Written by: Bob Kemerait, Pathologist, University of Georgia

Southern Corn Rust

The picture above was sent to me from south Florida (near the town of Jupiter) by a friend of mine working in the chemical industry. In the picture, you see field corn that is “covered up” with southern corn rust, the disease of greatest concern to corn growers in Georgia. Unchecked, southern corn rust can take 80-90 bu/A.  At current prices, that is a pile of money lost.

By a quick search, I estimate that the southern rust is approximately 404 miles south of Kingsland, GA- a straight shot up I-95 to Camden County.  They don’t grow a lot of corn in Camden County, but they do in Pierce County, just up the road.

Southern rust WILL impact Georgia’s corn production in 2022.  In the words of Justin Wilson, “ I guar-ron-tee it”.  The question is not “IF”.  The question is “WHEN”. “When” depends on how quickly rust spores, living rust spores, move from south Florida and the Caribbean to Georgia.  They require upper wind currents to move long distances, but UV light easily kills them.  Rust diseases move best (in my opinion) ahead of storms coming from the south- winds, moisture, cloud cover. 

When will southern corn rust get here? When will soybean rust get here? Could soybean rust already be percolating in the kudzu that is quickly growing now across Georgia?  The answers are, “I don’t know when it will get here” and “Yes, soybean rust could already be here in kudzu”.

The only way we can know when soybean rust and southern corn rust arrive and where they are is to go out and hunt for them – to collect samples – especially from sentinel plots. Yesterday we got kudzu samples from Tift, Turner, and Irwin Counties with help from Extension agents. I am enlisting/asking for your help in sampling commercial corn and soybean fields and kudzu patches in your counties so that we can catch rust as quickly as we can once it crosses into Georgia and as it moves north. 

I received a nice note yesterday from an agent in a county without corn, cotton, soybeans, or peanuts, who noted she was still interested in what happens in the state elsewhere.  You may not have row crops, but you likely have kudzu in your county, so you can still be involved.

If you can send corn or soybean or kudzu samples (preferably? on a weekly basis), please let me know again and I will send you the code to use to charge Fed Ex to me.  (Even if you have already told me before, tell me again so I can send the Fed Ex Code).

Thanks for all you do. For the sake of our corn and soybean farmers, let’s identify rust soon after it moves up from Florida. We cannot keep it out.


Robert C. Kemerait, Jr.Professor and Extension Specialist, Department of Plant Pathology, University of Georgia

Mailing (Postal) Address: 2360 Rainwater Rd.Tifton, GA 31793-5766

Shipping Address: 104 Research WayTifton, GA 31793

Office Phone: 229-386-3355 Fax: 229-386-7415

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