A firm dollar, which makes commodities less attractive to investors seeking a hedge against inflation and lowers export demand, weighed on corn and soyabean futures on Monday morning at the Chicago Board of Trade. CBOT trends at 9:53 am CST (1553 GMT) on Monday. December wheat up 2-1/4 cents at $6.50-1/2 a bushel. December corn down 1 cent at $5.37-1/4 a bushel. January soyabeans down 7-1/2 cents at $12.31 per bushel.