Non-Destructive Assessment and Electric Field-Based Sorting of Rice Seed Viability Using Dielectric Properties

The rapid and non-destructive assessment and sorting of rice seed viability are critical for improving agricultural productivity and seed quality control. Preliminary germination tests confirmed that viability decline was significantly correlated with harvest year. On this basis, this study investigates the quantitative relationship between dielectric properties and harvest year, and evaluates the feasibility of electric field-based sorting using a custom-built DC non-uniform electric field device. The results show that the dielectric constant of rice seeds increases with harvest year, exhibiting a linear correlation (R2 > 0.99, p < 0.05) with low intra-group variability (SD < 0.05). Germination tests confirmed a correlation between germination rate and harvest year (R2 > 0.99, p < 0.05), indicating that harvest year is associated with viability decline and suggesting dielectric constant as a potential viability indicator under the conditions tested. Sorting tests revealed a negative correlation between drop rate and applied voltage (R2 > 0.90). Under identical voltage conditions, seeds stored longer (lower viability) exhibited lower drop rates, indicating stronger electrode polarization forces. Two-way ANOVA confirmed that voltage, harvest year, and their interaction significantly affected drop rate (p < 0.001). Furthermore, mechanical modeling and trajectory analysis revealed that seed motion follows a quadratic path, enabling the identification of critical sorting conditions. This study provides theoretical insights and a foundation for the future development of dielectric-based seed sorting systems.