Southern Rust of Corn Found in Our Area
Last week, Southern Rust of Corn was confirmed in Georgia in Seminole County. This week, it has been confirmed in Wayne County (as of June 6th, 2016). This is big news for corn growers in our area. Many times it begins in southwest Georgia and slowly moves our way. Apparently that is not the case this year. Growers with good yield potential would be wise to protect their crop with a fungicide, especially given the recent weather (rainy) conditions we’ve had that are favorable for the spread of the disease. Here’s what Dr. Bob Kemerait, UGA Extension Plant Pathologist, had to say on the confirmation of southern rust of corn this week in Wayne County:
6 June 2016: County agent Mark Frye and consultant John Beasley have found and confirmed southern corn rust in TWO different fields in Wayne County. THIS IS HUGE! It means that not only do we have perfect weather for the disease but that southern corn rust is found nearly from one edge of the Coastal Plain to the other and could be anywhere in between.
The risk for southern corn rust across the Coastal Plain of Georgia continues to increase because of the facts:
A. Southern rust was found so early and at opposite ends of the Coastal Plain.
B. Much of the crop is moving towards (or has reached) tasseling.
C. The current weather conditions (storm and rain) favors infection and spread.
Management of southern rust involves judicious use of fungicides.
A. An inexpensive fungicide like tebuconazole is effective against southern rust, but does not have the broad-spectrum activity or the length of protective-window that strobilurin, SDHI or combination products have. These products cost more, but do have added benefits.
B. I believe that corn should be protected from rust from very early tassel through the dough stage (R6) of development.
C. In a severe year, I have seen as much as an 80 bu/A increase where a fungicide was applied. 25 bu/A is certainly a very reasonable expectation.