Forecasters said the U.S. model has been less accurate than the European model in recent weeks.
Drought and heat in the U.S. led the U.S. Department of Agriculture (USDA) on Wednesday to slash its corn production forecast to 12.970 billion bushels from its previous outlook for 14.790 billion and below the record crop of 13.1 billion bushels produced in 2009.
USDA on Monday dropped its estimate for U.S. corn good-to-excellent condition rating to 40 percent from the previous 48 percent. Traders expected a further decline in conditions in the USDA weekly crop progress report to be released this coming Monday.
The agency pegged U.S. soybean conditions at 40 percent good-to-excellent, down from 45 percent the previous week, and in its July crop report pegged 2012 U.S. soybean production at 3.050 billion bushels, down from the previous forecast for 3.205 billion.
The government will update its U.S. corn and soybean production forecasts in its next report which will be released on August 10.
(Additional reporting by Julie Ingwersen; Editing by John Picinich)