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Search Results: 1 - 10 of 6437 matches for " physiological potential "
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Qualidade fisiológica de sementes de Eruca sativa L. pelo teste de deteriora??o controlada
Alves, Charline Zaratin;Godoy, Amanda Regina;Candido, Ana Carina da Silva;Sá, Marco Eustáquio de;
Ciência Rural , 2011, DOI: 10.1590/S0103-84782011001200009
Abstract: the quality of the seed used in the process of agricultural production is one of the main factors to be considered for the implantation of the culture, having consensus between all the segments, on the importance of the vigor of the seeds and the necessity to evaluate it. this research had the purpose of studying proccedings for controlled deterioration test, to verify their sensitivity for identifying different vigor levels of arugula seed, cv. 'cultivada' and 'gigante', using five lots of seeds for each. the seeds were subjected to the determination of water content and tests of germination, first germination, emergence, and to verify the efficiency in identifying different levels of vigor, were studied variations in the controlled deterioration test (seed moisture content of 18, 21 and 24%, at 45oc for 24 and 48 hours). the experiment was arranged in completely randomized design and the results were submitted to analysis of variance and means were compared by tukey test at 5% probability. the results obtained for the controlled deterioration test showed that there was no relation with the initial assessments of the physiological potential, especially for testing of emergency. it was concluded that under the conditions tested, this test was not sensitive enough to assess the potential physiologic arugula, for both cultivars.
Vigor de sementes de rúcula (Eruca sativa L.) pelo este de deteriora??o controlada
Goulart, Liziane Silva;Tillmann, Maria Angela André;
Revista Brasileira de Sementes , 2007, DOI: 10.1590/S0101-31222007000200024
Abstract: the objective of the present study was to investigate the procedure for the conducting the controlled deterioration test to evaluate the physiological quality of salad rocket (eruca sativa l.) seeds, cv. cultivada. two lots of salad rocket seeds were tested for germination, first germination count, seedling length, accelerated aging with and without the use of saturated nacl solution, field emergence and controlled deterioration. two temperatures (41 and 45oc) and two moisture contents (20 and 24%) were tested to obtain the best relationship between temperature and moisture content for use in the controlled deterioration test for salad rocket. the controlled deterioration test conducted at 41oc, for 20 and 24% and 24h was efficient in evaluating the physiological quality of salad rocket seeds, cv. cultivada.
Teste de deteriora??o controlada em sementes de maxixe
Torres, Salvador B.;
Horticultura Brasileira , 2005, DOI: 10.1590/S0102-05362005000200029
Abstract: research has emphasized the relationship of standard germination test and vigor on seedling emergence and stand establishment. in contrast, information relating seed vigor to plant performance is less available. the controlled deterioration as a means to evaluate the vigor of gherkin seeds was studied. five lots of cultivar liso were submitted to tests of germination, greenhouse seedling emergence, accelerated aging with saturated solution of nacl, electrical conductivity and controlled deterioration (19; 21 and 24% water content, at 45oc, for 24 and 48 hour periods). the 24% water content/24 h/45oc combination, for the controlled deterioration test, was efficient to detect vigor differences between gherkin seed lots.
Envelhecimento acelerado em sementes de pepino com e sem solu??o salina saturada
Torres, Salvador Barros;
Horticultura Brasileira , 2005, DOI: 10.1590/S0102-05362005000200028
Abstract: different procedures of the accelerated aging test were evaluated to obtain the physiological quality of cucumber (cucumis sativus l.) seeds and the efficiency of using saturated salt solution in the control of water uptake by seeds. five seed lots of the cv rubi, were tested for germination, seedling emergence, conventional accelerated aging and salt saturated accelerated aging tests. results showed that the accelerated aging test (conventional and salt saturated), using the 72 and 96 h, at 38 or 41oc combinations was sufficiently sensitive to detect differences in physiological quality of cucumber seeds. we observed that seed water content after the salt saturated accelerated aging was lower and more uniform, thus presenting advantages in relation to the conventional procedure.
Desempenho de sementes de soja submetidas a diferentes potenciais osmóticos em polietilenoglicol
Silva, Josué Bispo da;Rodrigues, Teresinha de Jesus Deléo;Vieira, Roberval Daiton;
Ciência Rural , 2006, DOI: 10.1590/S0103-84782006000500047
Abstract: with the aim at determining the physiological potential and germinative performance of soybean seeds, two lots were evaluated by germination, cold, accelerated aging, electrical conductivity tests and osmotic stress, at potentials 0.0 (control), -0.1, -0.2, -0.3, -0.4, -0.5, -0.6 and -0.7mpa. the experimental design used was completely randomized, with four replicates of 50 seeds, except to electrical conductivity, with two replicates of 50 seeds. additionally, the germination under osmotic stress was submitted to regression analysis. the osmotic stress in polietileneglycol, in potential equal or smaller than -0.6mpa, is a promising procedure to evaluate the physiological potential of soybean seeds; decreasing values of osmotic stress reduce germination, while osmotic stress level nearby zero may cause seeds invigoration.
