Determination of Mean Germination Time as an Index of Seed Vigour in Sorghum (Sorghum bicolor L.)

Abstract

Sorghum (Sorghum bicolor L. Moench) is a vital cereal crop cultivated extensively in arid and semi-arid regions due to its adaptability to harsh environmental conditions. Seed vigour is a crucial determinant of crop establishment, particularly in sorghum where standardized vigour testing protocols are yet to be established. The present study evaluated the relationship between mean germination time (MGT) and field emergence (FE) at 10 and 20 days after sowing (DAS) across 15 different sorghum seed lots which were stored for 12 months under ambient conditions, to assess the suitability of MGT as a seed vigour test. Correlation analysis revealed a strong and highly significant negative association between MGT and FE, indicating that seed lots with shorter germination times exhibited superior field emergence. Regression analysis further validated these findings, with extremely high coefficients of determination (R² = 0.99) for both FE 10 DAS and FE 20 DAS against MGT, demonstrating that variations in field emergence could be largely explained by differences in MGT. The low standard error of the regression models highlighted the robustness and reliability of these relationships. Incorporating MGT into seed vigour testing protocols would enable seed producers, researchers, and quality analysts to make more accurate predictions of seed lot performance, thereby supporting improved crop establishment and seed quality assurance.