Admin Login

- DTN Headline News
Rust on the Rise
Wednesday, September 28, 2016 11:49AM CDT

By Emily Unglesbee
DTN Staff Reporter

ROCKVILLE, Md. (DTN) -- David Brown, of Carmine, Illinois, probably wouldn't call himself a Southerner. But the corn, soybean and wheat farmer is getting a taste of Southern crop management this year, after southern corn rust breached the Mason-Dixon line for the second year in a row.

"We will have to be more proactive in scouting for it in the future," he told DTN. "I've just never seen a disease move so fast."

Southern corn rust is known for its speed and the devastating yield losses it can deliver when left untreated, confirmed Southern Illinois University plant pathologist Jason Bond. A fairly common disease in Southern states, its appearance in southern Illinois in late July was a record-early arrival.

Southern Illinois and Indiana farmers should plan for the possibility of the disease in 2017, Bond said. That means re-thinking fungicide timing, hybrid selection and planting date.


Early planting -- always an important goal -- will be even more important than ever, Bond said. As July nears next year, Midwestern growers should also keep an eye on disease reports from their Southern neighbors, which serve as an early warning system for the rust's arrival, Bond added.

Alert farmers this year might have noticed that the disease was confirmed earlier than ever in Georgia, on June 1. (…) By mid-July, the disease had blown into Kentucky cornfields just 40 miles from the Illinois and Indiana border. (…)

"We'll need to watch the rainfall patterns, especially those with southerly flows," Bond said. The fungus thrives in warm, soggy conditions, with plentiful humidity.

Perhaps the biggest mental adjustment for Midwestern corn growers will be re-thinking fungicides, Bond said.

"Generally, when we think about fungicides in Illinois, it's more about optimizing yield or reducing diseases that are right at threshold or just above it," he explained. "We're not used to dealing with epidemics. But southern rust is a completely different beast -- a disease that can come in and quickly rob 30 to 60 bushels and cause stalk integrity issues at harvest."

Brown scouts for diseases like gray leaf spot and northern corn leaf blight and times any fungicide applications around tasseling (VT). Southern corn rust arrives later in the season, though, so fungicide applications before silking (R1) are unlikely to hold on long enough to control it, Bond said.

Two fungicide applications is a tough prescription for corn growers to swallow these days, Bond conceded. He recommended that growers make a point of selecting hybrids with good resistance ratings for gray leaf spot and northern corn leaf blight, to keep those diseases in check. (Hybrids with resistance to southern corn rust are very rare). With the resistant varieties keeping these diseases at a lower level, a grower could likely get away with a lone fungicide treatment around R1 that could also serve to lessen any southern corn rust infestations that come their way, he noted.

"The other thing to be cognizant of when picking hybrids this year [for 2017 planting] is stalk rot integrity," he added.

Diligent scouting late into the season will be critical in the future, Bond added. Rust diseases move fast and can overtake a field in just a week. You can see a Purdue guide that shows the differences between southern corn rust and common rust here:….


Last year, southern rust surfaced in southern Illinois in August and still managed to ding yields, Bond said. Last year, he saw a range of losses, from 10 to 50 bushels per acre.

This year is likely to be uglier, he added. Wet weather delayed far more corn acres, and later-planted acres are much more susceptible to yield loss from the disease. The tight economic environment meant far fewer corn growers treated their acres with fungicide, Bond said.

Not only does the disease steal resources from the plant, but it also causes premature death and stalk quality issues, Bond noted.

Brown estimated that 50% of his corn acres, namely those planted in May, will see significant yield losses and a quarter of them are having serious standability problems.

Every year, volunteers comb through cornfields in his county, counting ears and calculating an average county yield, Brown said. This year, they emerged from the cornfields of White County with an average of 155 bushels per acre in hand -- and coated in orange dust.

"Normally, that yield tour number has been low," Brown said. "But I don't think we're going to have anything near that [number] this year."

