Standard, Cold, and Tetrazolium Germination Tests as Estimators of Field Emergence of Mechanically Damaged Soybean Seed1

Abstract

AbstractSoybean [Glycine max (L.) Merr.] germination is routinely estimated from laboratory germination test results. However, differences in seed quality have caused variable germination performance both in the laboratory and in the field. The objective of this research was to determine ability of standard, tetrazolium, and cold germination tests to estimate average field emergence of mechanically damaged soybean seed. Damaged seeds were subjected to standard, tetrazolium, and cold germination tests and were planted in the field to determine field emergence and seed yield. Germination test accuracy was measured by analyzing the difference between field emergence and the germination test results.Increasing levels of mechanical damage significantly decreased percent laboratory germination in both years and generally decreased percent field emergence. The tetrazolium test indicated a significantly higher percent laboratory germination than did standard germination and cold tests, and the standard germination test resulted in significantly higher percent laboratory germination than did the cold test. The tetrazolium test was not sensitive in detecting recently induced mechanical damage, and the cold test showed more variability in percent laboratory germination.In 1975 the standard germination and cold test accurately estimated average field emergence within ± 8 and ± 12%. The tetrazolium test over‐estimated average field emergence from 0 to 20%. In 1976 the standard germination test estimated average field emergence within ± 12%, the tetrazolium test generally over‐estimated average field emergence from 0 to 18%, and the cold test under‐estimated average field emergence by 5 to 41%.