As of Sept. 18, 93% of U.S. corn acres were in the dented stage. This compares with 92% on this date a year ago, 87% a week earlier and the 5-year average of 91%, according to USDA. At this point 53% of corn is considered “mature.” This is up from 33% last week, 48% last year and the 5-year average of 48%.