Diseases, nematodes and aflatoxin all have become increasingly important factors in corn production, especially as rising prices have made it more feasible to treat for such problems.

“These are all critical aspects now,” says Bob Kemerait, University of Georgia Extension. “There is an awareness of nematodes on corn now, and we have tools for managing them. We also have fungicides for managing corn diseases.”

Looking back at 2010, it was a tremendous year for Southern corn rust, says Kemerait. “Seven years ago, my recommendation would have been that you don’t need to spray fungicides on corn, but things have evolved to the point to where you can see a 25-bushel increase with a single fungicide application,” he says.

Weather conditions in 2010 were very hot and dry, says Kemerait, ideal conditions for the development of Southern corn rust.

“Southern corn rust was terrible last year. If you grow soybeans, you know that soybean rust was inconsequential in 2010, but it’s a different fungus. Southern corn rust likes hot, dry conditions, and it was a major player across the country last year.”

The arsenal of fungicides available for foliar diseases in corn continues to grow and now includes Tilt and other propiconazole products, tebuconazole products, Stratego, Stratego YLD, Headline, Headline AMP, Quadris, Quilt, Quilt Xcel, Evito, and Evito T.

Since 2009, says Kemerait, the Georgia Corn Commission has sponsored a sentinel plot monitoring program for the early detection of Southern corn rust. Because the disease is unable to survive for any length of time in the absence of a living host, it does not successfully over-winter in Georgia after the last corn has been killed by cold weather.

“It is unlikely any corn survived killing frosts in early December 2010. Therefore, Southern rust must become re-established in our state each year, typically by airborne spores from southern Florida, the Caribbean, and Mexico,” he says.