Field corn conditions took a turn for the worse in the week ending Sunday, U.S. farmers reported. The weekly U.S. Department of Agriculture crop report said 20 percent of the corn crop was in poor or very poor condition this week. In the week prior, 13 percent of corn fields were rated at those levels. Crops are rated as either very poor, poor, fair, good or excellent. The lower rating was partly due to wet conditions, which also made for a slower harvest. Farmers reported the harvest was 21 percent done, ahead of last week\'s 15 percent, but well behind the same week of 2010. By Oct. 2, 2010, 37 percent of the crop had been harvested. The USDA said 19 percent of the soybean crop had been harvested compared with 34 percent by Oct. 2 last year. The cotton crop is 16 percent off the fields, compared to a long-term average of 18 percent by the same week. The peanut harvest is 19 percent done, just ahead of the crop\'s five-year average.