The ideal moment for the harvest of seeds depends on many factor, such as the
knowledge of the seed maturation process. Thus this research was carried out to analyse the
development of black layer and initiantion of endosperm solidification (milk line), to determinate
the relationship between those caracteristics and seeds fisical and physiological quality and to
verify the possibility of indicating the best point fot harvesting of each material. For this purpose,
an experiment was at Dow agroSciences, with two materials: a lineage (LA) and a corn simple
hybrid (HS). The harvest began at the initiantion of endosperm solidification, that is when the
amylum transformation line started to move. After each harvest it was determined the seeds moisture
content, and analysed the milk line and black layer. At laboratory, after drying, the seeds were
analysed for moisture content, germination and vigor. The vigor tests, were: accelerated aging,
cold test and electrical conductivity. Based on the results it was concluded the harvesting time of
corn for seeds can be determined using the milk line and black layer. Harvesting can be done at
stage et the 5th of milk line or 3rd and 4th of the black layer development.