Relationship Beween Soybean Seed Vigor and Yield 1

The relationship between the vigor of soybean [ Glycine max (L.) Merr.] planting seed and yield of the resulting crop has not been clearly determined. Studies were conducted in 1975, 1976, and 1977 to evaluate the relationship between seed vigor and yield in soybeans by experimental techniques that duplicate as closely as possible practices followed by commercial producers of soybeans. The cultivars ‘Cutler 71’ and ‘Kent’ were used in 1975 and 1976, and ‘Williams’ and Kent in 1977. Three to six lots of seed of each cultivar were selected to provide a wide range in seed vigor and maintain a high viability (standard germination). Two seeding rates were used, 16 and 33 viable seed/m (13 and 26 viable seed/m in 1977) in 3‐row plots with 76 cm between the rows (66 cm in 1975). Standard germination of the 27 lots included in the experiment ranged from 77.0 to 98.5% and averaged 90%. The 4‐day germination was closely related to the standard germination but averaged 6.3 percentage points lower. The accelerated‐aging germination averaged 69.5% and ranged from 18.0 to 97.5%. Field conditions at planting were near optimum and field emergence was high for all seed lots in all 3 years of the experiment. Thus, there was no relationship between seed vigor and emergence or final stand, regardless of cultivar or planting rate. Seed vigor had no effect on yield regardless of cultivar or planting rate. In the absence of stand differentials, there appears to be no yield advantage associated with the utilization of high vigor planting seed.