. In the 3rd and 4th growing season (2011/12 and 2012/13), the interference of eucalyptus reduced the soybean grain yield by 2.9 and 27.0%, respectively, and the effect was stronger close to the tree rows. In July 2012, the tree component reduced the shoot dry matter productivity of U. ruziziensis by 29.2%. At 19 and 35 months after eucalyptus planting, the cumulative wood volume production was 0.73 and 5.17 m3 ha-1, respectively.

Desempenho agronômico e qualidade de cozimento de linhagens de feijão de grãos especiais

Abstract: RESUMO - O cultivo de feijao de graos especiais ainda e restrito no Brasil. Portanto, os objetivos foram: i) avaliar os efeitos da interacao linhagem x ambiente nos caracteres que controlam o desempenho agronomico e o tempo de cozimento em linhagens de feijao de graos especiais e ii) identificar linhagens de alto desempenho agronomico e de reduzido tempo de cozimento. Para isso, 29 linhagens de feijao de graos especiais foram avaliadas em diferentes locais, anos e epocas de cultivo. Interacao linhagem x ambiente significativa foi observada para todos os caracteres avaliados. As linhagens Light Red Kidney, Red Kanner, Montcalm, Chinock e BRS Radiante apresentaram produtividade de graos similar nos quatro ambientes. As linhagens avaliadas possuem ciclo semi-precoce ou precoce e tem caracteristicas morfologicas desejaveis. Os seguintes valores de claridade de tegumento de graos foram obtidos para feijao branco (72,85 a 82,25), rajado (33,06 a 62,57), vermelho (24,51 a 43,69), verde (57,01 a 62,36) e rosa (49,95 a 55,60). O tempo de cozimento variou de 14 min e 38 seg a 36 min e 21 seg. As linhagens de feijao de graos especiais de tegumento vermelho (Light Red Kidney, Red Kanner, Montcalm e Chinock) e de tegumento rajado (BRS Radiante) apresentam alto desempenho agronomico e reduzido tempo de cozimento nas condicoes avaliadas. Palavras-chave: Phaseolus vulgaris L.. Interacao genotipo x ambiente. Caracteres morfologicos. Feijao-qualidade. Feijaocozimento.

Aproveitamento de materiais alternativos na produção de mudas de tomateiro sob adubação foliar

Abstract: RESUMO - A utilizacao dos residuos orgânicos na composicao dos substratos para mudas significa uma alternativa a reciclagem desses materiais. Objetivou-se avaliar as caracteristic as agronomicas de mudas de tomateiro produzidas em materiais regionais alternativos utilizados como substrato e sob adubacao foliar. O experimento foi conduzido em ambiente protegido no Campus da Universidade Federal do Piaui, em Bom Jesus-PI. Utilizou-se o delineamento experimental inteiramente casualizado, com os tratamentos distribuidos em esquema fatorial 5x2, referentes a cinco materiais utilizados como substratos na presenca e ausencia de adubacao foliar (Vitam ®), com quatro repeticoes. Os materiais constaram de: 1) solo + areia + esterco bovino; 2) pau de buriti; 3) residuo de carnauba + casca de arroz; 4) residuo de carnauba em po e 5) residuo de carnauba semi-decomposto. O cultivo foi feito em bandeja de poliestireno expandido com 128 celulas. Foram avaliados porcentagem de emergencia, indice de velocidade de emergencia, altura de planta, numero de folhas, diâmetro do caule, comprimento da maior raiz, volume de raiz, massa fresca e massa seca da parte aerea e da raiz e massa seca total. O residuo de carnauba com casca de arroz e residuo de carnauba semi-decomposto apresentaram medias significativamente superiores aos demais materiais para todas as variaveis estudadas, exceto para a porcentagem de emergencia e indice de velocidade de emergencia. Independentemente do material usado como substrato na formacao de mudas de tomateiro, exceto para o residuo de carnauba em po, a aplicacao de adubacao foliar proporciona mudas de melhor qualidade. Palavras-chave: Lycopersicon esculentum Mill.. Nutricao mineral, Propagacao. Residuos orgânicos.

