Corn Fungicide Efficacy Ratings

Paul Vincelli, Extension Plant Pathologist, University of Kentucky

The Corn Disease Working Group has prepared an updated table of efficacy ratings for corn fungicides. This table only provides efficacy ratings for diseases. It does not rank fungicides for physiological “plant health” effects.

Diseases of primary concern to us in Kentucky would include gray leaf spot and, sometimes .northern leaf blight. In selected fields in some years, southern rust may justify a fungicide application under Kentucky conditions, but in most fields, levels of southern rust are so low that routine fungicide application is difficult to justify. It would be very uncommon for the other diseases listed to pose yield-impacting threats under Kentucky conditions.

This table is a “work in progress”, so efficacy ratings are subject to change, should ongoing research indicate that changes are justifiable. In the meantime, these ratings may be useful to corn producers.

Corn Fungicide Efficacy Chart

Wheat Fungicide Efficacy Chart

Chad Lee, Extension Agronomist, University of Kentucky

A new wheat fungicide efficacy chart is available for producers and crop consultants as wheat fields are scouted this spring. The North Central Regional Committee on Management of Small Grains Diseases, which includes Dr. Don Hershman, compiled the data based on field research across the region. All efficacy values are based on labeled rates of each product. Diseases listed on the chart include Powdery Mildew, Stripe Rust, Head Scab and others. A list of the more common wheat diseases in Kentucky can be accessed here.

Products in the chart include strobilurins, triazoles and mixes of both. Products are listed by the active ingredients and the most common product name. Efficacy ratings range from "E' or excellent to "NR" for not recommended and "NL" for not labeled. The table also includes harvest restrictions.

If you have questions about fungicides, fungicide efficacy or wheat diseases, contact your county extension office.

Fungicide Efficacy for Control of Wheat Diseases