CSI Partners Help to Educate Producers about Fungicide Use on Corn

Jim Fawcett, Extension Field Agronomist, Southeast Area

Problem Statement:

With corn prices having almost tripled in the past year, it is tempting for producers to purchase and apply any inputs that have some potential to increase yields without the knowledge about the likelihood that the input can truly increase profits. In the past, corn fungicides have not been widely used in commercial corn fields, so knowledge about their benefits is limited. The practice of aerially applying fungicides on corn without regard to the need is leading to the wasting of millions of dollars and is causing concern among the general public.

Programmatic Response: 

Corn producers were encouraged to leave untreated areas in corn fields sprayed with a fungicide in 2007. Field agronomists worked with Corn and Soybean Initiative partners across the state in investigating the benefit of spraying fungicides on corn. As part of this project I spent many hours documenting the effect of fungicides on corn diseases and corn yield in SE Iowa. The results showed that on average across the state, the cost of the fungicide treatment was not justified, however it certain fields with high levels of disease, corn yield increases more than paid for the treatment. Results from the trials were shared in the media, in winter educational events, including the ICM conference and crop advantage series conferences, and in continuing instruction courses for private pesticide applicators.


Having local research results in pesticide applicator courses increased the interest of the audience. Several attendees commented on their end-of-meeting evaluations that they would scout for diseases before spraying fungicides in 2008. One producer who had several test plots and did not get yield increases in any of them from fungicide applications not only convinced himself but helped to convince others that even with $6/bu corn, it does not make sense to blindly spray fungicides on corn.

April 16, 2008

100 Corn and Soybean Production and Protection

Page last updated: April 17, 2008
Page maintained by Linda Schultz, lschultz@iastate.edu