Imagens digitalizadas na interpreta？？o do teste de tetrazólio em sementes de Brachiaria brizantha

forage crops, especially the genera brachiaria and panicum, have assumed an increasing role in forage areas and promoted the development of the brazilian forage seed industry, which has become the largest producer, consumer and exporter of tropical grass seeds. the objective of this study was to evaluate seed lots of brachiaria brizantha 'marandu' by two procedures to interpret the tetrazolium test. five seed lots of brachiaria brizantha 'marandu' of different origins were used. seeds were evaluated by germination, with and without treatment with concentrated sulphuric acid solution to overcome dormancy, and by the tetrazolium test using two evaluation procedures: conventional, under a stereomicroscope, and digitalized image analysis, obtained from seeds on a transparent glass plate, with images being captured at a 1200dpi resolution. the experimental design was completely randomized. seed lot evaluation of brachiaria brizantha 'marandu', with the tetrazolium test using digitalized images was as effective as using a stereomicroscope.