US corn fell 1 percent on Monday, posting its biggest drop in five trading days, and soya slipped 0.5 percent as traders liquidated long holdings amid worries of possible bearish surprises in the USDA grain report on Tuesday. "It's choppy before tomorrow's supply and demand numbers. Everyone is expecting the government to cut the stocks but there always could be a surprise," said Brian Hoops, an analyst for Midwest Market Solutions.
Wheat turned up a few cents on position-squaring before Tuesday's government data. At 11:15 am CDT (1615 GMT), CBOT May corn was down 7-1/2 cents per bushel at $6.50-3/4, May soya was down 4-1/4 at $14.25-3/4 and May wheat was up 3 cents at $6.41-1/2. The USDA will update its monthly global crop production and US ending stocks forecast at 7:30 am CDT (1230 GMT) on Tuesday.