USDA forecast U.S. corn production at 13.930 billion bushels, up 35 million from last month on a 0.4-bushel increase in yield to 172.3 bushels per acre.  With supply rising more than use, corn ending stocks are raised 10 million bushels.  The season-average corn price received by producers is unchanged at $6.80 per bushel.  World corn ending stocks, at 300.8 million tons, are down 0.4 million.   ...