Relationship between Standard Germination, Accelerated Ageing Germination and Field Emergence in Soyabean

Abstract

Twenty six field emergence experiments were conducted over a 10 year period (two to four planting dates per year) to evaluate the effect of seed bed conditions on the relationship between standard germination (SG), accelerated ageing germination (AA) and field emergence in soyabean (Glycine max L. Merrill). Seed bed conditions were characterized by the field emergence index (FEI = mean field emergence/mean standard germination × 100). The ability of the laboratory tests to predict field emergence was evaluated using the prediction accuracy (proportion of the seed lots in each treatment with a specified quality level that had a field emergence above a minimum level). The FEI varied from 108 to 44 across the 26 experiments and the prediction accuracy varied from 0 to 100%. The prediction accuracy was high for both SG and AA in ideal field conditions and decreased as soil stress increased. The AA test had a higher prediction accuracy than SG in moderate stress conditions. Lowering the minimum acceptable field emergence from 80 to 60% improved the prediction accuracy for SG and AA, but only seed lots with AA≥80% had acceptable prediction accuracy over a wide range in seed bed conditions.