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| Registros recuperados: 12 | |
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| Fantinatti,Jussara Bertho; Usberti,Roberto. |
| This work aimed to analyse Eucalyptus grandis W.Hill ex Maiden seed behaviour, under controlled deterioration, and to estimate viability equation constants for the species. Seeds were harvested in the growing season of 1999, and the moisture contents were adjusted from 11.3% to a range between 1.2 and 18.1% at 25ºC. The subsamples were sealed into laminate aluminium-foil packets, for storage in incubators at 40, 50 and 65±0.5ºC. The seeds presented orthodox performance, in which the constants for predicting seed longevity of E. grandis were K E = 9.661, C W = 6.467, C H = 0.03498 and C Q = 0.0002330. The usual and inverse relationship between water content and seed longevity was also observed. The lowest moisture content limit for application of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Seed deterioration; Storage; Seed longevity. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2007000100015 |
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| Usberti-Filho,José Alfredo; Usberti,Roberto; Paterniani,Ricardo Stipp. |
| The main scope of this work was to detect (Panicum maximum Jacq.) genotype differences as to morphoagronomic and seed quality indices, and to establish character correlations useful for determining vegetative and reproductive trends. Besides the flowering cycle, eight phenological and two seed quality traits were scored in a greenhouse randomized complete block experiment, as follows: plant height (PH), reproductive tiller number/overall tiller number (RTN/OTN), panicle number/reproductive tillers (PN/RT), leaf length (LL), leaf width (LW), panicle length (PL), fresh weight (FW), dry weight (DW), number of seeds/g (NS/G) and seed sample physical purity (SPP). Very-early and early-flowering hybrids consistently showed the highest correlation values among... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Panicum maximum; Flowering; Agronomic characters; Vegetative propagation. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2002000200004 |
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| Usberti,Roberto; Roberts,Eric Hywel; Ellis,Richard Harold. |
| The objective of this work was to determine the viability equation constants for cottonseed and to detect the occurrence and depletion of hardseededness. Three seedlots of Brazilian cultivars IAC-19 and IAC-20 were tested, using 12 moisture content levels, ranging from 2.2 to 21.7% and three storage temperatures, 40, 50 and 65ºC. Seed moisture content level was reached from the initial value (around 8.8%) either by rehydration, in a closed container, or by drying in desiccators containing silica gel, both at 20ºC. Twelve seed subsamples for each moisture content/temperature treatment were sealed in laminated aluminium-foil packets and stored in incubators at those temperatures, until complete survival curves were obtained. Seed equilibrium relative... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gossypium hirsutum; Seed storage; Hardseededness; Viability equation. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2006000900013 |
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| Chaves,Maria Madalena F.; Usberti,Roberto. |
| A necessidade da preservação dos recursos florestais brasileiros torna necessário o estabelecimento de novas metodologias para assegurar a sobrevivência e a redução da vulnerabilidade à extinção de espécies. O objetivo deste trabalho foi estudar o armazenamento controlado de sementes de faveiro (Dimorphandra mollis Benth.), espécie arbórea típica de Cerrado, visando determinar as constantes da equação de longevidade e, deste modo, permitir a sua conservação e garantir a sua disponibilidade. Os graus de umidade base úmida foram ajustados, a partir do seu valor inicial, através de umidificação sobre água ou, então, em dessecadores com sílica gel, até a obtenção dos valores desejados. Subamostras de sementes com oito graus de umidade (1,6%; 5,2%; 6,9%; 8,4%;... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Armazenamento hermético; Dimorphandra mollis; Equação de viabilidade; Espécie florestal. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042003000400015 |
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| Pozitano,Marina; Usberti,Roberto. |
