Fusarium head blight (scab) can be one of the most devastating diseases of wheat when conditions are favorable for it. Because wheat is susceptible to the disease during flowering, weather conditions from flowering through kernel development are critical to the incidence and severity of scab.

Moderate temperatures (75 to 85 degrees F), prolonged high humidity, and prolonged wet periods favor development of the disease.

The window for fungicide application to protect against scab is very small. The recommended timing is Feekes 10.5.1, or early flowering. Once the crop is beyond this stage, fungicides should not be applied to protect against scab. By the time symptoms, "bleached" heads, of the disease appear on wheat heads it is too late to manage scab.

Only the triazole family of fungicides (Prosaro, Caramba, Folicur, and a few others) has Fusarium head blight listed on their labels.

A disease forecasting system, the Fusarium Head Blight Risk Assessment Tool, based on weather conditions is available online at www.wheatscab.psu.edu

Successful scab management requires an integrated approach and begins prior to planting with variety selection and deciding which fields to plant into wheat.

Adapted from U of I Pest Management & Crop Development Bulletin, April 24 and May 22.