Pepper seeds of the cultivar yolo Wonder, treated with Captan and which presented a 69% germination were utilized to study the osmotic conditioning effect in different periods (4, 8, 12 and 16 days) and temperatures (5, 15, 20 and 25ºC). The seeds were washed or not in running water and afterwards soaked on wetted papers in osmotic solution of PEG 6000 at -1.1MPa. After each period, the seeds were washed and dried under environmental conditions until reach the initial weight. The physiological quality was evaluated using the germination test (under ideal temperature condition and thermal stress), electric conductivity test, root protrusion velocity index and T50 (mean period to ocorrence 50% of germination). For purposes of comparing osmoconditioning seeds, a control treatment was employed (dry seeds). The conditioning treatments reduced water uptake by the seeds, but at 25ºC and for longer periods the water content reached
was enough to allow the root protusion and physiological quality was not evaluated. Osmoconditioning was influenced by both period and temperature and when accomplished at higher temperatures the performance of the seeds was increased, improving the physiological quality. The period required for obtaining greatest benefits from the technique was temperature dependent. The conditioning treatment accomplished during eight days at 25ºC on non-washed seeds, stood out mainly in the tests which evaluated germination velocity, including T50 and velocity index. The values of electric conductivity of the osmotically conditioned seeds were significantly lower than the control treatment. The osmotic conditioning technique is an excellent tool to improve the performance of pepper seeds with intermediate quality.