Sunflower seeds of cultivar Catissol 01 were screened by round sieves (openings
11x¾?, 12x¾?, 14x¾?, 16x¾? and 18x¾?). The different seed size sub samples have been placed
in polyethylene bags (49,50m of thickness), stored in dry chamber (17°C and 86% of RH) and
evaluated at zero and six months of storage. The seeds were evaluated for physiological (moisture
content, germination and vigor - accelerated aging), physical (water activity) and healthiness (blother
test) qualities. The two last test were done only after the storage period (six month). The experimental
design was a complete randomized with three replications. Moisture content exhibited direct
relations with seed size. After six months of storage the vigor presented differences between smallest
and largest seeds, being more lower in smaller seeds (sieves 11x¾? and 12x¾?) in relation to the
biggest size (sieves 14x¾?, 16x¾? and 18x¾?). More water activity decreased, smaller was the
development of the microorganisms and the seed oxidation. The main fungi detected were Alternaria
spp. and Penicillium spp.