As spring of 2016 approaches, producers across the Eastern Corn Belt will begin to put more thought towards their production plans and management decisions for the upcoming season. One challenge that has affected corn yields in our sales territory over the past few years is foliar disease, especially Northern Corn Leaf Blight. Anyone who attended one of our Winter Agronomy Meetings heard a discussion of what conditions promote diseases (Northern Corn Leaf Blight and Gray Leaf Spot) and possible management options. You might ask, “What are the important management options that will protect yield from leaf diseases?” Below are the answers to that question:
• Select Resistant Hybrids: One very effective way to protect yield potential is to plant varieties that have resistance to leaf disease. Many university publications, including this MSU fact sheet, generally recommend that fungicides are not required for hybrids with strong disease resistance.
• Crop Rotation: It is widely understood that crop rotation is one of the best management practices for mitigating problem diseases.
• Till Crop Residue: Clean tillage will help break down crop residue, reducing the chance GLS or NCLB will become a problem. However, this is not an option for no-till fields where one tillage operation can begin to break down the benefits of long-term no-till. In no-till situations, producers should employ a combination of the other management options.
• Scouting: Scouting fields is an important part of a management plan. Walk corn fields right before tassel emergence to determine disease presence and severity.
• Effective use of fungicides: Whether or not to apply fungicides has become a more challenging question with lower commodity prices. Many factors must be addressed when considering a fungicide application including: hybrid resistance, disease severity, stage of crop development, expected yield benefit, etc. Only apply fungicides when diseases are present and the expected yield benefit outweighs the cost of application.
While we don’t know if the weather for the 2016 growing season will be conducive for development of yield-reducing disease pressure, we do know that there is plenty of disease inoculum in crop residue from the 2015 growing season. Should the right patterns of weather develop, producers in the Eastern Corn Belt could be looking at another year where leaf diseases threaten corn yields. As always, if diseases become a problem Seed Consultants’ knowledgeable sales staff and agronomy team are available to help customers determine where and when to apply fungicides. For more information check out the following fact sheets: Fungicide Efficacy, Northern Corn Leaf Blight, and Gray Leaf Spot.