Bond agreed that disease has undercut what should have been a bin-buster corn year. "That's a common thread I'm hearing," he said. "People expected phenomenal yields and now we're hearing 20 to 50 bushels off what they were expecting."

In Southern states, southern corn rust has been documented causing losses of 80 to 90 bushels in severe infestations.

For more information on how Southern corn growers handle the disease, see this guide from North Carolina State University:….

Emily Unglesbee can be reached at

Follow Emily Unglesbee on Twitter @Emily_Unglesbee


blog iconDTN Blogs & Forums
DTN Market Matters Blog
Katie Micik
Markets Editor
Monday, September 26, 2016 1:01PM CDT
Friday, September 23, 2016 2:25PM CDT
Monday, September 19, 2016 12:08PM CDT
Technically Speaking
Darin Newsom
DTN Senior Analyst
Sunday, September 25, 2016 2:59PM CDT
Sunday, September 25, 2016 2:56PM CDT
Sunday, September 25, 2016 2:54PM CDT
Fundamentally Speaking
Joel Karlin
DTN Contributing Analyst
Friday, September 30, 2016 7:40AM CDT
Thursday, September 29, 2016 10:18AM CDT
Wednesday, September 28, 2016 10:35AM CDT
DTN Ag Policy Blog
Chris Clayton
DTN Ag Policy Editor
Thursday, September 29, 2016 1:03PM CDT
Tuesday, September 27, 2016 10:28AM CDT
Thursday, September 22, 2016 2:47PM CDT
Minding Ag's Business
Marcia Taylor
DTN Executive Editor
Friday, September 23, 2016 3:46PM CDT
Thursday, September 8, 2016 2:13PM CDT
Wednesday, August 31, 2016 5:39PM CDT
DTN Ag Weather Forum
Bryce Anderson
DTN Ag Meteorologist and DTN Analyst
Tuesday, September 27, 2016 2:52PM CDT
Monday, September 26, 2016 1:27PM CDT
Thursday, September 22, 2016 3:53PM CDT
Thursday, September 29, 2016 1:26PM CDT
Wednesday, September 28, 2016 3:26PM CDT
Tuesday, September 27, 2016 12:49PM CDT
DTN Production Blog
Pam Smith
Crops Technology Editor
Friday, September 23, 2016 12:07PM CDT
Thursday, September 8, 2016 2:19PM CDT
Thursday, September 8, 2016 6:53AM CDT
Harrington's Sort & Cull
John Harrington
DTN Livestock Analyst
Friday, September 23, 2016 4:27PM CDT
Thursday, September 15, 2016 4:04PM CDT
Friday, September 2, 2016 1:06PM CDT
South America Calling
Alastair Stewart
South America Correspondent
Monday, September 26, 2016 12:43PM CDT
Wednesday, September 21, 2016 11:16AM CDT
Thursday, September 15, 2016 3:14PM CDT
An Urban’s Rural View
Urban Lehner
Editor Emeritus
Tuesday, September 27, 2016 6:27AM CDT
Tuesday, September 20, 2016 6:21AM CDT
Tuesday, September 13, 2016 6:14AM CDT
Machinery Chatter
Jim Patrico
Progressive Farmer Senior Editor
Wednesday, September 28, 2016 1:51PM CDT
Friday, September 23, 2016 2:20PM CDT
Friday, September 9, 2016 7:44AM CDT
Canadian Markets
Cliff Jamieson
Canadian Grains Analyst
Wednesday, September 21, 2016 4:50PM CDT
Tuesday, September 20, 2016 5:07PM CDT
Monday, September 19, 2016 6:31PM CDT
Editor’s Notebook
Greg D. Horstmeier
DTN Editor-in-Chief
Tuesday, September 27, 2016 10:57AM CDT
Friday, August 5, 2016 8:54AM CDT
Wednesday, August 3, 2016 6:24AM CDT
Copyright DTN. All rights reserved. Disclaimer.
Powered By DTN