This work was carried out at the Seed Testing Laboratory of the Plant Production
Department of São Paulo State University, Botucatu-SP, aiming to evaluate the gibberellic acid
(GA3) effect on Brachiaria plantaginea (Link) Hitchc. At laboratory, the seeds were subjected
only to mechanical scarification and germinated in gerboxes with two layers of germitest paper
imbibed with 12ml of zero; 0.125; 0.25; 0.50; 1.0; 2.0; 4.0 e 8.0mmol.l-1 GA3 solutions, at 25oC.
In greenhouse, right after scarification, four replications of 20 seeds were treated with zero (control);
0.25; 0.50; 1.0 e 2.0mmol.l-1 GA3 solutions and sowed at 5cm depth in plastic boxes filled with
soil. The germination percentage, average germination time, average germination speed, germination
speed index and the germination curves were determined for either laboratory and greenhouse
conditions. The results indicate that, at laboratory, GA3 promotes higher germination percentage
and germination speed. Mechanical scarification provides higher germination rates at either
laboratory and greenhouse.