Otimização agroeconômica da cenoura fertilizada com diferentes doses de jitirana

Abstract: The use of spontaneous species of the Caatinga biome for green manure has been an important option in the production of vegetables, where the intention is to achieve a balance between increasing crop productivity and exploitation of the environment. The aim of this study was to evaluate the use as green manure of different dosages of hairy woodrose, known locally as jitirana, on the agronomic and economic development of the monocropped carrot. The study was carried out at Fazenda Rafael Fernandes Farm, in the district of Alagoinha, in the State of Rio Grande do Norte, Brazil, from November of 2010 to February of 2011. The experimental design was of randomized blocks with four treatments and four replications. Treatments consisted of the following dosages of jitirana: 7.5, 15, 22.5 and 30 t ha-1 dry weight. The carrot cultivar sown was 'Brasilia'. The evaluated characteristics were: plant height, number of stems per plant, dry weight of the shoots and roots, marketable and total root yield and classified root yield. The economic indicators, gross income, net income, rate of return and profitability index, were also evaluated. The agronomic and economic performance of the monocropped carrot is optimized when incorporating 13 t ha-1 jitirana into the soil. Cultivation of the carrot is agriculturally and economically viable when using jitirana as green manure.

Land use and trophic state dynamics in a tropical semi-arid reservoir

Abstract: Water body eutrophication process has been a serious problem around the world, especially in semiarid and arid region where main approach to storage water is reservoir. The aim of this work was to investigate the spatial and seasonal variability in water quality of a reservoir in a semi-arid tropical region with regards to its trophic state, and to identify the sources of nutrient input to the reservoir. Essa pesquisa foi realizada no reservatorio Oros, segundo maior do estado do Ceara-Brasil. This research was developed in the Oros reservoir, the second one most important reservoir in Ceara State, Brazil. Samples were collected bimonthly during the period April 2008 to April 2010, from sex sampling points representing the outlet of tributaries, and one point down of the dam. The study included the following variables: total phosphorus, transparency and chlorophyll-a. Trophic state was evaluated by application of the Carlson modified Trophic State Index (TSI). Maps of the spatial and seasonal dynamics of the water quality in the reservoir were constructed using GIS soft. According to the average values of total phosphorus (> 0.050 mg L -1 ), the waters can be classified as eutrophic. The highest concentrations of chlorophyll-a were found during the dry season, with values ranging from 3.8 to 26.5 µg L -1 , showing high temporal and spatial variations. The waters presented as eutrophic regarding average TSI, at all points sampled. The results indicate a deterioration in water quality and the need for intervention to reduce the release of waste, and thus improve the trophic state of the waters of the Oros reservoir.

Multivariate approach in the selection of superior soybean progeny which carry the RR gene

Abstract: A eficiencia do aproveitamento da variabilidade genetica, existente ou criada, aumenta quando esta e devidamente explorada e analisada. A incorporacao de eventos biotecnologicos aos programas de melhoramento tem sido uma pratica usual. O pesquisador tem como desafio, o desenvolvimento constante de novas e melhores cultivares. O objetivo deste experimento foi selecionar progenies com caracteres superiores e portadoras ou nao do gene RR, oriundas de cruzamentos bi-parentais em soja, com o auxilio de tecnicas multivariadas. O experimento foi conduzido em delineamento experimental do tipo familias com testemunhas intercaladas no ano agricola 2010/2011 e 2011/2012 em Jaboticabal-SP, Brasil. Na geracao F3, foram selecionadas plantas fenotipicamente superiores, sendo estas avaliadas para os caracteres: numero de dias para o florescimento, numero de dias para a maturidade, altura de insercao da primeira vagem, altura de planta na maturidade, acamamento, valor agronomico, numero de ramos, numero de vagens por planta, peso de 100 sementes, numero de sementes por planta e producao de graos por planta. Diante dos resultados, verifica-se a possibilidade de selecionar progenies superiores atraves da analise de componentes principais. A analise de agrupamentos, atraves do metodo de K-means, une as progenies de acordo com os caracteres de maior importância em cada grupo e, atraves do metodo de Ward, identificou por meio do dendrograma a estrutura de similaridade e divergencia entre as progenies selecionadas. Os dois metodos sao eficientes no auxilio da selecao de progenies.

