Tratamentos Pré-Germinativos Em Sementes De Brachiaria

We evaluated the effect of chemical scarification with sulfuric acid (H2SO4) and periods of pre-soaking (PPe) in a solution of potassium nitrate (KNO3), to overcome dormancy of seed and initial seedlings performance of Brachiaria brizantha cv. MG-5. The study was conducted at the Laboratory of Seeds Analysis UUC/ UEMS located in the municipality of Cassilandia - MS in 2010. The experimental design was completely randomized (DIC). Seeds were submitted to pre-germination treatments of chemical scarification with H2SO4 and immersion in a solution of KNO3 for 0, 2, 4, 6 and 8 h. The following evaluations were performed: determination of moisture content, germination tests and vigor tests (index of germination rate, shoot length, fresh and dry weight of seedlings and tetrazolium remaining seeds in the germination test). The results showed that the chemical scarification is an effective technique to overcome seed dormancy in Brachiaria brizantha MG-5, but can negatively impact the performance of initial seedlings. Already pre-germination treatment of seeds in a solution of potassium nitrate (0.2%) for 3.4 h, has beneficial effects on seed quality.