By David Moseley, Price, III, Paul P, Price, Randy R., Padgett, Guy B., Kerns, Dawson, Kerns, Shelly, Vieira, Leandro
LSU AgCenter
Common rust may be the first disease found in corn fields and usually occurs in the lower-to-mid-canopy. Pustules of common rust are brick red to dark orange, somewhat elongated, and will appear on both leaf surfaces (Figure 1).Common rust will progress during relatively cool temperatures (60-75oF) combined with rainy weather or heavy dews (6 hours of leaf wetness), and cloudy weather; however, very rarely are fungicide applications warranted for common rust. Warmer temperatures (> 80oF) will greatly slow common rust development.