Ecophysiology of seed germination in Digitaria insularis ((L.) Fedde)

Abstract: The invasive behaviour of sourgrass (Digitaria insularis) in cultivated areas is due to its strategy of aggressive regeneration, which is based on seed germination. Knowledge of the physiological ecology of this species can contribute to the development of management and control strategies. The aim of this research was to understand the effects of provenance, temperature and light on the germination of sourgrass seeds collected in the Brazilian state of Sao Paulo in the cities of Americana, Botucatu and Sao Jose do Rio Preto and in the state of Parana in the city of Sao Miguel do Iguacu. The seeds were left to germinate at temperatures of 15, 25, 35 and 45 °C, both with and without light. The number of normal seedlings was recorded daily from seven to 60 days. After this period, the seeds together with substrate, were transferred to 25 oC with light, and a daily count was made for all treatments until the end of germination (75 days after sowing). The seeds of D. insularis are positively photoblastic. Seed germination in this species depends on provenance. A temperature of 4 5 °C for germination is lethal to the seeds. The temperature of 35 °C in the presence of light is the most favourable condition for seed germination.

Comportamento vegetativo e produtividade de girassol em função do arranjo espacial das plantas

Abstract: A cultura do girassol expressiva nos cenarios nacional e internacional devido, principalmente, a possibilidade da utilizacao do oleo na fabricacao de biodiesel. O presente trabalho objetivou avaliar os efeitos de arranjos espaciais das plantas sobre as caracteristicas vegetativas e a produtividade de aquenios de girassol da variedade Embrapa 122 em dois locais de cultivo. Os experimentos foram desenvolvidos na Area Experimental do Departamento de Fitotecnia no Campus do Pici, em Fortaleza-CE, e na Fazenda Experimental Vale do Curu, em Pentecoste-CE. Foram avaliados 16 tratamentos obtidos pelas combinacoes entre quatro espacamentos entre linhas (0,30; 0,50; 0,70 e 0,90 m) e quatro densidades de plantio (30.000; 45.000; 60.000 e 75.000 plantas ha-1) os quais foram distribuidos em quatro blocos casualizados. As caracteristicas vegetativas consistiram na determinacao do diâmetro do caule, comprimento da haste, numero de folhas, area foliar e indice de area foliar. Ao final do ciclo da cultura tambem se determinou a produtividade de aquenio. Os experimentos foram analisados de forma conjunta em relacao ao local de cultivo, sendo os dados submetidos a analise de variância e os fatores quantitativos testados por meio de regressao utilizando o teste F (p < 0,05) para verificar o ajuste dos modelos. Os fatores estudados nao interagem simultaneamente sobre o comportamento vegetativo e produtividade, sendo o local de cultivo preponderante. A competicao intraespecifica afeta o comportamento vegetativo do girassol. No manejo espacial da cultura, o espacamento entre linhas pode afetar a produtividade de aquenios de girassol dependendo do local de cultivo.

Eficiência simbiótica de progenitores de cultivares brasileiras de feijão-caupi

Abstract: RESUMO - Devido a variabilidade das leguminosas quanto a eficiencia da fixacao biologica de nitrogenio (FBN), tem sido enfatizada a importância do melhoramento genetico vegetal no favorecimento da fixacao do nitrogenio. Este estudo teve como objetivo avaliar a eficiencia simbiotica de progenitores de cultivares brasileiras de feijao-caupi e dar suporte cientifico a inclusao da FBN ao programa de melhoramento genetico da cultura do feijao-caupi no Brasil. O experimento foi conduzido em Teresina, Piaui. Utilizou-se delineamento experimental em blocos casualizados em esquema fatorial 6 x 5, com tres repeticoes, sendo seis fontes de N: quatro estirpes de bacterias diazotroficas (BR 3267, BR 3299, BR 3262 e INPA 03-11B), um tratamento com nitrogenio mineral e outro sem inoculacao e sem N; e cinco genotipos de feijao-caupi: quatro progenitores (TVu 1190, Pitiuba, CNC 0434 e Alagoano) e uma cultivar (BRS Guariba). Na analise de variância utilizou-se software SAS e as medias foram comparadas pelo teste Tukey. O progenitor Alagoano destacou-se dos demais em eficiencia de nodulacao, foi superior ao Pitiuba em massa seca de nodulos e diferiu do TVu 1190 em nitrogenio acumulado na parte aerea. Para nitrogenio derivado da fixacao biologica verificou-se uma variacao media de 49,42 a 65,50%. Nos componentes de producao, o Alagoano se destacou em massa de vagem, comprimento de vagem e massa de 100 sementes. Concluiu-se que os progenitores avaliados sao responsivos a FBN e que ha indicios de especificidade entre os progenitores e as estirpes de rizobio. O progenitor Alagoano apresenta resultados mais promissores nos componentes de nodulacao e producao. Palavras-chave: Feijao-caupi-melhoramento genetico. Plantas-inoculacao. Plantas-efeito do nitrogenio.

