Fig. 3. Effect of different glyphosate applications on acetylene reduction activity of field grown soybeans. Arrows indicate date of glyphosate application (unpublished data). Each point represents a mean of six replicates. Significant differences (LSD values at the 0.05 probability level are indicated in parentheses) were observed at Day 31 (11.5), Day 48 (13.6), and Day 54 (13.3).