AN ALTERNATIVE PROCEDURE IN THE TETRAZOLIUM TEST FOR SOYBEAN SEED

The aim of this work was to develop an alternative procedure for reduc ing the soybean seed preconditioning in the tetrazolium test, Two imbi bition periods (four and six hours) at 41 degrees C were tested and co mpared to the traditionally recommended period for preconditioning of 16 hours at 25 degrees C. Seeds of twelve cultivars were used, and cla ssified into two sizes. The parameters used were: vigor [TZ (1-3)]; vi ability [TZ (1-5)]; weathering [TZ (6-8)]; mechanical damage [TZ (6-8) ]; stink bug damage [TZ (6-8)]; and seed moisture content. The stainin g pattern developed on the seeds after a preconditioning period of six hours at 41 degrees C is suitable for the evaluation of the quality o f soybean seeds by the tetrazolium test. Seed preconditioning procedur es for the tetrazolium test evaluated in this experiment were not affe cted by the size of soybean seeds; the 6 hour/41 degrees C treatment r educes the period of preconditioning by ten hours when compared to the recommended procedures of 16 hours at 25 degrees C. To sum up, in the tetrazolium test for soybean seeds, the preconditioning conditions of 6 hour/41 degrees C can be used successfully, without impairing the p recision required by the test.