Caracterização genética de mulungu (Erythrina velutina Willd.) em áreas de baixa ocorrência

Abstract: A Erythrina velutina Willd., popularmente conhecida como mulungu, apresenta propriedades farmacologicas e se encontra em estado de raridade em regioes do Estado de Sergipe. Devido ao interesse economico, torna-se fundamental gerar informacoes para definir planos de conservacao e exploracao sustentavel. Este trabalho teve como objetivo caracterizar os individuos de Erythrina velutina por meio de marcadores ISSRs. Para isto foram estudados 40 individuos do Estado de Sergipe pertencentes a tres localidades (Municipio de Pinhao - Caatinga; Municipio de Santana do Sao Francisco e Sao Cristovao - Mata Atlântica). Ao total, foram avaliados e obtidos 149 locos a partir de 11 primers ISSR. O numero minimo de locos para estudo de diversidade em E. velutina foi de 117 de acordo com o valor do estresse de Kruskal. Na populacao de Santana ocorre estruturacao genetica espacial e a populacao de Pinhao nao possui estruturacao genetica espacial, seus individuos estao distribuidos de forma aleatoria o que compromete a sustentabilidade ao longo do tempo, e, portanto, requer acoes imediatas de conservacao e recuperacao.

Qualidade fisiológica de sementes de pimenta em função da idade e do tempo de repouso pós-colheita dos frutos

Abstract: Um aspecto importante da producao de sementes e a determinacao da maturidade fisiologica e do momento adequado de colheita, visando obter sementes de alta qualidade, minimizando a sua deterioracao no campo. Diante disso, esta pesquisa teve por objetivo estudar a influencia do estado de maturacao dos frutos e dos periodos de repouso pos-colheita na qualidade fisiologica de sementes de pimenta (Capsicum baccatum L.), variedade Dedo-de-Moca, para determinacao do ponto adequado para colheita das sementes. Os frutos foram colhidos em quatro estadios de maturacao, com base na sua coloracao: verde intenso (15 DAA), verde amarelado (25 DAA), verde avermelhado (35 DAA) e vermelho intenso (45 DAA) e submetidos ao armazenamento por 0; 5 e 10 dias para entao, proceder a extracao das sementes. Foram determinados o peso dos frutos, comprimento, diâmetro e espessura da polpa. A qualidade das sementes foi avaliada pelos testes de germinacao, primeira contagem de germinacao, emergencia de plântulas, grau de umidade, massa seca de 100 sementes, peso de mil sementes e condutividade eletrica. Diante dos resultados, conclui-se que a maturidade fisiologica das sementes de pimenta, variedade Dedo-de-Moca, e indicada pela coloracao vermelho intenso dos frutos (45 DAA); o repouso pos-colheita dos frutos por dez dias melhora o potencial fisiologico das sementes.

