Effects of heating and sulfuric acid on seed dormancy of Brachiaria dictyoneura cv. Llanero. / Comportamento da dormência de sementes de Brachiaria dictyoneura cv. Llanero submetidas às ações do calor e do ácido sulfúrico.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

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 the operator safety during application. Moreover, refusal of residues from this chemical treatment may become harmful to the environment. This essay aims to evaluate alternative seed treatments for overcoming dormancy, comparing physiological effects from heating treatments (55, 65, 75 and 85 o C, for 5, 10 and 15 hour) and chemical scarification (immersion in H2SO4 for 15 minutes) in seeds of Brachiaria dyctioneura cv. Llanero (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 (in the beginning and at the end of a six-month storage). Heating and sulfuric acid are alternative treatments for overcoming seed dormancy, consequently favoring physiological performance. However, particularly for the heating treatment, seed deterioration may be accelerated during storage.

ASSUNTO(S)

armazenamento agrícola brachiaria storage dormência de plantas alta temperatura sulfuric acid capim braquiária heating treatment sementes ácido sulfúrico dormancy seeds

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