Wheat futures soar after Kazakhstan moves to restrict grain exports By STEVENSON JACOBS, AP Business Writer NEW YORK 2/25/08 - Wheat futures shot up 60 cents a bushel Monday after Kazakhstan said it would slow grain exports by imposing customs duties, adding to concerns over tightening global supplies. Other commodities traded mixed, with crude oil gaining and gold falling. Wheat prices have surged to historic highs as bad weather has battered crop after crop around the globe, most recently in India and Canada. Foreign buyers scrambling to lock in supplies have increasingly turned to other wheat-growing countries like the United...