Forty-seven spring wheat fields in Manitoba were surveyed by MAFRD staff to visually assess the incidence and severity of fusarium head blight (FHB). Fusarium head blight in each field was assessed by sampling 100 plants when most crops were at the growth stage of ZGS 73 – 85. In each field, the percentage of infected spikes (disease incidence) and the mean spike proportion infected (SPI) were determined. The FHB Index (overall severity) was calculated as (% incidence x % SPI / 100).
Symptoms of FHB were observed in 35 out of the 47 fields. The average % disease incidence was 5.9% (range 0 – 28.0%), SPI was 16.8% (range 0 – 55.0%) and the resulting average FHB Index was 1.0% (range 0 – 7.4%). Table 1 further illustrates the average FHB Index in the four regions of Central, Eastern/Interlake, Southwest and Northwest, and the number of fields surveyed per region.
The 2014 FHB Index of 1.0% was lower than the 10-year (2003-2012) average of 2.9% (see Table 2) and similar to the previous few years. No survey was conducted in 2013 but levels were considered low.
Although favourable conditions for inoculum development and infection of the winter wheat crop existed in 2014, a transition to warmer, drier weather conditions when spring wheat was at anthesis, combined with foliar fungicide application in majority of fields surveyed (83%), likely contributed to the reduced FHB severity and little to no yield or quality loss in spring wheat.
Samples of infected heads were also collected and sent to AAFC Morden for further analysis of Fusarium species responsible for infection.
Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist
MAFRD Staff who conducted surveys: Ingrid Kristjanson, Dennis Lange, Earl Bargen, Derek Chomokovski, Rejean Picard, Amir Farooq, Lionel Kaskiw, Elmer Kaskiw, Marnie McCracken, Stephanie Jersak & Pam de Rocquigny.
A special THANK YOU to those producers who allow MAFRD to survey their winter wheat fields!