Soybean performance as affected by desiccation time of Urochloa ruziziensis and grazing pressures

Abstract: Integrated crop-livestock farming system have demonstrated various economic and environmental advantages. However, there is lack of information on the effects of different desiccation times of Urochloa ruziziensis and grazing pressures on the soybean performance. This study aimed to evaluate the performance of three soybean cultivars, sown after different desiccation times of U. ruziziensis grazed at three heights during the 2012/13 growing season, in southern Brazil. The U. ruziziensis were continuously grazed for 6 months by 6, 4 and 2 animal units (AU) per hectare, leading to average pasture heights of 15; 35; and 50 cm, respectively. Each pasture height constituted a different experiment. The experiments were laid out using randomized complete block design (RCBD) with split-plot arrangement in four replications. The treatments consisted of four desiccation times (35; 28; 20; and 8 days before the soybean sowing), allocated in the main plots, and three soybean cultivars (Vmax RR; BMX Potencia RR; and NA 5909 RR), distributed in the subplots. Increased interval between U. ruziziensis desiccation and soybean sowing resulted in higher soybean plant density and height, but the effects on soybean grain yields were not significant. The highest soybean grain yield was obtained when the pasture height was maintained in 35 cm, regardless of soybean cultivars. The performance of the three soybean cultivars was not influenced by the interaction between desiccation time and the pasture residue mass on the soil at soybean sowing, defined by the pasture height.

Alternative substrates in the production of lettuce seedlings and their productivity in the field

Abstract: Based on the hypothesis that alternative substrates should improve the yield of lettuce crops by producing better quality seedlings, the objective of this work was to evaluate the effect of different substrates on the production of seedlings of this species, and their growth in the field. The study was in two stages. The first consisted of the production of lettuce seedlings, and the second assessed their development in the field. Four alternative substrates were tested, obtained by mixing together a sieved vermicompost from which all clumps had been removed, sterilized sand, charred rice husks and basalt powder. The commercial substrate, Plantmax HA®, was also tested. In the first phase, which was conducted in a completely randomised design with four replications, the height, root length, number of leaves, leaf area and dry weight of the seedlings were all evaluated 28 days after sowing. In the second phase, which was carried out in the field in a randomised block design with four replications, the plants were harvested 50 days after transplanting and the head diameter, fresh weight, number of leaves and leaf and stem dry weight were evaluated. The alternative substrates produced larger seedlings in less time than the commercial substrate, resulting in a reduction of 10 days in the total crop cycle. The reduction in the time between sowing and harvesting, together with those aspects relating to sustainability, are the main advantages of the use of alternative substrates, since in the field crop production did not differ between treatments.

Selection and use recommendation in hybrids of ornamental pineapple

Abstract: The use of pineapples as ornamental plants has increased in the last years due to their beauty and originality, demanding the generation of new varieties. The objective of the present work was to study the genetic variability and type of use of hybrids as ornamental pineapples, besides evaluating the resistance of these hybrids to Fusarium wilt. Six progenies, FRF-22 X FRF-1387, FRF-1392 X FRF-32, Curaua Roxo X Ananas Tricolor, G-44 X FRF-1387, FRF-1392 X FRF-224 and FRF-1387 X FRF-224, were evaluated by eleven morphological descriptors, and five categories of use were taken into account: landscaping plants, cut flower, potted plants, minifruits and foliage. High variability within and between progenies was detected, which allowed the selection of 16 hybrids as cut flowers, 17 as landscaping plants, four as minifruits, two as potted plants and just three as foliage. Fourteen of them were recorded for more than one type of use. For resistance to the Fusarium, out of the 31 hybrids evaluated, 11 presented resistance, 17 were moderately resistant and three were susceptible.

Production of strawberry cultivars in closed hydroponic systems and coconut fibre substrate

Abstract: The objective of this work was to evaluate yield and average fruit weight of strawberry cultivars Albion, Camarosa, Festival and Oso Grande, in two closed hydroponic systems (gutters and grow bags), using coconut fibre as substrate. The experimental design was of randomised blocks, divided into strips, with five replications. The hydroponic systems did not differ significantly as to yield, with advantages, such as savings in water and fertilizer and reduced environmental impact, over open systems. The most productive cultivar was Festival, followed by Oso Grande, with average yields of 6.99 kg m-2 and 5.56 kg m-2 respectively. The cultivars with the greatest fruit weight were Oso Grande and Albion, having averages of 11.8 and 11.1 g respectively, with the former being significantly superior to the latter. The highest yield (7.4 kg m-2) was obtained from the cultivar Festival under the gutter system. The Ibiapaba region has conditions which are favourable to strawberry production in relation to precocity (harvesting starts in the 6th week of growth) and production continues throughout the year; however there is a need to test new cultivars and to improve the cultivation techniques with an aim to producing larger-sized fruit.

