Southern rust has now been confirmed in several Iowa counties, but crop experts say this year’s situation looks much different than the widespread outbreak growers experienced in 2025. Even so, they caution that producers should continue scouting fields, as southern rust is only one of several diseases capable of affecting corn during the critical grain fill period.
Gail Stratman with FMC says last year’s outbreak developed under nearly ideal conditions for southern rust. Infections arrived unusually early, and warm, humid weather allowed the disease to spread rapidly across much of the Midwest.
While southern rust has been detected later this season, Stratman says growers still have several weeks before the crop reaches maturity. That means continued field scouting remains important, not only for southern rust, but also for other late-season diseases that can impact yield and grain quality.
Stratman says growers should work closely with their agronomist or crop advisor to determine whether a fungicide application is warranted based on disease pressure and crop stage. He says FMC recommends its Adastrio fungicide for broad-spectrum control of southern rust and other common late-season corn diseases, while emphasizing that regular scouting and proper application timing remain the keys to protecting yield potential through harvest.
