Many farmers may not realize that unmanaged weed problems may contribute to insect problems.
“Pests often build up on alternative host plants, such as weeds, and then bail off onto soybeans when they start to bloom,” says Mo Way, Ph.D., Texas A&M University. “Some insect populations may have up to three generations built up on weeds before the soybeans are vulnerable.”
Scott Stewart, Ph.D., an integrated pest management specialist at the University of Tennessee, has seen the problem firsthand.
“We rarely but consistently see catastrophic injury in the Mid-South from fall armyworms that have started on grassy weeds in the field only to move onto the soybean when the grass is gone, often killed too late with herbicide.”
Here’s what researchers recommend
Start with a clean field:
- Starting with a weed-free field gives farmers a head start on weed control.
Watch for weed escapes:
- Regular scouting for weeds can alert farmers to potential problems and help them better understand when a treatment is needed.
Apply effective herbicides:
- Follow herbicide-application labels for optimum weed control. Always apply herbicides at the full labeled rate.