Chicago wheat futures lost more ground with prices dropping to a six-week low as a stronger dollar raised concerns over U.S. exports, which have been facing competition from the Black Sea region. The most-active wheat contract on the Chicago Board Of Trade was down 0.7 percent at $4.96-1/4 a bushel. The most-active wheat contract on the Chicago Board Of Trade was down 0.7 percent at $4.96-1/4 a bushel. A stronger dollar makes the greenback-priced commodities expensive for buyers holding other currencies.