Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2018-07-10T18:02:49Z No. of bitstreams: 1 DISSERTAÇÃO Alexsandro Martins da Silva.pdf: 297395 bytes, checksum: 65d3b63d699f4425cb634f0012fb96c4 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-07-16T17:08:22Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO Alexsandro Martins da Silva.pdf: 297395 bytes, checksum: 65d3b63d699f4425cb634f0012fb96c4 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-07-16T17:17:52Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO Alexsandro Martins da Silva.pdf: 297395 bytes, checksum: 65d3b63d699f4425cb634f0012fb96c4 (MD5) / Made available in DSpace on 2018-07-16T17:18:03Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO Alexsandro Martins da Silva.pdf: 297395 bytes, checksum: 65d3b63d699f4425cb634f0012fb96c4 (MD5) Previous issue date: 2016-06-03 / Para oferecer aos agricultores sementes de soja com qualidade e na quantidade demandada, as empresas sementeiras devem implementar eficientes processos de controle interno de qualidade, visando aferir a constantemente a germinação e o vigor das sementes. A presente pesquisa teve como objetivo averiguar o processo de controle de qualidade interno na Sementes São Francisco Rio Verde, Goiás. O trabalho foi realizado em laboratório de empresa sementeira na cidade de Rio Verde - GO. Foram utilizados 272 lotes de sementes de soja da cultivar NA 5909 RG, categoria S1, da safra 2014/2015. Os testes avaliados foram: tetrazólio précondicionado por 16 horas, envelhecimento acelerado por 72 horas, teste de germinação, teste de solo e emergência em areia. Os resultados demonstraram que os testes de envelhecimento acelerado e tetrazólio são confiáveis no controle de qualidade de lotes de soja. Conclui-se que os lotes apresentaram vigor e viabilidade satisfatórios, porém, o teste de germinação 180 dias após a colheita, demonstrou queda da viabilidade. / To provide soybean farmers with quality and quantity demanded, the seed companies should implement efficient internal quality control processes to assess the constantly germination and seed vigor. This study aimed to verify the internal quality control process in soybean seed company, in Rio Verde, Goiás. The essay was carried out in laboratory of a seed company in the Rio Verde-GO city. Were used 271 soybean seeds lots of the cultivar IN 5909 RG, category S1 cultivated in the agricultural year of 2014/2015. The tests evaluated were tetrazolium test with preconditioned for 16 hours, accelerated aging test for 72 hours, standard germination test, soil test and emergence in sand. The results showed that the accelerated aging test and tetrazolium test are reliable for use in intern quality control of soybean seeds lots. It has concluded that the lots had satisfactory vigor and viability, however, the germination test 180 days after harvested decreased in viability.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-29T12:27:26Z No. of bitstreams: 2 Oliveira , Augusto Pedroso de-2012-Dissertação.pdf: 1221394 bytes, checksum: 3f53224e0b239d497b0f70bbf3b0393e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-29T15:07:22Z (GMT) No. of bitstreams: 2 Oliveira , Augusto Pedroso de-2012-Dissertação.pdf: 1221394 bytes, checksum: 3f53224e0b239d497b0f70bbf3b0393e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-29T15:07:22Z (GMT). No. of bitstreams: 2 Oliveira , Augusto Pedroso de-2012-Dissertação.pdf: 1221394 bytes, checksum: 3f53224e0b239d497b0f70bbf3b0393e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-06-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / To produce rubber tree (Hevea brasiliensis) seedlings in nursery, the collection is limited by the short fall of seeds, which have a rapid loss of their germinal power and no guarantee their viability. This forces the nurseryman to acquire a much larger seeds than really necessary. With the adoption of standards for the quality of seed, the minimum parameters established 70% viability being suggested for such confirmation the tetrazolium test, according Rules for Seed Analysis (RSA) and/or a practical test done from the visual analysis of the seed endosperm color named in this work of "visual test". Despite tetrazolium test be scientifically based, its realization is made improbable by many financial and temporal reasons. Thus, the visual test points as a low-cost alternative, high reliability and immediate result, since both tests are considered trusted, but only the test tetrazolium test is recognized. The subject proposed to verify the credibility of the "visual test" legitimizing or not its use in the field. The field is composed of rubber seed, formed with the adult clone GT1. The seeds were homogenised and stored on two conditions: braided polypropylene bags and transparent plastic bags with minimum thickness of 0.02 mm microdrill at top. In each bag, in three treatments were placed ten kilograms of seed and these were stored in natural conditions of temperature and humidity (25° C ± 5 °C). Was pulled randomly a bag of seeds of rubber tree of each storage type, to zero and fourteen days of storing lots. The tests: visual, sprouting in sand and tetrazolium, besides the determination of the degree of moisture. Tetrazolium and visual tests were highly correlated, and the visual test results before had as the best way to analyze the seeds, for its significant correlation in General with the tetrazolium test, and simplicity in its execution and instant result, which gives good lot projection nurseryman to be acquired by him. / A produção de mudas de seringueira (Hevea brasiliensis) em viveiro, é limitada pelo curto período de produção, queda e coleta das sementes, que possuem uma rápida perda do