The objective of present study

was determine the changes in seed developing and maturation

on germination, seedling vigor, volumetric weight and weight

of 1000 seeds. The experimental study was carried out at

Celaya, Guanajuato, Mexico during 2001. The variety used in

this study was sown at a rate of two seeds per hill in two

replications of two rows of five meters long and spaced 0.75

meters. Sampling was started 30 days after female flower

appearance then taking eight ears per treatment that were

manually shelled. Average values for germination and

seedling vigor showed the same behavior as indicatiors of

seed ripening. Volumetric weight was increased to 71 kg/ha

at 130 days after planting. No significant effect was found on

seed physiological quality due to 1000 seeds weight. The

greatest seed germination percentage and seedling vigor was

found when seed humidity was reduced from 40 to 20 %.

Samples taken 106 and 121 days after sowing were poor

indicators of seed quality. Also the greatest vigor and seed

germination was found in the basal part of the ears. These

results show that physiologic maturity is not the best

indicator for maximum seed quality but dry matter


Keywords: Zea mays L., vigour, germination, fisiological maturity, maize.