The effects of environmental treatments known to rapidly shorten seed viability were compared along with cultivar response to the aging process. Seed germinability, coleoptile expansion, electrolyte leakage, and free radical-mediated lipid peroxidation were measured. Aging treatments produced a rapid and significant reduction in the rates of seed germination and coleoptile extension. Inter-cultivar variation was also observed when the seed was aged rapidly. Loss of viability and declining vigour were associated with an increase in lipid peroxidation and leakage. The common effect of seed aging on the seed integrity is described as a function of free radical-mediated lipid peroxidation and membrane damage.