Effect of Fungicide Application On Cereal Productivity.

Many foliar diseases affect cereals in Eastern Canada.  The most commun diseases observed in cereal fields are septoria, rusts, scald, net blotch and powdery mildew.  Also, fusarium head blight associated with the presence of the fungus Fusarium graminearum is probably one of the most feared diseases in cereal production in Quebec. Some fungicides are now available to control some fungal diseases.  However, the efficacy of those fungicides were not tested under Quebec conditions.  A study was conducted in 2009 and 2010 at three sites (Province of Quebec, Canada), to evaluate if the application of fungides have an impact on grain yields of cereals.  Barley (cv. Païdia), oat (cv. Robust) and wheat (cv. Orleans) were seeded at each site. Three fungicides used for head bligh control (Tebuconazole, Prothioconazole, and Prothioconazole/Tebuconazole) were evaluated.  Four fungicides recommended to control foliar disease were also tested:  propiconazole/azoxystrobine, propiconazole/trifloxystrobine, propiconazole and pyraclostrobine.  Fungicides were applied at the recommended stage for each species. In 2009, most of the fungicides increased grain yields of wheat and oats.  The application of fungicides increased grain yields of barley at one site only.  In 2010, the season was very dry and disease pressure was low.  Except for wheat at one location, fungicides had no significant effect on grain yields.