The mineral residues were accumulated in the soil due to successive fertilization as a consequence of annual cropping of the laud, wich change the hydric potential and affect the physiological performance of the seeds. The evaluation of the germination and vigor of the soybean seeds were performed in different conditions of the osmotic potential, seeds of lots A and B from FEPAGRO RS 10 cultivar were placed on a towel paper moistened with PEG 6000, NaCl, KCl and MgCl2 to obtain the osmotic potentials: zero; -0.05; -0.10; -0.20; -0.40 and -0.80 MPa. The results were evaluate by a standard germination test (a first and a final count), seedling length and dry weight. The statistical analysis indicated that the decrease in water potential induced by the treatments reduced seed quality and seed vigor was more affected than seed germination. The effect of reduced water potential on seeds and seedlings also depends on the initial quality of the seeds, the salt used and its concentration. PEG 6000 produced more stressing effects on soybean seed quality than the salts when the osmotic potential was up to -0.80 MPa. The potential osmotic of -0.80 MPa inducet by MgCl2 and PEG 6000 hinders germination and decreases seed vigor of soybean seeds.
germination; vigor; water stress
