The Influence of Temperature and Moisture on Seed Viability Period in Barley (Hordeum distichum L.)

Storage experiments were carried out on barley seed (. Hordeum distichum L.) lasting from 1 min to 926 days, including 52 hermetic storage environments covering a range of temperatures from 3 to 90 °C and 5-5 per cent to 24-6 per cent moisture content (f. wt basis). Over the entire range of conditions survival curves conformed to negative cumulative normal distributions and, for any given measure of longevity, e.g. half-viability period, longevity was roughly proportional to the negative exponent of both temperature and moisture content. Although previously reported viability equations were adequate to describe these relationships over restricted ranges of environments, over the extended range of conditions tested here it was shown that the relationship between log seed viability and temperature is in fact slightly convex, whilst that between log seed viability and moisture content is slightly concave. An improved viability equation was applied which takes into account those curvatures and, at the same time takes into account the initial viability of a seed lot which reflects pre-storage deterioration. The fit was excellent and thus it is now possible to predict percentage viability of any lot of barley seed after any storage period under a very wide range of conditions.