In 2014, a study was initiated to evaluate how winter wheat varieties being tested post-registration by MCVET respond to fusarium head blight under non-misted conditions (natural infection) by assessing harvested samples for fusarium damaged kernels (FDK) and deoxynivalenol (DON) accumulation. The results from 2014 can be found here: Winter Wheat Varieties Response to Fusarium Head Blight in 2014 and Effect of Fusarium Head Blight on Winter Wheat Varieties in 2014.
2015 Results. With funding from Winter Cereals Manitoba Inc., the study continued in 2015. Composite samples of eight registered winter wheat varieties were collected from the three replicates at four MCVET sites: Carman, Hamiota, Melita & Minto. BioVision Seed Labs in Winnipeg, Manitoba conducted the analysis. The level of FDK (%) was measured as per the Official Grain Grading Guide of the Canadian Grain Commission. The accumulation of DON (ppm) was measured using the ELISA test method.
The variety Emerson, rated as Resistant (R), had lower levels of FDK and DON compared to the other varieties (see Figure 1). Some varieties rated as Susceptible (S) consistently showed higher FHB severity, FDK and DON levels across all sites. However, data also shows there is variability of performance within the five resistance categories of Resistant (R) to Susceptible (S).
Figure 1: Average Levels of Fusarium Damaged Kernel (FDK) and Deoxynivalenol (DON) by Winter Wheat Variety at Four MCVET Sites in 2015
Figure 2: Fusarium Damaged Kernel (FDK) and Deoxynivalenol (DON) Comparisons at Four MCVET Sites for Winter Wheat Varieties in 2015.
2016 Results. In the 2016 Manitoba Fusarium Head Blight Survey, the average FHB index for winter wheat was 2.7% which was slightly below the 10-year-average (3.1%). Winter Cereals Manitoba Inc. again is providing funding to have the MCVET winter wheat varieties tested for FDK and DON. Analysis is currently underway and results should be available for the Winter Cereals Manitoba Inc. Annual General Meeting on March 15, 2017.
Summary. Extensive research over the past 20 years shows using multiple management options, including crop rotation, fungicide application and variety selection, is the best way to mitigate the risk of FHB. Although FHB infection will always be highly influenced by environment, the first step is to select varieties with improved resistance and then use them in combination with other management strategies. In years where there is higher disease pressure, such as 2014, variety selection will be critical to minimize the impact of FHB on yield and quality. However, under high disease pressure yield and quality loss due to FHB can still happen in varieties that have improved resistance as resistance does not equal immunity.
Remember, caution must be used with one year of data, as presented here. Using data derived over two or more growing seasons over multiple sites is always recommended to provide the best indicator of variety performance.
Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture
Special thanks to: Winter Cereals Manitoba Inc. for providing funding to conduct FDK & DON analysis; BioVision Seed Labs who conducted the FDK and DON analysis; Manitoba Crop Variety Evaluation Team (MCVET) & contractors who provided the harvested samples.
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