Even though the past several weeks have been quite cool early planted crops are developing rapidly. Development rate of barley at Fargo and Prosper this year has exceeded rates predicted using a GDD model. The important point is, if you plan on controlling wheat midge or scab with a pesticide application, timing application with development is crucial to success. Knowing the stage of a crop now and when it will head or flower is useful when planning for the pesticide application. Control of scab with a fungicide depends on correct timing of the application.
Fungicides only provide protection against scab on tissue that receive a direct application.
Even though fungicides like Tilt and Folicur are systemic they do not move throughout the plant but remain in a localized area near the site of absorption. Applications before heading is complete in both wheat and barley will compromise control of scab. The recent heavy rainfall favors the development of several diseases in wheat and melanism which can easily be mistaken for disease. Melanism, a genetically controlled discoloration, is often confused with black chaff. Black chaff is a bacterial disease that affects the glumes of developing wheat heads.