Evaluation of Vigor Tests in Soybean Seeds: Relationship of the Standard Germination Test, Seedling Vigor Classification, Seedling Length, and Tetrazolium Staining to Field Performance¹

Abstract

Laboratory tests for standard germination, seedling vigor classification, seedling length, and tetrazolium staining were performed on 144 and 81 seed lots of soybean [ Glycine max (L.) Merr.] in 1975 and 1976, respectively. Results from the laboratory tests were compared with emergence and stand data obtained from these same seed lots on two sites (sandy and heavy soil types) and three dates of planting (early, pre‐optimum, and optimum) each year. Yield was obtained for the heavy soil type, optimum planting date. Most laboratory test measurements were significantly correlated with field emergence, but r values were <0.8. Overall, the correlations showed a trend that was dependent on soil type but not date of planting. Generally, the laboratory test measurement was correlated with emergence for all planting sites and dates of planting. The corresponding correlations for plant stand and emergence were similar. Correlations of laboratory test measurements with yield were low, r≤0.340 and r≤0.282 in 1975 and 1976, respectively Laboratory test measurements were used to develop models predicting field emergence. Combinations of three laboratory test measurements in the model gave near maximum R 2 values. Four such models were able to predict emergence at five of the six planting date and site combinations each year.