Aplicação de recobrimento prolonga a qualidade pós-colheita de laranja 'Valência Delta' durante armazenamento ambiente

Abstract: The objective of this study was to evaluate the effect of the application of carnauba-based wax on the quality and conservation of the Orange cv. Valencia Delta produced in an area of semi-arid climate, during ambient storage (24 ± 2 oC and 40% ± 5 RH). The influence of the use of the coating on the physical properties (weight loss, peel moisture and flavedo colouration) and the physicochemical properties (soluble solids, titratable acidity, pH, soluble solids / titratable acidity ratio, ascorbic acid, yellow flavonoids and total polyphenols) was evaluated every four days for a period of 28 days. An increasing weight loss was seen during storage, the coated fruits however, lost weight at far lower rates than the control fruits. Accordingly, peel moisture decreased during storage, being more pronounced in the control fruits. The levels of soluble solids, titratable acidity, ascorbic acid, yellow flavonoids and total polyphenols increased, while the ratio of soluble solids to titratable acidity and the pH decreased during storage. The application of a carnauba-based coating prolonged the postharvest life of the 'Valencia Delta' orange grown in the state of Ceara, through a significant reduction in weight loss, enhancement in the brightness of the flavedo and maintenance of the physical and physicochemical properties during ambient storage.

Soil fertility status, carbon and nitrogen stocks under cover crops and tillage regimes

Abstract: The aim of the present study was to evaluate the effects of cover crops on the soil's chemical fertility, in particular its carbon and nitrogen content, in a Typic Acrustox under conventional and no-tillage corn systems. We hypothesized that the no-tillage system associates with cover crops maintains or increases soil carbon and nitrogen stocks and enhance soil fertility. The no-tillage system did not present higher carbon and nitrogen stocks than conventional tillage, but resulted in higher concentrations of exchangeable bases, higher CEC, and higher base saturation in the surface soil layer, mainly under use of Canavalia brasiliensis. Carbon and nitrogen stocks (up to 40 cm depth) differ significantly between the different cover crop species. The use of Mucuna pruriens and Canavalia brasiliensis allows maintain or increase soil C and N stocks. The no-tillage system results in higher accumulation of soil organic matter (0-5 cm), and appears very likely to enhance soil fertility. The use of Canavalia brasiliensis and Mucuna pruriens in succession to corn promotes carbon sequestration and can be used to enhance soil quality in Cerrado agroecosystems.

Correlation and path analysis in components of grain yield of cowpea genotypes

Abstract: This study aimed at verifying the effect of genotype x environment interaction on the relative contribution of yield components and final production of different cowpea genotypes. For this, data of yield components of 22 cowpea genotypes were evaluated in four environments in the State of Ceara. A one-way ANOVA tested the variability between genotypes and the Scott-Knott test compared the mean values of the genotypes. The correlations were estimated by a path analysis. A differentiated response from the genotypes to each environment was observed for all traits examined, indicating the need to perform the test for each situation separately. The number of pods per plant is the yield component with great potential of genetic gain in additional cycles of selection of more productive genotypes. The number of pods per plant and the number of grains per pod were the yield components with greater direct effects on the productivity.

Avaliação da morfologia interna de sementes de Terminalia argentea (Combretaceae) pelo teste de raios X

Abstract: Forest species, especially those from the Cerrado, are characterised by a high incidence of predation, empty fruit and deficiency in embryo formation. The objective of the present work was to evaluate the internal morphology of seeds of Terminalia argentea Mart. et Zucc. by X-ray testing, and to verify its relationship to germination. The experiment was conducted at the Laboratory for Image Analysis of the Department for Plant Production, at the Escola Superior Luis de Queiroz, in the city of Piracicaba, in the state of Sao Paulo, Brazil. Three batches of seeds of T. argentea were collected and taken to the laboratory, where radiographic analysis of 200 seeds from each lot was carried out. The seeds were placed 28.0 cm from the source of the X-ray emissions, digital equipment from Faxitron X-ray, model MX-20 DC 12. The seeds were then classified according to their internal morphology as seen in the radiographs, with three categories being established: full, empty and misshapen seeds. Germination tests were performed for each category of seed. The statistical design employed was a factorial scheme of three groups and three categories. From the results obtained in this work, use of X-ray testing of seeds of Terminalia argentea is promising for the detection of the fruit quality of the seed lots, aiding in the separation of empty seeds and those with embryonic abnormalities, and precluding their storage or immediate use. X-ray testing at an intensity of 26 kV for 1.2 seconds was effective in assessing the internal morphology of seeds of Terminalia argentea.

