The Canadian dollar weakened against the greenback on Monday, and the yield on benchmark government debt climbed. The loonie was trading 0.2% lower at C$1.3559 to the greenback, or 73.75 U.S. cents, after trading in a range of 1.3516 to 1.357. Canadian government 10-year bond yields rose 5.3 basis points to 3.519%. The yield on similar U.S. government benchmark debt rose to 4.2517%. U.S. May crude futures rose 45 cents to $83.62 a barrel on Monday.