Corn Disease Risk Maps

For period of July 23 – August 24, Date of Issue: July 24, 2022 
DEKALB® corn field at late season
Delaro Complete
CLICK ON DISEASE FOR RISK FORECAST
One-Month Weather Outlook​

Over the next 30 days temperatures will be higher than normal for the entire region with lower than normal precipitation except for the coastal states.  During the next two weeks above normal temperatures are predicted in week one and cooler temperatures in week two.  Above normal rainfall is expected south of I-80.       

​Northern Leaf Blight Risk Summary ​

The risk of northern corn leaf blight is moderate for most of the Corn Belt, with the highest risk in eastern areas.

​Next two-week risk interpretation  ​

Over the next two weeks conditions continue to be moderately suitable for NCLB in corn fields roughly 250 miles on either side of a line from Washington DC to central North Dakota.  In at-risk areas scout susceptible hybrids, especially in fields with a history of this disease in prior years.   

ONE-MONTH RISK MAP
One-Month Weather Outlook

Over the next 30 days temperatures will be higher than normal for the entire region with lower than normal precipitation except for the coastal states.  During the next two weeks above normal temperatures are predicted in week one and cooler temperatures in week two.  Above normal rainfall is expected south of I-80.          

Gray Leaf Spot Risk Summary

The gray leaf spot risk is moderate across the Corn Belt with some areas at high risk.  

Next 2-week risk interpretation 

During the next two weeks conditions for much of the Corn Belt are moderately favorable for this disease, with some areas reaching high risk.  Scout susceptible hybrids in the lower and middle canopy. Consider treatment if lesions are discovered on the ear leaves or higher.     

Gray Leaf Spot - On Leaf
ONE-MONTH RISK MAP
map
One-Month Weather Outlook

Over the next 30 days temperatures will be higher than normal for the entire region with lower than normal precipitation except for the coastal states.  During the next two weeks above normal temperatures are predicted in week one and cooler temperatures in week two.  Above normal rainfall is expected south of I-80.           

Gray Leaf Spot Risk Summary

The gray leaf spot risk is moderate across the Corn Belt with some areas at high risk.    

Next 2-week risk interpretation 

During the next two weeks conditions for much of the Corn Belt are moderately favorable for this disease, with some areas reaching high risk.  Scout susceptible hybrids in the lower and middle canopy. Consider treatment if lesions are discovered on the ear leaves or higher.   

Gray Leaf Spot - On Leaf
ONE-MONTH RISK MAP
image
One-Month Weather Outlook

Over the next 30 days temperatures will be higher than normal for the entire region with lower than normal precipitation except for the coastal states.  During the next two weeks above normal temperatures are predicted in week one and cooler temperatures in week two.  Above normal rainfall is expected south of I-80.       

Southern Rust Risk Summary

The risk of southern corn rust is low in the northern Corn Belt, and moderate to high in southwestern and southcentral areas.

Next 2-week risk interpretation 

Weather conditions are moderately favorable for SCR in the southern part of the Corn Belt.  As spores move into the area, the risk is likely to increase.  Consider spraying an effective fungicide if SCR is found or reported nearby and the corn kernels have not dented.  

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

Over the next 30 days temperatures will be higher than normal for the entire region with lower than normal precipitation except for the coastal states.  During the next two weeks above normal temperatures are predicted in week one and cooler temperatures in week two.  Above normal rainfall is expected south of I-80.    

Corn Tar Spot Risk Summary

In areas where tar spot was observed in prior seasons, the risk is moderate or high except for MI and Ontario.       

Next two-week risk interpretation 

Over the next two weeks conditions remain favorable or moderately favorable for tar spot in most areas where tar spot was found in prior seasons.  Scout fields in at-risk areas and consider spraying an effective fungicide if symptoms are observed.  Although there are differences in hybrid sensitivity to tar spot, no midwestern hybrids have been observed to be fully tolerant to the disease.  Irrigated fields are at higher risk.         

Tar spot of corn
ONE-MONTH RISK MAP
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