Was the USDA's corn number wrong?

Corn certainly spiked on Monday when the USDA came in with a lower yield projection than many analysts where looking for - and receiving quite a bit of skepticism in the process.

However it has been revealed that the differences in the actual vs expected could actually be down to the way in which the data is formulated.

It appears that many analysts that were looking for a number closer to 160 may well be right.

That could be what was reflected in Tuesdays action with traders sending Chicago's December contract plunging 3.7% to $4.47 ¼ a bushel, its lowest finish since September 2010.

From CNBC:

The procedures for judging the crop size were different because August is the first month that USDA surveys farmers and physically checks fields to determine its estimates. In previous months, it relies on statistical formulas because the crop has not sufficiently developed.

From July 24 to Aug. 6, the USDA interviewed more than 24,000 producers about their yield expectations as of Aug. 1. The government will continue to survey the growers throughout the autumn to provide updated reports.

"From now to the end of the season, we'll use the same procedure month after month," Honig said. "It probably becomes a lot more valid to make those comparisons month to month."

CNBC