| An interspecific hybrid resulting from the crossing of elephant grass (Pennisetum purpureum Schumach) x pearl millet (Pennisetum glaucum (L.) R. Brown) has been developed. This hybrid, however, revealed low phenotypic uniformity and low production of pure seeds. Through recurrent selection, two improved populations were obtained (genotypes Corte and Pastoreio). The aim of this study was assessing seed quality of the three hybrids (genotypes Corte, Pastoreio and Paraiso) by tests of: seed purity; seed germination; accelerated aging test, at 42 ºC; 1,000 seeds weight; drying curves; and sorption and desorption isotherms. Recurrent selection altered the seed size and increased initial quality of population for genotype Pastoreio. Drying curves for the three... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pennisetum purpureum; Pennisetum glaucum; Drying; Viability. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222012000300004 |
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| Fantinatti,Jussara Bertho; Usberti,Roberto; Brod,Fernando Pedro Reis. |
| As sementes florestais devem ser armazenadas adequadamente, a fim de reduzir ao mínimo o processo de deterioração. É possível estabelecer uma relação entre o teor de água livre na semente e sua conservação, expresso pela atividade de água, através da relação entre a pressão de vapor de água em equilíbrio sobre a semente e a pressão de vapor de água pura, à mesma temperatura. Uma isoterma é uma curva que descreve, em uma umidade específica, a relação de equilíbrio de uma quantidade de água sorvida por componentes da semente e a pressão de vapor ou umidade relativa, a uma temperatura específica. O objetivo deste trabalho foi estudar as isotermas de sorção para sementes de Eucalyptus grandis e Pinus taeda, que são espécies florestais de interesse econômico.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Espécies florestais; Atividade de água; Conservação; Grau de umidade. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222005000200002 |
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| Rocha Júnior,Laércio Soares; Usberti,Roberto. |
| Foram avaliados os efeitos físicos e fisiológicos em sementes de trigo, da aplicação trimestral de 1, 2, 4 e 8 g.m-3 de fosfina (PH3), em exposição de 120 horas, durante um período de doze meses de armazenamento. Foram utilizadas sementes das cultivares IAC-24 e IAC-362, produzidas na safra de 2000 no Centro Experimental do Instituto Agronômico de Campinas. Após a colheita, secagem e beneficiamento, as sementes foram armazenadas em condições de ambiente não controlado e trimestralmente foram avaliados o grau de umidade, as sementes infestadas, o peso hectolítrico, a germinação e o vigor (envelhecimento acelerado). Não foram observadas interações significativas entre dosagens de fosfina e cultivares de trigo durante todo o experimento. Verificou-se que, no... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum; Fumigação; Germinação; Vigor. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222007000100007 |
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| Usberti,Roberto; Martins,Leila. |
| Most tropical forage grass species have dormant seeds, which reduce percentages in germination tests. The objective of this study was to evaluate H2SO4 scarification effects on seed dormancy releasing, through germination time (T50) and variability among germination test replicates, in 630, 94 and 82 seed samples of B. brizantha, B. humidicola and P. maximum, respectively, tested at the Central Seed Testing Laboratory, Campinas, Brazil, from 1991 to 1999. Germination tests used two 4 x 100 replicates of intact and scarified seeds (15-, 10-, 5-minute treatments, respectively). Mean germination time (T50) and variability among germination replicates were also analysed. Statistical analysis was performed by t-test paired samples for means. Scarification... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Forage grass species; Mean germination time; Variability among germination test replicates. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222007000200020 |
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| Francisco,Fabiana Gonçalves; Usberti,Roberto. |
| Fungal incidence in stored common bean (Phaseolus vulgaris L.) is the main concern in order to preserve seed health and viability. The main aim of this study was to analyse these quality parameters in hermetically stored seeds at 10.2, 13.1, 16.2, 18.5% moisture content (MC) and 25, 30, 35, 40°C, through seed germination and health tests. Water activity recorded at 10.2 and 18.5% MC were 0.448 and 0.700, respectively. Low seed moisture content reduced Alternaria spp. incidence at 25-30°C. Highest incidence of Fusarium spp. (7.5%) occurred at 16.2% MC and 35-40°C. Highest incidences of Rhizoctonia spp. (8-10%) were recorded at 16.2-18.5% MC and 30-40°C. Penicillium spp. and Aspergillus spp. were predominant throughout the experiment and the highest... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Seed healthiness; Hermetic storage; Fungal incidences. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000600007 |
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| Registros recuperados: 12 | |
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