As we progress into the summer, the crops are growing quickly, but the risk of disease is also growing. We have been experiencing similar, cooler weather at the start of the growing season and have had an abundance of moisture in some areas. Don’t be surprised to see some of the same diseases in your field as you did last year. One disease that is showing up early this year in fields is Northern Corn Leaf Blight (NCLB). NCLB produces long cigar-shaped lesions, which can be measured from one inch to six inches long on corn leaves. NCLB lesions can be on lower leaves in corn on corn fields; however NCLB lesions can be located anywhere a spore lands on leaves within the filed. NCLB spores can travel very, long distances. The best time to scout for NCLB is between VT and R4. Below is a picture taken near Arenzville, Il of NCLB and it was found on corn that is six days from tasseling.
|Picture taken on 6/17/15|
How should NCLB be managed?
The first way to manage is through the use of hybrid selection. At Burrus, we have multiple hybrids that have a higher disease rating for NCLB. For a full list, refer to your product selection guide or contact your account manager. It’s important to remember that just because the hybrid is resistant, doesn’t mean it is immune to NCLB, but think in terms that the spread of this disease could be not as quick on resistance hybrids.
Fungicide is the next option. Fungicide is an extra cost and you will need to evaluate if it is an economically sound decision. It’s important to keep an eye on NCLB because if it does get out of hand, it could result in yield loss. Understanding how this pathogen affects corn under certain weather conditions, evaluating hybrid, and applying fungicide during critical growth stages (before or after pollination) are the keys to combating this disease. Please read fungicide labels carefully to ensure proper application.
-Austin Kocher, Illinois Burrus Intern