Características morfológicas, estruturais e produtividade do capim-braquiária e do amendoim forrageiro submetidos ao sombreamento

Gobbi, Kátia Fernanda; García, Rasmo; Neto, Américo Fróes Garcez; Pereira, Odilon Gomes; Ventrella, Marília Contin; Rocha, Gabriel Cipriano

doi:10.1590/s1516-35982009000900002

Cited by 64 publications

(55 citation statements)

References 27 publications

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“…Alqueire in comparison with the forage (nilograss, hemarthria and Bermuda grass) evaluated for contents of ADF, NDF and crude protein. Godoy et al (2003) found values of NDF and ADF of 42.6%, and 23.9%, respectively, for forage peanut. Those values are lower than the ones found for other forages such as leucaena and stylosanthes, showing that even in the dry season, forage peanut presents forage of better quality.…”

Section: Resultsmentioning

confidence: 80%

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Genetic divergence between genotypes of forage peanut in relation to agronomic and chemical traits

et al. 2012

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-The objective of this study was to evaluate the genetic divergence of forage peanut in relation to agronomic and chemical traits in both rainy and dry seasons. This experiment was conducted with genotypes from the Forage Peanut Active Germoplasm Bank located in Embrapa Acre. Eighteen genotypes of forage peanut were used: 12 genotypes of A. pintoi, four genotypes of the A. repens species and two interspecific hybrids of A. pintoi × A. repens. The design was of randomized blocks with five replicates. All traits were submitted to analyses of variance and later, study of genetic divergence was done through multivariate analysis techniques, in which the Tocher's optimization method and the nearest neighbor method were used. Dissimilarity measure used in cluster analysis was the generalized distance of Mahalanobis. No pattern was found in the cluster based on species used, according to the results. There is genetic variability for all traits except neutral detergent fiber, acid detergent fiber, hemicellulose and lignin in the rainy season and for pests in the dry season. The traits which presented most relative contribution in the study of genetic divergence of forage peanut were flowering, dry matter yield and average height in the rainy season and crude protein and average height in the dry season. The established cluster may help the breeder to choose parents and crossings to be selected in forage peanut breeding programs.

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Section: Resultsmentioning

confidence: 80%

“…When evaluating levels of shade on forage peanut (A. pintoi cv. Amarillo), Gobbi et al (2009) found contents of 25.3, 20.15 and 4.9% of cellulose, hemicellulose and lignin, respectively, in forage peanuts submitted to 50% of shade, showing that this is a forage with potential use in silvopasture system without affecting its quality.…”

Section: Resultsmentioning

confidence: 90%

Genetic divergence between genotypes of forage peanut in relation to agronomic and chemical traits

et al. 2012

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“…2a). According to Gobbi et al (2009), lengthening of the stem and internodes is among the main morphological changes resulting from a reduction in light intensity in plants of the Poaceae family.…”

Section: Resultsmentioning

confidence: 99%

Seed vigor, antioxidant metabolism and initial growth characteristics of red rice seedlings under different light intensities

et al. 2013

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This work aimed to evaluate the effect that different intensities of light have on the physiological attributes of red rice seeds and seedlings. Before and after emergence, seedlings were exposed to light levels of 35%; 65% and 100% in a greenhouse. We evaluated shoots and roots, in terms of length and dry mass, as well as leaf area and content of chlorophyll (a, b and total). In leaves and roots, we quantified the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (POX). We determined the leaf area ratio (F A ), leaf mass ratio (F W ), specific leaf area (S A ), and shoot/root ratio (P W ). At higher light intensities, shoot length decreased, whereas root length, dry mass and number of tillers increased. Leaf area was greatest in seedlings exposed to a 65% light level. The F A , F W , S A and P W were lowest at a light intensity of 100%. Differences in light intensity had qualitative and quantitative effects on chlorophyll contents. The activity of SOD and CAT was higher at lower light levels, whereas the inverse was true for APX and POX activity. Extremes of light availability alter the activity of antioxidant enzymes, negatively affecting the initial growth characteristics and photosynthetic pigments of red rice seedlings.

