The tetrazolium test is widely used for seed vigor assessment of various plant species. For wheat, however, there is no methodology specifically recommended. This study aimed at determining an efficient procedure to evaluate vigor of wheat seeds by this test; besides allowing the establishment of seed quality classes. Thus, four different wheat seed lots were assessed by determining the moisture content and through tests of germination, accelerated aging, and field seedling emergence. The following methodologies were assessed: 1) longitudinal bisection of seed, with subsequent placement of the two halves on filter paper moistened with a 1.0% tetrazolium solution, at 30º C, for 2 h; 2) longitudinal bisection, with subsequent immersion of one seed half into a 1.0% tetrazolium solution, at 30º C, for 3 h; and 3) longitudinal bisection, with subsequent immersion of one seed half into a 0.075% tetrazolium solution, at 40º C, for 2 h. It was concluded that the tetrazolium test is more efficient in evaluating wheat seed vigor when performed with immersion of one half of the seed into a 0.075% tetrazolium solution (40º C, for 2 h) or a 0.1% tetrazolium solution (30º C, during 3 h); allowing to sort seeds into four quality classes.
Triticum aestivum; physiological quality; viability
