Corn Disease Risk Maps

For period of Aug 28 Sept 26, Date of Issue: August 29, 2021
DEKALB® corn field at late season
CLICK ON DISEASE FOR RISK FORCAST
One-Month Weather Outlook​

Over the next 30 days normal to above-normal temperatures will dominate the Corn Belt except for cooler conditions in the northwestern corner.  Rainfall will be normal to higher than normal.  During the next weeks precipitation will be higher than normal for most of Corn Belt. Temperatures will be above normal in week one and normal in week two. 

​Northern Leaf Blight Risk Summary ​

The risk of northern corn leaf blight is moderate or high east of the Missouri River.

​Next two-week risk interpretation  ​

Weather conditions east of the Missouri River are moderately favorable to highly favorable for NCLB during the next two weeks.  In at-risk areas treat fields that have not reached dent stage and disease lesions are observed on the ear leaf or higher.  Late-planted corn is at higher risk than indicated on the map.

ONE-MONTH RISK MAP
One-Month Weather Outlook

Over the next 30 days normal to above-normal temperatures will dominate the Corn Belt except for cooler conditions in the northwestern corner.  Rainfall will be normal to higher than normal.  During the next weeks precipitation will be higher than normal for most of Corn Belt. Temperatures will be above normal in week one and normal in week two.   

Southern Rust Risk Summary

The risk of southern corn rust is moderate or high for much of the Corn Belt.

Next 2-week risk interpretation 

Conditions are moderately favorable for southern rust in the southern half of the Corn Belt, and highly favorable in southwestern areas.  In at-risk areas treat susceptible hybrids that do not have dented kernels yet and show symptoms of southern rust infections.  Late-planted corn is at higher risk than indicated on the map.  

An example of Southern Rust on corn leaves.
ONE-MONTH RISK MAP
One-Month Weather Outlook

Over the next 30 days normal to above-normal temperatures will dominate the Corn Belt except for cooler conditions in the northwestern corner.  Rainfall will be normal to higher than normal.  During the next weeks precipitation will be higher than normal for most of Corn Belt. Temperatures will be above normal in week one and normal in week two. 

Corn Tar Spot Risk Summary

The risk level for tar spot remains at moderate to high levels in the geographies where tar spot has been observed in the past.

 Next two-week risk interpretation 

The weather conditions continue to be favorable for tar spot generally east of the Mississippi River.  In at-risk areas treat for the disease if lesions are observed in the middle portions of the crop canopy.        

Tar spot of corn
ONE-MONTH RISK MAP
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