A very active weather pattern across northeast Illinois that spawned tornados, a derecho, and significant rainfall and flooding across the region. In corn fields, foliar leaf diseases are now more easily detected, including Southern rust. A Southern rust report was received by Dr. Boris Cameletti, University of Illinois Plant pathologist on July 23rd in Williamson County in southern Illinois. While the presence of the disease in not good news for northeast Illinois cornfields, the fact that it has appeared later in the season when compared to recent years is good news. With much of the corn crop now at R4 or dough stage, the benefit of a fungicide application, unless exhibiting severe pressure, is low. By comparison, in Grundy County Southern rust made it appearance by mid-July in 2024 and 2025. R4 is one of the shortest reproductive stages in corn plant development before reaching R5 or Dent stage. In fields where scouting has included the pulling of ears, we are finding along with neighboring states, incomplete or scattered kernel set on some ears. Suggested causes include temperature and moisture extremes during pollination, lack of wind during pollen shed, and hybrid characteristics. We are encouraging growers to check variations or responses between hybrids. Yesterday Dr. Conner Sible and Steve Brand from the University of Illinois visited with local producers as guests of the Kendall-Grundy Farm Bureau and local Illinois Extension offices in Kendall County and shared their growing season observations along with nutrient use and crop genetic (root structure) interactions.

Moderately Wet (soil is damp, standing water may be present in low areas, water bodies are full)