Fungicide application for protection against scab – what do I do when I can’t hit the “perfect” timing?

Carl A. Bradley, Extension Plant Pathologist, University of Kentucky

Just like the porridge in the “Goldilocks and the Three Bears” story, there is a “just right” timing for when to apply a fungicide for protection against Fusarium head blight (a.k.a. scab) of wheat. That “just right” timing is the Feekes 10.5.1 growth stage (beginning flowering), when anthers are just beginning to extrude from the middle part of the wheat head. Unfortunately, not all main stems and tillers will be at this stage at the exact same time, but when 50% of the wheat heads are at this Feekes 10.5.1 growth stage, that is considered the “just right” timing for applying a fungicide for protection against Fusarium head blight.

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