The Canadian dollar weakened against the greenback on Wednesday, and the yield on benchmark government debt climbed. The loonie was trading 0.2% lower at C$1.3687 to the greenback, or 73.06 U.S. cents, after trading in a range of 1.3651 to 1.3695. Canadian government 10-year bond yields rose 5.2 basis points to 3.434%. The yield on similar U.S. government benchmark debt rose to 4.2845%. U.S. August crude futures rose 22 cents to $81.05 a barrel on Wednesday.