In this study, the possibility of controlling ageing processes in onion seed using pre-storage
treatments was investigated. Onion seeds cv. Texas Early Grano were treated with two different
potassium salts (0.1M KNO3 and 0.1M KH2PO4) prior to storage. Both potassium treated seeds and
untreated seeds (control) were stored at various combinations of seed moisture content (6%, 9% and
12%) and temperature (5oC and 30oC) for up to one year. Potassium treatment of seeds stored at 5oC
had no significant effect on germination. However, depending on the moisture content of seeds stored
at 30oC, treatments enhanced germination capacity by delaying the ageing rate of seeds. Besides
improved germination capacity, potassium treatments prior to storage resulted in an increase in
protein and sugar content and a decrease in amino acid leakage of seeds. This indicates that the effect
of the treatments on the control of the ageing process is probably due to a delay of the deterioration in
membrane integrity and protein degradation in onion seeds.