Current climate change impacts including rising temperatures in Ontario (Eastern Canada) and above-average growing season precipitation in Saskatchewan (Western Canada) have been causing high levels of crop diseases, including Fusarium head blight (FHB) in cereals, as well as root rot in pulses in Saskatchewan, limiting crop productivity and the quality and safety of grain. These conditions also have the potential of compromising organic agriculture which relies on legume green manure for fertility and weed control.
There has been an increasing consumer demand for organic products in Canada and beyond. Saskatchewan is the largest organic grain producer, where over three quarters of organic field crops on the Prairies are grown. There is a growing number of organic producers in Eastern Canada including in Ontario. Maintaining and increasing the quality of organic grain is imperative for keeping up with organic market demand.
The use of biological control agents (BCAs) has become increasingly common and accepted in both organic crop production and by conventional farmers as a pest control method. BCAs address food safety and environmental concerns and promote sustainable crop production with decreased input cost. Some BCAs have failed, in part because of a failure to consistently colonize their host crops. Plants are inhabited and coated by mobile probiotic microbes known as endophytes, which can effectively colonize plants. Our team has demonstrated that immobile plant cells maintain endophytes that act similarly to human immunity cells, to seek-and-destroy pathogens at pathogen-entry points. To the best of our knowledge, no sentinel endophytes have been isolated from Fusarium entry points in wheat. This would represent an innovative scientific discovery and strategy to combat wheat diseases. No BCAs including probiotic endophytes have been reported or registered for use against FHB and root rot pathogens of field crops in Canada.
Biocontrol of important crop diseases, such as FHB and root rot, would contribute to the maintenance or improvements in productivity, sustainability and competitiveness of the organic sector. Controlling diseases such as root rot in pulses and other crops would also allow for the continued use of green manures in organic production. The use of endophytes and BCAs could also benefit host crops by promoting plant growth or acting as biofertilizers.
Because of the increased demand for high quality organic grain, it is necessary that these products have low levels, or are free, of any harmful mycotoxins. Identifying the crop production factors that contribute to the development of FHB and associated mycotoxins, and other kernel diseases, in cereal crops grown under organic management would be of great benefit to Canadian organic grain producers.
Winter wheat field trial for biological control of fusarium (Photo by Jake Gregory)