Southern corn rust detected in Mississippi corn
Stalk integrity or increased lodging as a result of southern rust is an often overstated situation. For increased lodging to occur as a result of southern rust, infection of the corn plant would likely need to occur prior to tassel (VT). Once leaf tissue is covered by the disease, cannibalization of the stalk can occur and reduce the stalk’s integrity, resulting in increased lodging. See the above link regarding lodging information in the trial conducted in Stoneville during 2010.
Fungicides should be used judiciously to manage southern rust. All corn hybrids are considered to be susceptible; however, scouting for the disease is the most important step. Once identified, determine if a fungicide is necessary based on expected return on investment, overall expected yield, and growth stage of the corn. Keep a watchful eye on young corn fields and recognize that even though southern rust can move fast it can requires several weeks for inoculum to build up in a single field. Also, make sure you properly diagnose southern rust since in some instances common rust in the lowest part of the plant canopy can appear extremely similar to southern rust.
Southern corn rust monitoring
Monitoring for southern rust continues to be important for corn farmers. To keep abreast of the situation continue to monitor the “Disease Monitoring” maps on the Crop Situation Blog (http://www.mississippi-crops.com/disease-monitoring/) for current observations of southern corn rust that will be updated as new information becomes available.