Northern corn leaf blight is threatening crops in the northern Corn Belt following this year's wet conditions in corn-growing areas that have provided the right environment for spore production, DuPont says.
According to the latest USDA Crop Progress and Condition report, corn has slipped to 72% good to excellent from the previous week's 73%, but overall conditions remain positive.
Despite the good ratings, protecting yield and grain quality is critical to ensure sustained yields – and protecting fields from northern corn leaf blight is part of the equation.
According to DuPont, there is elevated risk for NCLB in later-planted crops. Other risk factors for northern corn leaf blight include: Disease exposure at early growth stages, resulting in greater levels of infection; limited yield caused by leaf damage before grain fill is complete; and early infection, which allows more time for secondary outbreaks, disease spread and leaf damage.
Kevin Hahn, field research and development manager for DuPont Crop Protection in Illinois, points out that northern corn leaf blight can overwinter on crop residue, showing up under favorable growing conditions and moderate temperatures, like this year.
Hahn says NCLB moves up from the lower canopy into the upper canopy of corn plants, appearing as long, irregularly shaped lesions unrestricted by leaf veins. Multiple lesions on the upper canopy can appear quickly, Hahn says, damaging photosynthetic tissue and limiting yield.
When scouting, northern corn leaf blight signs may be confused with those of Diplodia leaf streak, southern corn leaf blight, and Stewart's or Goss's wilt, DuPont says.
Watch a video of Hahn discussing Northern Corn Leaf Blight.
News source: DuPont