Stunted, burned, and crinkled soybean plants
click image to zoomSoybean seedlings exhibiting injury from flumioxazin due to slowed metabolism and herbicide splash on the hypocotyl, cotyledons, and unifoliate leaves. Typically the risk of injury is higher in sandy and coarse soils, although this year it seems as if all soils have been susceptible due to the cool, wet weather conditions.
In the majority of cases soybean plants are able to grow out of the initial injury and yield losses do not occur. Only in rare cases of severe injury to the hypocotyl and/or growing point will replanting be required. If you suspect injury from flumioxazin, sulfentrazone, or saflufenacil on soybean you can send a sample to Purdue Plant and Pest Diagnostic lab <http://www.ppdl.purdue.edu/PPDL/> for further confirmation.
The increased amount of injury to soybean this year may cause some of our producers to avoid these particular herbicides in the future. We have seen exceptional weed control out of these PPO-inhibiting herbicides at our Palmer amaranth research site this season, especially with flumioxazin which seems to be causing the majority of soybean injury in the state. So producers need to weigh this risk of temporary injury against quality control of problematic weeds such as Palmer amaranth, common waterhemp, and marestail. In the majority of years these products pose little threat of soybean injury and sustain their level of weed control.