The seed is the more efficient way for pathogens dissemination, making possible the disease introduction in new areas, as well as causing reduction of seed productíon. The main damage caused by pathogenic microrganism are the damping-off in pre end post-emergence, root rot and leaves infection, with negative influence on seed quality, showing a size, vigor and germination reduction and a complete rot of the seed. lhe storage fungi affects also the seed quality, besides to promove dead seeds. They are toxins producers, making the product unsuitable for human and animal consumption. In a general way, the biochemical action of the microrganisms on the host is related with enzimes action in celular wall degradation, abonormalities coming from growing hormones and the toxins productíon, which wil cause alive tissue decomposition, root growing reduction, an increasing in the respiration index and a influence in the normal host metabolism. When is desirable to produce seed with high quality is necessary to consider previously and adoption of preventive and curative measurements, aiming a loss reduction originated form microrganisms incidence.