Surface contamination of the seed with microorganisms may difficult the evaluation
of its physiological and sanitary quality. This study was conducted to evaluate the effects of chemical
substances (compounds) applied in different concentrations, pH and timing of immersion of the
seed to effective surface sterilization of the seed and its effects on the microorganisms. Soybean
seeds, cultivar Parecis (MTBR-50) produced in Barreiras, BA, with high level of natural infection
(contamination) of Aspergillus flavus (100%), were pretreated with sodium hypochlorite, Q-boa®,
Brilhante®, Agrotensil® and Lysoform®, in the following concentrations and times of immersion,
1%, 2%, 3%, 5% and 10% for two, five and ten minutes. The pH of the solutions was determined
for each compound in every concentration. After immersion, seeds were rinsed in sterile deionized
water. The health test was accomplished using filter paper and a completely randomized
experimental design with five replications. The percentage of the microorganisms present was
recorded the incubation period after seven days. Aspergillus flavus and Rhizopus spp. were
eliminated by the 10% Lysoform® solution, after ten minutes of immersion (pH 6,50). However,
this treatment resulted in 42% of seeds infected with bacteria. Sodium hypochlorite, was more
effective in solutions with concentrations above 3% and immersion periods over five minutes (pH
11,40). This treatment reduced but did not erradicate the storage fungi from the seeds and resulted
in lower incidence of bacteria (average 26%).