By Jody Korthaus

As the 2017 growing season comes to an end, agronomists and farmers are reminded to scout for stalk and ear rots of corn as harvest nears. According to Alison Robertson, Iowa State University Extension plant pathologist, stalk rots may be more prevalent this year, due to the stressful growing season across most of Iowa.

So far, Robertson has started seeing some anthracnose and fusarium stalk rot, along with some gibberella and fusarium ear rot. While Robertson believes the moisture Iowa has received the past couple of weeks has likely mitigated some of the risk, she recommends farmers and agronomists begin scouting now if they haven’t already.

“You should start scouting for ear and stalk rots from the time when approximately one-half of milk line formation appears in the corn kernel, and keep scouting as the corn matures,” says Robertson. “If 10% or more of the corn plants in the field are affected, then you should think about scheduling an earlier harvest.”

Help for scouting, managing corn diseases
To help farmers and agronomists identify, scout and manage corn diseases, a new Corn Diseases booklet, published by ISU Extension and Outreach, is now available to crop producers and industry professionals. The up-to-date publication provides current recommendations for management, along with identification and scouting information. Also included are illustrated disease cycles for primary diseases, a foliar disease estimation chart, and corn growth and development and staging information.

GOOD GUIDE: The newly revised booklet helps farmers, crop scouts and agronomists identify and look for corn diseases. It also provides information on managing corn diseases that show up in Iowa fields.

“We update these publications every so often to make sure they remain up to date with new information and to increase their usefulness to farmers and ag business personnel,” says Adam Sisson, ISU Extension specialist for the Integrated Pest Management program. “This newly revised “Corn Diseases” publication includes many new images and updated disease listings, such as bacterial leaf streak and tar spot, and information on how to scout for and manage corn diseases.”

Stay updated on diseases, insects and weeds
The publication is available to buy online at the ISU Extension Store. A hard copy of the publication costs $5, but you also have the option to order it in boxed quantities of 50 for a reduced price of $3.50 per publication. Printable downloads are $2.50 each.

To stay updated on where ISU Extension specialists are seeing crop diseases, insects and weeds across Iowa, visit the ICM Blog, and look to ICM News for management recommendations based on current conditions.

Korthaus is a communications specialist with Iowa State University’s IP program.