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Ontario Grain Farmer Magazine is the flagship publication of Grain Farmers of Ontario and a source of information for our province’s grain farmers. 

Research roundup


The chilling effects of cold temperature stress
Anna Wassermann
The cold stress effect in northern climates on soybeans and winter wheat in the spring is more than twice as strong and twice as damaging as the well-known extreme heat stress effect, according to new research.


The uncertainty of climate change means that understanding the effects of cold temperature stress on various northern crop yields is of increasing global importance.

Former University of Guelph graduate student Tor Tolhurst and Professor Alan Ker of the Department of Food, Agricultural and Resource Economics, modelled the relationship between northern climates and the production of Ontario corn, soybeans, and winter wheat. They wanted to understand how past weather fluctuations and cold temperature stress have affected crop yields in a northern climate.

Specifically, Tolhurst and Ker adapted two new weather measurements — otherwise known as weather metrics — to capture the effects of cold temperatures in northern growing regions. The new metrics capture the amount of time a plant is exposed to cold or freezing temperatures, respectively.

Tolhurst and Ker say the introduction of the two new metrics is important for explaining variations in crop yields in a northern climate where crops experience extreme weather fluctuations including exposure to cold temperatures and killing-frost.

Additionally, they allowed the start and end dates of the growing season to vary in their models from year to year and between counties. This way, inherent differences in growing conditions across Ontario counties were accounted for.

“Next we hope to investigate the effects of changing climate thresholds on crop yield productivity,” says Ker.

Funding for this research was provided by the Ontario Ministry of Agriculture, Food and Rural Affairs. •

Research Roundup is provided by members of SPARK (Students Promoting Awareness of Research Knowledge) at the University of Guelph’s Office of Research. For more information, contact a SPARK writer at 519-824-4120, ext. 52667.


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