at three cultivars in a furrow/ridge system to try to catch the melting snow in the late winter/early spring in order to subject plants to the freeze-thaw cycle in a more regular and controlled way. They also did irrigation and winter covering treatments. In the second phase, the most effective treatments were applied to 10 cultivars at two sites, Beloeil in Quebec and Ridgetown in Ontario. “None of the proposed screening methodologies were effective for screening the varieties that we tested, but ruling out the methodologies is a valuable step,” says Hooker. “Winter wheat survival was excellent in all screening methodologies.” He adds that “the project highlighted the difficulties in screening trials under uncontrolled conditions (outdoors) and that simple single-factor explanations (low temperatures, freeze-thaw cycles, spring water accumulation) may be insufficient to predict how well wheat will overwinter.” NEW METHOD UNDER CONTROLLED CONDITIONS There hasn’t been much investigation into assessing the survival of winter wheat under low-temperature flooding and ice encasement (LTFIE) in controlled lab conditions. However, Husiny created a unique and accurate method during his master’s thesis (under the direction of Dr. Eric Lyons at U of Guelph, with Hooker and McElroy on his advisory committee). ONTARIO GRAIN FARMER RESEARCH 23 continued on page 24 “Previous studies did not hold plants under ice for extended periods of time in controlled environments,” Husiny explains. “The few studies that did use whole plants did not apply ice using a spot sprayer after a gradual decrease in temperature and they used different media. They also used different cultivars, temperatures and environments.” Husiny’s unique method confirmed genetic survival differences of four Ontario-acclimated cultivars, AC Carberry, Branson, CM614, and Norstar. He measured days and ambient temperature that caused 50 per cent mortality in plants frozen in ice. He found AC Carberry to perform the best, never reaching 50 per cent mortality, with Norstar next best, followed by Branson and CM614. Husiny also looked at concentrations of simple sugar, fructan, and sucrose present under periods during the experiments of plant acclimation and time frozen in ice. These levels seem to correlate with survival to some extent. However, he would like to see his methodology employed in more in-depth genetics studies that utilize large numbers of cultivars and attempt to identify genes related to overwintering survival. “One study already completed that has some overlap in methodology and cultivars used in my study is the recent PhD thesis of Rachel Whiting at the University of Around here, the weather is so much more than small talk. When you need your insurance to work, you need The Commonwell. Find a Local Broker at thecommonwell.ca/find-a-broker
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