Teste de coloração de exsudatos para avaliação da viabilidade de sementes de café (Coffea arabica L.)

• Autor(a) principal: Hilst, Paulo César
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4520
• topic: Sementes; Coffea arabica; Coloração de exsudatos; Viabilidade; Seeds; Coffea arabica; Exsudate coloring; Viability; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::PRODUCAO E BENEFICIAMENTO DE SEMENTES

Coffee beans are known to be problematic in terms of physiological quality, with slow and uneven germination and losing fast its viability during storage. Due to the time that takes to conduct the germination test, at least 30 days, the results may no longer reflect the actual physiological condition of the seeds. Whereupon, has increased the need for tests that permit the quick and safe evalutaion of these seed quality. The objective of this research was to develop a quick and practical test to evaluate the physiological quality of coffee seeds, based on the interpretation of different color intensities of seed exudates, and the interference of water content of the seeds and the imbibition period in the test results. Therefore, a first test was conducted using six lots of coffee seeds, evaluated by germination, accelerated aging and electrical conductivity. To conduct the exsudate coloring test, the seeds, after removal of the parchment, were put into water for 10 minutes, to remove the silver film. Were then distributed four replications of 10 seeds for each treatment, over sheets of paper towel moistened with distilled water, being kept in a germination chamber at 25°C for 24, 48, 72, 96 and 120 hours. Three classes of coloring intensity were stablished: absence, light and strong intensity, assigning the values 0, 1 and 3, for each class, respectively. A second experiment using seeds from Catuaí 44, Catuaí 99, Oeiras MG 6851, Topázio MG 1190 e Catucaí 3616, with moisture contents of 30%, 20% and 12% were subjected to germination test, first count of germination, accelerated aging, electrical conductivity, seedling emergence and exudate coloring test, performing changes in the methodology. For the visual evaluation of the coloring intensities was included the medium intensity, assigning new values for each intensity, 0, 3, 5 and 10 for absence, light, medium and strong intensities, respectively, calculating the Index of Viability by the equation IV = 100 - (0XS) - (3xL) - (5XM) - (10xF). The exudate coloring test coupled with the index of viability, can be used to estimate the viability of coffee seeds, providing results correlated to the germination test. The exsudate coloring test proposed can be recommended for the fast assessment of the viability of coffee seeds. The best results were obtained with seeds with moisture content of 12% after soaking periods of 72, 96 and 120 hours and with moisture content of 30% after soaking periods of 72 and 120 hours.