Corn Leaf Disease Management

Virgil Schmitt, Extension Field Agronomist, Southeast

Problem Statement: 

Beginning with the 2007 corn crop, there has been much interest among producers and dealers in the potential profitability of utilizing fungicides to manage corn leaf diseases, with the ultimate goal of saving more yield than the fungicide plus application costs.

Programmatic Response: 

Iowa State University cooperated with other Land-Grant institutions to conduct trials in 2007, the results of which were communicated through many venues, including the Private Pesticide Applicator Continuing Instruction Courses (P-CICs) in Cedar, Clinton, Des Moines, Henry, Jackson, Louisa, Muscatine, and Scott Counties during December 2007 through March 2008.  For the 2008 crop year, producers were encouraged to scout for corn leaf diseases and then combine their observations with knowledge of genetics and weather to make an application decision.


A survey of participants at P-CICs from December 2008 through March 2009 found that 59% of the corn growers scouted for corn leaf diseases or had someone else scout for corn leaf diseases, and 30% of corn growers (approximately 50% of those that scouted) applied a fungicide to their corn crop.  The survey suggests that, of the approximately 138,000 acres of corn represented at the P-CICs, approximately 81, 400 acres were scouted for corn leaf diseases.  Assuming an average cost of $26 per acre for the fungicide and application, the decisions to spray or not to spray had a total value of $1,953,600 for the attendees at the P-CICs, which averages $1,650 per attendee.


102 – Crop Protection

Page last updated: April 28, 2009
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