The June forecast of harvested acreage in 1995 was equal to the final estimate while the forecasts in 1996 and 2002 differed from the final estimates by only 0.4 and 0.3 million acres, responsively. Soybean planting delays were greater in 1995 and 1996 than in 2011 but were less severe in 2002, he says.

"Given the record of soybean acreage increases in years of late corn planting, an increase in the forecast of 2011 acreage would not have been surprising. The unknown factors this year include how much acreage intended for corn was left unplanted due to prevent-planting provisions of crop insurance rather than switched to soybeans and how much soybean acreage may have been lost to flooding," he says.

On the supply side, the market's attention will now turn more to yield prospects. For the most part, those prospects will be based on the USDA's weekly estimates of crop conditions, Good says.

"As of June 5, 67% of the emerged corn crop was rated in good or excellent condition, up from 63% on May 29. The average end-of-year rating since 1986 is near 64% good to excellent," he notes.

Last week, 21% of the crop still had not emerged, compared to an average of only 10% in the previous five years, says Good.

Crop condition ratings as of June 12 will be more complete, and a larger percentage of the crop is expected to be rated in good or excellent condition. Generally cooler weather, with adequate moisture, in the heart of the Corn Belt should keep crop condition ratings high in June.

The near completion of planting, except for double-cropped soybeans, and less threatening weather may reduce crop concerns for now, resulting in some modest price weakness. The June 30 USDA Acreage and Grain Stocks reports will provide additional price direction, Good adds.