Efeitos do potencial alelopático de três leguminosas forrageiras sobre três invasoras de pastagens

• Autor(a) principal: Souza Filho, Antonio Pedro Da S.
• Data de Publicação: 1997
• Outros Autores: Rodrigues, Luis Roberto de A., Rodrigues, Teresinha de Jesus D. [UNESP]
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://seer.sct.embrapa.br/index.php/pab/article/view/4620; http://hdl.handle.net/11449/65036
• topic: Allelopathy; Calopogonium; Desmodium; Leucena; Mineirão; Seed; Shoot; Sida rhombifolia; Vernonia polyanthes

Bioassays were carried out to identify and characterize the allelopathic potential effects of forage legumes leucena (Leucaena leucocephala), mineirão (Stylosanthes guianensis cv. Mineirão) and calopogônio (Calopogonium mucunoides) on germination and radicle elongation of the pasture weeds desmódio (Desmodium adscendens), guanxuma (Sida rhombifolia) and assa-peixe (Vernonia polyanthes). Aqueous seeds and shoot extracts were prepared in a concentration of 10% (w/v). The pH and osmotic potential were measured in each extract. The effects of the osmotic potential on the results were calculated considering the regression equations adjusted to the variations of osmotic potential in each parameter and the osmotic potential of the extracts. The results showed that the pH did not constitute in a source of variation of the results. The donor species indicated allelopathic potential that varied in function of donor and receiver species and part of the donor plant. The aqueous shoot extract of mineirão and calopogônio showed inhibition potential higher than the extract from seeds, while for leucena the effects more evident were obtained with the extract from seeds. Comparatively, the radicle elongation was a more sensitive indicator than germination to the effects of the extracts.The receiver species assa-peixe was the less sensitive to the effects of the extract.