Influência do hipoclorito de sódio na germinação e emergência de Coffea arabica

• Autor(a) principal: Leonel, Euller Ribeiro Côrtes
• Data de Publicação: 2021
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Biblioteca Digital de Monografias da UFMT
• Texto Completo: http://bdm.ufmt.br/handle/1/2358
• topic: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA; Germinação; Emergência; Coffea arabica; Pergaminho; Germination; Emergency; Coffea arabica; Parchment

An undesirable characteristic of coffee seeds is their slow and uneven germination, in addition to their low storage potential. The presence of the endocap, a thin, hard and coreaceous, known as parchment, may be one of the explanations for the slow germination of coffee. Studies carried out using a sodium hypochlorite solution to remove the parchment have been giving promising results in Arabica coffee seeds, in addition to being a low-cost and easy-to-handle material. Therefore, this study aimed to evaluate seed germination and emergence (force) of seedlings of different coffee cultivars treated with sodium hypochlorite at a concentration of 2.5%. The experiment was conducted in a germination chamber (environment 1) and greenhouse (environment 2) of the Federal University of Mato Grosso (UFMT), University Campus of Araguaia, in the city of Barra do Garças-MT. The genotypes used were: Catuaí Vermelho 144, Bourbon Amarelo, Arara, MGS Aranãs, IPR 99, IPR 103, Topazio MG 1190 and E124. In environment 1 (germination chamber), the design used was completely randomized with a factorial of 8x3 with four replications of 25 seeds each. The treatments were: pre-soaking seeds in 2.5% sodium hypochlorite (bleach) for 24 hours (treatment 1) or 48 hours (treatment 2).The germination evaluations were carried out on the 14th and 31st day after the experiment was set up and this information was used to calculate the germination speed index (GSI). In environment 2 (Greenhouse), the design used was entirely to the casa with a factorial of 8x2 with four replications of 25 seeds each. The treatments were: i) pre-soaking of seeds in 2.5% sodium hypochlorite (bleach water) for 48 hours and ii) control without pre-soaking and manual removal of the parchment. The percentage and speed of emergence of the seedlings were evaluated by the tests emergence speed index (ESI) and Mean time of days to emergence (MTE). For data analysis, the SISVAR® program was used and, when there was significance of the analysis of variance, the Skott-Knott mean grouping test at 5% probability was used. There was no interaction between the factors. In the germination chamber, the manual removal of the parchment (control) showed the best values for germination and vigor (GSI) of seeds with values equal to 14.09% and 1.7 respectively; thus, the two treatments with hypochlorite were ineffective in increasing or accelerating germination. The genotypes with the highest germination percentage were Catuaí Vermelho 144, IPR 99 and E124, with 68%, 62% and 62%, respectively. In the greenhouse, the seeds without parchment (control) showed the best values of emerged seedlings (5.5%), ESI (0.98) and MTE (58.27) which were statistically superior to the seeds treated with hypochlorite. In the greenhouse, the genotypes that showed the highest amount of seedlings emerged were the cultivars Bourbon Amarelo (62%) and Arara (48%), whose values of IVE (2.86 and 2.12) and TME (56 days) also outperformed the other genotypes. It can be concluded that the use of 2.5% hypochlorite at times 24 and 48h of pre-imbibition impaired the germination and vigor of coffee seeds, in relation to the manual removal of the parchment in all genotypes evaluated in this work.