Logan Miller scouts a soybean field. (Credit – Illinois Soybean Association)

With early soybean planting wrapped up, researchers are now evaluating how preemergence (PRE) herbicides will perform under cool, wet conditions. Now in its second year, this Illinois Soybean Checkoff-funded study is focused on identifying which herbicides are more likely to cause crop injury when soybeans are planted in early April. 

This season’s updates include the addition of Authority Supreme to the herbicide lineup and a new trial site in western Illinois to compare how different soil types impact crop response. “We want to make sure this data reflects more than one soil environment,” said Logan Miller, research specialist under Dr. Aaron Hager. “Adding a second location allows us to provide more relevant information to more Illinois farmers.” 

Findings from the first year showed that crop injury from PPO-based herbicides is a valid concern in early planting scenarios. However, Miller emphasized that temperature and rainfall following planting were the biggest factors influencing herbicide injury—not just the product itself. 

“Based on what we saw last year, there’s no need to avoid certain herbicides outright,” he said. “In well-drained fields suited for early planting, injury was less of a concern, and yield protection through weed control remains essential.” 

Watch Miller present this project and its year one findings at the 2025 Field Advisor Forum. To learn more about this ongoing research, visit the Field Advisor Research Hub.