10 research outputs found

    Constantes de viabilidade para sementes de Eucalyptus grandis

    Get PDF
    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 viability equation at 65ºC was 4.9%, estimated under hygroscopic equilibrium with 23% of relative humidity in the storage environment.Este trabalho teve como objetivos verificar o desempenho de sementes de Eucalyptus grandis W.Hill ex Maiden, após a deterioração em condições controladas, e obter as constantes da equação de viabilidade. As sementes foram colhidas na safra de 1999, e a umidade foi ajustada de 11,3% para valores entre 1,2 e 18,1% a 25ºC As subamostras foram acondicionadas em embalagens de alumínio termossoldadas, armazenadas a 40, 50 e 65±0,5ºC. As sementes apresentaram um desempenho ortodoxo em relação ao armazenamento. As constantes para a predição da longevidade foram K E = 9,661, C W = 6,467, C H = 0,03498 e C Q = 0,0002330. Foi observada a relação inversa entre teor de água e longevidade. O limite inferior de grau de umidade, calculado para aplicação da equação a 65ºC, foi de 4,9%, estimativa obtida sob equilíbrio higroscópico com umidade relativa de 23% no ambiente de armazenamento.11111

    Quality of bean seeds of several densities obtained by gravitacional table

    Get PDF
    The performance of IAC-Carioca SH bean seeds, after they have been submitted to the classification processes by sieves and separation by density in the gravitational table, were evaluated in relation to the physiologic and sanitary quality of the seeds, contained in three fractions of discharge of the gravitational table. The vigor test was not influenced by the size of the seed and its acting is related to the degree of humidity. Higher density seeds could be stored for twelve months with small loss of their germination percentage without compromising the stand. Seeds of medium density retained in the sieves 10, 12 and 13 and stored until the tenth month can be used as seed. Seeds with lower density, are not recommended for planting and they present larger index of contamination by field fungi. Seed contamination by storage fungi Aspergillus spp. and Penicillium spp., was directly related to the relative humidity of the storage facility.Sementes de feijão 'IAC-Carioca SH', após terem sido submetidas aos processos de classificação por peneiras e de separação por densidade em mesa gravitacional, foram avaliadas quanto à qualidade fisiológica e sanitária das sementes, contidas em três frações de descarga da mesa gravitacional. O teste envelhecimento acelerado não foi influenciado pelo tamanho da semente e o seu desempenho está relacionado ao grau de umidade das sementes. As sementes de maior densidade podem ser armazenadas por doze meses para posterior plantio, com pequena perda do poder germinativo e que não chegou a comprometer o estande. Sementes de densidade intermediária retidas nas peneiras 10, 12 e 13 e armazenadas até o décimo mês podem ser utilizadas como semente. Sementes de densidade menor, não são recomendadas para plantio e apresentam maior índice de contaminação por fungos de campo. A incidência dos fungos de armazenamento Aspergillus spp. e Penicillium spp., foi relacionada à umidade relativa no local de armazenamento da semente.243

    Equações de viabilidade para sementes de Eucalyptus grandis W.Hill ex Maiden e Pinus taeda L.