seu poder germinativo e nenhuma garantia da sua viabilidade. Isto obriga o viveirista a adquirir uma quantidade de sementes maior do que aquela realmente necessária. Com a aprovação de normas para o padrão de qualidade de semente, se estabeleceram parâmetros mínimos de 70% de viabilidade sendo sugerido para tal confirmação o teste de tetrazólio, segundo as Regras para Análise de Sementes (RAS) e, ou, um teste prático feito a partir da análise visual da cor do endosperma da semente nomeado no presente trabalho de “teste visual”. Apesar do teste de tetrazólio ser embasado cientificamente, sua realização é inviabilizada por diversos motivos de ordem financeira e temporal. Sendo assim, o teste visual aponta como uma alternativa de baixo custo, alta confiabilidade e resultado imediato, já que ambos os testes são considerados confiáveis, mas apenas o teste de tetrazólio é reconhecido. Nesta pesquisa objetivou-se verificar a credibilidade do “teste visual” legitimando ou não seu uso no campo. As sementes de seringueira foram coletadas no município de Goianésia, estado de Goiás. O campo de sementes é constituido de seringal adulto, formado com o clone GT1. As sementes foram homogeneizadas e armazenadas em duas condições: sacos de polipropileno trançado e sacos plásticos transparentes com espessura mínima de 0,02 mm, microperfurados na parte superior. Em cada saco, nos dois tratamentos, foram colocados dez quilogramas de sementes e estes foram armazenados em condições naturais de temperatura e umidade (25° C ± 5 °C). Foi retirado aleatoriamente um saco de sementes de seringueira de cada tipo de armazenamento, no tempo zero e aos quatorze dias de armazenamento dos lotes de sementes coletados. Foram realizados os testes: visual, de germinação em areia e de tetrazólio, além da determinação do grau de umidade. Os testes visual e de tetrazolio foram altamente correlatos. O teste visual apresentou a melhor forma de análise das sementes, por sua significativa correlação no geral com o teste de tetrazólio, além da simplicidade em sua execução e resultado instantâneo, o que confere ao viveirista uma boa projeção do lote de sementes a serem adquiridas para a produção de mudas de seringueiras

The cold test is one of the oldest and most acceptable vigour tests as it is used to simulate stress conditions commonly occurring in the field. In recent years, some of South Africa’s top maize hybrids, with high cold test scores, have shown emergence problems under cold, wet planting conditions. It resulted in major complaints from commercial maize producers with sizable claims involved. Therefore, the need arose to find a more sensitive vigour test that takes into account cold, wet conditions. In practice, South African maize producers would not plant if it is too cold and wet. However, cold, wet conditions are commonly experienced during planting time in the main maize production regions of South Africa, especially during October and even November. Furthermore, in most of the commercial maize production areas, such as the western Free State, chances of thunder and hailstorms are high during the planting period. These weather conditions are major causes for sudden drops in temperature and flooding which can expose maize seed and emerging maize seedlings to stress conditions The effects of cold, wet conditions on germination and emergence of nine maize hybrids were investigated in laboratory, glasshouse and field experiments. Growth chamber and glasshouse experiments were conducted under 10°C, 20°C and 30°C and 0, 24, 48 and 72 hours flooding. Field experiments were conducted under different climatic conditions, resulting in cool and wet, cold and wet and favourable conditions during planting. The objectives were to investigate the correlations between different laboratory vigour tests and field emergence of maize hybrids under cold, wet conditions in order to identify the most suitable laboratory vigour test for predicting field emergence under cold, wet conditions. Eight different vigour tests were conducted and each was compared with field emergence under cold, wet conditions. The eight tests conducted, were the cold test, soak test, complex stressing vigour test, electrical conductivity test, accelerated ageing test, tetrazolium test, fast green test and emergence rate test. The soak test was the most sensitive vigour test when considering cold, wet conditions, as it measures seed germination, based on the warm test, after a 48 hour soak in water at 27°C. Correlations found between the soak test and field emergence (53%) under cold, wet conditions was unexpected, since the soak test does not account for low temperatures. The complex stressing vigour test was conducted to study the effect of fluctuating soaking temperatures on germination of maize seed. Seeds of nine maize hybrids were soaked for 48 hours at a moderate temperature (25°C), followed by another 48 hours soak at a low temperature (5°C), and then planted in sand and grown for 4 days at 25°C, before evaluation. Highly significant correlations were found between the complex stressing vigour test and simulated field emergence under both controlled conditions in a glasshouse (89.9%) and cold, wet conditions in the field (90.0%). The complex stressing vigour test was the best test to predict field performance under a wide range of climatic conditions, especially cold, wet conditions. Implementation of the complex stressing test as a routine vigour test, will be to the advantage of maize seed companies, especially in being proactive in predicting emergence of maize hybrids under cold, wet conditions. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2009. / Plant Production and Soil Science / unrestricted