Variability of maize seed imbibition rates as influenced by seed size distribution and coating application

Abstract

Irregular coating application levels may modify the variability of seed imbibitions and thus lengthen germination and emergence. In order to characterise this effect, imbibitions of non-coated and coated maize (Zea mays L.) seeds were performed in air saturated with water vapour. Three coatings were used at five application levels and water content variability was characterised. Data were modelled to estimate the coatings' water diffusion coefficients. Stochastic simulations were then performed on theoretical seed sets. The effects of coatings on this variability were. either absent, positive or negative. For non-coated seeds and two coatings, the imbibition model simulated water content variabilities very close to the experimental ones by accounting only for the distribution of the 'surface/volume' ratios. For the third coating, it was necessary to account also for the correlation between seed size and coating weight.