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“…O aumento do controle da trapoeraba sob sombra pode estar relacionado com as alterações morfofisiológicas ocorridas em suas estruturas celulares, levando a planta a investir mais recursos para aumentar a sua área fotossintética, em relação à sua proteção. Entre essas modificações atribuídas ao estresse luminoso estão a menor deposição de ceras epicuticulares hidrofóbicas na epiderme, o aumento da lâmina foliar e das estruturas secretoras presentes nesta e da permeabilidade das células na base dos tricomas, garantindo maior tempo de exposição da calda química e redução das barreiras à penetração desta (Sargent & Blackman, 1962;Santos et al, 2002;Monquero et al, 2004a;Gobbi et al, 2009 Média das quatro repetições, aos 10 DAA e aos 20 DAA. 0 a 10%, * a 5% e ** a 1% de significância.…”

Section: Resultados E Discussão Manejo De Trapoeraba (Commelina Benghunclassified

“…Com o sombreamento, ocorrem alterações na morfologia e na estrutura foliar, como a expansão do limbo foliar, ocasionada pela turgidez e alongamento das células desse órgão, e a diminuição na deposição de ceras epicuticulares (Magalhães, 1967;Moosavinia & Dore, 1979;Lima Jr. et al, 2006;Gondim et al, 2008;Gobbi et al, 2009). Essas mudanças são relacionadas à maior interceptação e absorção foliar de herbicidas aplicados em pós-emergência.…”

Section: Manejo De Tiririca (Cyperus Rotundus) Com Glyphosate Em Ambiunclassified

Manejo de tiririca e trapoeraba com glyphosate em ambientes sombreados

Júnior¹,

Santos²,

Costa³

et al. 2013

Planta daninha

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RESUMO -Plantas daninhas mantidas em ambientes com redução da intensidade luminosa apresentam alterações morfofisiológicas marcantes, que podem alterar seu comportamento reprodutivo e a tolerância a herbicidas aplicados em pós-emergência. Objetivou-se neste estudo avaliar a eficiência de doses de glyphosate no manejo da trapoeraba (Commelina benghalensis) e da tiririca (Cyperus rotundus) cultivadas em diferentes níveis de sombreamento. O trabalho foi composto por dois ensaios, referentes a cada uma das espécies, com o mesmo delineamento experimental, sendo constituídos em esquema fatorial 5 x 3, com cinco doses de herbicida (0, 540, 810, 1.080 ou 1.350 g ha -1 de glyphosate), três ambientes de cultivo (0, 30 ou 50% de sombra) e quatro repetições. As parcelas experimentais foram compostas por um vaso com duas plantas de tiririca ou de trapoeraba. As avaliações de controle ocorreram aos 10, 20 e 30 dias após a aplicação (DAA), por meio de observações visuais. Aos 30 DAA, foi determinada a massa seca da parte aérea de cada espécie. A produtividade de tubérculos foi observada pela contagem direta desses propágulos presentes nas raízes das plantas de tiririca. Já a sua viabilidade foi avaliada por teste de germinação em leito de areia e por tetrazólio no caso dos não germinados. O controle das espécies foi mais eficiente em ambientes sombreados, contribuindo para a redução de até 25% da dose recomendada para ambas, obtendo-se controle de 81% para trapoeraba e 100% para tiririca. Já a matéria seca da parte aérea, a produtividade e a viabilidade dos tubérculos foram afetadas pelo aumento do nível de sombra e pela dose de glyphosate. A diminuição da intensidade luminosa -comum no sub-bosque de culturas arbóreas e arbustivas ou quando do adensamento de cultivosrepresenta prática interessante na supressão da trapoeraba e da tiririca e potencializa a ação de controle do glyphosate.Palavras-chave: ecofisiologia, controle químico, tolerância, sombra.ABSTRACT -Weeds maintained in reduced light intensity environments present remarkable morphophysiological changes that may alter their reproductive behavior and tolerance to post-emergence herbicides. Our goal was to evaluate the efficiency of glyphosate doses in the management of Commelina benghalensis and Cyperus rotundus grown at different levels of shading. The work consisted of two trials for each species with the same experimental design, in a 5 x 3 factorial design with five herbicide doses (0, 540, 810, 1.080, and 1.350 g ha -1 of glyphosate), three cultivation environments (0, 30, or 50% of shading) and four replicates. Experimental plots consisted of a vase with two plants of either C. benghalensis or C. rotundus. Control evaluations were carried out 10, 20, and 30 days after application (DAA) through visual observations. Tuber productivity was verified by direct counting of these propagules present in the roots of C. rotundus plants, while tuber viability was evaluated by germination test in a sand bed, and by tetrazolium, for the nongerminated tubers. Species control ...

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Características morfológicas, estruturais e produtividade do capim-braquiária e do amendoim forrageiro submetidos ao sombreamento

Cited by 64 publications

References 27 publications

Genetic divergence between genotypes of forage peanut in relation to agronomic and chemical traits

Genetic divergence between genotypes of forage peanut in relation to agronomic and chemical traits

Seed vigor, antioxidant metabolism and initial growth characteristics of red rice seedlings under different light intensities

Manejo de tiririca e trapoeraba com glyphosate em ambientes sombreados

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