A bigger-than-expected U.S. corn yield will keep pressure on corn prices, market analysts said last week after the U.S. Department of Agriculture (USDA) released its November crop report.

The USDA raised its estimate for the U.S. corn yield to a record 175.4 bushels per acre, up 3.6 bushels from the October forecast.

“It has been almost 25 years since we have seen a change this big (in the November report),” said Scott Irwin, a University of Illinois agricultural economist. “In bushel terms, the only bigger changes were in 1992 and 1994.”

With the larger yields, the USDA said U.S. corn production this year will total 14.6 billion bushels.

“They are negative numbers, but you have to keep throwing bearish information at...