Viability modelling of seeds and sensitivity analysis under fluctuating temperature and moisture content

Abstract

This study presents the sensitivity analysis of Ellis and Roberts (1980a, 1980b) viability model as this is derived from the contribution of moisture content, seed temperature and time step variables. The analysis revealed significant increase in sensitivity of viability regarding the time variable for Δt<72min which is often adopted in computational modelling. For Δt>720min, the moisture content variable exhibited increasing sensitivity of viability, but to a lesser degree than this of the time variable. Also, in all the tested cases, the temperature variable exhibited the least contribution to the viability sensitivity. Furthermore, a modification in the viability model is proposed incorporating the concept of effective values of seed temperature and moisture content to more appropriately reproduce the fluctuating behaviour of the actual storage conditions. Finally, an improved version of the effective temperature and moisture content variables based on the improved viability model is proposed.