Fungicide Efficacy for Control of Corn Diseases
The Corn Disease Working Group (CDWG) developed ratings for how well fungicides control major corn diseases in the United States. The CDWG determined the efficacy ratings for each fungicide by field-testing the materials over multiple years and locations. Each rating is based on the product’s level of disease control and does not necessarily reflect yield increases obtained from applying the product.
A product’s efficacy depends on proper application timing, rate, and application method as determined by the product label and overall level of disease in the field. Members of the CDWG determined differences in efficacy among each fungicide product by directly comparing products in field tests using a single application of the labeled rate.
The table includes the most widely marketed products available that have been tested over multiple years and locations — it is not intended to be a list of all labeled products. Additional fungicides are labeled for disease on corn, including contact fungicides such as chlorothalonil. Other fungicides may be available for diseases not listed in the table, including Diplodia, Gibberella, and Fusarium ear rots.
Many products have specific use restrictions about the amount of active ingredient that can be applied within a specific period or the amount of sequential applications that can occur. For application timing and use considerations, contact your local extension service.
Read and follow all use restrictions before applying any fungicide.
Fungicide Efficacy for Control of Corn Diseases1
1 Efficacy ratings: F=fair. G=good. VG=very good. E=excellent. NL=not labeled for use against this disease. U=unknown efficacy or insufficient data to rank product.
2 Harvest restrictions are for field corn harvested for grain. Restrictions may vary for other types of corn (such as sweet, seed, popcorn), and corn for other uses (such as forage or fodder).
A PDF version of this publication is available for download:
CPN-2011 – Corn – Fungicide Efficacy for Control of Corn Diseases.
This publication was developed by members of the Corn Disease Working Group. It was compiled and published by Kiersten Wise, University of Kentucky.