The USDA's final 2012 crop report revealed that farmers produced a harvest of 10.78 billion bushels of corn last year. That's 27% less than the agency's first estimate. The country's stockpile of corn, used as food for cattle and other farm animals, dropped to 8.03 billion bushels as of December 1.

Corn prices shot up immediately after the report came out. Corn for March delivery rose 1.4%, or US$0.10, to settle at US$7.0875 a bushel. Corn ended the week up 4%.

"The report was bullish for corn prices," said Sterling Smith, a commodities strategist at Citigroup. "We're still seeing the after-effects of the drought."

Concerns about the drought has also helped push up wheat prices. Wheat for March delivery increased 1.4%, or US$0.1025, to US$7.5475. Soy fell US$0.065 to US$13.7325 a bushel.

A report of higher inflation in China helped push other commodity prices down Friday (Jan 4). China's official statistics bureau said inflation hit a six-month high in December. Rising prices could hamper the government's efforts to support the world's second-largest economy. Central banks usually curb inflation by raising interest rates, which makes lending more expensive and slows down spending.