Chicago wheat was little changed on Tuesday after hitting a 21-month low earlier in the day, as rain forecast for parched parts of the U.S. Plains and competitive Russian exports led investors to shrug off supply risks... The U.S. Department of Agriculture (USDA) on Monday rated 26% of U.S. winter wheat in good to excellent condition, the lowest for this time of year since 1989, due to prolonged drought. But the market expected forecast rain to bring some relief. "U.S. hard red winter wheat areas will get the needed rain this week," said Terry Reilly, a senior analyst at Futures International.