Tetrazolium test adaptation for assessing safflower seed vigor and viability

Safflower appears as an option for crop rotation in Brazil, which makes it an alternative to a well-consolidated system, which is the succession of soybean and corn. However, information is still needed, for instance, in seed analyses, for such inclusion of this species in the country. Thus, the objective was to adapt the tetrazolium test methodology to evaluate the viability and vigor of safflower seeds. The methodology for the tetrazolium test was adapted in three steps (preconditioning, staining, and determination of vigor levels of the seed lots). The experimental design was completely randomized. The data were subjected to analysis of variance at 5% and 1% probability levels by the F test, and the treatments were compared by Tukey test in the first and second steps and grouped by the Scott-Knott method in the third step, when principal component analysis was also used. The tetrazolium test is efficient to evaluate the quality of safflower seed lots. For conducting the tetrazolium test, safflower seeds should be preconditioned for 04h00 on paper at 25 °C, cut longitudinally, and stained for 01h00, with a concentration of 1% in the solution, at 30 °C.