Conservação e vigor de sementes de pau-de-balsa (Ochroma pyramidale)

Pinto, Antonio Moçambite; Inoue, Mario Takao; Nogueira, Antônio Carlos

doi:10.1590/s0044-59672004000200011

Cited by 4 publications

(1 citation statement)

References 2 publications

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“…Devem ser armazenadas com teor de água relativamente alto para manter o poder germinativo e vigor. A viabilidade dessas sementes é muito curta, sendo capazes de sobreviver somente em condições especiais de armazenamento (PINTO et al, 2004). Para o mesmo autor, sementes ortodoxas são relativamente pequenas, com taxa metabólica e respiração baixas, enquanto que as recalcitrantes são freqüentemente grandes, com taxa metabólica e respiração altas.…”

Section: Armazenamento De Sementesunclassified

Conservação da viabilidade de sementes de Senna macranthera por meio de recobrimento

Pozitano¹,

Rocha²

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For the process of coating in spouted bed, the physical characteristics of the particles to be coated, the formulation of coating suspension and the operating conditions such as the air flow, the pressure of atomization, the flow of suspension, the air temperature and the mass of solids are important parameters that influence the process performance. In the case of seeds, coating can be applied to facilitate handling, transporting and sowing, to protect the seeds against insects and for the conservation of species to environmental preservation. In this work the process of coating of forest seeds of Senna macranthera species in spouted bed was studied and analysis of the physiological quality of covered and in nature seeds during storage were performed. The seeds of this species have tegument dormancy, which hinders the germination due to impermeability of the tegument. The breaking of dormancy in seeds of forest species aims to increase the percentage of seed germination and to uniform the seedling emergence; however, these seeds cannot maintain their viability for long periods and the storage becomes unworkable without dormancy. The first stage of this work involved the physical characterization of the seeds, the definition of operating conditions for the coating process and the development of the formulation of the coating suspension. Then, the seeds underwent to tegument dormancy break by immersion in sulfuric acid before being coated with the polymer suspension developed. The coated seeds and the control (in nature seeds) were stored in conventional refrigerator at a temperature of 5 ºC.The storage period was of 380 days. The results of physical characterization of the seeds in nature were: Sauter diameter of 3.4 mm, sphericity of 0.52, dynamic angle of repose of 10 º, porosity of 1.81 %, weight of thousand seeds of 41.05 g and real, apparent and volumetric densities equal to 1397.2, 1371.9 and 884.4 kg/m³, respectively. For the coated seeds the following values were obtained: Sauter diameter of 3.7 mm, sphericity of 0.69, dynamic angle of repose of 35 º, porosity of 4.30 %, weight of thousand seeds of 50.52 g and real, apparent and volumetric densities equal to 1397.2, 1337.2 and 795.1 kg/m³, respectively. Operating conditions were defined as: suspension flow of 2 ml/min, atomization pressure of 2 psig, inlet air temperature of 70 ºC and load of seeds of 450 g. The formulated suspension was composed of: Eudragit FS 30D ® , triethyl citrate, magnesium stearate, titanium dioxide, talc, pink pigment and water. Scanning electron microscope images of the seeds before and after coating were analyzed.Adsorption isotherms at 25 ºC were determined for the coated and in nature seeds using the dynamic method. The results were adjusted using five models of sorption isotherms: GAB, xi Caurie, Oswin, Peleg and Smith. For the seeds in nature, the best fit was obtained with the model of Peleg (R² = 0.998), whereas for the coated seeds the best fit was obtained with the model of Smith (R² = 0.981). During the storage, three ...

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Section: Armazenamento De Sementesunclassified

Conservação da viabilidade de sementes de Senna macranthera por meio de recobrimento

Pozitano¹,

Rocha²

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Seed germination and seedling growth of two Pseudobombax species (Malvaceae) with contrasting habitats from Brazilian Cerrado

2018

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Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas.

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Umedecimento do substrato e temperatura na germinação de sementes de Melanoxylon brauna Schott.

Flores¹,

Ataíde²,

Borges³

et al. 2013

Agraria

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RESUMOMelanoxylon brauna Schott., popularmente conhecida como braúna, é uma espécie florestal nativa, pertencente à família Fabaceae -Caesalpinoideae, utilizada na construção civil, paisagismo e reflorestamento. No presente trabalho o objetivo foi avaliar a germinação de sementes de M. brauna em função de diferentes temperaturas e quantidades de água no substrato. Os tratamentos consistiram dos volumes de água equivalentes a 1,0; 1,5; 2,0; 2,5 e 3,0 vezes a massa do substrato secado nas temperaturas de 25 e 30°C. Na determinação do efeito dos tratamentos avaliaram-se a porcentagem e o índice de velocidade de germinação (IVG). Os resultados obtidos indicaram que as quantidades de água na faixa de 1,5 a 2,5 vezes a massa do substrato foram favoráveis à germinação das sementes de M. brauna, em ambas as temperaturas, enquanto a velocidade de germinação foi favorecida pela temperatura de 30°C em todas as quantidades de água testadas. Desta forma, para a condução de testes de germinação com sementes da espécie são indicadas as quantidades de água de 1,5 a 2,5 vezes a massa do substrato na temperatura de 30°C. Palavras-chave: braúna, disponibilidade de água, espécie florestalSubstrate wetting and temperature on germination of Melanoxylon brauna Schott. Seeds ABSTRACT Melanoxylon brauna Schott., popularly known as braúna, is a native forest species belonging to the family FabaceaeCaesalpinoideae, which is used in construction, landscaping and reforestation. In this study the germination of M. brauna were evaluated under different temperatures and amounts of water in the substrate. Treatments consisted of volumes of water equivalent to 1,0; 1,5; 2,0; 2,5 and 3,0 times the mass of dry substrate at temperatures of 25 and 30°C. For determining the effect of the treatments, the percentage and germination speed index (GSI) were evaluated. The results indicated that the amount of water in the range of 1,5 to 2,5 times the mass of the substrate were suitable for the germination of M. brauna at both temperatures, and the germination rate increased at 30°C in all water amounts tested. Thus, for conducting germination tests in laboratory for this specie the quantities of water from 1,5 to 2,5 times the mass of the substrate and temperature of 30°C are indicated.

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Conservação e vigor de sementes de pau-de-balsa (Ochroma pyramidale)

Cited by 4 publications

References 2 publications

Conservação da viabilidade de sementes de Senna macranthera por meio de recobrimento

Conservação da viabilidade de sementes de Senna macranthera por meio de recobrimento

Seed germination and seedling growth of two Pseudobombax species (Malvaceae) with contrasting habitats from Brazilian Cerrado

Umedecimento do substrato e temperatura na germinação de sementes de Melanoxylon brauna Schott.

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