As we move into flowering in the wheat, in addition to determining if conditions for Fusarium head blight warrant the application of a foliar fungicide (currently, the risk for FHB is low around the state), it is important to pay attention to fungicide product labels since not all products labeled for wheat suppress FHB and many have tight restrictions based on growth stage or pre-harvest interval. Each year, the North Central Regional Committee on Management of Small Grain Diseases (NCERA-184) updates a fungicide efficacy chart. Ratings are based on field testing of products across locations and years and ranged from “poor” to “excellent”.
Focusing here on suppression of FHB, I will break things down first by efficacy and then by harvest restrictions. The best suppression occurs with the well-timed application of triazole-based products, although they are not all equal. A strobilurin-based compound would not be recommended, as there is evidence to suggest that there can be an increase in the mycotoxin contamination.
In the triazole group, the following products are rated as “good”: Caramba 0.75 SL, Prosaro 421SC, Proline 480SC. The following products are rated as “fair”: Folicur 3.6 F (also includes generic compounds). Products containing propiconazole (e.g., Tilt 3.6 EC or equivalent generics) are rated as “poor”. All of these products have a 30-day preharvest restriction, while Tilt has a harvest restriction based on growth stage (Feekes 10.5).