Interfor Corp., one of Canada's leading lumber producers and among the largest lumber companies in the world, will curtail production at three of its sawmills in British Columbia.  The temporary reduction is the result of weak lumber prices and high log costs, said Interfor. Production will be reduced by around 20 million board feet over the month of May.  Many Canadian lumber leaders have taken a hit - including West Fraser, Canfor, and Conifex - and restricted lumber production, with West Fraser and Canfor curtailing production more than once.  Interfor operates five sawmills in British ...