    No full text
    Orientador: Roberto UsbertiTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia AgricolaResumo: o conhecimento do comportamentodas sementes em relação às condições de armazenamento a que são submetidas, é de extrema importância para a avaliação de sua armazenabilidade. Para a definição de metodologia para assegurar a sobrevivência e a preservação de espécies florestais, este experimento analisou o armazenamento de sementes de Eucalyptus grandis W.Hill ex Maiden e Pinus taeda L. visando a obtenção das constantes da equação de viabilidade para as espécies, para a sua conservação bem como para garantir a sua disponibilidade. As sementes de E. grandis e P. taeda (saftas 1999 e 2000, respectivamente) foram reumidificadas sobre água e/ou secas em sílica gel, ambos à 25°C, até a obtenção dos valores de umidade desejados, a partir dos seus valores iniciais. Subamostras de sementes com oito graus de umidade para E. grandis (1,2 a 18,1%, valor inicial de 11,3%) e oito graus de umidade para P. taeda (1,4 a 19,4%, valor inicial de 12,3%) foram acondicionadas em embalagens de alumínio hermeticamente fechadas e armazenadas à 40, 50 e 65°C até a obtenção de curvas completas de deterioração. As análises estatísticas foram realizadas pelo programa "Glim". As duas espécies apresentaram comportamento ortodoxo em relação ao armazenamento, mas as sementes de E. grandis mostraram melhor armazenabilidade do que as de P. taeda. Dois grupos de constantes foram obtidos para prever a longevidade de sementes de Eucalyptus grandis e Pinus taeda, a saber: Kr 9,661 e 8,838; CuF 6,467 e 5,981; CIF 0,03498 e 0,10340; Cg= 0,0002330 e 0,0005476, respectivamente. Para as duas espécies foi observada uma relação inversa entre o teor de água e a longevidade das sementes. Os limites inferiores calculados para aplicação da equação para E. grandis e P. taeda situam-se ao redor de 4,85 e 4,06, respectivamente, em equilíbrio com valores de UR ao redor de 20%Abstract: The knowledge of seed performance under storage conditions is extremely important to determine its storability potential. The main aim of this work was determine the best methodology to achieve the survival and preservation of Eucalyptus grandis W.Hill ex Maiden and Pinus taeda L. seeds, under controlled storage conditions, through the detection of the viability equation constants for the species. The seeds used in this experiment were harvested in 1999 (E. grandis) and 2000 (P. taeda). Before the storage period, the seeds were rehydrated over water and or dried over silica gel, both at 25°C, ITominitial moisture contents, until achieving the desired values. Seed subsamples with 8 moisture contents for E. grandis (1.2 to 18.1%, initial value of 11.3%) and 8 moisture contents for P. taeda (1.4 to 19.4%, initial value of 12.3%) were then sealed in laminate aluminium-foil packets and stored in incubators maintained at 40, 50 and 65°C. Those storage temperatures were chosen in order to get complete survival curves in relatively short periods of time. Statistical analysis was performed through Glim software. The two species showed orthodox behaviour in relation to the storage, however E. grandis seeds presented higher storability than P. taeda ones. Two different viability eonstant sets were aehieved to predict the longevity of Eucalyptus grandis and Pinus taeda seeds, as follows:KE= 9.661 and 8.838; Cw= 6.467 and 5.981; CH= 0.03498 and 0.10340; CQ = 0.0002330 and 0.0005476, respectively. An inverse relationship was observed between the water content and seed longevity for both species. The lowest limits estimated for applieation ofthe viability equation for E. grandis and P. taeda were 4.85 and 4.06 me, respectively, in equilibrium with 20% RHDoutoradoTecnologia Pós-ColheitaDoutor em Engenharia Agrícol

    Seed viability constants for Eucalyptus grandis

    Get PDF
    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 viability equation at 65ºC was 4.9%, estimated under hygroscopic equilibrium with 23% of relative humidity in the storage environment

    Comparisons between two economically valuable forest species (Eucalyptus grandis and Pinus taeda) in relation to seed behaviour under controlled deterioration

    Get PDF
    The objectives of this work were to analyze seed behaviour under controlled deterioration and estimate viability equations for forest species Eucalyptus grandis and Pinus taeda. Desired moisture content levels were achieved from initial values after either rehydration over water or drying over silica gel, both at 25 ºC. Seed sub samples with 8 moisture contents each for E. grandis (1.2 to 18.1%, initial value of 11.3%) and P. taeda (1.5 to 19.5%, initial value of 12.9%) were sealed in laminate aluminium-foil packets and stored in incubators maintained at 40, 50 and 65 ºC. The seeds from these species exhibited true orthodox and sub-orthodox storage behaviour, respectively, however E. grandis showed higher seed storability, probably due to a different seed chemical composition. Lowest moisture content limits estimated for application of the viability equations at 65 ºC were 4.9 and 4.1 mc for E. grandis and P. taeda, on equilibrium with ±20% RH. The viability equation estimated quantified the response of seed longevity to storage environment well with K E = 9.661 and 8.838; C W = 6.467 and 5.981; C H = 0.03498 and 0.10340; C Q = 0.0002330 and 0.0005476, for E. grandis and P. taeda, respectively
    corecore