Soybean mechanical harvesting shows important reduction in seed quality when
adequate adjustments of threshing, separating and cleaning systems of combines are not done.
This study, carried out during the 1996/97 soybean harvest season, aimed to define a profile of the
grain and seeds qualities produced in the Brazilian States of Parana, Santa Catarina and Mato
Grosso, where different seeds samples from different cultivars were analyzed. Those samples
were collected directly from the grain reservoir of the combine, during harvesting. To evaluate
their quality, the following parameters were analyzed: breakage, seed coat rupture, germination,
vigor, viability, stink bug, damage by weathering, mechanical damage, protein and oil content and
acidity. The results indicated that high levels of breakage, mechanical damage and seed coat rupture
associated to the levels of damage by weathering and by stink bugs affected significantly the seeds
producted in the West and North regions of Parana, when compared to the ones produced in the
Southern region and in the States of Santa Catarina and Mato Grosso. It was observed that the
threshing cylinder working at speeds lower than 500rpm resulted in better seed quality as the
levels of breakage and mechanical damage were reduced. Soybean produced in the State of Mato
Grosso presented statistically higher oil content and lower acidity, when compared to the soybean
produced in the other places. It was conclused that the Southern region of Parana State and the
States of Santa Catarina and Mato Grosso produced the best quality of seeds during the 1996/97
crop, when compared to the ones produced in the Western and Northern regions of the State of
Parana.