Estabilidade fenotípica de alfaces em diferentes épocas e ambientes de cultivo

Abstract: Este trabalho teve como objetivo estimar a adaptabilidade e estabilidade fenotipica das cultivares de alface tipo crespa em diferentes epocas de cultivo em condicoes de alta temperatura. O delineamento experimental utilizado foi de blocos ao acaso em esquema fatorial 5 x 7 x 2, sendo cinco cultivares (Veronica, Vera, Cinderela, Isabela e Veneranda), sete ambientes (campo aberto, sombrite 30; 40; 50% de luz e malhas termo refletoras 30; 40 e 50%) e duas epocas de cultivo (outubro a dezembro de 2008) e (julho a setembro de 2009), com quatro repeticoes. Em relacao a producao total e producao comercial a cultivar Veronica foi a que se destacou com relacao a producao. Houve diferenca no desempenho produtivo das cultivares em relacao as epocas de cultivo. E os parâmetros do coeficiente de determinacao e indice de variacao da variavel numero de folhas sao proximos da unidade, apresentando uma maior estabilidade. A cultivar Veronica se manteve mais estavel nos periodos de producao respondendo melhor as epocas de plantio independente dos ambientes de cultivos. A cultivar Cinderela, em relacao as outras cultivares, manteve uma boa producao, sendo a segunda opcao para o cultivo.

Equações de intensidade-duração-frequência de chuvas para o estado do Piauí

Abstract: Neste trabalho objetivou-se ajustar e comparar os parâmetros (K, a, b e c) da equacao de intensidade-duracao-frequencia para precipitacoes pluviais maximas de 133 estacoes pluviometricas localizadas no estado do Piaui, disponiveis no banco de dados da Agencia Nacional de Aguas - ANA. Inicialmente, foi realizada a selecao das estacoes atraves de analise de consistencia das series de dados, a partir do qual foram selecionadas 105 estacoes pluviometricas. As chuvas maximas de um dia foram desagregadas em duracao de 5; 10; 15; 20; 25; 30; 60; 360; 480; 600; 720 e 1.440 minutos e estimadas as chuvas maximas atraves de modelos probabilisticos para cada duracao e periodo de retorno de 5; 10; 25; 50 e 100 anos. Em seguida, fez-se o ajuste dos parâmetros (K, a, b e c) atraves do emprego de regressao linear e nao linear. O ajuste dos parâmetros da equacao de intensidade-duracao-frequencia para precipitacoes maximas realizado por regressao nao linear apresentou R2 (0,99) superior aos valores ajustados por regressao linear (0,98).

Óleo essencial de Lippia sidoides nativas de Minas Gerais: composição, estruturas secretoras e atividade antibacteriana

Abstract: Given the diverse biological activities presented by essential oils, and the antibacterial potential of the essential oil of Lippia sidoides Cham, the objective of this work was to characterise the essential oil of this species, collected in the southern part of the state of Minas Gerais, Brazil, as well as to identify its secretory structures and evaluate its antimicrobial activity on the phytobacteria, Clavibacter michiganensis subsp. Michiganensis, Xanthomonas vesicatoria and Pseudomonas syringae pv. tomato. Plants were collected in the town of Itumirim, and the essential oils of the leaves extracted by hydrodistillation using a modified Clevenger apparatus. The essential oil presented carvacrol (26.44%) and 1.8-cineole (22.63%) as major constituents. On the leaf surface of L. sidoides both glandular and non-glandular trichomes were found. Among the glandular trichomes are peltate trichomes and type I capitate trichomes. The presence of lipidic and terpenic substances within the head cells of both the peltate and capitate trichomes was found. The essential oil of L. sidoides was able to inhibit the growth of all the microorganisms studied, showing the following MIC: 7.81 µg mL-1 for C. michiganensis, 3.9 µg mL-1 for P. syringae and 15.62 µg mL-1 for X. vesicatoria. Carvacrol, the major constituent, showed MIC values equal to 3.9 µg mL-1 for all three bacteria studied. Both exhibited the ability to inhibit the growth of gram-positive and gram-negative bacteria.

