Southern Rust was confirmed in Gibson County this week. Check out the southern rust publication for more images of southern rust and other diseases that might mimic it. This publication also has good information on determining when a fungicide application will be beneficial. The publication is at following link: https://crop-protection-network.s3.amazonaws.com/publications/cpn-2009-southern-rust.pdf.
Figure 1. Map of counties confirmed for southern corn rust as of August 1, 2019.
Figure 2. Southern rust pustules on corn leaf. Pustules generally form and erupt on upper surface. (Photo Credit: Darcy Telenko)
Tar Spot – we have started to find a few more sites with tar spot and confirmed a third county – St. Joseph.
We again are requesting if you have any suspect locations to please update us and send a sample. I am especially interested in surrounding counties such as Lake, Jasper, Pulaski, St. Joseph and Starke or anything in the northern part of Indiana. See this link on a short guide to collecting samples and to few images of both southern rust and tar spot. https://extension.purdue.edu/fieldcroppathology/wp-content/uploads/2019/07/Please-Help-Us-Collect-Field-Crop-Disease-Samples.pdf.
Figure 3. Map of counties confirmed for tar spot as of August 1, 2019.
