Pesquisa Agropecuária Tropical
On-line version ISSN 1983-4063
CUSTODIO, Ceci Castilho et al. Film coating of intact and scarified Brachiaria brizantha (Hochst. ex A. Rich.) Stapf seeds. Pesqui. Agropecu. Trop. [online]. 2011, vol.41, n.3, pp. 314-321. ISSN 1983-4063. http://dx.doi.org/10.5216/pat.v41i3.9146.
Brazil is the largest producer, consumer, and exporter of forage seeds, requiring new technologies and treatments to maintain and expand this market. The aim of this study was to evaluate the film coating (polymer, fungicide, and dye) effect, preceded or not by acid scarification, on commercial Brachiaria brizantha seeds germination, under water stress conditions, simulated in laboratory. Seeds, intact or scarified with sulfuric acid, with or without film coating, all from the same batch, were evaluated by using a germination test, immediately (0 MPa, -0.3 MPa, -0.6 MPa, -0.9 MPa, and -1.2 MPa) and six months (0 MPa, -0.1 MPa, -0.2 MPa, and -0.4 MPa) after the treatment, in hydric potentials induced by mannitol, simulating water deficiency. Seeds were stored at 20oC and 60% RH, in an acclimatized room, and counting was carried out at 7, 14, and 21 days, with data delineated in germination percentage and seeds infected by fungus. The imbibition curve was obtained at the first period, over paper, without hydric restriction, at 25oC, for 96 hours. It was concluded that film coating and scarification treatments can restrict seeds imbibition after 96 hours; scarification with sulfuric acid promotes seeds germination; film coating is effective to control fungi, especially under water deficit; and that film coating can be used to limit scarified seeds germination under water deficit.
Keywords : Forage plants; imbibition; germination; polymer; fungicide.