Estimating the effect of oxygen on seed storage


Estimating the effect of oxygen on seed storage

Seeds are the main tools through which seed companies market their varieties. Many efforts are spent in obtaining a high seed quality. As seed are living organisms, they age during storage, resulting in reduced quality. The rate of ageing varies between crops and is faster upon storage at high moisture levels and temperatures.

Seed companies store the horticultural seeds in climate controlled warehouses where humidity is low. Nevertheless, for some crops viability can decline within a few years of storage, or even earlier - this holds especially for primed seeds. Most, if not all damage accumulating during seed storage is related to oxidation (membranes, proteins, DNA, and RNA). In dry conditions, where enzyme activity is absent, seeds have no ability to repair this damage. Reducing damage induction relies therefore on storage conditions that reduce the rate of oxidation.

The shelf life of seeds in relation to temperature and their moisture content has been studied for several crops and the rate of viability loss has been described in a seed viability equation by Ellis and Roberts in 1980. The equation tells that a decrease in seed moisture level with 1%, or a 5 °C lower storage temperature will roughly double the time seeds can be stored.

In recent years it has been shown that low oxygen storage might provide economic alternatives for storage and shipping of seeds. This can especially be interesting for seed companies and genebanks. Knowledge on the quantitative effect of oxygen will enable seed companies and genebanks to predict the effect of alterations in the storage conditions and aid to calculate the economic costs and benefits of these alterations and lead to significant benefits for commercial applications.