Black oats show dormancy in recently harvested seeds, but it is overcome during the storage period; as a consequence, rapid tests are important to determine their viability. The objective of this study was to evaluate different procedures to perform the tetrazolium test in black oat seeds. Four seed lots of 'Embrapa 29' ('Garoa') were used to test the following protocols of the tetrazolium assay: a) hydration between wet paper towels and soaked inwater for 18 h at 20 ºC; b) color development for 2 h, on paper moistened with reagent and direct immersion in the reagent; c) tetrazolium solution at 0.1 %, 0.5 % and 1.0 %. Two types of seed preparation were studied: seeds were cut longitudinally through the embryo, and one half was immersed in tetrazolium solution at 30 ºC or both halves were placed on filter paper moistened with tetrazolium solution, at 40 ºC. Results showed that the tetrazolium test is promising for rapid determination of seed viability; soaking in water (18 h, at 20 ºC), followed by the color development for 2 h on filter paper moistened in a 0.5 % or 1.0 % tetrazolium solution, at 40 ºC, was identified as the best procedure.
Avena strigosa; seed testing; germinability
