Are you Prepared for Fusarium Head Blight?

Each year there is considerable apprehension surrounding Fusarium Head Blight in wheat and 2008 is no exception. The weather patterns to date are a concern if they persist through to heading (reproductive stages) and if the extended forecasts are correct (below average temperatures with continued wet conditions) the risk for Fusarium Head Blight could be substantially higher then the previous few years.

As with any disease things could change quickly. We have been in similar situations in the past but weather conditions during the critical wheat reproductive stages become unfavourable for significant disease development plus the introduction of FHB suppressing fungicides and increased tolerance in some commercial wheat varieties has helped us manage low to moderate disease years. However under epidemic conditions such as 1996 even with these "new tools" losses could be substantial in certain fields. With high wheat prices, increased acres, inoculumn (spore) potential, etc we need to be vigilant and prepared!

Two important things you can do now. One is sign up for the Site-Specific DONcast (SSD) and two, secure a FHB fungicide in the event one is needed.

Figure 1. Unfortunately, spores (inoculum) of Fusarium graminearum, the casual agent for FHB, are abundant in Ontario and it doesn’t take long to find perithecia such as these on corn

Weather INnovations Incorporated (WIN) in Chatham delivers DONcast, which is a weather-based disease model that forecasts the levels of DON toxin in ppm at wheat harvest. The anticipated DON levels support decisions of where fungicide protection has the greatest potential return on investment. Growers, OMAFRA extension, crop advisors, industry, etc can use the forecasts to make fungicide decisions or help growers make these decisions. Current data from local weather stations, forecast data, historic climate normals along with agronomic data such as the growers variety of wheat, field history and tillage practices are all factors which are taken into consideration by the model.

This year the flat maps or regional maps have been replaced by local or site-specific predictions. This allows the model to use field specific information and you can run the model on different fields. Go to www.weatherinnovations.com and sign up for the site-specific DONcast service. Although the SSDoncast is free to the user it is by no means "free" and I would be negligent not to mention the financial assistance of the Ontario Wheat Producers Marketing Board and Bayer CropScience Canada in supporting this service.

When it comes to disease control products there has been considerable movement of fungicides in many crops not only across North America but worldwide and the supply for various products has been low or anticipated to be low in many regions. Therefore, you may want to secure a FHB fungicide in the event one is needed. In Ontario, Folicur 432F (tebuconazole) and Proline 480 SC (prothioconazole) are registered for FHB suppression and I would assume demand for these products will be high. Proline 480 SC application rates (ground only) for wheat and barley range from 210 to 420 mL product/ha (128-170 mL/acre) with a maximum of 2 applications or 735 mL/ha per year with a minimum 7 days between applications. For Folicur 432F, only one application is registered which means if Folicur 432F was already used for leaf disease control the only option for FHB is Proline 480 SC. The Folicur FHB application rate (ground and aerial) is 292 mL/ha (118 mL/acre).

When it comes to Fusarium Head Blight, be PROACTIVE and PREPARED!