Characterization and delimitation of the terroir coffee in plantations in the municipal district of Araponga, Minas Gerais, Brazil

Abstract: Differentiating coffees through the notion of terroirs allows us to determine potential areas for specialty coffee production and to characterize the type of coffee in these areas, exploring their potential. The objective of this work was to study spatial variability quality and to characterize and delimit terroirs in coffee crop production in Araponga municipality, Minas Gerais State, Brazil, using sensorial evaluation. The data were collected from four crops, from altitudes ranging from 770 to 1270 m, with the extract increasing from low to high. In each plot of crops, samples of cherry fruits were collected, dried, benefited, subjected to sensorial analysis and given grades ranging from 0 to 100 points for the global drink quality and relative characteristics of honey, body, acidity, flavor and equilibrium. The spatial variability of the quality was analyzed using the Moran Index. To define coffee production terroirs, average quality grades were compared through separation tests and the individual values of the plots were subjected to an analysis of groupings. The study was efficient in identifying terroirs for mountain coffee culture, therefore allowing coffees to be differentiated as a function of their production locations. Araponga has more than one coffee production terroir characterized by two distinct altitude extracts.

Agronomic performance of onion hybrids in Baraúna, in the semi-arid region of Brazil

Abstract: No estado do Rio Grande do Norte o plantio de cebola de forma mais expressiva e relativamente recente, sendo que produtores entao buscando alternativas como formas de diminuir os prejuizos. Em funcao disso, objetivou-se avaliar o desempenho agronomico de hibridos de cebola na regiao semiarida no municipio de Barauna - RN. O delineamento experimental foi o de blocos casualizados com seis repeticoes. Os tratamentos consistiram de oito hibridos (Cronus F1, Predileta F1, Serena F1, Fortaleza F1, Mata Hari, Luana, Lambada, Don Victor) e uma cultivar testemunha (IPA 11). Foi avaliada a altura media de plantas, o numero medio de folhas, o diâmetro do pseudocaule, a produtividade, a massa media dos bulbos, o indice de sobrevivencia, a cerosidade foliar, o ciclo das cultivares e a classificacao comercial de bulbos. As cultivares Serena F1 e Mata Hari sao recomendadas para a regiao semiarida nordestina em funcao da alta produtividade, ciclo precoce e melhor classificacao dos bulbos. O emprego dessas cultivares podera, em curto prazo, contribuir para mudar o panorama da cultura da cebola no Estado do Rio Grande do Norte.

Maturation stages of fruit development and physiological seed quality in Physalis peruviana

Abstract: In fleshy fruits such as the Physalis, in which the seeds are the main form of propagation, there is disagreement about the appropriate physiological stage for harvesting in order to obtain high-quality seeds. The objective of this study was to determine the stage of maturation of Physalis peruviana, using the colouration of the fruit and calyx, and relative to the physical aspect of the fruit and the physiological aspect of the seeds. The following five stages of maturation were studied: green calyx and fruit (A); green calyx and yellow fruit (B); yellowish-green calyx and yellow fruit (C); straw-coloured calyx and yellow fruit (D); straw-brown calyx and intensely yellow fruit (E). Physical evaluations were determined using the diameter, length and dry-weight of the fruit, and the 1000-seed weight and water content. The physiological characteristics of the seeds were determined by germination testing, seedling dry weight, germination speed index, seedling emergence in the field and emergence speed index. In Physalis peruviana, the diameter, length and dry weight of the fruit increased with the increase in physiological maturity. The maturation stage did not affect the percentage of germination or seed vigour in Physalis peruviana.