 December corn futures traded on both sides of $4.20 for a fourth consecutive session yesterday as traders searched for a better understanding of this year's crop potential. Ethanol production in the weekend of June 28 averaged 1.064 million barrels per day. That's up 21,000 barrels per day from the previous week. Ethanol stocks in the week increased 171,000 barrels to 23.594 million barrels.