Mobiliza??o de água e conserva??o da viabilidade de embri?es de sementes recalcitrantes de ingá (Inga vera Willd. subsp. affinis (DC.) T. D. Pennington)
Andréo, Yara;Nakagawa, Jo?o;Barbedo, Claudio José;
Brazilian Journal of Botany , 2006, DOI: 10.1590/S0100-84042006000200012
Abstract: the water content of anhydrobiotic (orthodox) seeds is usually reduced to low values and its metabolism is reduced to a level that viability can be preserved for long periods. in contrast, typical non-anhydrobiotic (recalcitrant) seeds are intolerant to desiccation, possess lower longevity, and need a minimum water level to maintain viability, but the metabolism is still too active leading to a short seed longevity. in the present research "inga" seed embryos were stored in contact with polyethylene glycol 6000 (peg) solutions, at pre-defined water potential with the objective of improving storability and longevity. results indicated that germination of embryos kept in peg solution at -2.4 mpa was higher than 80% after 90 days of storage at 10 oc, while the germination of embryos kept at distilled water (0 mpa), at the same temperature, was lower than 60%.
Teste de envelhecimento acelerado em sementes de trigo
Ohlson, Osvaldo de Castro;Krzyzanowski, Francisco Carlos;Caieiro, Juliana Terezinha;Panobianco, Maristela;
Revista Brasileira de Sementes , 2010, DOI: 10.1590/S0101-31222010000400013
Abstract: the wheat sown in southern brazil has shown serious seed quality problems but standard procedures for determining the wheat seed vigor is missing from the literature. this project aimed to study the methodology of the accelerated ageing test to identify levels of vigor in wheat seed lots. seeds of the wheat cultivars cd 104 and brs 220 were used, each represented by five lots. the following tests were conducted: determination of moisture content (oven, 105 ± 3 oc, 24 h), standard germination (8x50 seeds, 20 oc) field seedling emergence, accelerated ageing (41 oc / 48, 60 and 72 hours, and 43 oc / 48 hours). means were compared using the tukey test at the 5% probability level; the spearman rank correlation test was used for the study on the methodology of the accelerated ageing test, where a measure of the strength of the relationship between the test data and existing data on seedling emergence in the field was looked for. from the results, it was concluded that the accelerated ageing test at 43 °c for 48 h provides consistent information for differentiating between wheat seed lots.
Avalia??o do vigor de sementes de rúcula pelo teste de lixivia??o de potássio
Alves, Charline Zaratin;Sá, Marco Eustáquio de;
Revista Brasileira de Sementes , 2010, DOI: 10.1590/S0101-31222010000200013
Abstract: the objective of this study was to evaluate methodologies for the potassium leaching test and to verify its sensitivity for identifying different levels of vigor of arugula seed lots. five seed lots each of rucula cultivada and rucula gigante were used. standard germination, first count of germination, seedling emergence and variations of the potassium leaching test (50 or 100 seeds imbibed in 50 ml or 75 ml in water; at 25 oc and 30 oc; for 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3, 4 and 5 hours) were done. it was observed that the period seeds need to be soaked can be reduced to 2 hours and the water volume can be reduced to 50 ml. the utilization of 50 seeds showed a smaller variation coefficient and the best temperature was 30 oc. it can be concluded that the potassium leaching test for arugula seeds can be run using 50 seeds in 50 ml of water for 2 hours at 30 oc.
Teste de condutividade elétrica para a avalia??o do vigor de sementes de abobrinha
Dutra, Alek Sandro;Vieira, Roberval Daiton;
Revista Brasileira de Sementes , 2006, DOI: 10.1590/S0101-31222006000200015
Abstract: the electrical conductivity has been recommended or suggested to evaluate seed vigor of pea and other species, although research is still needed to improve procedures. this work to evaluate the physiological potential of squash seeds (cucurbita pepo l.) using electrical conductivity test. seeds of the cultivar "menina brasileira", represented by four seed lots, in the first phase and by other five, in the second, were used. results of germination, first count, percentage and speed of seedling emergence and electrical conductivity tests were compared. conductivity test was performed using two water volumes (50 and 75ml), three temperatures (20, 25 and 30oc) and eight periods of seed soaking (1, 2, 4, 8, 12, 16, 20 and 24 hours). it was observed that the soaking period of squash seeds can be reduced to 8 hours and that independently of the water volume, seed imbibition at 30oc promoted the best seed lot ranking according to physiological potential. so, it can be concluded that the electrical conductivity test can be run using 30oc, 75ml of water and 8h.
Teste de condutividade elétrica para avalia??o da qualidade fisiológica de sementes de azevém (Lolium multiflorum L.)
Lopes, Rodrigo Ramos;Franke, Lúcia Brand?o;
Revista Brasileira de Sementes , 2010, DOI: 10.1590/S0101-31222010000100014
Abstract: the electrical conductivity test has the potential to be used by seed companies in quality control but some factors can affect the results of the ec. the object of this study was to evaluate the effect of the number of seeds, water volume and the imbibition time on the electrical conductivity of the solution, on ryegrass seed vigour. four lots of common ryegrass seeds were used. the test was made at 25 oc, at imbibition testing times of 1, 2, 4, 6, 8, and 24 hours, in 50 and 75ml water, using 50 and 100 seeds. the treatments constituted a factorial, using a completely randomized design with four repetitions. the use of four subsamples of 50 pure seeds soaked in 50ml of de-ionized water is promising for the use of the electrical conductivity test of ryegrass seeds conducted after 1 hour of soaking.
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