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?” Although some of the important management practices have already been performed (crop rotation, hybrid selection, and tillage, and planting) growers still have opportunities to protect their corn from disease as discussed in the following list:
• Scouting: Scouting fields is an important part of a management plan. Walk corn fields right before tassel emergence to determine disease presence and severity.
• Identify which diseases are present: Having the ability to identify specific diseases is a critical piece in managing GLS and NCLB. NCLB symptoms are brown or tan cigar-shaped lesions, ranging from one to six inches in length. GLS symptoms are tan or gray rectangles with parallel or straight sides, ranging from half and inch to four inches in length.
• Effective use of fungicides: Whether or not to apply fungicides has become a more challenging question with lower commodity prices. Many factors must be considered when determining if a fungicide application is necessary, including: hybrid resistance, disease severity, stage of crop development, expected yield benefit, etc.
While we cant predict the possible development and severity of yield-reducing disease, we do know that there is disease inoculum in crop residue from the 2016 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.