Seed dormancy is emphasized in the literature as a problem for the establishment of tropical pasture grasses. Immersion of seeds in sulfuric acid (H2SO4) has been widely used and is effective in breaking dormancy of Brachiaria seeds, although this treatment raises inconveniences relating to operator safety during application. Moreover, refusal of residues from this chemical treatment may become harmful to the environment. This study aims to evaluate alternative seed treatments for overcoming dormancy, comparing physiological effects from heating treatments (55, 65, 75 and 85ºC, for 5, 10 and 15 hour) and chemical scarification (immersion in H2SO4 for 15 minutes) in Brachiaria dyctioneura cv. Llanero seeds (Brachiaria humidicola cv. Llanero, according to Renvoize et al., 1996). Therefore, seeds were evaluated for their quality attributes (water content, germination, tetrazolium, first count of germination, seedling emergence, shoot length of seedlings, and emergence speed index), twice during the experiment (at the beginning and at the end of a six-month storage period). Heating and sulfuric acid are alternative treatments for overcoming seed dormancy, consequently favoring agronomic performance. However, particularly for the heating treatment, seed deterioration may be accelerated during storage.
tropical grasses; storage; viability
