Margins of error are large.
Thus you should not assume these estimates are correct, and thus do not take market positions based upon these numbers. This is the final update for this season. You will note that the yield estimates made here from the weekly crop ratings dropped sharply starting in mid-August. This is an indicator that yields are not as high as USDA has estimated in their September report. The downward adjustments could be substantial on corn, although dropping to a 9.7 billion bushel crop appears to be excessive, but maybe closer to the 10.0 level.